Preparation of Dimethylaminoethylmethacrylate Grafted Polymeric Adsorbent by Using Radiation-Induced Grafting Technique for Removal of Anions

International Nuclear Information System (INIS)

Kavakli, P. A.

2006-01-01

The development of efficient separation and purification techniques is very important from industrial, environmental and economic points of view. Polymeric materials having polyfunctional groups such as carboxylic, amide, nitrile, iminodiacetic acid, amidoxime, and ammonium groups, etc., not only possess good hydrophilic properties, but also have good ion exchange properties which make them suitable for metal recovery from aqueous solutions. Radiation induced grafting is a powerful technique capable of controlling the introduction of various functional groups to the polymeric materials, keeping the original properties and especially the mechanical strength of the base material, and thus, allowing the synthesis of more stable polymeric adsorbents. The main objective of this study was to develop special polymeric adsorbents to remove NOx and PO 4 anions from aqueous systems. For this purpose, a novel nonwoven fabric was prepared by radiation-induced graft polymerization of imethylaminoethylmethacrylate (DMAEMA) onto polypropylene coated polyethylene nonwoven fabric. The trunk polymer was irradiated by electron beam at a voltage of 2 MeV and a current of 3 mA in a nitrogen atmosphere at dry-ice temperature at different doses. The degree of grafting was determined as a function of the total dose, monomer concentration, temperature, and reaction time. It was found that the degree of grafting of grafted polymer was greatly affected by reaction conditions. Grafting conditions were optimized, and about 150 % degree of grafting samples was used for further experiments. DMAEMA grafted polymer was later protonated by using acid solution to prepare adsorbent for the removal of anions. Adsorption experiments were performed in column mode for removal of phosphate. Approximately 2000 bed volumes of phosphate-free water can be produced from 10 ppb phosphate solution at high space velocity

Desalination by electrodialysis with the ion-exchange membrane prepared by radiation-induced graft polymerization

Energy Technology Data Exchange (ETDEWEB)

Choi, Seong-Ho; Han Jeong, Young; Jeong Ryoo, Jae; Lee, Kwang-Pill E-mail: kplee@kyungpook.ac.kr

2001-07-01

Ion-exchange membranes modified with the triethylamine [-N(CH{sub 2}CH{sub 3}){sub 3}] and phosphoric acid (-PO{sub 3} H) groups were prepared by radiation-induced grafting of glycidyl methacrylate (GMA) onto the polyolefin nonwavon fabric (PNF) and subsequent chemical modification of poly(GMA) graft chains. The physical and chemical properties of the GMA-grafted PNF and the PNF modified with ion-exchange groups were investigated by SEM, XPS, TGA, and DSC. Furthermore, electrochemical properties such as specific electric resistance, transport number of K{sup +}, and desalination were examined. The grafting yield increased with increasing reaction time and reaction temperature. The maximum grafting yield was obtained with 40% (vol.%) monomer concentration in dioxane at 60 deg. C. The content of the cation- and anion-exchange group increased with increasing grafting yield. Electrical resistance of the PNF modified with TEA and -PO{sub 3} H group decreased, while the water uptake (%) increased with increasing ion-exchange group capacities. Transport number of the PNF modified with ion-exchange group were the range of ca. 0.82-0.92. The graft-type ion-exchange membranes prepared by radiation-induced graft copolymerization were successfully applied as separators for electrodialysis. (author)

Modification of flax fibres by radiation induced emulsion graft copolymerization of glycidyl methacrylate

International Nuclear Information System (INIS)

Moawia, Rihab Musaad; Nasef, Mohamed Mahmoud; Mohamed, Nor Hasimah; Ripin, Adnan

2016-01-01

Flax fibres were modified by radiation induced graft copolymerization of glycidyl methacrylate (GMA) by pre-irradiation method in an emulsion medium. The effect of reaction parameters on the degree of grafting (DOG) such as concentration of bleaching agent, absorbed dose, monomer concentration, temperature and reaction time were investigated. The DOG was found to be dependent on the investigated parameters. The incorporation of poly(GMA) grafts in the bleached flax fibres was confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The structural and mechanical changes were evaluated by X-ray diffraction (XRD) and mechanical tester, respectively. The results revealed that reacting bleached flax fibres irradiated with 20 kGy with 5% GMA emulsion containing 0.5% polyoxyethylene-sorbitan monolaurate (Tween 20) surfactant at 40 °C for 1 h led to a maximum DOG of 148%. The grafted fibres showed sufficient mechanical strength and hydrophobicity which make them promising precursors for development of adsorbents after appropriate chemical treatments. - Highlights: • Flax fibers were modified by radiation induced emulsion grafting of GMA. • Bleaching with 0.7 wt% Na-chlorite was essential for achieving high DOGs. • Effect of reaction parameters on the degree of grafting were established. • The incorporation of poly-GMA grafts was proved by SEM, FTIR and XRD. • The obtained poly-GMA grafted flax fibers have potential for adsorbent making.

'Like new': plastic wastes regeneration by radiation induced grafting

International Nuclear Information System (INIS)

Laizier, J.; Gaussens, G.; Lemaire, F.

1978-01-01

The reclaiming and the recycling of plastic wastes is made especially difficult when those wastes are a mixture of various plastics; this is due to the incompatibility of the polymers. The radiation induced grafting allows to overcome this incompatibility. Results are given which shows that, for various mixtures of reclaimed polyethylene, PVC and polystyrene, an improvement of the properties of the processed blends is obtained by grafting the mixtures of wastes by a suitable polymer; the obtained properties of those regenerated plastic blends are enough attractive from the technical point of view to open a market to those products with a reasonable economical value [fr

A study on radiation-induced graft copolymerization of monomer onto natural silk fabric

International Nuclear Information System (INIS)

Xiang Zhengyu; Wan Dairong; He Qian

1995-02-01

In order to improve the properties of natural silk fabric, the mechanism and method of the radiation induced graft copolymerization of monomers onto natural silk fabric were studied. Three monomers, acrylamide, methylacrylamide and hydroxymethyl acrylamide, were selected for grafting test according to requirements of graft processing. The processing conditions of monomer infusion were studied. The properties of grafted samples were measured. The results are as follows: the rate of weight increasing is 10%∼29%; the rate of thickness increasing is 5%∼20%; the abrupt elasticity rose by 30%; the retarded elasticity rose by 12%; wet elasticity rose by 40%; and the brightness of colour and lustre were improved. It is concluded that while the radiation grafted silk kept its natural characteristics, other properties were improved. It became even chubby and thicker. (4 refs., 3 figs., 3 tabs.)

Radiation induced, raft mediated grafting of styrene onto poly(ethylene-alt-tetrafluoroethylene) (ETFE)

International Nuclear Information System (INIS)

Celik, G.; Barsbay, M.; Gueven, O.

2011-01-01

Complete text of publication follows. The development of cost-effective proton exchange membranes to replace the state-of-the-art and expensive perfluorinated membranes such as Nafion, Flemion, and Aciplex is one of the main challenges for commercialization of polymer electrolyte fuel cell technology. Recently, partially fluorinated poly(ethlyene-alt-tetrafluoroethylene) (ETFE) has been identified as a promising alternative base polymer film to prepare low-cost polymer electrolyte membranes because of its advantageous characters like superior mechanical properties and high resistance to radiation-induced damage. The radiation-induced grafting technique, based on the utilization of a polymer material such as ETFE in combination with further chemical modification steps (sulfonation) allows the functionalization of the base material and the introduction of the desired property (proton conductivity) for preparing a fuel cell membrane. However this simple conventional method suffers from one simple flaw: The molecular weight and the polydispersity of the grafted chains cannot be controlled. Predetermined molecular weights and low dispersities as well as homogeneous composition and desired architecture can be achieved by grafting of monomer onto base polymer under living/controlled free radical polymerization (CRP) conditions. Among the CRP methods, Reversible Addition Fragmentation-Chain Transfer (RAFT) is of particular interest as a very wide range of functional monomers can be polymerized in a controlled manner under non-demanding reaction conditions (e.g., tolerance to oxygen and low temperatures). The present study deals with the RAFT mediated radiation-induced (0.032 kGyh -1 , 60 Co) grafting of styrene on ETFE films followed by the sulfonation of the polystyrene grafts. The effect of monomer concentration, absorbed dose and RAFT agent concentration on the grafting were investigated. The synthesized films were characterized by ATR-FTIR, XPS, DSC and TGA methods

Research work of radiation induced graft polymerization for synthesis and modification of polymer materials in CRICI

Energy Technology Data Exchange (ETDEWEB)

Hu Fumin; Ma Xueming [Chenguan Research Institute of Chemical Industry, Chengdu (China)

2000-03-01

The direct and post radiation induced graft polymerization had been studied in CRICI (Chenguan Research Institute of Chemical Industry). The method consists of irradiation of various polymer substrates in the presence (or absence) of monomers in a liquid, saturated vapour or gaseous and non-saturated vapour. 1. Grafting of functional monomers. --- It is possible to divide the grafting into two main approaches for synthesis of functional polymer materials. The first is grafting of monomers attached required functional group such as unsaturated carboxylic acid (acrylic and methacrylic acid), unsaturated nitrogen containing (alkali) base (vinylpyridine), monomers with hydrophilic unionized and polar groups (acrylamide, N-vinylpyrrolidone glycidylmethacrylate) and so on. The second is grafting of monomers capable of continuing chemical modification after graft polymerization. This approach essentially expands synthetic possibility of RGP for preparing functional polymers. 2. The effect of some salts on aqueous solution graft polymerization. The grafting of AA or AAm onto PE by direct or post radiation method in the presence of Mohr's salt or cupric nitrate was studied in detail. 3. Radiation induced graft polymerization by gaseous phase of monomers. This method consists of irradiation or preirradiation of various polymer substrates in the presence (or absence for preirradiation) of monomer in a gaseous of nonsaturated vapour state. (J.P.N.)

Research work of radiation induced graft polymerization for synthesis and modification of polymer materials in CRICI

International Nuclear Information System (INIS)

Hu Fumin; Ma Xueming

2000-01-01

The direct and post radiation induced graft polymerization had been studied in CRICI (Chenguan Research Institute of Chemical Industry). The method consists of irradiation of various polymer substrates in the presence (or absence) of monomers in a liquid, saturated vapour or gaseous and non-saturated vapour. 1. Grafting of functional monomers. --- It is possible to divide the grafting into two main approaches for synthesis of functional polymer materials. The first is grafting of monomers attached required functional group such as unsaturated carboxylic acid (acrylic and methacrylic acid), unsaturated nitrogen containing (alkali) base (vinylpyridine), monomers with hydrophilic unionized and polar groups (acrylamide, N-vinylpyrrolidone glycidylmethacrylate) and so on. The second is grafting of monomers capable of continuing chemical modification after graft polymerization. This approach essentially expands synthetic possibility of RGP for preparing functional polymers. 2. The effect of some salts on aqueous solution graft polymerization. The grafting of AA or AAm onto PE by direct or post radiation method in the presence of Mohr's salt or cupric nitrate was studied in detail. 3. Radiation induced graft polymerization by gaseous phase of monomers. This method consists of irradiation or preirradiation of various polymer substrates in the presence (or absence for preirradiation) of monomer in a gaseous of nonsaturated vapour state. (J.P.N.)

The use of radiation-induced graft polymerization for modification of polymer track membranes

International Nuclear Information System (INIS)

Shtanko, N.I.; Kabanov, V.Ya.; Apel, P.Yu.; Yoshida, M.

1999-01-01

Track membranes (TM) made of poly(ethylene terephtalate) (PET) and polypropylene (PP) films have a number of peculiarities as compared with other ones. They have high mechanical strength at a low thickness, narrow pore size distribution, low content of extractables. However, TM have some disadvantages such as low chemical resistance in alkaline media (PET TM), the low water flow rate due to the hydrophobic nature of their surface. The use of radiation-induced graft polymerization makes it possible to improve the basic characteristics of TM. In this communication our results on the modification of PET and PP TM are presented. The modified membranes were prepared by radiation-induced graft polymerization from the liquid phase. Three methods of grafting were used: (a) the direct method in argon atmosphere; (b) the pre-irradiation of TM in air followed by grafting in argon atmosphere; (c) pre-irradiation in vacuum followed by grafting in vacuum without contacting oxygen. The aim of the work was to investigate some properties of TM modified by grafted poly(methylvinyl pyridine) (PMVP) and poly(N-isopropylacrylamide) (PNIPAAM). It was shown that the modification of TM with hydrophilic polymer results in the growth of the water flow rate. In the past few years many works have been devoted to the synthesis of new polymers - the so-called 'intelligent' materials - such as PNIPAAM. However, it is very difficult to make thin membranes of this polymer. Recently, it has been proposed to manufacture composite membranes by grafting stimulus-responsive polymers onto TM. Following this principle, we prepared thermosensitive membranes by the radiation-induced graft polymerization of N-isopropylacrylamide (NIPAAM) onto PET TM. PET TM with the pore size of about 1 μm and pore density of 10 6 cm -2 were first inserted into a solution of NIPAAM containing inhibitor of homopolymerization (CuCl 2 ) and then exposed to the γ-rays from a 60 Co source. The transport properties of the

The use of radiation-induced graft polymerization for modification of polymer track membranes

Science.gov (United States)

Shtanko, N. I.; Kabanov, V. Ya.; Apel, P. Yu.; Yoshida, M.

1999-05-01

Track membranes (TM) made of poly(ethylene terephtalate) (PET) and polypropylene (PP) films have a number of peculiarities as compared with other ones. They have high mechanical strength at a low thickness, narrow pore size distribution, low content of extractables. However, TM have some disadvantages such as low chemical resistance in alkaline media (PET TM), the low water flow rate due to the hydrophobic nature of their surface. The use of radiation-induced graft polymerization makes it possible to improve the basic characteristics of TM. In this communication our results on the modification of PET and PP TM are presented. The modified membranes were prepared by radiation-induced graft polymerization from the liquid phase. Three methods of grafting were used: (a) the direct method in argon atmosphere; (b) the pre-irradiation of TM in air followed by grafting in argon atmosphere; (c) pre-irradiation in vacuum followed by grafting in vacuum without contacting oxygen. The aim of the work was to investigate some properties of TM modified by grafted poly(methylvinyl pyridine) (PMVP) and poly(N-isopropylacrylamide) (PNIPAAM). It was shown that the modification of TM with hydrophilic polymer results in the growth of the water flow rate. In the past few years many works have been devoted to the synthesis of new polymers - the so-called "intelligent" materials - such as PNIPAAM. However, it is very difficult to make thin membranes of this polymer. Recently, it has been proposed to manufacture composite membranes by grafting stimulus-responsive polymers onto TM. Following this principle, we prepared thermosensitive membranes by the radiation-induced graft polymerization of N-isopropylacrylamide (NIPAAM) onto PET TM. PET TM with the pore size of about 1 μm and pore density of 10 6 cm -2 were first inserted into a solution of NIPAAM containing inhibitor of homopolymerization (CuCl 2) and then exposed to the γ-rays from a 60Co source. The transport properties of the grafted

Modeling and optimization aspects of radiation induced grafting of 4-vinylpyridene onto partially fluorinated films

International Nuclear Information System (INIS)

Nasef, Mohamed Mahmoud; Ahmad Ali, Amgad; Saidi, Hamdani; Ahmad, Arshad

2014-01-01

Modeling and optimization aspects of radiation induced grafting (RIG) of 4-vinylpyridine (4-VP) onto partially fluorinated polymers such as poly(ethylene-co-tetrafluoroethene) (ETFE) and poly(vinylidene fluoride) (PVDF) films were comparatively investigated using response surface method (RSM). The effects of independent parameters: absorbed dose, monomer concentration, grafting time and reaction temperature on the response, grafting yield (GY) were correlated through two quadratic models. The results of this work confirm that RSM is a reliable tool not only for optimization of the reaction parameters and prediction of GY in RIG processes, but also for the reduction of the number of the experiments, monomer consumption and absorbed dose leading to an improvement of the overall reaction cost. - Highlights: • Comparative study of radiation induced grafting of 4-VP onto PVDF and ETFE films. • Optimization of reaction parameters for both grafting systems was made using RSM. • Single factor design for both grafting systems was used as a reference. • Two quadratic regression models were developed for prediction of grafting yield. • RSM is an effective tool for handling grafting reactions under different conditions

Solvent influence during radiation induced grafting of styrene in PVDF

International Nuclear Information System (INIS)

Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B.

2013-01-01

Radiation-induced grafting was studied to produce styrene grafted poly(vinylidene fluoride) (PVDF) membranes. PVDF films with 0.125 mm thickness were irradiated at doses between 5 and 20 kGy in the presence of styrene/N,N-dimethylformamide (DMF), styrene/acetone or styrene/toluene solutions (1:1, v/v) at dose rate of 5 kGy h -1 by simultaneous method, using gamma rays from a Co-60, under nitrogen atmosphere and at room temperature. The films were characterized before and after modification by grafting yield (GY %), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM and EDS), differential scanning calorimetry (DSC) and thermogravimetry (TG/DTG). GY results shows that grafting increases with dose and toluene hinders the grafting, leading to a small GY comparing to DMF and acetone. It was possible to confirm the grafting of styrene by FT-IR due to the new characteristics peaks and by the TG and DSC due to changes in thermal behavior of the grafted material. SEM and EDS show surface and cross-section distribution of the grafting, which takes place on the surface and heterogeneously with toluene as solvent and homogeneously and penetrating into the inner layers of the matrix using DMF and acetone as solvent. (author)

Solvent influence during radiation induced grafting of styrene in PVDF

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B., E-mail: hp.ferreira@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2013-07-01

Radiation-induced grafting was studied to produce styrene grafted poly(vinylidene fluoride) (PVDF) membranes. PVDF films with 0.125 mm thickness were irradiated at doses between 5 and 20 kGy in the presence of styrene/N,N-dimethylformamide (DMF), styrene/acetone or styrene/toluene solutions (1:1, v/v) at dose rate of 5 kGy h{sup -1} by simultaneous method, using gamma rays from a Co-60, under nitrogen atmosphere and at room temperature. The films were characterized before and after modification by grafting yield (GY %), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM and EDS), differential scanning calorimetry (DSC) and thermogravimetry (TG/DTG). GY results shows that grafting increases with dose and toluene hinders the grafting, leading to a small GY comparing to DMF and acetone. It was possible to confirm the grafting of styrene by FT-IR due to the new characteristics peaks and by the TG and DSC due to changes in thermal behavior of the grafted material. SEM and EDS show surface and cross-section distribution of the grafting, which takes place on the surface and heterogeneously with toluene as solvent and homogeneously and penetrating into the inner layers of the matrix using DMF and acetone as solvent. (author)

Application of radiation-induced graft polymerization to preparation of functional materials

International Nuclear Information System (INIS)

Sugo, Takanobu

2010-01-01

Radiation-induced graft polymerization is a powerful method for appending various functionalities onto existing fabrics, nonwoven fabrics, fibers, membranes, and beads while maintaining the shape and mechanical strength. By using this method, the author has developed and commercialized functional polymeric materials over 45 years. The materials produced by the fruits of radiation chemistry contributed to the improvement of our lives and environments and the collection of rare metal resources. (author)

Radiation-induced graft polymerization of acrylic acid onto fluorinated polymers: Pt. 2

International Nuclear Information System (INIS)

Abdel-Ghaffar, M.; Hegazy, E.A.; Dessouki, A.M.; El-Sawy, N.M.; El-Assy, N.B.

1991-01-01

Radiation induced grafting of acrylic acid onto poly (tetrafluoroethylene-perfluorovinyl ether) (PFA) films was investigated. The grafted films rapidly absorbed Fe 3+ , Co 2+ , Ni 2+ , and Cu 2+ ions in high efficiency. The polyacrylic acid grafted onto PFA acted as a chelating site for the previously selected transition metal ions. Such prepared copolymer-metal complexes were confirmed spectrophotometrically via IR, UV-spectrometry, X-ray fluorescence, X-ray diffraction, and colour index measurements. Electrical conductivity and mechanical properties of PFA grafted copolymer-metal complexes were investigated. The applications of such prepared copolymer-metal complexes in the field of semiconductors besides its performance as a cation-exchange membrane may be of great interest. (author)

Environmental application of radiation grafting

International Nuclear Information System (INIS)

Tamada, Masao

2007-01-01

Adsorbent having high selectivity against a certain metal ion was synthesized by means of radiation-induced graft polymerization for the purpose of environmental application. The resulting adsorbents were utilized for the removal of toxic metal from scallop waste and the collection of uranium from seawater. As a novel application of grafting, the biodegradability of poly-hydroxybutylate was controlled by grafting. The biodegradability could be depressed by the graft chain and then recovered by external stimuli such as thermal and chemical treatments. (author)

Characteristics of the chrome-tanned sheep leather treated by radiation-induced graft of BA

International Nuclear Information System (INIS)

Zhou Dezhong; Deng Yongzhen; Li Ying

1986-01-01

The characteristics of the chrome-tanned sheep leather treated by radiation-induced graft of BA is presented. Using the method of radiation-induced graft of BA instead of the chrome-retanning, the leather has been obviously improved not only in the surface, such as the brightness, fullness, uniformity of the thickness but also in the physical characteristics such as retaining of tensile strength, decreasing of water absorption after being immersed in water for 2h, and 24h, enhancement of tearing strength and stitch tear strength. Although the air permeability and water vapor permeability are a bit worse than the control, however is still in the range of the standard issued by Light Industry Ministry of China

Radiation Grafted Polymer Membranes for Fuel Cell Applications

International Nuclear Information System (INIS)

Scherer, G.G.; Wallasch, F.; Ben Youcef, H.; Gubler, L.

2012-01-01

Partially fluorinated proton exchange membranes prepared via radiation induced graft copolymerization ('radiation grafting') offer the prospect of cost-effective and tailor made membrane electrolytes for the polymer electrolyte fuel cell (PEFC). The composition and structure of radiation grafted membranes can be adjusted in a broad range to balance the different requirements of proton transport and mechanical robustness. Based on the earlier work on Styrene grafting, the novel monomer combination α-methyl-styrene/methacrylonitrile (AMS/MAN) is introduced for improved stability in the prevailing fuel cell environment. Successful fuel cell experiments proved the concept. (author)

Radiation Grafted Polymer Membranes for Fuel Cell Applications

Energy Technology Data Exchange (ETDEWEB)

Scherer, G G; Wallasch, F; Ben Youcef, H; Gubler, L [Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen (Switzerland)

2012-09-15

Partially fluorinated proton exchange membranes prepared via radiation induced graft copolymerization ('radiation grafting') offer the prospect of cost-effective and tailor made membrane electrolytes for the polymer electrolyte fuel cell (PEFC). The composition and structure of radiation grafted membranes can be adjusted in a broad range to balance the different requirements of proton transport and mechanical robustness. Based on the earlier work on Styrene grafting, the novel monomer combination {alpha}-methyl-styrene/methacrylonitrile (AMS/MAN) is introduced for improved stability in the prevailing fuel cell environment. Successful fuel cell experiments proved the concept. (author)

Thermosensitive membranes by radiation-induced graft polymerization of N-isopropyl acrylamide/acrylic acid on polypropylene nonwoven fabric

International Nuclear Information System (INIS)

Ikram, Saiqa; Kumari, Mamta; Gupta, Bhuvanesh

2011-01-01

Radiation-induced graft copolymerization of N-isopropylacrylamide (NIPAAm) and acrylic acid (AA) mixture was investigated on polypropylene nonwoven fabric to develop a thermosensitive material. The grafting was carried out using methanol, acetone and butanone as homopolymerization inhibitor in the reaction medium. Butanone was observed to give the maximum grafting. It was observed that the grafting is significantly influenced by the reaction conditions, such as radiation dose, monomer concentration, monomer ratio, solvent composition and reaction temperature. The degree of grafting increased as the AA and NIPAAm concentration in the reaction medium increased. The degree of grafting increased as the AA fraction in the NIPAAm/AA mixture increased. The temperature dependence of the grafting process is very much governed by the thermosensitive nature of the grafted chains right from the stage when initial grafting has taken place.

Thermosensitive membranes by radiation-induced graft polymerization of N-isopropyl acrylamide/acrylic acid on polypropylene nonwoven fabric

Energy Technology Data Exchange (ETDEWEB)

Ikram, Saiqa; Kumari, Mamta [Department of Chemistry, Jamia Millia Islamia (Central University), New Delhi-110025 (India); Gupta, Bhuvanesh, E-mail: bgupta@textile.iitd.ernet.i [Department of Textile Technology, Indian Institute of Technology, New Delhi-110016 (India)

2011-01-15

Radiation-induced graft copolymerization of N-isopropylacrylamide (NIPAAm) and acrylic acid (AA) mixture was investigated on polypropylene nonwoven fabric to develop a thermosensitive material. The grafting was carried out using methanol, acetone and butanone as homopolymerization inhibitor in the reaction medium. Butanone was observed to give the maximum grafting. It was observed that the grafting is significantly influenced by the reaction conditions, such as radiation dose, monomer concentration, monomer ratio, solvent composition and reaction temperature. The degree of grafting increased as the AA and NIPAAm concentration in the reaction medium increased. The degree of grafting increased as the AA fraction in the NIPAAm/AA mixture increased. The temperature dependence of the grafting process is very much governed by the thermosensitive nature of the grafted chains right from the stage when initial grafting has taken place.

The Use of Membranes Prepared by Radiation - Induced Grafting in Waste Water Treatment

International Nuclear Information System (INIS)

El-Arnaouty, M.B.; Abdel Aal, S.E.; Dessouki, A.M.

2000-01-01

Membranes were prepared by the radiation-induced grafting of N-vinylpyrrolidone onto low density polyethylene and the possibility for their practical use in the removal of two dyes: Acid red 116(Erionyl red 2B) and blue reactive (Brilliant bright blue) was studied. The effect of the degree of grafting on the adsorption of these pollutants was investigated and showed maximum adsorption occurred at 394 % grafting. Radiation degradation of the dyes with a dose of ∼ 5 KGy was followed by adsorption of the residual concentration of the dyes by the membranes, which resulted in the complete removal of these pollutants as well as the radiolysis products present in the irradiated solutions. Also, characterization of the membranes before and after adsorption was carried out using thermogravimetric analysis and scanning electron microscopy

Production and installation of equipments for radiation-induced graft polymerization in liquid phase and dipping techniques

International Nuclear Information System (INIS)

Seko, Noriaki; Kasai, Noboru; Tamada, Masao; Hasegawa, Shin; Katakai, Akio; Sugo, Takanobu

2005-01-01

Fibrous adsorbent which is synthesized by radiation induced graft polymerization on the trunk polymers such as polymer nonwoven fabrics and woven cloths exhibits an excellent selective adsorption against heavy metal ions and toxic gases at extremely low concentrations. Two equipments were installed to synthesize the metal-ion and gas adsorbents by means of the radiation-induced graft polymerization in the liquid phase and the dipping, respectively. In the reation chamber of the liquid phase reactor, the oxygen decreased to 100 ppm. The inside temperature was elevated at 80C. These characteristics satisfied the specification. The fabric transport can regulate the rate in the range from 1 to 10 m/min. The reactor for the dip grafting could reduce the inside oxygen to 100ppm and inside temperature could reach to 80C, also. The transport system is stable during the dip grafting reaction. The grafting of glycidyl methacrylate was carried out as a characteristic test. The degree of grafting was controlled in the range of 40-70%. The both equipments can graft the trunk polymer, 2000mm in maximum width and 1m in maximum diameter. This size is enough for confirmation practical scale synthesis. (author)

Optimization strategies for radiation induced grafting of 4-vinylpyridine onto poly(ethylene-co-tetraflouroethene) film using Box–Behnken design

International Nuclear Information System (INIS)

Mahmoud Nasef, Mohamed; Shamsaei, Ezzatollah; Ghassemi, Payman; Ahmed Aly, Amgad; Hamid Yahaya, Abdul

2012-01-01

The radiation induced grafting of 4-vinylpyridine (4-VP) onto poly(ethylene-co-tetrafluoroethene) (ETFE) was optimized using the Box–Behnken factorial design available in the response surface method (RSM). The optimized grafting parameters; absorbed dose, monomer concentration, grafting time and reaction temperature were varied in four levels to quantify their effect on the grafting yield (GY). The validity of the statistical model was supported by the small deviation between the predicted (GY=61%) and experimental (GY=57%) values. The optimum conditions for enhancing GY were determined at the following values: monomer concentration of 48 vol%, absorbed dose of 64 kGy, reaction time of 4 h and temperature of 68 °C. A comparison was made between the optimization model developed for the present grafting system and that for grafting of 1-vinylimidazole (1-VIm) onto ETFE to confirm the validly and reliability of the Box–Behnken for the optimization of various radiation induced grafting reactions. Fourier transform infrared (FTIR), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) were used to investigate the properties of the obtained films and provide evidence for grafting. - Highlights: ► Radiation induced grafting of 4-VP onto ETFE was studied in comparison of that of VIm onto ETFE. ► The parameters of grafting reaction were optimized using Box–Behnken factorial design. ► A statistical model to predict G% was developed taking the nature of 4-VP into account. ► The predicted response value agreed well with the experimental data as indicated by a 4% deviation. ► The model proved to be valid and reliable tool for predicting various radiation grafting reactions.

Development of Novel Absorbents and Membranes by Radiation-Induced Grafting for Selective Purposes

Energy Technology Data Exchange (ETDEWEB)

Hegazy, E A; Abdel-Rehim, H; Hegazy, D; Ali, A A; Kamal, H; Sayed, A [National Center for Radiation Research and Technology, Atomic Energy Egypt, P.O.Box 29, Nasr City, Cairo (Egypt)

2012-09-15

The direct radiation grafting technique was used to graft glycidyl methacrylate (GMA) monomer containing epoxy ring, onto polypropylene fibres. The ring opening of the epoxy ring in GMA by different amino groups was studied to introduce various chelating agents. Some properties of grafted fibres were studied and the possibility of its practical use for water treatment from iron and manganese metals was investigated. The radiation initiated grafting of acrylic acid (AAc) or acrylamide (AAm) monomers onto poly(vinyl alcohol) (PVA), a 2-acrylamide-2-methyl propane sulfonic acid (AMPS) polymer was studied. Cationic/anionic membranes were also prepared by radiation-induced grafting of styrene/methacrylic acid (Sty/MAA) binary monomers onto LDPE films. To impart reactive cationic/anionic characters in the grafted membranes, sulfonation and alkaline treatments for styrene and carboxylic acid groups, respectively, were carried out. The possibility of their applications in the selective removal of some heavy metals was studied. The prepared grafted materials had a great ability to recover the metal ions such as: Ni{sup 2+}, Co{sup 2+}, Cu{sup 2+}, Cd{sup 2+}, Mg{sup 2+}, Zn{sup 2+}, Mn{sup 2+} and Cr{sup 3+} from their solutions. It was found that AMPS content in the grafted copolymers is the main parameter for the selectivity of the copolymer towards metal ions. The higher the AMPS content the higher the selectivity towards Co and Ni ions. In case of LDPE-g-P(STY/MAA), the sulfonation and alkaline treatments are the most effective methods to influence metal absorption and swelling behaviour of the prepared membranes. Graft composition, dose and pH have also a great influence on the membrane characteristics and applicability in wastewater treatments from heavy and toxic metals. Results revealed that the prepared grafted materials with different functionalized groups are promising as ion selective membranes and could be used for wastewater treatment. (author)

Radiation-induced grafting of styrene on to LDPE films for preparation of cation exchange membranes, i. effect of grafting conditions

International Nuclear Information System (INIS)

Mohamed Mahmoud Nasef; Hamdani Saidi; Hussin Mohd Nor; Khairul Zaman Mohd Dahlan; Kamaruddin Hashim

1999-01-01

PE-g-polystyrene copolymers were prepared by simultaneous radiation-induced graft copolymerization of styrene onto low density polyethylene (LDPE) films. The effects of irradiation conditions such as monomer concentration, Mohr's salt and sulfuric acid addition, irradiation dose and dose rate were investigated. It was found that the degree of grafting increases with the monomer concentration and reaches its maximum value at styrene concentration of 80 vol %. The addition of Mohr's salt as well as sulfuric acid caused a considerable increase in the degree of grafting with various styrene concentrations. The degree of grafting also increased with the increased in irradiation dose, however it remarkably decreased with the increase in dose rate. The formation of graft copolymers was confirmed by FTIR analysis. The structural investigation of the graft copolymer was carried out by x-ray diffraction (XRD). The degree of crystallinity content was found to be decreased with the increase in the degree of grafting and influenced the mechanical properties of the graft copolymer to some extent. (Author)

Preparation of metal ion exchange resin by radiation-induced graft copolymerization

International Nuclear Information System (INIS)

Nakase, Yoshiaki; Akasaka, Nobuhiro.

1982-06-01

Radiation-induced graft copolymerization of 2-acrylamide-2-methyl propane sulfonic acid (AMPS) onto polyvinylchloride (PVC) and polyvinylidene chloride resin (PVD) was investigated in the water-acetone system and their adsorptive activities to metal ion were also examined. In the case of PVC, the degree of grafting increased with the increase of acetone content, but the adsorptive activity to metal ions (mainly lithic ion) became maximum in the system with water/acetone of 2/3. Grafted PVC prepared at about 35 0 C and at a higher concentration of AMPS showed higher adsorption activity than the other cases. In the case of PVD, a similar result was obtained with the case of PVC except the temperature dependence and effect of swelling agent. Polymerizations at temperatures of 35 and 50 0 C showed no effect on the degree of grafting, and the usage of a swelling agent was quite effective to the adsorptive activity. Glass transition temperature of the grafted copolymer was the same as that of original polymer, and their thermal stability was confirmed up to the temperature at which homopolymer of AMPS decomposed, about 180 0 C. (author)

Radiation-induced graft copolymerization of methyl acrylate and acrylic acid onto rubber wood fiber

International Nuclear Information System (INIS)

Saliza Jam; Mansor Ahmad; Wan Md Zin Wan Yunus; Khairul Zaman Mohd Dahlan

2001-01-01

Graft copolymerization of methyl acrylate and acrylic acid monomers onto rubber wood fiber (RWF) was carried out by simultaneous radiation-induced technique. The parameters affecting the grafting reaction were investigated and the optimum conditions for both monomers obtained are as follows: impregnation time = 16 hours, total dose = 30 kGy, methanol : water ratio, 3:1, monomers concentration = 40 v/v % and sulphuric acid concentration = 0.1 mol/L. Fourier Transform Infrared (FTIR), thermogravimetry analysis (TGA), and scanning electron microscope (SEM) analyses used to characterize graft copolymers. The structural investigation by x-ray diffraction (XRD) shows the degree of crystallinity of rubber wood fiber decreased with the incorporation of poly(methyl acrylate) and poly(acrylic acid) grafts. (Author)

Optimization of reaction parameters of radiation induced grafting of 1-vinylimidazole onto poly(ethylene-co-tetraflouroethene) using response surface method

Energy Technology Data Exchange (ETDEWEB)

Nasef, Mohamed Mahmoud, E-mail: mahmoudeithar@fkkksa.utm.my [Institute of Hydrogen Economy, International Campus, Universiti Teknologi Malaysia, 54100 Kuala Lumpur (Malaysia); Aly, Amgad Ahmed; Saidi, Hamdani; Ahmad, Arshad [Institute of Hydrogen Economy, International Campus, Universiti Teknologi Malaysia, 54100 Kuala Lumpur (Malaysia)

2011-11-15

Radiation induced grafting of 1-vinylimidazole (1-VIm) onto poly(ethylene-co-tetraflouroethene) (ETFE) was investigated. The grafting parameters such as absorbed dose, monomer concentration, grafting time and temperature were optimized using response surface method (RSM). The Box-Behnken module available in the design expert software was used to investigate the effect of reaction conditions (independent parameters) varied in four levels on the degree of grafting (G%) (response parameter). The model yielded a polynomial equation that relates the linear, quadratic and interaction effects of the independent parameters to the response parameter. The analysis of variance (ANOVA) was used to evaluate the results of the model and detect the significant values for the independent parameters. The optimum parameters to achieve a maximum G% were found to be monomer concentration of 55 vol%, absorbed dose of 100 kGy, time in the range of 14-20 h and a temperature of 61 {sup o}C. Fourier transform infrared (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to investigate the properties of the obtained films and provide evidence for grafting. - Highlights: > A precursor for phosphoric acid membrane for a high temperature PEM fuel cell was prepared. > The grafting parameters for radiation induced grafting of 1-VIm onto ETFE film were optimized. > Surface response method was used to predict the degree of grafting. > The predicted value agreed well with the experimental data as indicated by a 3% deviation. > The number of the experiments and cost of radiation induced grafting were reduced.

Radiation induced vapour phase grafting of styrene onto fluorinated substrates

International Nuclear Information System (INIS)

Dargaville, T.; Hill, D.; George, G.; Cardona, F.

2000-01-01

Full text: Polytetrafluoroethylene (PTFE) is well known for being inert towards heat, solvents and harsh chemicals. However, in contrast, PTFE is extremely sensitive to radiation suffering from a dramatic decrease in mechanical strength even when exposed to low doses. In this study we have used a copolymer of PTFE, poly(tetrafluoroethylene-co-perfluoropropylvinyl ether) (PFA). The effect of the ether comonomer is to render the polymer melt processable, lower the crystallinity and increase the radical yield when compared with PTFE. When grafting styrene to PFA using a radiation initiated process, the resulting polymer has the desirable chemical and thermal resistance of the PFA substrate combined with the functionality of the styrene, however, due to the incidental degradative effect of radiation on the PFA substrate it is important to find conditions where the best graft is achieved without exposing the substrate to extraneous levels of radiation. We have successfully grafted styrene to PFA by simultaneously exposing PFA to styrene vapour and gamma radiation. This process was found to be independent of dose rate at low dose rates suggesting a diffusion controlled mechanism. The penetration of the graft into the PFA substrate was measured by mapping a cross-section using micro-probe Raman spectroscopy

Desalination by electrodialysis with ion-exchange membrane prepared by radiation-induced graft polymerization

Energy Technology Data Exchange (ETDEWEB)

Choi, Seong-Ho; Jeong, Young Han; Ryoo, Jae Jeong; Lee, Kwang-Pill [Department of Chemistry Graduate School, Kyungpook National University, Taegu (Korea)

2000-07-01

Ion-exchange membranes modified with triethylamine [-N(CH{sub 2}CH{sub 3}){sub 3}] and phosphoric acid (-PO{sub 3}H) groups were prepared by radiation-induced grafting of glycidyl methacrylate (GMA) onto polyolefin nonwavon fabric (PNF) and subsequent chemical modification of poly (GMA) graft chains. The physical and chemical properties of the GMA-grafted PNF and the PNF modified with ion-exchange groups were investigated by SEM and XPS. The ion-exchange capacities of the cation- and anion-exchange membrane were 0.20 and 1.24mmol/g, respectively. The content of cation- and anion exchange group increased with increasing grafting yield (d.g.=100%). Electrical resistance of PNF modified with TEA and -PO{sub 3}H group decreased with increasing ion-exchange group capacities. Application of the graft-type ion-exchange membranes as separators for electrodialysis enabled use to reduce the time required to achieve 85.5% desalination of the 0.5M NaCl solution. (author)

Radiation induced grafting of tetrafluoroethylene on Nafion Films for ion exchange membrane application

International Nuclear Information System (INIS)

Geraldes, Adriana Napoleao; Silva, Dionisio Furtunato da; Ferreto, Helio Fernando Rodrigues; Souza, Camila Pinheiro; Parra, Duclerc Fernandes; Lugao, Ademar Benevolo

2011-01-01

Grafting of TFE nanocomposites onto Nafion was studied for synthesis of ion exchange membranes. Radiation-induced grafting of TFE gas onto Nafion films was investigated after simultaneous irradiation using a 60 Co source. The thermal degradation of polytetrafluoroethylene (PTFE) waste has been used for production of TFE. Nafion films were irradiated at 15 kGy dose at room temperature and chemical changes were monitored after contact with TFE gas for grafting. The modified films were evaluated by differential scanning calorimetry analysis (DSC), thermogravimetric analysis (TG), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Characterization by XRD suggests crystallinity changes after TFE grafting. The ion exchange capacity (IEC) of membranes was determined by acid-base titration and the values for modified films were achieved similar to Nafion pristine films. DSC measurements revealed a displacement in the endothermic peaks and it was probably associated with the TFE graft. The graft forces the Nafion polymer chains to re-organize themselves and form a more cross-linked structure within the clusters. (author)

Radiation induced grafting of tetrafluoroethylene on Nafion Films for ion exchange membrane application

Energy Technology Data Exchange (ETDEWEB)

Geraldes, Adriana Napoleao; Silva, Dionisio Furtunato da; Ferreto, Helio Fernando Rodrigues; Souza, Camila Pinheiro; Parra, Duclerc Fernandes; Lugao, Ademar Benevolo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2011-07-01

Grafting of TFE nanocomposites onto Nafion was studied for synthesis of ion exchange membranes. Radiation-induced grafting of TFE gas onto Nafion films was investigated after simultaneous irradiation using a {sup 60}Co source. The thermal degradation of polytetrafluoroethylene (PTFE) waste has been used for production of TFE. Nafion films were irradiated at 15 kGy dose at room temperature and chemical changes were monitored after contact with TFE gas for grafting. The modified films were evaluated by differential scanning calorimetry analysis (DSC), thermogravimetric analysis (TG), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Characterization by XRD suggests crystallinity changes after TFE grafting. The ion exchange capacity (IEC) of membranes was determined by acid-base titration and the values for modified films were achieved similar to Nafion pristine films. DSC measurements revealed a displacement in the endothermic peaks and it was probably associated with the TFE graft. The graft forces the Nafion polymer chains to re-organize themselves and form a more cross-linked structure within the clusters. (author)

Radiation-induced grafting of acrylamide onto guar gum in aqueous medium: Synthesis and characterization of grafted polymer guar-g-acrylamide

Energy Technology Data Exchange (ETDEWEB)

Biswal, Jayashree [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Kumar, Virendra [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Bhardwaj, Y.K. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India)]. E-mail: ykbhard@magnum.barc.ernet.in; Goel, N.K. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Dubey, K.A. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Chaudhari, C.V. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Sabharwal, S. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India)

2007-10-15

Mutual radiation grafting technique has been applied to carry out grafting of acrylamide (AAm) onto guar gum (GG) using high-energy Co{sup 60} {gamma} radiation to enhance its flocculating properties for industrial effluents. The grafted product was characterized using analytical probes like elemental analysis, thermal analysis, Fourier transformed infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The grafting extent was observed to decrease with the dose rate and increase with the concentration of AAm. Thermo gravimetric analysis (TGA) of grafted and ungrafted samples indicated better stability of grafted product. {gamma} and microwave radiation effect on grafted and virgin GG has also been reported.

Study on radiation grafting reaction of MMA onto hydroxyapatite

International Nuclear Information System (INIS)

Jiang Bo

1996-01-01

The grafting reaction of MMA onto hydroxyapatite has been studied with the pre-irradiation method in air. The effects of radiation dose, monomer concentration, reaction temperature and inorganic acid on the system are observed. The grafting copolymerization is found to be controlled by the kinetics. If proper kinetic conditions are selected, a better grafting yield can be obtained. Employing weight method, burning method as well as SeM and IR analysis, it has been proved that MMA is definitely grafted onto hydroxyapatite by chemical bonds, which shows that it is possible to improve the interface of inorganic-organic composite materials and to make bioactive ceramics by using radiation induced-grafting copolymerization

Radiation induced graft copolymerization of jute fibre

International Nuclear Information System (INIS)

Al-Siddique, F.R.; Khan, A.U.; Sheikh, R.A.

1983-01-01

Graft copolymerized jute fibres (GCJF) were prepared by γ-ray induced graft copolymerization of various monomers onto bleached and de-waxed jute samples. The effect of γ-ray dose on the tendency of various monomers to form graft co-polymer was studied. It was found that the tendency decreases as follows: methylmethacrylate (MMA)>acrylonitrile (AN)>styrene (STY)>vinylacetate (VA). When the effect of monomer concentration on the formation of graft co-polymer was studied, it was found that a mixture of AN and STY gave a higher amount of grafting than what was observed for STY or AN alone, when used at a comparable concentration. A study on the effect of concentration of methyl alcohol (a swelling agent for jute) on the tendency of the monomers to form graft co-polymer showed that although there is no effect when only AN is used, an appreciable effect is observed if AN is mixed with STY. In the later case the tendency of graft co-polymerization increases with the increase of CH 3 OH concentration. It was further observed that the increase of CH 3 OH also has a positive influence on MMA to form graft co-polymer in the range of 40-90% CH 3 OH. The affinity of GCJF towards moisture has been found to decrease with the increase of polymer loading onto jute. The presence of swelling agents during graft copolymer formation was also found to decrease the affinity of GCJF towards moisture. (author)

The use of radiation-induced graft polymerization for obtaining polymeric biomaterial on the basis of preparation 'Piyavit'

International Nuclear Information System (INIS)

Kudryavtsev, V.N.; Degtyareva, T.V.; Kabanov, V.Ya.

1998-01-01

The purpose of the present study is to obtain hemocompatible polymeric materials. The method of modification of polymer surface have been elaborated using the radiation-induced graft polymerization after which the surface is capable of coupling with the biologically active substances (BAS) produced from the medicinal leeches. At the Biological Department of Lomonosov Moscow State University was created a medicinal preparation 'Piyavit' isolated from the salivary glands secretion of the medicinal leeches (Hirudo medicinalis). It possess a wide spectrum of biological action on the human organism thanks to the presence of an unique complex natural of BAS (enzymes, inhibitors of proteolityc ensymes, prostanoids and et. al) guaranteed the anticoagulating, thrombolytic, antithrombotic, antiphlogistic, antiatherosclerotic, hypotentic effects and et al.. It has several advantages over anticoagulant heparin which is widely used for above mentioned purpose. 'Piyavit' is the multifunctional preparation, has not negative side-effects and is more cheap. The method of obtaining biocompatible polymers (basically polyethylene) with immobilized 'Piyavit' consist of three stages: 1. The modification of polymer surface by the radiation-induced graft polymerization of acrylic acid to obtain grafted chains polyacrylic acid (PAA) with controlled number and length. 2. The treatment of radiation grafted PAA by thionyl chloride that lead to conversion carboxyl groups of PAA in highly reactive acide chloride groups. 3. The covalent immobilization BAS of 'Piyavit' by acylation amino- and hydroxy-groups (functional groups in BAS) by acide chloride of PAA grafted on the polymere. (author)

Radiation grafting of dimethylaminopropylacrylamide and dimethylaminopropylmethacrylamide onto polyethylene

Energy Technology Data Exchange (ETDEWEB)

Burillo, Guillermina; Oseguera, M.A. [UNAM, Inst. de Ciencias Nucleares, Mexico City (Mexico); Vazquez, Carmen; Castillo, L.P. del [UNAM, Inst. de Investigaciones en Materiales, Mexico City (Mexico)

1997-11-01

Radiation-induced grafting of dimethylaminopropylacrylamide and dimethylamino-propylmethacrylamide onto polyethylene films, by direct grafting of the vinyl monomers to a polymer by mutual irradiation, has been investigated. The kinetics of the reaction were studied at different irradiation temperatures, monomer concentration and dose rates of gamma rays, and the appropriate reaction conditions for graft polymerization were determined. The thermal and mechanical behavior of the grafted films by means of DMA, TMA, DSC and TGA were also investigated. (author).

Ionic membranes obtained by radiation-induced graft copolymerization, I-preparation. Vol. 3

Energy Technology Data Exchange (ETDEWEB)

Abd El-Rehim, H A; Hegazy, E A [National Center for Radiation and Technology, Atomic Energy Authority, Cairo, (Egypt); Ali, A M.I.; Nowier, H G; Aly, H F [Hot Laboratories Center, atomic Energy Authority, Cairo, (Egypt)

1996-03-01

A study has been made on the preparation of ionic membranes by radiation-induced graft copolymerization of acrylic acid (AAC) onto low density polyethylene (LDPE) films. The Suitable conditions at which the grafting proceeds homogeneously were determined. To minimize the homo polymerization of AAC during irradiation process different types of inhibitors were investigated to find that the addition of Fe Cl{sub 3} (1.5 Wt%) effectively reduced such process when compared with other inhibitors used. The suitable diluent for this grafting system is found to be distilled water, methanol and methanol water mixture. The effect of diluent mixture composition, irradiation time, addition of mineral or organic acid and metal chlorides on the grafting yield and its homogeneity in the graft copolymer was determined. It was observed that the grafting yield increased as the content of water increased in MeOH/H{sub 2} O mixture. The addition of oxalic acid to the reaction medium enhanced the grafting process, however, the addition of HCl or H{sub 2} S O{sub 4} resulted in a more homogeneous grafting. The same effect was also observed when metal salts; namely N H{sub 4} Cl, NaCl and Cu Cl{sub 2} were added and resulted in homogeneous grafted membranes. The swelling and permeability of the grafted films prepared were also investigated. Results obtained in this study showed a great promise for the possible practical use of such prepared graft copolymers as a good hydrophilic membrane. The possibility of its use as an ion-exchange membrane for metal waste will be considered.4 figs., 5 tabs.

Functionalization of poly (4-vinylpyrrolidone) through γ - radiation induced grafting

International Nuclear Information System (INIS)

Pande, C.S.; Ambasta, A.K.; Kumari, Mamta; Sharma, Ajay

2002-01-01

Cross-linked poly(N-vinylpyrrolidone) and N-vinylimidazole were mutually irradiated in water under nitrogen with γ-radiations. A detailed study of grafting was made under various reaction parameters. The results have been compared with the grafting done in air. (author)

Modification of flax fibres by radiation induced emulsion graft copolymerization of glycidyl methacrylate

Science.gov (United States)

Moawia, Rihab Musaad; Nasef, Mohamed Mahmoud; Mohamed, Nor Hasimah; Ripin, Adnan

2016-05-01

Flax fibres were modified by radiation induced graft copolymerization of glycidyl methacrylate (GMA) by pre-irradiation method in an emulsion medium. The effect of reaction parameters on the degree of grafting (DOG) such as concentration of bleaching agent, absorbed dose, monomer concentration, temperature and reaction time were investigated. The DOG was found to be dependent on the investigated parameters. The incorporation of poly(GMA) grafts in the bleached flax fibres was confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The structural and mechanical changes were evaluated by X-ray diffraction (XRD) and mechanical tester, respectively. The results revealed that reacting bleached flax fibres irradiated with 20 kGy with 5% GMA emulsion containing 0.5% polyoxyethylene-sorbitan monolaurate (Tween 20) surfactant at 40 °C for 1 h led to a maximum DOG of 148%. The grafted fibres showed sufficient mechanical strength and hydrophobicity which make them promising precursors for development of adsorbents after appropriate chemical treatments.

Radiation induced graft copolymerization of n-butyl acrylate onto poly(ethylene terephthalate) (PET) films and thermal properties of the obtained graft copolymer

Energy Technology Data Exchange (ETDEWEB)

Ping Xiang [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Wang Mozhen, E-mail: pstwmz@ustc.edu.c [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Ge Xuewu, E-mail: xwge@ustc.edu.c [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2011-05-15

n-Butyl acrylate (BA) was successfully grafted onto poly(ethylene terephthalate) (PET) film using simultaneous radiation induced graft copolymerization with gamma rays. When BA concentration ranges from 20% to 30%, the Degree of Grafting (DG), measured by gravimetry and {sup 1}H NMR, increases with the monomer concentration and absorbed dose, but decreases with dose rate from 0.83 to 2.53 kGy/h. The maximum DG can reach up to 22.1%. The thermal transition temperatures such as glass-transition temperature (T{sub g}) and cold-crystallization temperature (T{sub cc}) of PET in grafted films were little different from those in original PET film, indicating that microphase separation occurred between PBA side chains and PET backbone. This work implied that if PET/elastomers (e.g., acrylate rubber) blends are radiated by high energy gamma rays under a certain condition, PET-g-polyacrylate copolymer may be produced in-situ, which will improve the compatibility between PET and the elastomers so as to improve the integral mechanical properties of PET based engineering plastic.

Radiation-induced grafting of styrene onto poly-vinylidene fluoride) film by simultaneous method with two different solvents

International Nuclear Information System (INIS)

Ferreira, H.P.; Parra, D.F.; Lugao, A.B.

2011-01-01

Complete text of publication follows. Radiation-induced grafting to create membranes with ion exchange capacity in fluorinated polymers has been studied for applications such as fuel cells, filtration and waste treatment and polymeric actuators due to their good physical and chemical properties. In this work, radiation-induced grafting of styrene into poly(vinylidene fluoride) (PVDF) films with 0.125 mm thickness at doses of 1 and 2.5 kGy in the presence of a styrene/N,N- dimethylformamide (DMF) solution (1:1, v/v) and at doses of 20, 40 and 80 kGy in presence of a styrene/toluene solution (1:1, v/v) at dose rate of 5 kGy h-1 was carried out by simultaneous method under nitrogen atmosphere and at room temperature, using gamma-rays form a Co-60. The films were characterized before and after modification by the grafting yield (GY), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetry (TG/DTG). GY results shows that grafting increases with dose, and it was possible to confirm the grafting of styrene by FT-IR due to the new characteristics peaks and by the TG and DSC due to changes in thermal behavior of the grafted material. Results showed that the system allows the homogeneous grafting of styrene into PVDF using gamma irradiation at doses as low as 1 kGy when DMF is used and heterogeneous grafting when toluene is used, showing the importance of the solvent nature during the simultaneous method.

Graft copolymers of polypropylene films. 1. radiation induced grafting of mixed monomers. Vol. 3

International Nuclear Information System (INIS)

El-Salmawi, K.M.; El-Naggar, A.M.; Said, H.M.; Zahran, A.H.

1996-01-01

Radiation graft copolymerization of co monomer mixtures of acrylic acid (AAC), and styrene (S) onto polypropylene (PP) film by mutual method has been investigated. The effects of different factors that may affect the grafting yield such as inhibitor concentration (Mohr's salt), solvent composition (MeOH and H 2 O), radiation dose and dose rate were considered. It was found that the role of Mohr's salt is very effective when the ratio of AAC in the co monomer mixtures was at lower values. However, the addition of 1.25 Wt% of Mohr's salt reduced the homo polymer formation and enhances the grafting process. Graft copolymerization in presence of solvent mixture composed of methanol and water was found to afford higher grafting than in pure methanol regardless of the composition of the co monomer mixture used. However, the highest degree of grafting was obtained at a solvent composition of 20% H 2 O:80%MeOH and a co monomer mixture of 20%AAC:80%sty. An attempt was made to determine each PAAC and PS fractions in the total graft yield obtained. Two methods of analysis based on using the reactivity ratios reported in literature, elemental analysis and IR spectroscopy. The determination of poly (acrylic acid) and polystyrene fractions by elemental analysis is believed more accurate than these by reactivity ratio. The precise results obtained by elemental analysis with respect to the chemical structure of known polymer prepared under identical conditions. The results obtained by IR measurements go well with that obtained with the reactivity ratio methods. 5 figs., 3 tabs

Radiation-induced grafting of acrylic acid onto polypropylene film and its biodegradability

Science.gov (United States)

Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Chaudhari, C. V.; Dubey, K. A.; Varshney, L.

2016-06-01

Polypropylene based commodity polyolefins are widely used in packaging, manufacturing, electrical, pharmaceutical and other applications. The aim of the present work is to study the effect of grafting of acrylic acid on the biodegradability of acrylic acid grafted polypropylene. The effect of different conditions showed that grafting percentage increased with increase in monomer concentration, radiation dose and inhibitor concentration but decreased with increase in radiation dose rate. The maximum grafting of 159.4% could be achieved at optimum conditions. The structure of grafted polypropylene films at different degree of grafting was characterized by EDS, FTIR, TGA, DSC, SEM and XRD. EDS studies showed that the increase in acrylic acid grafting percentage increased the hydrophilicity of the grafted films. FTIR studies indicated the presence of acrylic acid on the surface of polypropylene film. TGA studies revealed that thermal stability decreased with increase in grafting percentage. DSC studies showed that melting temperature and crystallinity of the grafted polypropylene films lower than polypropylene film. SEM studies indicated that increase in acrylic acid grafting percentage increased the wrinkles in the grafted films. The maximum biodegradability could be achieved to 6.85% for 90.5% grafting. This suggested that microorganisms present in the compost could biodegrade acrylic acid grafted polypropylene.

Graft copolymers of polypropylene films. 1. radiation induced grafting of mixed monomers. Vol. 3

Energy Technology Data Exchange (ETDEWEB)

El-Salmawi, K M; El-Naggar, A M; Said, H M; Zahran, A H [Radiation Chemistry Department, National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo, (Egypt)

1996-03-01

Radiation graft copolymerization of co monomer mixtures of acrylic acid (AAC), and styrene (S) onto polypropylene (PP) film by mutual method has been investigated. The effects of different factors that may affect the grafting yield such as inhibitor concentration (Mohr`s salt), solvent composition (MeOH and H{sub 2} O), radiation dose and dose rate were considered. It was found that the role of Mohr`s salt is very effective when the ratio of AAC in the co monomer mixtures was at lower values. However, the addition of 1.25 Wt% of Mohr`s salt reduced the homo polymer formation and enhances the grafting process. Graft copolymerization in presence of solvent mixture composed of methanol and water was found to afford higher grafting than in pure methanol regardless of the composition of the co monomer mixture used. However, the highest degree of grafting was obtained at a solvent composition of 20% H{sub 2} O:80%MeOH and a co monomer mixture of 20%AAC:80%sty. An attempt was made to determine each PAAC and PS fractions in the total graft yield obtained. Two methods of analysis based on using the reactivity ratios reported in literature, elemental analysis and IR spectroscopy. The determination of poly (acrylic acid) and polystyrene fractions by elemental analysis is believed more accurate than these by reactivity ratio. The precise results obtained by elemental analysis with respect to the chemical structure of known polymer prepared under identical conditions. The results obtained by IR measurements go well with that obtained with the reactivity ratio methods. 5 figs., 3 tabs.

Radiation induced emulsion graft polymerization of 4-vinylpyridine onto PE/PP nonwoven fabric for As(V) adsorption

International Nuclear Information System (INIS)

Akkaş Kavaklı, Pınar; Kavaklı, Cengiz; Seko, Noriaki; Tamada, Masao; Güven, Olgun

2016-01-01

A novel nonwoven fabric adsorbent having 4-vinylpyridine functional groups was prepared by using radiation-induced emulsion graft polymerization method and grafting 4-vinylpyridine monomer onto a polyethylene-coated polypropylene nonwoven fabric (NWF) in aqueous emulsion solution. The grafting conditions of the 4-vinylpyridine monomer onto the NWF were optimised and 150% D g VP-g-NWF was prepared using 30 kGy pre-irradiation dose, 5% VP monomer concentration and 0.5% (w/w) Tween 20 in aqueous emulsion. Grafted 4-vinylpyridine chains on the NWF were then quaternized for the preparation of QVP-g-NWF adsorbent. All fabric structures were characterized by using Fourier-transform infrared spectrometer, x-ray photoelectron spectrometer and scanning electron microscope. QVP-g-NWF adsorbent was used in batch adsorption experiments for As(V) ions by studying the pH, contact time, and initial As(V) ion concentration parameters. Results showed that QVP-g-NWF adsorbent has significant As(V) adsorption and experimental As(V) adsorption capacity was 98.04 mg As(V)/g polymer from 500 mg/L initial As(V) concentration at pH 7.00. - Highlights: • Radiation induced grafting of 4-vinylpyridine onto PE/PP nonwoven fabric in emulsion. • 4-vinylpyridine grafting was characterized by FTIR, SEM and XPS. • As(V) adsorption was studied by QVP-g- NWF. • As(V) adsorption capacity was found to be 98.04 mg As(V)/g polymer.

Radiation induced graft copolymerization of methyl methacrylate onto chrome-tanned pig skins

International Nuclear Information System (INIS)

Pietrucha, K.; Pekala, W.; Kroh, J.

1981-01-01

Graft copolymerization of methyl methacrylate (MMA) onto chrome-tanned pig skins was carried out by irradiation with 60 Co γ-rays. The grafted polymethyl methacrylate (PMMA) chains were isolated by acid hydrolysis of the collagen backbone in order to characterize the graft copolymers. Proof of grafting was obtained through the detection of amino acid endgroups in the isolated grafts by reaction with ninhydrin. The grafting yield of MMA in aqueous emulsion was found to be higher than that for pure MMA and MMA in acetone. The degree of grafting increases with increasing monomer concentration in emulsion and reaches maximum at radiation dose ca 15 kGy. The yield of grafting is very high. The present paper reports the physical properties of chrome-tanned pig skins after graft polymerization with MMA in emulsion. Modified leathers are more resistant against water absorption and abrasion in comparison with unmodified ones. They have more uniform structure over the whole surface, greater thickness and stiffness. The mechanism of some of the processes occurring during radiation grafting of MMA in water emulsion on tanned leathers has been also suggested and discussed. (author)

Radiation induced graft copolymerization of methyl methacrylate onto chrome-tanned pig skins

Energy Technology Data Exchange (ETDEWEB)

Pietrucha, K.; Pekala, W.; Kroh, J. (Lodz Univ. (Poland))

1981-01-01

Graft copolymerization of methyl methacrylate (MMA) onto chrome-tanned pig skins was carried out by irradiation with /sup 60/Co ..gamma..-rays. The grafted polymethyl methacrylate (PMMA) chains were isolated by acid hydrolysis of the collagen backbone in order to characterize the graft copolymers. Proof of grafting was obtained through the detection of amino acid endgroups in the isolated grafts by reaction with ninhydrin. The grafting yield of MMA in aqueous emulsion was found to be higher than that for pure MMA and MMA in acetone. The degree of grafting increases with increasing monomer concentration in emulsion and reaches maximum at radiation dose ca 15 kGy. The yield of grafting is very high. The present paper reports the physical properties of chrome-tanned pig skins after graft polymerization with MMA in emulsion. Modified leathers are more resistant against water absorption and abrasion in comparison with unmodified ones. They have more uniform structure over the whole surface, greater thickness and stiffness. The mechanism of some of the processes occurring during radiation grafting of MMA in water emulsion on tanned leathers has been also suggested and discussed.

Polymer electrolyte membranes for fuel cells by radiation induced grafting with electron beam irradiation: state-of-the-art

International Nuclear Information System (INIS)

Nasef, M.M.; Nasef, M.M.

2010-01-01

Polymer electrolyte membranes have generated considerable interest in various fields of industrial interest due to their wide spread applications in fuel cells, batteries, electrolyzers sensors and actuators. Such diversity in applications implies a strong demand to architect the membranes towards particular properties for specific applications. Radiation induced grafting of vinyl and acrylic monomers into polymeric films, is an appealing method for producing various polymer electrolyte membranes. This method has the advantages of simplicity, controllability over the composition leading to tailored membrane properties and absence of shaping problem as preparation starts with substrate in a film form. It also has the flexibility of using various types of radiation sources such as gamma-rays and electron beam. Of all, electron beam (EB) accelerator is an advantageous source of high energy radiation that can initiate grafting reactions required for preparation of the membranes particularly when pilot scale production and commercial applications are sought. The grafting penetration can be varied from surface to bulk of membranes depending on the acceleration energy. This lecture reviews the-state of- the-art in the use of EB irradiation in preparation of composite and grafted polymer electrolyte membranes for fuel cell applications by radiation induced grafting with simultaneous irradiation and preirradiation methods. The use of simultaneous EB irradiation method was found to simplify the process and reduce the reaction time as well as the monomer consumption whereas the use of preirradiation method in a single-step route provides a shorter route to prepare polymer electrolyte membranes with improved properties and reduced cost in addition of setting basis for designing a continuous line to produce these membranes with dedicated EB facilities

Advances in radiation grafting

International Nuclear Information System (INIS)

Hegazy, El-Sayed A.; AbdEl-Rehim, H.A.; Kamal, H.; Kandeel, K.A.

2001-01-01

Graft copolymerization is an attractive means for modifying base polymers because grafting frequently results in the superposition of properties relating to the backbone and pendent chains. Among the various methods for initiating the grafting reaction, ionizing radiation is the cleanest and most versatile method of grafting available. Ion-exchange membranes play an important role in modern technology, especially in separation and purification of materials. The search for improved membrane composition has considered almost every available polymeric material because of its great practical importance. Grafting of polymers with a mixture of monomers is important since different types of chains containing different functional groups are included. A great deal is focused on the waste treatment of heavy and toxic metals from wastewater because of the severe problems of environmental pollution. Functionalized polymers suitable for metal adsorption with their reactive functional groups such as carboxylic and pyridine groups suitable for waste treatment were prepared by radiation grafting method. More reactive chelating groups were further introduced to the grafted copolymer through its functional groups by chemical treatments with suitable reagents. The advances of radiation grafting and possible uses are briefly discussed

Crystallization of calcium carbonate on radiation-grafted polyethylene films

International Nuclear Information System (INIS)

Hou Zhengchi; Zhang Fengying; Deng Bo; Yang Haijun; Chen Shuang; Sheng Kanglong

2006-01-01

In biomineralization processes, nucleation and growth of inorganic crystals can be regulated by organic template molecules. This has inspired great interest in studying mimic biomineralization. In our study, growing CaCO 3 crystals on PE films functionalized through radiation-induced grafting was attempted. PE films grafted with different functional groups of different distributions and densities were used as substrates for CaCO 3 nucleation and crystal growth from Ca(HCO 3 ) 2 supersaturated solution under different environmental conditions (e.g. additives and temperature) to study the effects and mechanisms. The grafted PE films were analyzed by ATR-FTIR and AFM, and the evolution of CaCO 3 crystal formation on the grafted PE film was characterized by SEM, FTIR, and XRD. The results indicated that heterogeneous nucleation of CaCO 3 crystals was significantly facilitated by the functional groups grafted on the surface of PE films, that the morphology of CaCO 3 crystals could be controlled by distribution and density of the grafted functional groups, and that polymorphism of CaCO 3 crystal could be regulated by selection of grafting functional groups. We believe that studying the effects of chemical structures on inorganic crystallization is of great importance since radiation-induced grafting is an effective method to graft desirable functional groups onto different polymers by selected monomers, in the endeavor of developing advanced organic/inorganic composites with high performance, with a wide availability of polymers, monomers and inorganic solutions. (authors)

Radiation effect on polystyrene deposited and grafted on silica gel

International Nuclear Information System (INIS)

Kusama, Y.; Udagawa, A.; Takehisa, M.

1978-01-01

The effect of radiation on polystyrene was studied in the presence and absence of silica gel by molecular weight measurement with gel permeation chromatography (GPC). Polystyrene crosslinked under vacuum in the absence of silica gel, but it either crosslinked or degraded by radiation, depending on the molecular weight of the polymer in the presence of silica gel. part of the deposited polymer bonded to silica gel by radiation; the G value for graft-chain formation is in the range of 0.01 to 0.1. Irradiation of polystyrene grafted on silica gel resulted in degradation of the graft chain because of the transfer of energy from silica gel. The G value for main chain scission was about 2 when graft polymer was irradiated in the absence of homopolymer. The degradation of graft polymer was suppressed when the polymer was irradiated in the presence of homopolymer, and the amount of unextractable polymer from silica gel increased with increasing irradiation. This adds evidence to the estimation that an increase in grafting percent coupled with a slight decrease in molecular weight at a later stage of radiation-induced polymerization of styrene adsorbed on slica gel is due to a secondary effect of radiation on the polymer

Characterization of polyethyleneterephthalate (PET) based proton exchange membranes prepared by UV-radiation-induced graft copolymerization of styrene

Energy Technology Data Exchange (ETDEWEB)

Ahmed, Mostak; Khan, Mohammad B.; Alam, S. Shamsul; Khan, M. Anwar H. [Department of Chemistry, Shahjalal University of Science and Technology, Sylhet 3114 (Bangladesh); Khan, Mubarak A. [Radiation and Polymer Chemistry Laboratory, Institute of Nuclear Science and Technology, Bangladesh Atomic Energy Commission, P.O. Box 3787, Dhaka (Bangladesh); Halim, Md. Abdul [Department of Chemistry, Jahangirnagar University, savar, Dhaka (Bangladesh)

2011-01-15

Polymer electrolyte membranes (PEMs) were successfully prepared by simultaneous ultraviolet (UV) radiation-induced graft copolymerization of styrene (35 vol.% concentration) onto poly(ethyleneterephthalate) (PET) film, followed by sulfonation on the styrene monomer units in the grafting chain using 0.05 M chlorosulfonic acid (ClSO{sub 3}H). The radiation grafting and the sulfonation have been confirmed by titrimetric and gravimetric analyses as well as Fourier Transform Infrared (FTIR) spectroscopy. The maximum ion-exchange capacity (IEC) of the PEM was measured to be 0.04385 mmol g{sup -1} at its highest level of grafting and sulfonation. They exhibited high thermal and mechanical properties as well as oxidative stability. They are highly stable in H{sub 2}SO{sub 4} solutions and can be used in the acidic fuel cells. The membranes showed low water uptake as well as low proton conductivity than Nafion. In this study, the preparation of PEMs from commodity-type polymers is found to be very inexpensive and is a suitable candidate for applications in fuel cells. (author)

Superabsorbent Prepared by Radiation Induced Graft Copolymerization of Acrylic Acid onto Cassava Starch. Chapter 18

Energy Technology Data Exchange (ETDEWEB)

Suwanmala, P.; Tangthong, T.; Hemvichian, K. [Thailand Institute of Nuclear Technology (Thailand)

2014-07-15

Superabsorbent was synthesized by radiation induced graft polymerization of acrylic acid onto cassava starch. Parameters such as the absorbed dose and the amount of monomer were investigated in order to determine the optimum conditions for the grafting polymerization. Water retention, germination percentage, and germination energy were also determined in order to evaluate the possibility of superabsorbent in agricultural applications, especially in arid regions. The graft copolymer was characterized by the Fourier transform infrared spectroscopy (FTIR). Results indicated that the sand mixed with 0.1% wt superabsorbent could absorb more water than the sand without superabsorbent. The germination energy of corn seeds mixed with 0.5% superabsorbent was obviously higher than those without superabsorbent. These experimental results showed that the superabsorbent has considerable effects on seed germination and the growth of young plants. (author)

Additives in UV and ionising radiation grafting and curing processes

International Nuclear Information System (INIS)

Garnett, J.L.; Ng, L.T.; Viengkhou, V.

1998-01-01

Full text: Curing of polymers induced by both UV and ionising radiation are now established technologies. Currently both systems are predominantly based on acrylate chemistry. UV processes use photoinitiators to achieve fast polymerisation. In the proposed paper the significance of the occurrence of concurrent grafting with cure will be examined. particularly with respect to the recycling of finished product. Basic studies on grafting initiated by UV and ionising radiation will be discussed. Polar methyl methacrylate (MMA) and non-polar styrene will be used as representative monomers with cellulose and propylene typifying the backbone polymers. The additives chosen for examination in this study are predominantly components used in radiation curing formulations since grafting and curing are known to be mechanically related. The additives used were mineral acid, photoinitiators, vinyl ethers, oligomers, polyfunctional monomers including multifunctional acrylates (MFAs) and methacrylates (MFMAs). For the first time the use of charge transfer complexes in the Mulliken sense as additives in radiation grafting will be discussed. The CT complexes themselves, being monomers, have also been grafted to the above polymers. Recent developments with excimer laser sources for initiating these processes will be discussed, especially the use of non-acrylate chemistry. Excimer laser sources are shown to complement conventional UV and ionising radiation and are photoinitiator free. Mechanisms for the above grafting and curing processes will be outlined

Radiation Induced Grafting of Styrene onto ETFE: Influence of Crosslinker

International Nuclear Information System (INIS)

Gursel, S. A.

2006-01-01

Polymer electrolyte fuel cells are promising types of electrochemical devices for future power production with low operation temperature. In order to make this technology attractive, further cost reduction and improved reliability are required. These can be achieved in part by means of radiation induced grafting for the preparation of low cost proton-conducting polymer membranes. Indeed, the method can be performed with low-cost starting materials (fluorinated and partially fluorinated polymers). In our laboratory at Paul Scherrer Institut, most of the work has been performed using styrene and DVB as the monomers and poly (tetrafluoroethylene-co-hexafluoropropylene) as the base material. Performance comparable to Nafion 112 membranes and durability of several thousands hours at steady-state conditions have been achieved for this type of membranes under fuel cell operation conditions. Previously, poly(ethylene-alt-tetrafluoroethylene) (ETFE) based membranes have been prepared in the presence of divinylbenzene (DVB) as the crosslinking agent and found to exhibit encouraging fuel cell performance. However, the synthesis parameters were not optimized in detail to further improve the membrane properties. Recently, we have investigated the parameters of ETFE based grafting without crosslinking agent. In this study, proton-exchange membranes were prepared by pre-irradiation grafting of styrene onto ETFE and subsequent sulfonation in the presence of DVB containing different isomers (m- and p-isomer of DVB and m- and p-ethylvinylbenzene) as the crosslinker. The grafted films and membranes with varying DVB concentrations and similar degree of grafting (25%) were characterized by Fourier transform infrared spectroscopy (FTIR-ATR) and differential scanning calorimetry (DSC). In addition, dimensional changes and fuel cell relevant properties were examined. FTIR-ATR measurements revealed that the p- isomers are more reactive than m-isomers, and the grafted films are more highly

Study of radiation grafted and sulfonated poly(tetrafluoroethylene-co-hexafluoropropylene), FEP, membranes

International Nuclear Information System (INIS)

Mohamed Mahmoud Nasef; Hamdani Saidi; Hussin Mohd Nor

1999-01-01

Radiation grafted and sulfonated FEP membranes were prepared by radiation-induced grafting of styrene onto poly(tetrafluoroethylene-co-hexafluoropropylene) films at room temperature and subsequently sulfonated. The membrane composition was controlled via variation of the grafting conditions such as type of diluent, irradiation dose, dose rate and monomer concentration. The membrane properties such as water uptake, ion exchange capacity and ionic conductivity were found to be strongly dependent upon the degree of grafting. The membranes were shown to have a good combination of physico-chemical properties, which made them promising for development of low cost proton exchange membranes

Modification of polyetherurethane for biomedical application by radiation-induced grafting. I. Grafting procedure, determination of mechanical properties, and chemical modification of grafted films

International Nuclear Information System (INIS)

Jansen, B.; Ellinghorst, G.

1985-01-01

Radiation grafting of monomers onto suitable trunk polymers is a useful tool for tailoring new polymers for special purposes. This technique has been used in the past for the development of biocompatible materials, e.g., by grafting hydrogels onto mechanically stable polymers. In this first part of our work, the radiation grafting of hydrophilic or reactive monomers onto a polyetherurethane film using the pre-swelling technique is described. Following this technique the trunk polymer was swollen in the monomer before irradiation. As monomers 2-hydroxyethyl methacrylate (HEMA), 2,3-epoxypropyl methacrylate (GMA), 2,3-dihydroxypropyl methacrylate (GOMA), and acrylamide (AAm) were used. The kinetics of the grafting reactions were examined, and the distribution of the graft component inside the trunk polymer was investigated by means of infrared (IR) spectroscopy. Surface-grafted as well as bulk- and surface-grafted products could be obtained. The mechanical behavior of the grafted films--especially in the water-swollen state--was examined and compared with that of the pure trunk polymer. In nearly all cases it was found that the tensile strength sigma B and the elongation at break epsilon R decreases as the grafting yield increases. Modification of GMA- and AAm-grafted films via chemical reactions was performed to create new functional groups of biomedical interest. In this manner a diol structure, a carboxylic acid structure, and a sulfonic acid group could be introduced in the grafted polymer. The water uptake of such modified films is increased markedly when compared with that of the unmodified samples

Radiation-induced grafting polymerization of MMA onto polybutadiene rubber latex

International Nuclear Information System (INIS)

Peng Jing; Wang Maolin; Qiao Jinliang; Wei Genshuan

2005-01-01

The grafting of methyl methacrylate (MMA) onto polybutadiene rubber latex by the direct radiation method was carried out. The effects of monomer concentration, absorbed dose and dose rate of gamma rays on the grafting yield were investigated. The graft copolymers were characterized by transmission electron microscopy (TEM), FTIR spectroscopy, and differential scanning calorimetry. TEM photographs revealed that the core-shell structures of latex particles are formed at low MMA content, and with the increasing of MMA content, the semi-IPN-like structure with core-shell could be developed due to the high gel fraction of polybutadiene (PBD) seed particles. In addition, infrared analysis confirmed that MMA could be grafted onto PBD molecular chains effectively under appropriate irradiation conditions. The interfacial adhesion between PBD rubber (core) and PMMA (shell) phases could be enhanced with the increase of MMA concentration

Protective immunity to UV radiation-induced skin tumours induced by skin grafts and epidermal cells

International Nuclear Information System (INIS)

Ronald Sluyter; Kylie S Yuen; Gary M Halliday

2001-01-01

There is little evidence that cutaneous dendritic cells (DC), including epidermal Langerhans cells (LC), can induce immunity to UV radiation (UVR)-induced skin tumours. Here, it is shown that cells within skin can induce protective antitumour immunity against a UVR-induced fibrosarcoma. Transplantation of the skin overlying subcutaneous tumours onto naive recipients could induce protective antitumour immunity, probably because the grafting stimulated the tumour Ag-loaded DC to migrate to local lymph nodes. This suggests that cutaneous APC can present tumour Ag to induce protective antitumour immunity. Previously, it has been shown that immunization of mice with MHC class II+ epidermal cells (EC) pulsed with tumour extracts could induce delayed-type hypersensitivity against tumour cells. Here, this same immunization protocol could induce protective immunity against a minimum tumorigenic dose of UVR-induced fibrosarcoma cells, but not higher doses. Epidermal cells obtained from semiallogeneic donors and pulsed with tumour extract could also induce protective immunity. However, presentation of BSA Ag from the culture medium was found to contribute to this result using semiallogeneic EC. The results suggest that LC overlying skin tumours may be able to induce protective immunity to UVR-induced tumours if stimulated to migrate from the skin. Copyright (2001) Australasian Society of Immunology Inc

Radiation-induced grafting of vinylbenzyl chloride onto a poly(ether ether ketone) film

International Nuclear Information System (INIS)

Hwang, Mi-Lim; Song, Ju-Myung; Ko, Beom-Seok; Sohn, Joon-Yong; Nho, Young-Chang; Shin, Junhwa

2012-01-01

In this study, the effects of various irradiation conditions including solvent, monomer concentration, total dose, and dose rate on the radiation grafting of a VBC monomer onto a PEEK aromatic hydrocarbon film for the preparation of a PVBC-grafted PEEK (PEEK-g-PVBC) film were investigated. The results show that the desired PVBC-grafted PEEK film can be prepared using a simultaneous irradiation grafting method, and that the degree of grafting (DOG) of the film is largely influenced by the irradiation conditions. Among the applied solvents, halogenated solvents, dichloromethane and chloroform, were found to be suitable for grafting. The successful preparation of the grafted film was confirmed using analytical instruments such as FT-IR, TGA, and SEM-EDX.

Electron beam induced modification of grafted polyamides

International Nuclear Information System (INIS)

Timus, D.M.; Brasoveanu, M.M.; Bradley, D.A.; Popov, A.M.

1998-01-01

It is well known that irradiation, when applied on its own or in combination with other physical and chemical treatments, can manifest in radiation damage to materials. Radiation processing technology focuses upon producing favourable modification of materials through use of relatively high dose and dose rates. Current interest is in modifying the thermal and electrical properties of textured polymers in an effort to improve safety and wear comfort of clothing. No less important is the production of textiles which are safe to use, both in homes and offices. Present investigations provide additional data in support of findings which show that polyamides, a particular class of textured polymer, are amenable to radiation processing. Accelerated electron beam irradiation of sheets of polyamide fibre results in induced grafting of acrylic and methacrylic acids. The degree of grafting is critically dependent upon irradiation dose and the extent of monomers dilution. Of particular importance is the high correlation which is found between degree of grafting and a decrease in the softening rate of the modified polyamide. A systematic modification of electrical conductivity is also observed. (author)

Dyed grafted films for large-dose radiation dosimetry

Energy Technology Data Exchange (ETDEWEB)

Abdel Rehim, F; El-Sawy, N M; Abdel-Fattah, A A [National Centre for Radiation Research and Technology, Cairo (Egypt)

1993-07-01

By radiation-induced polymerization of acrylic acid onto poly(ethylene-tetrafluoroethylene) (ET) copolymer film and reacting the resulted grafted film with both Rhodamine B (RB) and Malachite Green (MG), new dosimeter films have been developed for high-dose gamma radiation applications in the range of absorbed doses from 10 to 180 kGy. The radiation-induced color bleaching has been analysed with visible spectrophotometry, either at the maximum of the absorption band peaking at 559 nm (for ETRB) or that peaking at 627 nm (for ETMG). The effects of different conditions of absorbed dose rate, temperature and relative humidity during irradiation and post-irradiation storage on dosimeter performance are discussed. (author).

Synthesis and Characterization of PVP-Grafted-Starch Hydrogels Using Gamma Radiation

International Nuclear Information System (INIS)

Suwanmala, Phiriyatorn; Hemvichian, Kasinee; Sonsuk, Manit

2004-10-01

A Series of hydrogels were prepared from gelatinized cassava starch and vinylpyrrolidone by radiation-induced graft copolymerization. Gel fraction, swelling ratio and gel strength of the obtained hydrogels were characterized. The experimental results show that the swelling ratio is inversely dependent on the radiation dose. The results from PVP-grafted-starch were subsequently compared with those of PVP hydrogels and PVP-blended-starch hydrogels. It was found that the PVP-grafted-starch hydrogels, with gel fraction higher than 80% can be prepared at the dose of 10 kGy, while PVP and PVP-blended-starch hydrogels require at least 30 kGy to obtain gels with more than 80% gel fraction

In-situ formation of silver nanoparticles on poly (lactic acid) film by γ-radiation induced grafting of N-vinyl pyrrolidone

Energy Technology Data Exchange (ETDEWEB)

Wang, Jingxia; Chen, Hao; Chen, Zhuping; Chen, Yuheng; Guo, Dan; Ni, Maojun; Liu, Siyang; Peng, Chaorong, E-mail: pengchaorong_siae@163.com

2016-06-01

A fast, easy and novel method for preparing biodegradable polymer films with silver nanoparticles was investigated to endow the material with excellent biocompatibility and antibacterial property. Silver nanoparticles (Ag NPs) were immobilized on the surface of polylactic acid (PLA) film by gamma radiation induced grafting of N-vinyl pyrrolidone (NVP). In this method, poly (N-vinyl pyrrolidone) (PVP) was produced and grafted onto the surface of PLA film by gamma radiation polymerization of NVP. PVP acted as both a bridge to connect the Ag NPs with the PLA film, and a stabilizer to protect the Ag NPs from agglomeration. The effect of various reaction parameters, including NVP/Ag mole ratio and radiation dose, on the fabrication of PLA-g-NVP/Ag film was demonstrated. Moreover, the interaction between PVP and Ag NPs was studied by X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy, that revealed the Ag NPs coordinated through the oxygen atom on the carbonyl group of PVP at 15 kGy radiation dose, but through the nitrogen atom and the oxygen atom of the amide group of PVP at 1 kGy dose. - Highlights: • PLA-graft-NVP/Ag film was produced by a simple one-step method. • Ag nanoparticles were immobilized on PLA film by gamma radiation grafting technology. • PVP acted as a bridge to connect Ag nanoparticles and PLA film. • Different content and size of Ag NPs can be reached by varying radiation dose.

In-situ formation of silver nanoparticles on poly (lactic acid) film by γ-radiation induced grafting of N-vinyl pyrrolidone

International Nuclear Information System (INIS)

Wang, Jingxia; Chen, Hao; Chen, Zhuping; Chen, Yuheng; Guo, Dan; Ni, Maojun; Liu, Siyang; Peng, Chaorong

2016-01-01

A fast, easy and novel method for preparing biodegradable polymer films with silver nanoparticles was investigated to endow the material with excellent biocompatibility and antibacterial property. Silver nanoparticles (Ag NPs) were immobilized on the surface of polylactic acid (PLA) film by gamma radiation induced grafting of N-vinyl pyrrolidone (NVP). In this method, poly (N-vinyl pyrrolidone) (PVP) was produced and grafted onto the surface of PLA film by gamma radiation polymerization of NVP. PVP acted as both a bridge to connect the Ag NPs with the PLA film, and a stabilizer to protect the Ag NPs from agglomeration. The effect of various reaction parameters, including NVP/Ag mole ratio and radiation dose, on the fabrication of PLA-g-NVP/Ag film was demonstrated. Moreover, the interaction between PVP and Ag NPs was studied by X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy, that revealed the Ag NPs coordinated through the oxygen atom on the carbonyl group of PVP at 15 kGy radiation dose, but through the nitrogen atom and the oxygen atom of the amide group of PVP at 1 kGy dose. - Highlights: • PLA-graft-NVP/Ag film was produced by a simple one-step method. • Ag nanoparticles were immobilized on PLA film by gamma radiation grafting technology. • PVP acted as a bridge to connect Ag nanoparticles and PLA film. • Different content and size of Ag NPs can be reached by varying radiation dose.

Production of sorption-active polypropylene fibers by radiation-induce grafting of glycidyl methacrylate as a precursor monomer

International Nuclear Information System (INIS)

Bondar, Yu.V.; Kim, H.J.; Lim, Y.J.; Kravets, L.I.

2004-01-01

Full text: Two types of sorption-active polypropylene fiber carrying strong-acid sulfonate groups and amino groups have been synthesized by radiation-induced graft polymerization of glycidyl methacrylate (GMA) with subsequent chemical modification of the epoxy groups of poly-GMA graft chains. The effect of various polymerization parameters on the GMA grafting degree was investigated in detail. The epoxy ring-opening of poly-GMA graft chains with introduction of strong-acid sulfonate groups was carried out with sodium hydrogen sulfite in water-dimethylformamide solution at 70 o C. The main peculiarities of the sulfonation reaction in depending on the reaction time and GMA grafting degree have been investigated. It was shown that for the samples with GMA grafting degree more than 50% two simultaneous processes take place during the sulfonation reaction, namely the incorporation of the sulfonate groups via opening of the GMA epoxy-rings as well as hydrolysis of the GMA epoxy-rings with the formation of α-glycol groups. Amine groups were incorporated by treatment of GMA-grafted polypropylene fibers with excess of diethylene triamine reagent. The conversion of the epoxy groups into the functional groups was investigated as a function of the degree of GMA grafting and reaction time. The ion-exchange characteristics of obtained sorption-active polypropylene fibers were determined

Production of sorption-active polypropylene fiber by radiation-induce grafting of glycidyl methacrylate as a precursor monomer

International Nuclear Information System (INIS)

Bondar, Yu.V.; Kim, H.J.; Lim, Y.J.; Kravets, L.I.

2004-01-01

Two types of sorption-active polypropylene fiber carrying strong-acid sulfonate groups and amino groups have been synthesized by radiation-induced graft polymerization of glycidyl methacrylate (GMA) with subsequent chemical modification of the epoxy groups of poly-GMA graft chains. The effect of various polymerization parameters on the GMA grafting degree was investigated in detail. The epoxy ring-opening of poly-GMA graft chains with introduction of strong-acid sulfonate groups was carried out with sodium hydrogen sulfite in water-dimethylformamide solution at 70 o C. The main peculiarities of the sulfonation reaction in depending on the reaction time and GMA grafting degree have been investigated. It was shown that for the samples with GMA grafting degree more than 50% two simultaneous processes take place during the sulfonation reaction, namely the incorporation of the sulfonate groups via opening of the GMA epoxy-rings as well as hydrolysis of the GMA epoxy-rings with the formation of α-glycol groups. Amine groups were incorporated by treatment of GMA-grafted polypropylene fibers with excess of diethylene triamine reagent. The conversion of the epoxy groups into the functional groups was investigated as a function of the degree of GMA grafting and reaction time. The ion-exchange characteristics of obtained sorption-active polypropylene fibers were determined. (author)

Radiation grafting processes and properties of leathers modified with butyl acrylate

International Nuclear Information System (INIS)

Pietrucha, K.

1982-01-01

Conditions for radiation induced grafting with butyl acrylate dispersed in water emulsion onto chrome-tanned pig skins have been worked out for γ-rays and electron beam irradiations. The highest yield of grafting was observed at monomer concentration approximately 25% (w/w), dose equal to 25 kGy and dose rate not exceeding 10 MGy/h. At these conditions the yield of grafting attained a value approximately 25% and content of homopolymer in the leather amounted to 6%. The efficiency of monomer to polymer conversion decreases when the concentration of monomer in emulsion and dose rate increases. Yield of homopolymer is independent of the dose rate. An explanation of the observed relations has been proposed. The physical and used properties of grafted leathers were tested. Radiation processed leathers were found superior to samples finished by traditional methods. One has to point to better tolerance against chemical cleaning and reduced water take-up without loss of high permeability of water vapour, responsible for good hygienic properties of leather products. Recommendations for industrial scale radiation grafting are given. (author)

Influence of temperature on radiation-induced graft polymerization of styrene onto poly(ethylene terephthalate) nuclear membranes and films

International Nuclear Information System (INIS)

Zhitaryuk, N.I.; Shtan'ko, N.I.

1989-01-01

Temperature effect on kinetics of radiation-induced graft polymerization of styrene onto poly(ethylene terephthalate) (PETP) nuclear membranes with various parameters (pore diameter, the average distance between the pores) as well as onto PETP films with different thickness has been studied. Graft polymerization has been carried out by the methods of preirradiation in air and in vacuum. The overall activation energy of grafting as well as the activation energy of swelling of PETP in toluene has been obtained. It was found that in the method of preirradiation in vacuum the initial grafting rate in Arrhenius plot has two linear ranges. Activation energy in low temperature range correlates with activation energy of PETP swelling. Activation energy in high temperature range is determined by kinetics of graft polymerization in the method of preirradiation in air. Arrhenius plot of the initial grafting rate gives the activation energy that approximately corresponds to the initiation of grafting with oxyradicals. Dependence of PETP matrix critical thickness on temperature has also been obtained. The form of this dependence is identical to the one of the rate of graft polymerization. 33 refs.; 6 figs.; 2 tabs

Novel features of radiation-induced bystander signaling in Arabidopsis thaliana demonstrated using root micro-grafting

Science.gov (United States)

Wang, Ting; Li, Fanghua; Xu, Wei; Bian, Po; Wu, Yuejin; Wu, Lijun

2012-01-01

Radiation-induced bystander effects (RIBE) have been well demonstrated in whole organisms, as well as in single-cell culture models in vitro and multi-cellular tissues models in vitro, however, the underlying mechanisms remain unclear, including the temporal and spatial course of bystander signaling. The RIBE in vivo has been shown to exist in the model plant Arabidopsis thaliana (A. thaliana). Importantly, the unique plant grafting provides a delicate approach for studying the temporal and spatial course of bystander signaling in the context of whole plants. In our previous study, the time course of bystander signaling in plants has been well demonstrated using the root micro-grafting technique. In this study, we further investigated the temporal cooperation pattern of multiple bystander signals, the directionality of bystander signaling, and the effect of bystander tissues on the bystander signaling. The results showed that the bystander response could also be induced efficiently when the asynchronously generated bystander signals reached the bystander tissues in the same period, but not when they entered into the bystander tissues in an inversed sequence. The absence of bystander response in root-inversed grafting indicated that the bystander signaling along roots might be of directionality. The bystander signaling was shown to be independent of the bystander tissues. PMID:23072991

Radiation synthesis of chitosan beads grafted with acrylic acid for metal ions sorption

International Nuclear Information System (INIS)

Benamer, S.; Mahlous, M.; Tahtat, D.; Nacer-Khodja, A.; Arabi, M.; Lounici, H.; Mameri, N.

2011-01-01

Radiation-induced grafting of acrylic acid onto chitosan beads was performed in solution at a dose rate of 20.6 Gy/min of cobalt-60 gamma rays. The effect of absorbed dose on grafting yield was investigated. The characterization of the grafted material was performed by FTIR spectroscopy and the swelling measurements at different pHs. The grafting yield increased with the increase in dose, it reached 80% at 40 kGy irradiation dose. The removal of Pb and Cd ions from aqueous solutions was investigated with both ungrafted and grafted chitosan beads. The sorption behavior of the sorbents was examined through pH, kinetics and equilibrium measurements. Grafted chitosan beads presented higher sorption capacity for both metal ions than unmodified chitosan beads. - Highlights: → Pb and Cd ions are removed from aqueous solution by adsorption on chitosan beads. → Crosslinking process improves chemical stability of chitosan beads. → Radiation grafting of acrylic acid onto chitosan improves its metal adsorption capacity. → Increase in grafting degree enhances the adsorption capacity of the material. → Gamma radiation is a powerful tool for an accurate control of the grafting yield.

Ionic membranes obtained by radiation - induced graft copolymerization, II-characterization and waste treatment. Vol. 3

International Nuclear Information System (INIS)

Ali, A.M.I.; Nowier, H.G.; Aly, H.F.; Abd El-Rehim, H.A.; Hegazy, E.A.

1996-01-01

Ionic membranes were prepared by radiation-induced grafting of acrylic acid onto low density polyethylene films. To elucidate the possibility of practical use, a study was made for the characterization of the grafted and chemically treated mechanisms. The selectivity of such prepared membranes towards the chelation or absorption of different alkali metals was investigated, to find that the higher affinity was observed for K + , Na + and Li + ions compared to other alkali metals used. The metal uptake percent was determined using different techniques; flame photometer, and X-ray fluorescence (XRF). The uptake of metal from its feed solution by the the grafted membrane increased as the degree of grating increased, i.e. it is directly proportional to the functional carboxylic acid groups in the graft copolymer. As a consequence, the electrical conductivity of metal feed solution decreased during such process of metal chelation by membrane. The higher the grafting degree of membrane, the lower the electrical conductivity of metal feed solutions observed. the changes in thermal properties of the membranes prepared were investigated and characterized using differential scanning calorimetry, (DSC), and thermal gravimetric analysis (TGA). The thermal stability of these membranes increased with degree of grafting due to the formation of cross linked network structure via hydrogen bonding. furthermore, such stability is enhanced for the alkali-treated membranes even at high elevated temperatures. The membranes prepared showed a great promise for possible use in some practical applications such as metal waste treatment. 3 figs., 5 tabs

Obtention of cationic polymeric membranes by radiation-induced grafting method

International Nuclear Information System (INIS)

Marin H E, H.

1994-01-01

Radiation-induced grafting of LDPE with the monomers, acrylic acid and methacrylic acid, has been studied. The grafting was made with several presentations of LDPE (foil, powder and pellets) by direct method using a Co 60 gamma rays. The irradiation was carried out in vacuum at room temperature at different doses (0.02 kGy - 0.2 kGy) with a rate dose of 0.8632 kGy/h. The graft yield was measured by the relation of initial and final weights. The variations of the LDPE structure was followed by infrared absorption spectroscopy and the results showed that there was important variations in LDPE structure when the dose increases. The tensile strong properties of the copolymers were investigated and it was found that the structure of LDPE was modified by the presence of chains of poly (acrylic) and poly (methacrylic) acid and this was reflected in the tensile properties of the polymer. A trial has been made in order to use the powder presentation of the copolymer like ion exchange resin first we measured volumetrically the quantity of milliequivalents per gram of carboxylic groups by titration 5 ml. of a solution 0.1 N of NaOH, which was 48 h. in contact with the copolymer, with a solution 0.1 N of HCl and we found that the quantity of milliequivalents enhance according with the irradiation dose. Finally, we made ion exchange experiments by passing a solution containing Ca +2 ions through ion exchange columns packed with the copolymer the results showed that these copolymers has good properties in retaining Ca +2 ions. We conclude that these copolymers can be used for ion exchange process however final conditions must be improved. (Author)

Development of EPDM based thermoplastic elastomers for oil resistant applications: optimization of radiation grafting parameters

International Nuclear Information System (INIS)

Chaudhari, C.V.; Dubey, K.A.; Bhardwaj, Y.K.; Sabharwal, S.

2008-01-01

Full text: Ethylene-propylene diene terpolymer (EPDM) is currently among the most industrially useful elastomers because of its certain unique properties like excellent heat resistance, resistance towards ozone deterioration, high impact strength. However EPDM has a serious drawback of weak adhesion properties and tendency to swell in contact with paraffin oil and aromatic hydrocarbons. Blending EPDM with suitable polar elastomers or grafting polar polymer chains onto EPDM is an easy method to overcome this drawback. Radiation grafting of Acrylonitrile (ACN) on EPDM provides an easy and effective method of incorporating ACN uniformly on the EPDM backbone. Grafting of ACN on EPDM is expected to result grafted copolymer with better oil resistance, hardness and better compatibility with polar polymer matrices. In the present study radiation induced grafting of ACN onto EPDM rubber film was investigated by mutual radiation grafting technique. Effect of experimental variables viz. radiation dose, dose rate, types of solvents and monomer content on extent of grafting was studied. The solvent composition of Acetone:CCl 4 (20:80) was found to be the optimum mixture which resulted in highest degree of grafting. It was found that the degree of grafting increases with radiation dose, monomer content and decreases with dose rate

Influence of radiation-induced grafting process on mechanical properties of ETFE-based membranes for fuel cells

Energy Technology Data Exchange (ETDEWEB)

Ben Youcef, H.; Alkan Guersel, S.; Buisson, A.; Gubler, L.; Wokaun, A.; Scherer, G.G. [Electrochemistry Laboratory, Paul Scherrer Institut, Villigen PSI (Switzerland)

2010-06-15

The mechanical stability is, in addition to thermal and chemical stability, a primary requirement of polymer electrolyte membranes in fuel cells. In this study, the impact of grafting parameters and preparation steps on stress-strain properties of ETFE-based proton conducting membranes, prepared by radiation-induced grafting and subsequent sulphonation, was studied. No significant change in the mechanical properties of the ETFE base film was observed below an irradiation dose of 50 kGy. It was shown that the elongation at break decreases with increasing both the crosslinker concentration and graft level (GL). However, the tensile strength was positively affected by the crosslinker concentration. Yield strength and modulus of elasticity are almost unaffected by the introduction of crosslinker. Interestingly, yield strength and modulus of elasticity increase gradually with GL without noticeable change of the inherent crystallinity of grafted films. The most brittle membranes are obtained via the combination of high GL and crosslinker concentration. The optimised ETFE-based membrane (GL of {proportional_to}25%, 5% DVB v/v), shows mechanical properties superior to those of Nafion registered 112 membrane. The obtained results were correlated qualitatively to the other ex situ properties, including crystallinity, thermal properties and water uptake of the grafted membranes. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Production of sorption-active polypropylene fibers by radiation-induced grafting of glycidyl methacrylate as a precursor monomer

International Nuclear Information System (INIS)

Bondar, Yu.V.; Kim, H.J.; Lim, Y.J.

2006-01-01

The design and development of sorption-active natural and synthetic polymer fibers and textile materials is of great scientific and practical interest. The advantages of that type of polymeric adsorbents, as their highly developed specific surface, excellent ion-exchange and adsorption parameters and ease of their use especially under continuous conditions, allow them to find a great application in the chemical, biomedical, ecological and industrial fields. To obtain functional polymer materials with the desired performance, the non-active polymer surface have to be modified. Among different innovative techniques used for the introduction of graft chains, the radiation-chemical method of initiation has some economical and ecological preferences over others. It allows to introduce into inert polymeric matrix chains of a monomer already containing a desirable functional group, or to graft chains of a precursor-monomer and subsequently its chemical modification to form required functional groups. At present an epoxy-group containing monomer, glycidyl methacrylate (GMA), is successfully used as a precursor-monomer for production of polymeric adsorbents of variety applications on the base of membranes, films, fibers and fabrics. Two types of sorption-active polypropylene fiber carrying strong-acid sulfonate groups and amino groups have been synthesized by radiation-induced graft polymerization of GMA, with subsequent chemical modification of the epoxy groups of poly-GMA graft chains. The effect of various polymerization parameters on the GMA grafting degree was investigated in detail. The epoxy ring-opening of poly-GMA graft chains with introduction of strong-acid sulfonate groups was carried out with sodium hydrogen sulfite in water-dimethylformamide solution at 70 deg C. The main peculiarities of the sulfonation reaction in depending on the reaction time and GMA grafting degree have been investigated. Amine groups were incorporated by treatment of the GMA-grafted

Radiation induced emulsion graft polymerization of 4-vinylpyridine onto PE/PP nonwoven fabric for As(V) adsorption

Science.gov (United States)

Akkaş Kavaklı, Pınar; Kavaklı, Cengiz; Seko, Noriaki; Tamada, Masao; Güven, Olgun

2016-10-01

A novel nonwoven fabric adsorbent having 4-vinylpyridine functional groups was prepared by using radiation-induced emulsion graft polymerization method and grafting 4-vinylpyridine monomer onto a polyethylene-coated polypropylene nonwoven fabric (NWF) in aqueous emulsion solution. The grafting conditions of the 4-vinylpyridine monomer onto the NWF were optimised and 150% Dg VP-g-NWF was prepared using 30 kGy pre-irradiation dose, 5% VP monomer concentration and 0.5% (w/w) Tween 20 in aqueous emulsion. Grafted 4-vinylpyridine chains on the NWF were then quaternized for the preparation of QVP-g-NWF adsorbent. All fabric structures were characterized by using Fourier-transform infrared spectrometer, x-ray photoelectron spectrometer and scanning electron microscope. QVP-g-NWF adsorbent was used in batch adsorption experiments for As(V) ions by studying the pH, contact time, and initial As(V) ion concentration parameters. Results showed that QVP-g-NWF adsorbent has significant As(V) adsorption and experimental As(V) adsorption capacity was 98.04 mg As(V)/g polymer from 500 mg/L initial As(V) concentration at pH 7.00.

Ionic membranes obtained by radiation - induced graft copolymerization, II-characterization and waste treatment. Vol. 3

Energy Technology Data Exchange (ETDEWEB)

Ali, A M.I.; Nowier, H G; Aly, H F [National Center for Radiation and Technology, Atomic Energy Authority, Cairo, (Egypt); Abd El-Rehim, H A; Hegazy, E A [Hot Laboratories Center, Atomic Energy Authority, Cairo (Egypt)

1996-03-01

Ionic membranes were prepared by radiation-induced grafting of acrylic acid onto low density polyethylene films. To elucidate the possibility of practical use, a study was made for the characterization of the grafted and chemically treated mechanisms. The selectivity of such prepared membranes towards the chelation or absorption of different alkali metals was investigated, to find that the higher affinity was observed for K{sup +}, Na{sup +} and Li{sup +} ions compared to other alkali metals used. The metal uptake percent was determined using different techniques; flame photometer, and X-ray fluorescence (XRF). The uptake of metal from its feed solution by the the grafted membrane increased as the degree of grating increased, i.e. it is directly proportional to the functional carboxylic acid groups in the graft copolymer. As a consequence, the electrical conductivity of metal feed solution decreased during such process of metal chelation by membrane. The higher the grafting degree of membrane, the lower the electrical conductivity of metal feed solutions observed. the changes in thermal properties of the membranes prepared were investigated and characterized using differential scanning calorimetry, (DSC), and thermal gravimetric analysis (TGA). The thermal stability of these membranes increased with degree of grafting due to the formation of cross linked network structure via hydrogen bonding. furthermore, such stability is enhanced for the alkali-treated membranes even at high elevated temperatures. The membranes prepared showed a great promise for possible use in some practical applications such as metal waste treatment. 3 figs., 5 tabs.

Grafting

Energy Technology Data Exchange (ETDEWEB)

Garnett, J L [New South Wales Univ., Kensington (Australia). School of Chemistry

1979-01-01

The unique value of ionizing radiation for the initiation of grafting to backbone polymers is discussed. The principles of the technique are briefly reviewed. The conditions under which free radicals and ions participate in these reactions are examined. Examples of representative grafting processes are considered to illustrate where the technique can be of potential commercial value to a wide range of industries. The general principles of these grafting reactions are shown to be applicable to radiation induced rapid cure technology such as is provided by electron beam processing facilities. Grafting reactions initiated by UV are also treated and shown to be of importance because of the many similarities in properties of the ionizing radiation and UV systems, also the rapid industrial exploitation of EB and sensitized UV processing technology. Possible future trends in radiation grafting are outlined.

Biodiesel fuel production from waste cooking oil using radiation-grafted fibrous catalysts

Science.gov (United States)

Ueki, Yuji; Saiki, Seiichi; Hoshina, Hiroyuki; Seko, Noriaki

2018-02-01

Waste cooking oil, which can be used as a raw material for biodiesel fuel (BDF), contains two kinds of oil components: triglycerides (TGs) and free fatty acids (FFAs). Therefore, both alkaline-type and acid-type catalysts are needed to produce BDF from waste cooking oil. In this study, an alkaline-type grafted fibrous catalyst bearing OH- ions was synthesized by radiation-induced emulsion grafting of 4-chloromethylstyrene onto a polyethylene-coated polypropylene (PE/PP) nonwoven fabric, amination with trimethylamine, and further treatment with NaOH. Furthermore, an acid-type catalyst bearing H+ ions was synthesized by radiation-induced emulsion grafting of ethyl p-styrenesulfonate onto a PE/PP nonwoven fabric, saponification with NaOH, and protonation with HNO3. The OH- and H+ densities of the grafted fibrous catalysts were controlled by the grafting yield. The maximum OH- and H+ densities of the catalysts were 3.6 mmol-OH-/g-catalyst and 3.4 mmol-H+/g-catalyst, respectively. The performances of the catalysts were evaluated in the batchwise transesterification of TGs and ethanol, and the batchwise esterification of FFAs and ethanol. In both cases, TGs and FFAs were gradually converted into BDF. The mixed oil and four actual waste cooking oils, which contained both TGs and FFAs, were completely converted into BDF by sequential catalytic reactions with the acid-type grafted fibrous catalyst and then the alkaline-type grafted fibrous catalyst.

Tissue banking and clinical research on radiation and ethylene oxide sterilization of tissue grafts

International Nuclear Information System (INIS)

Pe Khin

1987-06-01

The research works carried out in Rangoon, Burma under the Agency supported project RC4420/RB have dealt with an elucidation of the radiation interaction(s) with the species of biomolecules such as proteins, lipids, collagens, connective tissues present in the cleaned and freeze-dried non-viable tissue grafts. Radiation as a cool process furthermore effectively helps to destroy the microbial bioburden as the undesirable contaminants which may associate the tissue grafts. Radiation also concomitantly helps to suppress the tissue-specific immunogenicity. All these attributes of radiation induced effects have proved successful towards the development of a sterilization process. A series of non-viable tissue grafts, such as bone, nerve, fascia, dura, cartilage, chorion-amnion (as dressings in burn wounds) and tympanic membrane have been successfully attempted in Burma and many more possibilities seem to still remain unexplored. Radiation sterilization modality has proved as a blessing for the promotion of clinical surgical applications of tissue allografts in the corrective/reconstructive surgery on the disability cases due to diseases which accompany tissue losses. The investigator in Burma has reported on the case histories where freeze dried radiation sterilized tissue allografts have been successfully used in the osteogenic inductions (bone grafts); midear tympanoplasty; partial recovery of nerve sensation throught nerve allografts; rapid healing of high degree burn wounds through the use of amnion dressings. Besides, there have been a widespread surgical use of radiation sterilized dura and fascia as allografts. A national tissue banking facility has been established in Burma surrounding the processing and clinical utilization of tissue allografts which has involved over ten hospital centres throughout the country. Radiation induced effects on the biomolecules of clinical significance in the tissue grafts have been researched to help gain insight into a better

Radiation-induced polymerization and radiation effect on polymers

International Nuclear Information System (INIS)

Seguchi, Tadao

1977-12-01

The processes of radiation-induced polymerization of monomers and also radiation effects on polymers have been studied by instrumental analyses of electron spin resonance (ESR), nuclear magnetic resonance (NMR) and electron microscopy. In radiation-induced polymerization, graft-copolymerization and absorbed state polymerization were taken up. For graft-copolymerization, monomers such as methylmethacrylate and butadiene were made to react with irradiated polyethylene, and behaviors of the initiating radicals and propagating radicals were followed under the reaction by ESR. For absorbed state polymerization, acrylonitrile/zeolite and methylmethacrylate/zeolite were chosen. Absorbed monomers were irradiated at 77 0 K and polymerized at room temperature. Active species and the concentrations were measured by ESR and the yields of polymer were observed by NMR. In radiation effect on polymers, polyvinylfluoride, polyvinylidenfluoride and polytetrafluoroethylene were taken up. Active species trapped in the polymer matrixes were identified and decay and reactivity of the species were also studied. On the basis of information from the electron microscopy and x-ray analysis, radiation effects on these polymers are described. In polytetrafluoroethylene produced by radiation polymerization, the relation between morphology and polymerization conditions and also the process of crystallization during polymerization were studied. (auth.)

Pedicle omental graft created by laparoscopic surgery for filling a radiation-induced ulcer in a woman with breast cancer

International Nuclear Information System (INIS)

Ida, Katsuya

2002-01-01

In patients with advanced or recurrent breast cancer, it is difficult to reconstruct chest wall ulcers due to postoperative irradiation, which is often infected. We present a laparoscopic technique for creating and mobilizing an omental flap. A 63-year-old woman diagnosed with parasternal lymph node metastases from left breast cancer 11 months after standard radical mastectomy underwent lymph node resection with radiation therapy. She developed ulceration of the irradiated chest wall 3 years and 10 months later. An omental flap obtained by laparoscopy was used to fill the space after the radiation-induced ulcer was resected and covered with a free skin graft. The skin graft adapted to the omentum. This laparoscopic procedure is more cosmetrically acceptable and less invasive than laparotomy in obtaining the omentum while yielding equivalent results in chest wall reconstruction. (author)

Pedicle omental graft created by laparoscopic surgery for filling a radiation-induced ulcer in a woman with breast cancer

Energy Technology Data Exchange (ETDEWEB)

Ida, Katsuya [Kosai General Hospital, Shizuoka (Japan)

2002-06-01

In patients with advanced or recurrent breast cancer, it is difficult to reconstruct chest wall ulcers due to postoperative irradiation, which is often infected. We present a laparoscopic technique for creating and mobilizing an omental flap. A 63-year-old woman diagnosed with parasternal lymph node metastases from left breast cancer 11 months after standard radical mastectomy underwent lymph node resection with radiation therapy. She developed ulceration of the irradiated chest wall 3 years and 10 months later. An omental flap obtained by laparoscopy was used to fill the space after the radiation-induced ulcer was resected and covered with a free skin graft. The skin graft adapted to the omentum. This laparoscopic procedure is more cosmetrically acceptable and less invasive than laparotomy in obtaining the omentum while yielding equivalent results in chest wall reconstruction. (author)

Additive effects in radiation grafting and curing

International Nuclear Information System (INIS)

Viengkhou, V.; Ng, L.

1996-01-01

Full text: Detailed studies on the accelerative effect of novel additives in radiation grafting and curing using acrylated monomer/oligomer systems have been performed in the presence of ionising radiation and UV as sources. Methyl methacrylate (MMA) is used as typical monomer for these grafting studies in the presence of the additives with model backbone polymers, cellulose and propropylene. Additives which have been found to accelerate these grafting processes are: mineral acid, occlusion compounds like urea, thermal initiators and photoinitiators as well as multifunctional monomers such as multifunctional acrylates. The results from irradiation with gamma rays have also been compared with irradiation from a 90W UV lamp. The role of the above additives in accelerating the analogous process of radiation curing has been investigated. Acrylated urethanes, epoxies and polyesters are used as oligomers together with acrylated monomers in this work with uv lamps of 300 watts/inch as radiation source. In the UV curing process bonding between film and substrate is usually due to physical forces. In the present work the presence of additives are shown to influence the occurrence of concurrent grafting during cure thus affecting the nature of the bonding of the cured film. The conditions under which concurrent grafting with UV can occur will be examined. A mechanism for accelerative effect of these additives in both grafting and curing processes has been proposed involving radiation effects and partitioning phenomena

The role of hydroperoxides as a precursor in the radiation-induced graft polymerization of methyl methacrylate to ultra-high molecular weight polyethylene

Energy Technology Data Exchange (ETDEWEB)

Enomoto, Ichiro, E-mail: enomoto.ichiro@iri-tokyo.j [Tokyo Metropolitan Industrial Technology Research Institute, KFC bldg., 12F, 1-6-1, Yokoami, Sumida-ku, Tokyo 130-0015 (Japan); School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Katsumura, Yosuke [School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai-mura, Ibaraki 319-1195 (Japan); Kudo, Hisaaki [School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Sekiguchi, Masayuki [Tokyo Metropolitan Industrial Technology Research Institute, KFC bldg., 12F, 1-6-1, Yokoami, Sumida-ku, Tokyo 130-0015 (Japan)

2010-06-15

A graft polymerization of methyl methacrylate (MMA) to ultra-high molecular weight polyethylene (UHMWPE) with Co-60 gamma-ray irradiation in air at room temperature has been carried out. The grafting yields were measured as a function of the storage time (elapsed time from the end of irradiation to the start of grafting), and it was found that the yields reach at the maximum values at around several days since the end of irradiation. In order to clarify the precursor of the graft polymerization, changes of the radical yields and the carbonyl groups were measured as a function of storage time with ESR and microscopic FT-IR, respectively. From the similarities between the depth profiles of the hydroperoxide formation and the grafting products, it was concluded that the hydroperoxides can be main precursors of the grafting of the radiation-induced polymerization of MMA to UHMWPE under the given conditions.

The role of hydroperoxides as a precursor in the radiation-induced graft polymerization of methyl methacrylate to ultra-high molecular weight polyethylene

International Nuclear Information System (INIS)

Enomoto, Ichiro; Katsumura, Yosuke; Kudo, Hisaaki; Sekiguchi, Masayuki

2010-01-01

A graft polymerization of methyl methacrylate (MMA) to ultra-high molecular weight polyethylene (UHMWPE) with Co-60 γ-ray irradiation in air at room temperature has been carried out. The grafting yields were measured as a function of the storage time (elapsed time from the end of irradiation to the start of grafting), and it was found that the yields reach at the maximum values at around several days since the end of irradiation. In order to clarify the precursor of the graft polymerization, changes of the radical yields and the carbonyl groups were measured as a function of storage time with ESR and microscopic FT-IR, respectively. From the similarities between the depth profiles of the hydroperoxide formation and the grafting products, it was concluded that the hydroperoxides can be main precursors of the grafting of the radiation-induced polymerization of MMA to UHMWPE under the given conditions.

Adsorption of Cr(VI) using silica-based adsorbent prepared by radiation-induced grafting

International Nuclear Information System (INIS)

Qiu Jingyi; Wang Ziyue; Li Huibo; Xu Ling; Peng Jing; Zhai Maolin; Yang Chao; Li Jiuqiang; Wei Genshuan

2009-01-01

Silica-based adsorbent was prepared by radiation-induced grafting of dimethylaminoethyl methacrylate (DMAEMA) onto the silanized silica followed by a protonation process. The FTIR spectra and XPS analysis proved that DMAEMA was grafted successfully onto the silica surface. The resultant adsorbent manifested a high ion exchange capacity (IEC) of ca. 1.30 mmol/g and the Cr(VI) adsorption behavior of the adsorbent was further investigated, revealing the recovery of Cr(VI) increased with the adsorbent feed and the equilibrium adsorption could be achieved within 40 min. The adsorption capacity, strongly depended on the pH of the solution, reached a maximum Cr(VI) uptake (ca. 68 mg/g) as the pH was in the range of 2.5-5.0. Furthermore, even in strong acidic (4.0 mol/L HNO 3 ) or alkaline media (pH 11.0), the adsorbent had a sound Cr(VI) uptake capacity (ca. 22 and 30 mg/g, respectively), and the adsorption followed Langmuir mode. The results indicated that this adsorbent, prepared via a convenient approach, is applicable for removing heavy-metal-ion pollutants (e.g. Cr(VI)) from waste waters.

Effect of crosslinking on the physico-chemical properties of radiation grafted PEM fuel cell membranes

International Nuclear Information System (INIS)

Mohamed Mahmoud Nasef; Hamdani Saidi

2006-01-01

The effect of crosslinking on the physico-chemical properties of radiation grafted proton conducting membranes (PFA-g-PSSA) was investigated. The membranes were prepared by radiation induced grafting of styrene/divinylbenzene (DVB) mixtures onto poly (tetrafluoroethylene-co-perfluorovinyl either) (PFA) films followed by sulfonation reactions. The variation of DVB content in the grafting mixture was in the range of 1-4 vol %. The equivalent weight, swelling, behavior and the proton conductivity of crosslinked membranes having equal degrees of grafting prepared found to be dependent predominantly on the level of crosslinking. The obtained membranes were found to posses a good combination of physico-chemical properties that is matching the commercial Nation 117 membranes

Study by the positron annihilation technique of Graft copolimerization of methyl methacrylate in polyethylene induced by gamma radiation

International Nuclear Information System (INIS)

Zaldivar Gonzalez, M.E.

1992-01-01

Radiation initiated grafting is a very broad field which has attracted considerable interest over the last two decades. Graft copolymers may combine suitable properties of two polymeric components. Radiation methods are particulary appropiate for the production of a large variety of graft copolymers having interesting properties. Ionizing radiation has provided a convenient and clean method to activate a sustrate polymer and undoubtedly, it has added impetus to this field of research. In the present work, graft polymerization of methyl methacrylate (MMA) onto low density polyethylene (LDPE) was carried out. The effect of gamma ray irradiation dose on the grafting degree was investigated for two different methods: direct and preirradiation. The best method to prepare the copolymer for the LDPE film thickness studied: 0.05 and 0.2 mm., was direct method. In both polyethylene thickness, the grafting degree increased as a function of the reaction time. However, grafting for LDPE 0.2 mm. it is better, because the copolymer with that thickness conserve the main physical-chemistry properties of the LDPE along the different grafting degrees obtained, which it is important for practical purposes. Infrared spectroscopy was used to probe the changes ocurred in the LDPE structure with the graft of MMA, first spectrum showed typical bands for LDPE structure, while in the second spectrum new bands appeared which corresponded to PMMA structure grafted onto LDPE. Positron annihilation lifetime technique was applied to study the copolymer microstructure according to increase of grafting degree. O-PS lifetime and intensity tend to decrease. This behavior could be due to the diminution of free volume in the original LDPE matrix as grafting proceeds. Copolymer morphology was observed using optical microscopy (Author)

Modification of polyetherurethane for biomedical application by radiation induced grafting. II. Water sorption, surface properties, and protein adsorption of grafted films

International Nuclear Information System (INIS)

Jansen, B.; Ellinghorst, G.

1984-01-01

A series of polyetherurethane films grafted by means of gamma radiation with hydrophilic or reactive monomers (2-hydroxyethyl methacrylate, 2,3-epoxypropyl methacrylate, 2,3-dihydroxypropyl methacrylate, and acrylamide) and partially chemically modified were subjected to various physico-chemical investigation methods involving water sorption, contact angle, and protein adsorption measurements. From contact angle data the interfacial free energy gamma sw between grafted films and water was calculated. It was found that the water uptake of grafted films increases with grafting yield or, in the case of grafted and afterwards chemically modified films, with reaction yield; the diffusion coefficient of water in the modified films also increases with grafting yield. Contact angle studies revealed all grafted films to have surfaces more hydrophilic than the ungrafted trunk polymer. The degree of hydrophilicity--especially of HEMA-grafted films--strongly depends on grafting conditions. For some grafted samples with high surface hydrophilicity very low interfacial free energies approaching zero were measured. The study of the competitive adsorption of bovine serum albumin, gamma-globulin, and fibrinogen from a synthetic protein solution onto modified films showed that the adsorption of albumin increases markedly with increasing grafting yields, whereas the fibrinogen and gamma-globulin adsorption only slightly increases. A correlation between interfacial free energy and protein adsorption in the sense of the minimum interfacial free energy hypothesis was found only for samples with grafting yields below 5%. At higher grafting yields the increased surface area complicates the analysis

Effect of 60Co radiation-induced grafting of methyl methacrylate on mechanical properties of bamboo

International Nuclear Information System (INIS)

Zhang Hao; Zhou Liang; Liu Shengquan; Qian Liangcun; Fei Benhua; Jiang Zehui

2011-01-01

In order to investigate the effect of radiation grafting on mechanical properties of bamboo, the original and carbonized bamboo soaked with monomer MMA were radiation grafted by 60 Co γ rays with the doses of 60-220 kGy. The results showed that compared with original blanks, treated with MMA and irradiated with the dose of 180 kGy the specific gravity, bending strength modulus of elasticity of original bamboo increased by 6.7%, 4.4%, and 28%, meanwhile its oven-dried radial, tangential and volumetric shrinkage decreased by 38.9%, 47.4%, and 32.9%, respectively. What is more, treated with MMA and irradiated with the doses of 140 kGy the specific gravity and modulus of elasticity of carbonized bamboo increased by 6.8% and 20%, while its oven-dried radial, tangential, volumetric shrinkage decreased by 11%, 4.6% and 12%, respectively. The study reveals that mechanical properties of original and carbonized bamboo can be enhanced by radiation grafting copolymerization with suitable absorbed doses, which may be valuable for the further research of developing new bamboo plastic composites. (authors)

Effect of blood transfusion and skin grafting on rats with combined radiation-burn injury

International Nuclear Information System (INIS)

Yan Yongtang; Ran Xinze; Wei Shuqing

1990-01-01

The therapeutic effect of escharectomy and skin grafting at different times on rats with combined radiation-burn injuries (5 Gy total body irradiation plus flash radiation from a 5 kW bromotungstenic lamp to induce a 15% TBSA full thickness burn on back) treated with blood transfusion (BT) were studied. The treatment with BT and escharectomy plus skin grafting at 24, 48, and 72 h after injury showed significant therapeutic effects. In these treated groups, early recovery of WBC counts, the granulocytes and total lymphocytes, T, B-cells, bone marrow cells or CFU-F counts were evident within 30 days after injury. The 30-day survival rates of the skin grafts in the group treated with BT and skin grafting at 24 h after injury was 80%, in the group with skin grafting alone was 50%, while all the skin grafts sloughted within 30 days when the grafting was performed 48 and 72 h after injury. The 30-day survival rate of the recipients treated with skin grafting plus BT was higher than that of the animals with skin grafting alone. The results showed that satisfactory results were achieved with BT plus escharectomy and skin grafting within 24 h after injury, while skin grafting performed at 48 or 72 h after injury was ineffective for the survival of skin grafts

Radiation-induced graft polymerization of amphiphilic monomers with different polymerization characteristics onto hydrophobic polysilane

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Hidenori; Iwasaki, Isao; Kunai, Yuichiro [Research Reactor Institute, Kyoto University, Asashironishi 2-1010, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Sato, Nobuhiro, E-mail: sato-n@rri.kyoto-u.ac.j [Research Reactor Institute, Kyoto University, Asashironishi 2-1010, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Matsuyama, Tomochika [Research Reactor Institute, Kyoto University, Asashironishi 2-1010, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan)

2011-08-15

The structures of poly(methyl-n-propylsilane) (PMPrS) amphiphilically modified through {gamma}-ray-induced graft polymerization were investigated with {sup 1}H NMR measurement. By the use of methyl methacrylate (MMA) or diethyl fumarate (DEF) as monomers for the graft polymerization, grafting yield rose with increasing total absorption dose and monomer concentrations, but decreased with increasing dose rate. This result means that grafting yield of modified PMPrS can be controlled by changing irradiation conditions. However, the number of PMMA or PDEF graft chains per PMPrS chain was estimated to be less than 1.0 by analysis of {sup 1}H NMR spectra, and this value was lower than that we had expected. To improve graft density, maleic anhydride (MAH), which is known as a non-homopolymerizable monomer in radical polymerization, was used as a monomer for grafting. As a result, high density grafting (one MAH unit for 4.2 silicon atoms) was attained. It demonstrates that the structure of {gamma}-ray-modified polysilane strongly depends on the polymerization characteristics of grafted monomers.

Location of radiation-induced grafted chains in polymers studied by solid-state NMR

International Nuclear Information System (INIS)

Whittacker, A.; Liu, H.

1998-01-01

In this study styrene and N-phenyl maleimide monomers were grafted onto poly(ethylene) (PE) chains using gamma radiation. Of main interest is the distribution of grafted chains within the polymer matrix, as this will determine the efficacy of mixing with the glassy polymers. It is expected that grafting will occur within the amorphous regions, and especially near the interface of the crystalline and amorphous regions. A suitable method for characterising the location of the grafted chains is solid-state 13 C NMR spectroscopy. The 13 C CPMAS spectrum of the blend of PE and N-phenyl maleimide mixed in the melt at 150 deg C , prior to reaction, is shown above. The spectrum shows the typical peaks for poly(ethylene) due to the amorphous and crystalline phase at 30.5 and 32.5 ppm, respectively. Peaks are also seen in the aromatic and carbonyl region due to the maleimide (not plotted). Experiments will be described where the NMR magnetisation is prepared in either the crystalline and amorphous regions of the poly(ethylene) prior to spin diffusion to the maleimide and styrene fractions. The location of the grafted monomers can then be determined by monitoring the changes in signal of polymer and graft with time

Significance of grafting in radiation curing reactions. Comparison of ionising radiation and UV systems

International Nuclear Information System (INIS)

Zilic, E.; Ng, L.; Viengkhou, V.; Garnett, J.L.

1998-01-01

Full text: Radiation curing is now an accepted commercial technology where both ionising radiation (electron beam) and ultra violet light (UV) sources are used. Grafting is essentially the copolymerisation of a monomer/oligomer to a backbone polymer whereas curing is the rapid polymerisation of a monomer/oligomer mixture onto the surface of the substrate. There is no time scale theoretically associated with grafting processes which can occur in minutes or hours whereas curing reactions are usually very rapid, occurring within a fraction of a second. An important difference between grafting and curing is the nature of the bonding occurring in each process. In grafting covalent carbon-carbon bonds are formed, whereas in curing, bonding usually involves weaker Van der Waals or London dispersion forces. The bonding properties of the systems are important in determining their use commercially. Thus the possibility that concurrent grafting during curing could occur in a system is important since if present, grafting would not only minimise delamination of the coated product but could also, in some circumstances, render difficulties recycling of the finished product especially if it were cellulosic. Hence the conditions for observing the occurrence of concurrent grafting during radiation curing are important. In the present paper, this problem has been studied by examining the effect that the components used in radiation curing exert on a typical reaction. Instead of electron beam sources, the spent fuel element facility at Lucas Heights is used to simulate such ionising radiation sources. The model system utilised is the grafting of a typical methacrylate to cellulose. This is the generic chemistry used in curing systems. The effect of typical additives from curing systems including polyfunctional monomer and oligomers in the grafting reactions have been studied. The ionising radiation results have been compared with analogous data from UV experiments. The significance

Homogeneous cation exchange membrane by radiation grafting

International Nuclear Information System (INIS)

Kolhe, Shailesh M.; G, Agathian; Ashok Kumar

2001-01-01

Preparation of a strong cation exchange membrane by radiation grafting of styrene on to polyethylene (LDPE) film by mutual irradiation technique in the presence of air followed by sulfonation is described. The grafting has been carried out in the presence of air and without any additive. Low dose rate has been seen to facilitate the grafting. Further higher the grafting percentage more is the exchange capacity. The addition of a swelling agent during the sulfonation helped in achieving the high exchange capacity. The TGA-MASS analysis confirmed the grafting and the sulfonation. (author)

Preparation of High Density Polyethylene/Waste Polyurethane Blends Compatibilized with Polyethylene-Graft-Maleic Anhydride by Radiation

Directory of Open Access Journals (Sweden)

Jong-Seok Park

2015-04-01

Full Text Available Polyurethane (PU is a very popular polymer that is used in a variety of applications due to its good mechanical, thermal, and chemical properties. However, PU recycling has received significant attention due to environmental issues. In this study, we developed a recycling method for waste PU that utilizes the radiation grafting technique. Grafting of waste PU was carried out using a radiation technique with polyethylene-graft-maleic anhydride (PE-g-MA. The PE-g-MA-grafted PU/high density polyethylene (HDPE composite was prepared by melt-blending at various concentrations (0–10 phr of PE-g-MA-grafted PU. The composites were characterized using fourier transform infrared spectroscopy (FT-IR, and their surface morphology and thermal/mechanical properties are reported. For 1 phr PU, the PU could be easily introduced to the HDPE during the melt processing in the blender after the radiation-induced grafting of PU with PE-g-MA. PE-g-MA was easily reacted with PU according to the increasing radiation dose and was located at the interface between the PU and the HDPE during the melt processing in the blender, which improved the interfacial interactions and the mechanical properties of the resultant composites. However, the elongation at break for a PU content >2 phr was drastically decreased.

Development of a water purifier for radioactive cesium removal from contaminated natural water by radiation-induced graft polymerization

Science.gov (United States)

Seko, Noriaki; Hoshina, Hiroyuki; Kasai, Noboru; Shibata, Takuya; Saiki, Seiichi; Ueki, Yuji

2018-02-01

Six years after the Fukushima-nuclear accident, the dissolved radioactive cesium (Cs) is now hardly detected in environmental natural waters. These natural waters are directly used as source of drinking and domestic waters in disaster-stricken areas in Fukushima. However, the possibility that some radioactive Cs adsorbed on soil or leaves will contaminate these natural waters during heavy rains or typhoon is always present. In order for the returning residents to live with peace of mind, it is important to demonstrate the safety of the domestic waters that they will use for their daily life. For this purpose, we have synthesized a material for selective removal of radioactive Cs by introducing ammonium 12-molybdophosphate (AMP) onto polyethylene nonwoven fabric through radiation-induced emulsion graft polymerization technique. Water purifiers filled with the grafted Cs adsorbent were installed in selected houses in Fukushima. The capability of the grafted adsorbent to remove Cs from domestic waters was evaluated for a whole year. The results showed that the tap water filtered through the developed water purifier contained no radioactive Cs, signifying the very effective adsorption performance of the developed grafted adsorbent. From several demonstrations, we have commercialized the water purifier named "KranCsair®". Furthermore, we have also developed a method for the mass production of the grafted nonwoven fabric. Using a 30 L grafting reactor, it was possible to produce the grafted nonwoven fabric with a suitable range of degree of grafting. When an irradiated roll of nonwoven trunk fabric with a length of 10 m and a width of 30 cm was set in the reactor filled with glycidyl methacrylate (GMA), AMP, Tween 80 monomer emulsion solution at 40 °C for 1 h, the difference of Dgs in the length and the width on roll of fabrics was negligible.

Radiation induced graft copolymerization of cellulosic fabric waste and its application in the removal of cyanide and dichromate from aqueous solution

International Nuclear Information System (INIS)

El-Kelesh, N.A.; Hashem, A.; Sokker, H.H.; Abd Elaal, S.E.

2005-01-01

Graft polymerization and crosslinking in radiation processing are attractive techniques for modification of the chemical and physical properties of the conventional polymers. The graft polymerization and subsequent chemical treatment can introduce a chelate agent function into a conventional polymer such as cellulosic fabric. Cellulosic graft copolymers were prepared by the reaction of the fiber with acrylonitrile (AN) and 2-acrylamido-2-methyl propane sulfonic acid (AMPS) in DMF initiated by gamma-radiation 60 Co. The grafted fabric was chemically treated with hydroxyl amine to obtain amidoxime form. Factors affecting on the grafting such as radiation dose, monomer concentration and solvent concentration as well as monomer composition was investigated. The chemically modified graft fabric was applied for recovery of cyanide and dichromate from aqueous solution. The CN show removal percent 89%, whereas dichromate has 65% removal percent

Radiation graft polymerization of 4- vinylpyridine on polyvinylchloride-films. [Gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Kudryavtsev, V.N.; Shapiro, A.; Endrikhovska-Bonamur, A.M.

1984-01-01

Radiation graft liquid phase polymerization of 4-vinylpyridine on PVC-films by the method of direct radiation is investigated. The samples are irradiated by Co/sup 60/ ..gamma..-source at 20 deg C and the dose rate of 39 Gy/s for 4-vinylpyridine solutions in methonol, as well as at-78 deg C and dose rate of 1.3 kGy/s for monomer solutions in hexane. Modified polyvinylchloride films with grafted poly-4-vinylpyridine chains are prepared. Being introduced in grafted polyvinylpyridine chains of ion-exchange groups, materials are characterized by good swelling in water and are good to prepare anion-exchange membranes.

Study of radiation induced grafting of [(methacryloylamino)-propyl] trimethyl ammonium chlorite (MPTAC) on to cotton fabrics and its application

International Nuclear Information System (INIS)

Selambakkannu, S.

2014-01-01

Quaternary ammonium salt, [(methacryloylamino)-propyl] trimethyl ammonium chlorite (MPTAC) had been used as monomer in mutual radiation grafting process on cotton fabrics with the aid of high energy gamma radiation source. The polymer chains of MPTAC were successfully grafted covalently onto cotton fabrics. Effect of selected experimental variables such as irradiation dose, monomer concentration, and ambient conditions and effect of inhibitors on extent of grafting had been analyzed. Grafting yield increases steadily with monomer concentration. The highest grafting yield obtained at 2 kGy and reduces thereafter then become almost constant at higher dose range. The grafted samples characterized for its surface morphology. Finally the grafted cotton subjected to its dye uptake capacity and antibacterial efficacy. The grafted cotton fiber was used in absorption studies of aqueous basic dye solution, namely AB74. The grafted cotton posses very good dye uptake capacity. The maximum dye uptake capacity of the grafted cotton sample was 150 mg/g. Antibacterial efficacy has been tested by qualitative and quantitative methods against model bacteria S. aureus and E. coli from gram positive and gram negative respectively. 20 % grafted cotton was found to be responsible of 2 log cycle reductions for the E.coli and S.aureus colonies. (author)

Radiation Induced Crosslinking of Polyethylene in the Presence of Bifunctional Vinyl Monomers

DEFF Research Database (Denmark)

Joshi, M. S.; Singer, Klaus Albert Julius; Silverman, J.

1977-01-01

Several reports have been published showing that the radiation induced grafting of bifunctional vinyl monomers to low density polyethylene results in a product with an unusually high density of crosslinks. The same grafting reactions are shown to reduce the incipient gel dose by more than a factor...... of fifty. This paper is concerned with the apparent crosslinking produced by the radiation grafting of two monomers to polyethylene: acrylic acid and acrylonitrile....

Acid effects in the styrene comonomer technique for radiation grafting to wool

International Nuclear Information System (INIS)

Garnett, J.L.; Kenyon, R.S.

1977-01-01

Two processes are thought to contribute to the grafting of monomers to wool in the presence of acid under the influence of ionizing radiation. At temperatures of 45 0 C, acid alone will catalyze grafting to wool over a period of 18 hr and at much slower rates at room temperature. However, cellulose and polyolefins do not readily graft at these temperatures by acid-catalyzed process alone, radiation is also necessary. It is thought that in grafting to wool the radiation chemistry mechanisms and the mechanical swelling of acid both contribute appreciably to the radiation copolymerization; but with cellulose and the polyolefins, where acid-catalyzed grafting is approximately zero, the radiation process predominates

Radiation-Induced Graft Polymerization of Vinyl Monomers with Anion Groups onto MWNT Supports and Their Application as Electrogenerated Chemiluminescence (ECL Biosensors

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Ji-Hye Park

2014-01-01

Full Text Available Vinyl polymer-grafted multiwalled carbon nanotube (MWNT supports with anion groups were prepared for use as biosensor supports by radiation-induced graft polymerization (RIGP of the vinyl monomers acryloyl diphosphoric acid (ADPA, acrylic acid (AA, sodium styrenesulfonate (NaSS, and methacrylic acid (MA onto the surface of MWNTs. The electrogenerated chemiluminescence sensors based on a glass carbon electrode (ECL-GCE and a screen printed electrode (ECL-SPE were fabricated by immobilization of Ru(bpy3 2+ complex after coating of vinyl polymer-grafted MWNT inks on the surface of the GCE and SPE without any polymer binders in order to obtain high electrogenerated chemiluminescence intensity. For detection of alcohol concentration, alcohol dehydrogenase (ADH was immobilized onto an ECL-GCE sensor prepared by poly(NaSS-g-MWNT supports. The prepared biosensor based on ADH is suitable for the detection of ethanol concentration in commercial drinks.

Preparation of well-defined erythromycin imprinted non-woven fabrics via radiation-induced RAFT-mediated grafting

Science.gov (United States)

Söylemez, Meshude Akbulut; Barsbay, Murat; Güven, Olgun

2018-01-01

Radiation-induced RAFT polymerization technique was applied to synthesize well-defined molecularly imprinted polymers (MIPs) of erythromycin (ERY). Methacrylic acid (MAA) was grafted onto porous polyethylene (PE)/polypropylene (PP) nonwoven fabrics, under γ-irradiation by employing 2-pheny-2-propyl benzodithioate as the RAFT agent and ethylene glycol dimethacrylate (EGDMA) as the crosslinker. MAA/erythromycin ratios of 2/1, 4/1, 6/1 were tested to optimize the synthesis of MIPs. The highest binding capacity was encountered at a MAA/ERY ratio of 4/1. Non-imprinted polymers (NIPs) were also synthesized in the absence of ERY. The MIPs synthesized by RAFT method presented a better binding capacity compared to those prepared by conventional method where no RAFT agent was employed.

Radiation-induced malignant tumours: a specific cytogenetic profile?

International Nuclear Information System (INIS)

Chauveinc, L.; Gaboriaux, G.; Dutrillaux, A. M.; Dutrillaux, B.; Chauveinc, L.; Ricoul, M.; Sabatier, L.; Dutrillaux, B.

1997-01-01

To date, there is no criterion enabling to determine the spontaneous or radio-induced origin of malignant tumour occurring in a previously irradiated patient. Biological studies are rare. The cytogenetic data which could be found in the literature for eleven radio-induced tumours suggest that aneuploidies and polyclonality are frequent events. We studied, by R-Banding cytogenetic technique, five patients with short-term cultures (3 cases), short and long-term cultures (1 case) and xeno-grafting on nude pattern a high rate of balanced translocations, numerous random break points and a polyclonal evolution (10 clones). All other tumours, including the xeno-grafting sarcoma, had a monoclonal profile with complex karyotypes, hypo-diploid formulas and many deletions. These results show that the mechanism of radiation-induced tumours frequently involves chromosomes losses and deletions. The most likely explanation is that these alterations unmask radiation induced recessive mutations of tumour suppressor genes. (authors)

A study on the morphology of polystyrene-grafted poly(ethylene-alt-tetrafluoroethylene) (ETFE) films prepared using a simultaneous radiation grafting method

International Nuclear Information System (INIS)

Song, Ju-Myung; Ko, Beom-Seok; Sohn, Joon-Yong; Nho, Young Chang; Shin, Junhwa

2014-01-01

The morphology of polystyrene-grafted poly(ethylene-alt-tetrafluoroethylene) (ETFE) films prepared using a simultaneous radiation grafting method was investigated using DMA, DSC, XRD, and SAXS instruments. The DMA study indicates that the ETFE amorphous phase and PS amorphous phase are mixed well in the PS-grafted ETFE films while the ETFE crystalline phase and the PS amorphous phase are separated, suggesting that the PS chains are grafted mainly on the ETFE amorphous regions. The DSC and XRD data showed that the natural crystalline structures of ETFE in the grafted ETFE films are not affected by the degree of grafting. The SAXS profiles displayed that the inter-crystalline distance of the ETFE films increases with an increasing degree of grafting, which further implies that the PS graft chains formed by the simultaneous irradiation has a significant impact on the amorphous morphology of the resulting grafted ETFE film. Thus, these results indicate that the styrene monomers are mainly grafted on the ETFE amorphous regions during the simultaneous radiation grafting process. - Highlights: • PS-grafted ETFE films were prepared by a simultaneous radiation grafting method was investigated. • The natural crystalline structures of grafted ETFE films are not affect by the degree of grafting. • The inter-crystalline distance of the ETFE films increase with increasing degree of grafting. • The styrene monomers are mainly grafted on the ETFE amorphous regions during a simultaneous radiation grafting using gamma-ray

Insolubilisation of biologically active materials with novel radiation graft copolymers

International Nuclear Information System (INIS)

Garnett, J.L.; Jankiewicz, S.V.; Levot, R.; Sangster, D.F.

1984-01-01

The use of radiation grafting to immobilise a typical enzyme, trypsin, is reported. The technique involves radiation grafting to a backbone polymer a monomer containing an appropriate functional group to which the enzyme is bonded. In the present work, p-nitrostyrene has been grafted to representative trunk polymers, polypropylene and PVC, the nitro group in the resulting copolymer converted to the isothiocyanato derivative to which trypsin is attached. Of importance to this insolubilisation process, especially for radiation sensitive backbone polymers, is the inclusion of additives which enhance grafting. A new class of additives which increase the grafting yields is reported using as representative backbone polymers, naturally occurring cellulose and synthetic low density polyethylene. The new additives are specific metal salts such as LiClO 4 . The reactivity of these salts in grafting enhancement has been compared with that of mineral acid which has previously been used as an additive to increase grafting yields in both preirradiation and simultaneous techniques. A new model for grafting enhancement in the presence of the metal salts as well as acids is proposed whereby increased grafting yields are attributed to increased partitioning of monomer into the graft region in the presence of ionic solutes. The value of these additives in preparing copolymers suitable for general reagent insolubilisation reactions is discussed

Grafting heterogeneous catalyst with gamma radiation

International Nuclear Information System (INIS)

Garnett, J.L.; Long, M.A.; Levot, R.G.

1984-01-01

A process for the production of a heterogeneous catalyst comprises the steps of: irradiating an organic macromolecular substrate or a metal substrate with ionising or ultra violet radiation in the presence of a monomer selected from the group consisting of o-, m-, or p- styryl diphenyl phosphine and o-, m- or p- phenyl acrylyl diphenyl phosphine, to graft the monomer to the substrate; and reacting the graft copolymer with a homogeneous catalyst selected from the group consisting of catalytic metal salts and catalytic organometallic complexes such that the graft copolymer conjugate becomes a ligand of the catalyst

Radioactive cesium removal from seawater using adsorptive fibers prepared by radiation-induced graft polymerization

International Nuclear Information System (INIS)

Goto, Shota; Kawai-Noma, Shigeko; Umeno, Daisuke; Saito, Kyoichi; Fujiwara, Kunio; Sugo, Takanobu; Kikuchi, Takahiro; Morimoto, Yasutomi

2015-01-01

The meltdown of three reactors of the TEPCO Fukushima Daiichi nuclear power station (NPS) caused by the Great East Japan Earthquake on March 11th 2011 resulted in the emission of radionuclides such as cesium-137 and strontium-90 to the environment. For example, radioactive cesium exceeding the legal discharge limit (90 Bq/L, 2×10 -13 M) was detected in the seawater of the seawater-intake area of the NPS at the end of September 2014. Adsorbents with a high selectivity for cesium ions over other alkali metal ions such as sodium and potassium ions are required for cesium removal from seawater because sodium and potassium ions dissolve respectively at much higher concentrations of 5×10 -1 and 1×10 -2 M than cesium ions (2×10 -9 M). In addition, the simple operations of the immersion in seawater and the recovery of the adsorbents from seawater are desirable at decontamination sites. We prepared a cobalt-ferrocyanide-impregnated fiber capable of specifically capturing cesium ions in seawater by radiation-induced graft polymerization and chemical modifications. First, a commercially available 6-nylon fiber was irradiated with γ-rays. Second, an epoxy-group-containing vinyl monomer, glycidyl methacrylate, was graft-polymerized onto the γ-ray-irradiated nylon fiber. Third, the epoxy ring of the grafted polymer chain was reacted with triethylenediamine to obtain an anion-exchange fiber. Fourth, ferrocyanide ions, [Fe(CN) 6 ] 4 - , were bound to the anion-exchange group of the polymer chains. Finally, the ferrocyanide-ion-bound-fiber was placed in contact with cobalt chloride to precipitate insoluble cobalt ferrocyanide onto the polymer chains. Insoluble cobalt ferrocyanide was immobilized at the periphery of the fiber. However, the impregnation structure remains unclear. Here, we clarified the structure of insoluble cobalt ferrocyanide impregnated onto the polymer chain grafted onto the fiber to ensure the chemical and physical stability of the adsorptive fiber in

Synthesis of Radiation Grafted Polymer Matrices for Separation and Industrial Applications

Energy Technology Data Exchange (ETDEWEB)

Bhardwaj, Y K; Virendra, K; Goel, N K; Sarma, K S.S.; Sabharwal, S [Radiation Technology Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India)

2012-09-15

Grafting of acrylonitrile onto non-woven porous polypropylene fibre sheet using electron beam was carried out by post-irradiation grafting. Grafting extent of {approx}125% was achieved. The grafted nitrile groups were amidoximated and studied for uranium uptake from sea water and heavy metal ions (Co{sup 2+}, Ni{sup 2+}, Mn{sup 2+}, and Cd{sup 2+}) from aqueous solutions. Adsorption and elution of adsorbed ions in suitable eluents was studied. The grafting process was upgraded to pilot scale to obtain 1x1 m{sup 2} sheets. Mutual radiation grafting technique was used for grafting of vinylbenzyltrimethyl ammonium chloride, [2- (methacryloyloxy)ethyl] trimethylammonium chloride and [2-(acryloyloxyethyl)]trimethylammonium chloride onto cotton cellulose substrate. The grafted matrices showed significantly higher water uptake and good water retention properties. The antibacterial efficacy of the grafted products was found to be a function of extent of grafting and the type of bacteria (Escherichia coli, Pseudomonas flourescens, Staphylococcus aureus and Bacillus cereus). PVBT-g-cotton was studied for its protein adsorption behaviour in continuous column process using Bovine serum albumin (BSA) as a model protein. Mutual radiation grafting technique was used to graft acrylic acid on micrometer thick micro-porous polypropylene membrane. Contact angle measurement studies showed that initial grafting as well as radiation treatment of poly(propylene) in aqueous medium and in presence of Mohr's salt enhances its affinity towards the grafting solution. The enhancement in the polar component of surface energy of treated polypropylene membrane is the primary cause of grafting enhancement. The membranes grafted to an extent of {approx}20% were found to perform comparably with the battery separator presently being used by battery industry. Acrylic acid was grafted to Teflon scrap by mutual radiation grafting technique. The grafting extent decreased with increasing dose rate and

Ion exchange fiber prepared by radiation grafting, (2)

International Nuclear Information System (INIS)

Sekiguchi, Hideaki; Fujiwara, Kunio; Fujii, Toshiaki; Takai, Takeshi; Kobayashi, Atsushi

1991-01-01

Ion exchange fiber prepared by radiation grafting has the capabilities for wide application as high performance materials. Extensive studies were made to evaluate the ion exchange fiber prepared by radiation grafting for removing some toxic or malodorous gases, continuing from the previous work (presented in Ebara Engng. Review, No. 146), in which the ability of removing ammonia with cation exchange fiber was investigated. The results of this study can be summarized by the following conclusions: (1) Methods of evaluating the ability of removing ammonia, acetaldehyde, and some lower fatty acids in low concentration were established, (2) Besides being effective for the removal of acidic or basic gases, neutral gas such as acetaldehyde can also be removed by adding some functional compounds to the ion exchange fiber, and (3) Ion exchange fiber prepared by radiation grafting is effective as a deodorizing filter. (author)

Radiation induced deposition of copper nanoparticles inside the nanochannels of poly(acrylic acid)-grafted poly(ethylene terephthalate) track-etched membranes

Science.gov (United States)

Korolkov, Ilya V.; Güven, Olgun; Mashentseva, Anastassiya A.; Atıcı, Ayse Bakar; Gorin, Yevgeniy G.; Zdorovets, Maxim V.; Taltenov, Abzal A.

2017-01-01

Poly(ethylene terephthalate) PET, track-etched membranes (TeMs) with 400 nm average pore size were UV-grafted with poly(acrylic acid) (PAA) after oxidation of inner surfaces by H2O2/UV system. Carboxylate groups of grafted PAA chains were easily complexed with Cu2+ ions in aqueous solutions. These ions were converted into metallic copper nanoparticles (NPs) by radiation-induced reduction of copper ions in aqueous-alcohol solution by gamma rays in the dose range of 46-250 kGy. Copper ions chelating with -COOH groups of PAA chains grafted on PET TeMs form polymer-metal ion complex that prevent the formation of agglomerates during reduction of copper ions to metallic nanoparticles. The detailed analysis by X-Ray diffraction technique (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) confirmed the deposition of copper nanoparticles with the average size of 70 nm on the inner surface of nanochannels of PET TeMs. Samples were also investigated by FTIR, ESR spectroscopies to follow copper ion reduction.

Correlation between morphology, water uptake, and proton conductivity in radiation-grafted proton-exchange membranes

DEFF Research Database (Denmark)

Balog, Sandor; Gasser, Urs; Mortensen, Kell

2010-01-01

An SANS investigation of hydrated proton exchange membranes is presented. Our membranes were synthesized by radiation-induced grafting of ETFE with styrene in the presence of a crosslinker, followed by sulfonation of the styrene. The contrast variation method was used to understand the relationship...

Improvement of blood compatibility of polyurethane elastomer by radiation graft copolymerization of 2-hydroxyethyl methacrylate in polymer matrix

International Nuclear Information System (INIS)

Li Ximing; Chen Wenming; Yuan Zhijian; Li Song; Lu Mei

1988-01-01

The γ-radiation induced grafting of 2-hydroxyethyl methacrylate (HEMA) onto polyurethane-elastomers (PUE) tube by preswelling technique to prepare biomedical materials with blood compatibility is studied. The graft yield can be controlled by regulating the preswelling time and temperature, or by change the irradiation dose and dose rate. After antithrombogenic test in vitro it has been confirmed that the blood compatibility of original polyurethane tube has been considerably improved by grafting

Synthesis and characterization of superabsorbent polymer prepared by radiation-induced graft copolymerization of acrylamide onto carboxymethyl cellulose for controlled release of agrochemicals

International Nuclear Information System (INIS)

Hemvichian, Kasinee; Chanthawong, Auraruk; Suwanmala, Phiriyatorn

2014-01-01

Superabsorbent polymer (SAP) was synthesized by radiation-induced grafting of acrylamide (AM) onto carboxymethyl cellulose (CMC) in the presence of a crosslinking agent, N,N′-methylenebisacrylamide (MBA). The effects of various parameters, such as dose, the amount of CMC, AM, MBA and ionic strength on the swelling ratio were investigated. In order to evaluate its controlled release potential, SAP was loaded with potassium nitrate (KNO 3 ) as an agrochemical model and its potential for controlled release of KNO 3 was studied. The amount of released KNO 3 was analyzed by an inductively coupled plasma mass spectrometry (ICP–MS). The results from controlled release experiment agreed very well with the results from swelling experiment. The synthesized SAP was characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The obtained SAP exhibited a swelling ratio of 190 g/g of dry gel. - Highlights: • SAP was synthesized by radiation-induced grafting of AM onto CMC. • The synthesized SAP exhibited a maximum swelling ratio of 190 g/g. • The potential of SAP for controlled release of KNO 3 was studied. • The amount of KNO 3 released increased with increasing loading percentage of SAP. • SAP's swelling ratio decreased as the ionic strength of the medium increased

Immobilization of urease on grafted starch by radiation method

International Nuclear Information System (INIS)

Nguyenanh Dung; Nguyendinh Huyen

1995-01-01

The acrylamide was grafted by radiation onto starch which is a kind of polymeric biomaterial. The urease was immobilized on the grafted starch. Some experiments to observe the quantitative relationships between the percent graft and the activity of immobilized enzyme were determined. The enzyme activity was maintained by more than seven batch enzyme reactions. (author)

Effect of mineral acid on polymer produced during radiation-induced grafting of styrene monomer

International Nuclear Information System (INIS)

Garnett, J.L.; Jankiewicz, S.V.; Sangster, D.F.

1982-01-01

The inclusion of mineral acid in a solution of styrene in methanol subjected to 60 Co γ irradiation markedly enhances the yield of monomer grafted to cellulose and other radiation grafting systems. Results were reported from a preliminary investigation into the mechanism of this acid effect through a study of the action of acid during the solution polymerization process. It was found that the presence of acid in a monomer solution such as styrene in 1, 4-dioxan led to an enhancement in the homopolymer yield of styrene; and it was showed that the acid also effected the number-average molecular weight of this homopolymer. 1 figure, 4 tables

Radiation grafting of bis[2-(methacryloyloxy)ethyl]phosphate unto kenaf fiber for adsorption of rare earth elements

International Nuclear Information System (INIS)

Nor Azillah Fatimah Othman; Selambakkannu, S.; Norliza Ishak; Nor Azwin Shukri; Zulkafli Ghazali

2016-01-01

Full text: In this work kenaf bast fibers were used as trunk polymer for grafting with bis[2-(methacryloyloxy)ethyl]phosphate monomer through radiation induced grafting technique. Kenaf fibers were treated with different concentration of sodium chlorite (NaClO_2) solution at 70 degree Celsius for 6 hours. Kenaf fibers were irradiated with electron beam and reacted with bis[2-(methacryloyloxy)ethyl]phosphate/ water emulsion. Formation of grafting was observed from the increase in degree of grafting and confirmed by FTIR and SEM results. Effects of irradiation dose, reaction time, reaction temperature and monomer concentration on the degree of grafting were studied. Performance of the grafted kenaf fibers were then tested for adsorption of rare earth elements, namely Dysprosium, Neodymium and Holmium. (author)

Radiation-initiated graft polymerization of methyl acrylate onto chrome-tanned sheepskin

International Nuclear Information System (INIS)

Kaldirimci, C.; Bas, N.

1982-01-01

Radiation grafting method was applied to obtain leather-polymer composite. Grafting of methyl acrylate onto chrome-tanned, bluestock sheepskin was investigated under the initiatory effect of 60 Co radiation of 0.20 11.50 Mrad. The percent of grafting was determined and water adsorption and shrinkage temperature measurements were carried out. It was shown that 2-4 Mrad is convenient to produce leather-polymer composite. (author)

Study on radiation-induced polymerization of vinyl monomers adsorbed on inorganic substances. II. Radiation-induced polymerization of methyl methacrylate adsorbed on several inorganic substances

International Nuclear Information System (INIS)

Fukano, K.; Kageyama, E.

1975-01-01

The radiation-induced polymerization of methyl methacrylate (MMA) adsorbed on such inorganic substances as silica gel, white carbon, silicic acid anhydride, zeolite, and activated alumina was carried out to compare with the case of styrene. The rate of radiation-induced polymerization adsorbed on inorganic substances was high compared with that of radiation-induced bulk state polymerization, as was the case with styrene. Inorganic substrates which contain aluminum as a component element are more likely to be grafted than those which consist of SiO 2 alone, as with styrene. The molecular weight distribution of unextractable polymer and extractable polymer differs, depending on the type of inorganic substance. Experiments by a preirradiation method were carried out in case of silica gel, white carbon, and silicic acid anhydride. GPC spectra of the polymer obtained were different from those of polymer formed by the simultaneous irradiation method. It appears that all the unextractable polymer is grafted to the inorganic surface with chemical bond

Effects of combined radiation-burn injury on survival rate of allogeneic skin grafts and immune reaction in rats

International Nuclear Information System (INIS)

Ran Xinze; Yan Yongtang; Cheng Tianmin; Li Yuan; Wei Shuqing

1996-01-01

The effects of combined radiation-burn injury on survival rate of allogeneic skin grafts and immune reaction were studied in rats with combined injury of 3-8 Gy 60 Co γ-ray irradiation plus 15% total body surface area full thickness burn induced by exposure to a 5 kw bromotungsten lamp. The allogeneic skin was transplanted 24 hours after injury. It was found that all the skin grafts failed to survive in 10 days and the immune reaction significantly increased in the early stage of burn injury. But the immune reaction was obviously suppressed by the combined radiation-burn injury. The survival rates of skin grafts were 20% and 30% in the combined injury of burn plus 3 and 4 Gy irradiation respectively. When the radiation doses increased to 5,6 and 8 Gy, the survival rates elevated to 69%, 88% and 100% respectively (in the group of 8 Gy, bone marrow transplantation was conducted before receiving skin graft). At day 30 post-transplantation the survival rates were still 36%, 42% and 100% respectively. Compared with burn group, there was a significant difference in survival rate when the radiation doses were higher than 5 Gy. These results indicate that the survival rate of the allogeneic skin graft increases concurrently with the increase in radiation dose and decreases with the elapse of the post-transplantation time

The tolerance of skin grafts to postoperative radiation therapy in patients with soft-tissue sarcoma

International Nuclear Information System (INIS)

Lawrence, W.T.; Zabell, A.; McDonald, H.D.

1986-01-01

During the last ten years at the National Cancer Institute, 11 patients have received 12 courses of postoperative adjuvant radiation therapy to skin grafts used for wound closure after the resection of soft-tissue sarcomas. The intervals between grafting and the initiation of radiation ranged between 3 and 20 weeks, and 4 patients received chemotherapy at the same time as their radiation. Ten of the 12 irradiated grafts remained intact after the completion of therapy. One graft had several small persistently ulcerated areas that required no further surgical treatment, and one graft required a musculocutaneous flap for reconstruction of a persistent large ulcer. Acute radiation effects on the grafted skin sometimes developed at slightly lower doses than usually seen with normal skin, but these acute effects necessitated a break in therapy on only five occasions. Concurrent chemotherapy and a relatively short interval between grafting and the initiation of radiation seemed to contribute to more severe radiation reactions. This experience indicates that postoperative adjuvant radiation therapy can be delivered to skin grafted areas without undue fear of complications, especially if the graft is allowed to heal adequately prior to initiating therapy and if chemotherapy is not given in conjunction with radiation

Study on grafting of monomer onto natural rubber latex by radiation technique

International Nuclear Information System (INIS)

Nguyen Tan Man; Le Hai; Tran Thi Tam; Le Huu Tu, Pham Thi Sam; Dao Minh Phuong; Ha Thuc Huy

2004-01-01

Radiation vulcanization of natural rubber latex has been extensively developed through programmers assisted by the IAEA and UNDP under RCA in Asia and Pacific Region. R-D has been done in most of the Member States with technical assistance from Japan's Takasaki Radiation Chemistry Establishment. Radiation vulcanized natural rubber latex (RVNRL) has many advantages over the conventional sulfur vulcanized latex, such as absence of nitrosamine and low cytotoxicity. Radiation crosslinking is a room temperature process, itself an important cost advantage, it is easily controlled and desired extend of crosslinking is easily achieved by controlling the dose (irradiation time). Disadvantages of RVNRL to be improved are poor physical properties of film such as low tensile strength and tear strength. The research groups of Japan, Thailand and Indonesia concentrated on the improvement of physical properties of RVNRL using radiation grafted PMMA as additive [2]. F. Sundardi and W. Sofiarti have reported that tensile strength and hardness increased by radiation grafting of styrene onto NR [5]. Ono et al have reported the grafting of MMA onto NR by gamma irradiation at a dose of 5 kGy for producing thermoplastic elastomers [4]. The objective of this project is to report the results of studies of radiation graft-copolymerization of methyl methacrylate (MMA) or styrene (St) onto natural rubber latex in order to improve their physico-mechanical properties and evaluation of grafted material using Small-Angle Neutron Scattering through FNCA Project. The grafting degree of MMA and St onto NR increased with the increase of irradiation dose and monomer concentration. The alteration of grafted products structure was determined by IR method. Tensile strength, Shore A hardness, 100% modulus of grafted products increased with the increase of monomer concentration and irradiation dose while elongation at break decreased. The grafted products were characterized by Transmission Electron

Specitic gene alterations in radiation-induced tumorigenesis

Energy Technology Data Exchange (ETDEWEB)

Ahn, Joo Mee; Kang, Chang Mo; Lee, Seung Sook; Cho, Chul Koo; Bae, Sang Woo; Lee, Su Jae; Lee, Yun Sil [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2004-07-01

To identify a set of genes involved in the development of radiation-induced tumorigenesis, we used DNA microarrays consisting of 1,176 mouse genes and compared expression profiles of radioresistant cells, designated NIH3T3-R1 and -R4. These cells were tumorigenic in a nude mouse grafting system, as compared to the parental NIH3T3 cells. Expressions of MDM2, CDK6 and CDC25B were found to increase more than 3-fold. Entactin protein levels were downregulated in NIH3T3-R1 and -R4 cells. Changes in expression genes were confirmed by reverse transcription-PCR or western blotting. When these genes were transfected to NIH3T3 cells, the CDC25B and MDM2 overexpressing NIH3T3 cells showed radioresistance, while 2 CDK6 overexpressing cells did not. In the case of entactin overexpressing NIH3T3-R1 or R-4 cells were still radioresistant. Furthermore, the CDC25B and MDM2 overexpressing cells grafted to nude mice, were tumorigenic. NIH3T3-R1 and R4 cells showed increased radiation-induced apoptosis, accompanied by faster growth rate, rather than and earlier radiation-induced G2/M phase arrest, suggesting that the radioresistance of NIH3T3-R1 and R4 cells was due to faster growth rate, rather than induction of apoptosis. In the case of MDM2 and CDC25B overexpressing cells, similar phenomena, such as increased apoptosis and faster growth rate, were shown. The above results, therefore, demonstrate involvement of CDC25B and MDM2 overexpression in radiation-induced tumorigenesis and provide novel targets for detection of radiation-induced carcinogenesis.

ESR spectroscopic investigations of the radiation-grafting of fluoropolymers

Energy Technology Data Exchange (ETDEWEB)

Huebner, G; Roduner, E [University of Stuttgart (Germany); Brack, H P; Scherer, G G [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

ESR spectroscopic investigations have clarified the influence of several preparative parameters on the reaction rates and yields obtained in the radiation-grafting method used at PSI to prepare proton-conducting polymer membranes. At a given irradiation dose, a higher concentration of reactive radical sites was detected in ETFE films than in FEP films. This higher concentration explains the higher grafting levels and rates of the ETFE films found in our previous grafting experiments. Taken together, the in-situ ESR experiments and grafting experiments show that the rates of disappearance of radical species and grafting rates and final grafting levels depend strongly on the reaction temperature and the oxygen content of the system. Average grafted chain lengths were calculated to contain about 1,000 monomer units. (author) 2 figs., 4 refs.

Radiation Induced Preparation of Polymer Membranes Grafted with Basic and Acidic Monomers for Application in Wastewater Treatment

Energy Technology Data Exchange (ETDEWEB)

Ajji, Z [Polymer Technology Division, Radiation Technology Department, Atomic Energy Commission of Syria (AECS), 17th Nissan Street, Kafar Sousah, Damascus (Syrian Arab Republic)

2012-09-15

Polymer membranes (PP and PE) had been grafted with basic and acidic functional groups using gamma radiation. Two binary mixtures had been used for the grafting reactions: acrylic acid/N-vinyl pyrrolidone, and acrylic acid/N-vinyl imidazole. The influence of different reaction parameters on the grafting yield had been investigated as: type of solvent and solvent composition, comonomer concentration and composition, addition of inhibitors, and dose. Water uptake with respect to the grafting yield had also been evaluated. The ability of PP films, grafted with acrylic acid/ vinyl pyrrolidone, to uptake heavy metal ions such as Hg{sup 2+}, Pb{sup 2+}, Cd{sup 2+}, Co{sup 2+}, Ni{sup 2+} and Cu{sup 2+} was elaborated. The uptake of the metal ions increases with increasing the grafting yield. Furthermore, the Pb{sup +2} uptake was much higher than the uptake of the Hg{sup 2+} and Cd{sup 2+} ions. The membranes may be considered for the separation of Pb{sup 2+} ions from Hg{sup 2+} or Cd{sup 2+} ions. Also the ability of PE films, grafted with acrylic acid/ N-vinyl imidazole to uptake heavy metal ions such as Pb{sup 2+}, Cd{sup 2+}, Co{sup 2+} and Ni{sup 2+} was elaborated. An increase in the uptake of the metal ions was observed as the grafting yield increased. (author)

Ion exchange fiber by radiation grafting, 1

International Nuclear Information System (INIS)

Fujiwara, Kunio

1990-01-01

Radiation grafting is gaining attention as a method for producing high performance materials. This method can be applied to add functions to existing polymer plastics. The author participated in the research program on the production of ion exchange fiber by radiation grafting and its applicability at the Japan Atomic Energy Research Institute, Takasaki Radiation Chemistry Research Establishment. Consequently, it was clarified that it was possible to introduce the cation exchange group, represented by sulfonic and carboxyl groups, and the anion exchange group, represented by the quarternary ammonium group, to polypropylene fiber available on the market. The ion exchange capacity was able to be controlled by the degree of grafting, i.e. approximately up to 3 meq/g in both strong acid and strong base and approximately up to 5 meq/g in weak acid were obtained. The adsorption performance of ammonia, a representative malodorous substance, was also studied using test cation exchange fiber. The adsorption rate of H type strong acid cation exchange fiber was great, due to the H type having neutral reaction, and the adsorption capacity matched the ion exchange capacity. Although the Cu and Ni types features coordinated adsorption and their adsorption rates were from 1/2 to 1/3 of that of the H type, their adsorption capacities showed increase along with the metal adsorbed. (author)

A short review of radiation-induced raft-mediated graft copolymerization: A powerful combination for modifying the surface properties of polymers in a controlled manner

Science.gov (United States)

Barsbay, Murat; Güven, Olgun

2009-12-01

Surface grafting of polymeric materials is attracting increasing attention as it enables the preparation of new materials from known and commercially available polymers having desirable bulk properties such as thermal stability, elasticity, permeability, etc., in conjunction with advantageous newly tailored surface properties such as biocompatibility, biomimicry, adhesion, etc. Ionizing radiation, particularly γ radiation is one of the most powerful tools for preparing graft copolymers as it generates radicals on most substrates. With the advent of living free-radical polymerization techniques, application of γ radiation has been extended to a new era of grafting; grafting in a controlled manner to achieve surfaces with tailored and well-defined properties. This report presents the current use of γ radiation in living free-radical polymerization and highlights the use of both techniques together as a combination to present an advance in the ability to prepare surfaces with desired, tunable and well-defined properties.

A short review of radiation-induced raft-mediated graft copolymerization: A powerful combination for modifying the surface properties of polymers in a controlled manner

International Nuclear Information System (INIS)

Barsbay, Murat; Gueven, Olgun

2009-01-01

Surface grafting of polymeric materials is attracting increasing attention as it enables the preparation of new materials from known and commercially available polymers having desirable bulk properties such as thermal stability, elasticity, permeability, etc., in conjunction with advantageous newly tailored surface properties such as biocompatibility, biomimicry, adhesion, etc. Ionizing radiation, particularly γ radiation is one of the most powerful tools for preparing graft copolymers as it generates radicals on most substrates. With the advent of living free-radical polymerization techniques, application of γ radiation has been extended to a new era of grafting; grafting in a controlled manner to achieve surfaces with tailored and well-defined properties. This report presents the current use of γ radiation in living free-radical polymerization and highlights the use of both techniques together as a combination to present an advance in the ability to prepare surfaces with desired, tunable and well-defined properties.

A short review of radiation-induced raft-mediated graft copolymerization: A powerful combination for modifying the surface properties of polymers in a controlled manner

Energy Technology Data Exchange (ETDEWEB)

Barsbay, Murat [Department of Chemistry, Hacettepe University, 06800 Beytepe, Ankara (Turkey)], E-mail: mbarsbay@hacettepe.edu.tr; Gueven, Olgun [Department of Chemistry, Hacettepe University, 06800 Beytepe, Ankara (Turkey)], E-mail: guven@hacettepe.edu.tr

2009-12-15

Surface grafting of polymeric materials is attracting increasing attention as it enables the preparation of new materials from known and commercially available polymers having desirable bulk properties such as thermal stability, elasticity, permeability, etc., in conjunction with advantageous newly tailored surface properties such as biocompatibility, biomimicry, adhesion, etc. Ionizing radiation, particularly {gamma} radiation is one of the most powerful tools for preparing graft copolymers as it generates radicals on most substrates. With the advent of living free-radical polymerization techniques, application of {gamma} radiation has been extended to a new era of grafting; grafting in a controlled manner to achieve surfaces with tailored and well-defined properties. This report presents the current use of {gamma} radiation in living free-radical polymerization and highlights the use of both techniques together as a combination to present an advance in the ability to prepare surfaces with desired, tunable and well-defined properties.

Improvement of the polymer stability by radiation grafting

International Nuclear Information System (INIS)

Ranogajec, F.; Mlinac-Misak, M.

2004-01-01

Losses of the stabilizer due to extractability or volatility immediately affect the ultimate performance of polymer products. A new approach to increase the persistence of the stabilizer in the final product is to chemically bind it to the polymer backbone. Radiation grafting or crosslinking could be an efficient method for this, when the stabilizer is polymerizable. By a mutual gamma irradiation method photoprotector 2-hydroxy-4-(3-methacryloxy-2-hydroxy-propoxy) benzophenone has been readily grafted to low-density polyethylene in benzene, tetrahydrofuran and methanol solution, respectively. Surface grafting occurs in a methanol solution of stabilizer, while in benzene and tetrahydrofuran solutions of the stabilizer, grafting proceeds more or less in the inner parts of the polymeric film as well. UV stability tests and changes in the mechanical properties of artificially and naturally aged films indicate pronounced protective effect achieved by the grafted stabilizer. Surface grafting is an efficient photostabilization method since the grafted stabilizer is chemically bound to a polymeric surface and in this way the problem of evaporation of blended stabilizers during the prolonged use of polymeric materials is eliminated

Control of Polymer Nanostructure and Functionality via Radiation Grafting

International Nuclear Information System (INIS)

Palmese, G.R.

2006-01-01

Radiation grafting provides a useful means for controlling polymer structure and performance. Particularly, it is appropriate for combining materials with distinct thermodynamic characteristics chemically at interfaces. Therefore polymeric materials that generally will not mix - i.e hydrophilic and hydrophobic polymers - can be combined efficiently using radiation based methods. This is of particular importance when attempting to form polymer-polymer nanocomposites where the thermodynamic penalty associated with high specific interfacial surface area is very large. Generally, the combination at small scales of such distinct materials is appropriate when specific functionality is desired while maintaining structural performance characteristics. In such cases the hydrophilic polymer lends functional characteristics such as ionic conductivity, self-healing, and actuation, while the hydrophobic polymer component provides structural stability. In this communication a summary of our recent work concerning the use of radiation grafting for the synthesis of nanostructured functional materials is given. Examples to be discussed include toughing of polymeric systems, the synthesis polymeric and inorganic nanotubes, and the design of permeation selective membranes. These examples will be used to demonstrate the effectiveness of radiation grafting techniques for controlling polymer properties and small-scale structure

Improvement of polymer stability by radiation grafting

International Nuclear Information System (INIS)

Ranogajec, F.; Mlinac-Misak, M.

1999-01-01

Losses of the stabilizer due to extractability or volatility immediately affect ultimate performance of polymer product. A new approach to increase the persistence of the stabilizer in the final product is to chemically bind it to the polymer backbone. Radiation grafting or crosslinking could be an efficient method for this, when the stabilizer is polymerizable. By a mutual gamma irradiation method, photoprotector 2-hydroxy-4-(3-methacryloxy-2- hydroxy-propoxy) benzophenone (HMB) has been readily grafted to low density polyethylene (LDPE) in benzene, tetrahydrofuran and methanol solution, respectively. Surface grafting occurs in a methanol solution of stabilizer, while in benzene and tetrahydrofuran solutions of stabilizer, grafting proceeds more or less in the inner parts of the polymeric film as well. The grafted LDPE film in methanol and tetrahydrofuran (containing 1 w/w % of grafted HMB), 1 w/w % blended HMB with LDPE and nongrafted LDPE film, were all exposed to accelerated aging and natural weathering and their spectral changes, expressed by the carbonyl index, were then compared. The change of elongation at break and tensile strength were measured in the course of aging. UV stability tests on aged films and change in mechanical properties indicate a pronounced protective effect achieved by grafted stabilizer. Grafting in methanol solution appears to be an efficient photostabilization treatment and the most economical with respect to the consumption of monomer, the grafting yield being less than 0.5%. Surface grafting is an efficient photostabilization method since grafted stabilizer is chemically bound to a polymeric surface and in this way the problem of evaporation of blended stabilizers during the prolonged use of polymeric materials is eliminated. (author)

Study of the simultaneous grafting and heparinisation of poly(vinyl chloride), by gamma radiation

International Nuclear Information System (INIS)

Panzarini, Luz Consuelo Gonzalez Alonso

2003-01-01

resonance spectroscopy showed that the kinetical decay of radicals of PVC-co-DMAEMA-coheparin is strongly induced by radicals formed throughout the radiolysis of DMAEMA and PVC. The PVC-co-DMAEMA-co-heparin graft copolymer that presented less thrombogenic surfaces was obtained by means of a simultaneous radiation beam dose of 5,0 KGy on PVC films immersed in aqueous solutions containing DMAEMA (30%), heparin sodium salt (0,25%w/v) and isopropanol (0,02 mol L -1 . (author)

Chronic graft-versus-host disease in the rat radiation chimera. III. Immunology and immunopathology in rapidly induced models

International Nuclear Information System (INIS)

Beschorner, W.E.; Tutschka, P.J.; Santos, G.W.

1983-01-01

Although chronic graft-versus-host disease (GVHD) frequently develops in the long-term rat radiation chimera, we present three additional models in which a histologically similar disease is rapidly induced. These include adoptive transfer of spleen and bone marrow from rats with spontaneous chronic GVHD into lethally irradiated rats of the primary host strain; sublethal irradiation of stable chimeras followed by a booster transplant; and transfer of spleen cells of chimeras recovering from acute GVHD into second-party (primary recipient strain) or third-party hosts. Some immunopathologic and immune abnormalities associated with spontaneous chronic GVHD were not observed in one or more of the induced models. Thus, IgM deposition in the skin, antinuclear antibodies, and vasculitis appear to be paraphenomena. On the other hand, lymphoid hypocellularity of the thymic medulla, immaturity of splenic follicles, and nonspecific suppressor cells were consistently present in the long term chimeras, and in all models. These abnormalities therefore may be pathogenetically important, or closely related to the development of chronic GVHD

Gamma radiation grafted polymers for immobilization of Brucella antigen in diagnostic test studies

Science.gov (United States)

Docters, E. H.; Smolko, E. E.; Suarez, C. E.

The radiation grafting process has a wide field of industrial applications, and in the recent years the immobilization of biocomponents in grafted polymeric materials obtained by means of ionizing radiations is a new and important contribution to biotechnology. In the present work, gamma preirradiation grafting method was employed to produce acrylics hydrogels onto polyethylene (PE), polyvinyl chloride (PVC) and polystyrene (PS). Two monomers were used to graft the previously mentioned polymers: methacrylic acid (MAAc) and acrylamide (AAm), and several working conditions were considered as influencing the degree of grafting. All this grafted polymers were used to study the possibility of a subsequent immobilization of Brucella antigen (BAg) in diagnostic test studies (ELISA).

Gamma radiation grafted polymers for immobilization of Brucella antigen in diagnostic test studies

International Nuclear Information System (INIS)

Docters, E.H.; Smolko, E.E.

1990-01-01

The radiation grafting process has a wide field of industrial applications, and in the recent years the immobilization of biocomponents in grafted polymeric materials obtained by means of ionizing radiations is a new and important contribution to biotechnology. In the present work, gamma preirradiation grafting method was employed to produce acrylics hydrogels onto polyethylene (PE), polyvinyl chloride (PVC) and polystyrene (PS). Two monomers were used to graft the previously mentioned polymers: methacrylic acid (MAAc) and acrylamide (AAm), and several working conditions were considered as influencing the degree of grafting. All these grafted polymers were used to study the possibility of a subsequent immobilization of Brucella antigen (BAg) in diagnostic test studies (ELISA). (author)

Gamma radiation grafted polymers for immobilization of Brucella antigen in diagnostic test studies

Energy Technology Data Exchange (ETDEWEB)

Docters, E H; Smolko, E E [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Direccion de Radioisotopos y Radiaciones; Suarez, C E [Instituto Nacional de Tecnologia Agropecuaria, Castelar (Argentina)

1990-01-01

The radiation grafting process has a wide field of industrial applications, and in the recent years the immobilization of biocomponents in grafted polymeric materials obtained by means of ionizing radiations is a new and important contribution to biotechnology. In the present work, gamma preirradiation grafting method was employed to produce acrylics hydrogels onto polyethylene (PE), polyvinyl chloride (PVC) and polystyrene (PS). Two monomers were used to graft the previously mentioned polymers: methacrylic acid (MAAc) and acrylamide (AAm), and several working conditions were considered as influencing the degree of grafting. All these grafted polymers were used to study the possibility of a subsequent immobilization of Brucella antigen (BAg) in diagnostic test studies (ELISA). (author).

Radiation effects on regeneration and T-cell-inducing function of the thymus

International Nuclear Information System (INIS)

Hirokawa, K.; Sado, T.

1984-01-01

Radiation effects on regeneration and T-cell-inducing function of the thymus were studied in three sets of experiments. When TXB mice were grafted with 1-week-old thymus which had been previously irradiated at various doses, an exponential decrease was observed in the morphological regeneration of the thymus grafts and in their T-cell-inducing function at doses of 600 R and over, showing about 10% that of the control at 1500 R. When in situ thymus of adult mice was locally irradiated, the radiation effect on T-cell-inducing function was less pronounced as compared with the first experiment; i.e., about 40% of the control at 1797 R. When in situ thymus of 1-day-old newborn mice was locally irradiated, regeneration potential of 1-day-old newborn thymus was highly resistant to radiation exposure and no effect on immunological functions was observed even by local irradiation of 2000 R

Graft copolymers of polyurethane with various vinyl monomers via radiation-induced miniemulsion polymerization: Influential factors to grafting efficiency and particle morphology

Energy Technology Data Exchange (ETDEWEB)

Wang Hua [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China); Wang Mozhen [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China)], E-mail: pstwmz@ustc.edu.cn; Ge Xuewu [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China)], E-mail: xwge@ustc.edu.cn

2009-02-15

Graft copolymers of polyurethane (PU) with various vinyl monomers were synthesized through a one-pot but two-step miniemulsion polymerization process. Firstly, the polycondensation of isophorone diisocyanate (IPDI) with hydroxyl-terminated polybutadiene (HTPB) had been performed in aqueous miniemulsion at 40 deg. C in order to obtain PU dispersions. Consecutively, an in-situ graft copolymerization of the vinyl monomers with the synthesized PU was initiated by {gamma}-ray radiation at room temperature. The grafting efficiency of PU with vinyl monomer (G{sub PU/monomer}) was calculated from {sup 1}H NMR spectra and the particle morphology of the final hybrid latex was observed by transmission electron microscopy (TEM). As there was no monomer transferring in miniemulsion system, homogenous hybrid particles would be synthesized provided that the monomer was miscible with PU, such as styrene. With the increase of the polarity of the monomer, the compatibility of PU with monomer decreased. G{sub PU/monomer} varied as G{sub PU/styrene}(37%)>G{sub PU/butyl} {sub acrylate} {sub (BA)}(21%)>G{sub PU/methyl} {sub methacrylate} {sub (MMA)}(12%). The proportion of homogeneous nucleation would increase as the hydrophilicity of the monomer increased. High temperature would destabilize the miniemulsion so as to result in a less grafting efficiency. Compared to the phase separation during the seeded emulsion polymerization, the miniemulsion polymerization method facilitated the preparation of homogeneous materials owing to its monomer droplet nucleation mechanism.

Synthesis of a hollow fiber type porous chelating resin containing the amide oxime group by radiation induced graft polymerization for the uranium recovery

International Nuclear Information System (INIS)

Hori, Takahiro; Saito, Kyoichi; Furusaki, Shintaro; Sugo, Takanobu; Okamoto, Jiro.

1986-01-01

A hollow fiber type porous chelating resin containing amide oxime as a functional group was synthesized and used as an adsorbent for the recovery of uranium. Hollow fiber type porous polyethylene was used as a base polymer. Acrylonitrile was grafted onto it by the radiation-induced graft polymerization. By changing the reaction time, four kinds of graft polymer were obtained. The degree of grafting ranged from 79 % to 127 %. Each resin was soaked in hydroxylamine solution, and the cyano group was converted to amide oxime group. By elemental analysis, the amount of nitrogen introduced on the graft polymer resin in amidoximation was determined to range from 4.3 mmol to 8.5 mmol per 1 g of base polymer. Most of the nitrogen is considered to belong to the amide oxime group. The pore radius, which was initially distributed broadly from about 500 A to 10000 A for the base polymer, was changed to about 1000 A with narrow distribution by the grafting. The pore volume was 1.2 ∼ 1.4 cm 3 per 1 gram of the amide oxime resin, which was about half of that of the initial base polymer. But the pore volume per 1 g base polymer of the amide oxime resin increased with an increase in the grafting degree, e.g. 4.5 cm 3 /g base polymer at 127 % of grafting degree. Specific surface area, which was 30 m 2 /g in base polymer, decreased with an increase in the grafting degree, e.g. 15 m 2 /g at 127 % of grafting degree. Both the amounts of the adsorbed hydrochloric acid and the adsorbed copper were about 1.5 times of the amount of nitrogen introduced in the amidoximation. The reason is considered to be caused by the formation of hydroxamic acid and amide from the measurements of the IR spectra. The amount of uranium adsorbed on the resin was 64 % of the amount of nitrogen introduced in the amidoximation. (author)

Application of radiation grafting techniques to prepare the high molecular weight water-soluble polymer

International Nuclear Information System (INIS)

Le Hai; Nguyen Quoc Hien; Nguyen Tan Man; Truong Thi Hanh; Le Huu Tu; Tran Thi Tam; Pham Thi Sam; Pham Anh Tuan; Le Dinh Lang

2003-01-01

The results of the study on the preparation of the high molecular weight water-soluble polymers by radiation grafting and their properties is presented as follows: 1/ by radiation grafting, the molecular weight of PVA was increased 20 times and PAM was increased only 3 times; 2/ the thermal and medium stability of poly(vinyl alcohol) grafted with acrylamide was obviously improved. (LH)

Radiation induced graft copolymerization of vinyl monomers onto synthetic polymeric films

International Nuclear Information System (INIS)

Chauhan, G.S.; Kaur, Inderjeet; Misra, B.N.

1997-01-01

Polyethylene (PE) and polyamide (PA) films have been modified by radiochemical grafting of methylacrylate (MA), ethylacrylate (EA), methyl methacrylate (MMA) and ethyl methacrylate (EMA) in aqueous medium in air. Grafted films show increased area and lower thermal stability. The swelling behaviour of these films vary as a function of percent grafting (P g ). (author). 8 refs., 1 tab

Graft-copolymerization onto carbon black

International Nuclear Information System (INIS)

Nakase, Yoshiaki; Nishii, Masanobu; Kijima, Toshiyuki; Kato, Hiroshi.

1988-07-01

Radiation-induced graft copolymerization of vinyl monomer onto carbon black was performed. During the γ-ray- and electron beam-induced polymerization (In-source), or the electron beam post-polymerization, the graft-copolymerization behavior was affected by the kinds of both carbon blacks and monomers, i.e. the smaller the size of carbon black particles, the higher the apparent grafted fraction. Homopolymer in the grafted carbon black samples was washed out by the solvent of the polymer, and the extracted polymer seemed to be dimer or trimer of the used monomer. In the case of the post-polymerization with the pre-irradiation doses of 50 Mrad, homopolymer was hardly observed. The polymer sheets of plastics or rubbers with grafted carbon black had an electrical conductivity unalterable considerably by the heating cycles. The particles of grafted carbon black in the sheet might be kept much more at the surface layer within 100 nm depth than at the inner layer. (author)

Phthalate Migration Study from PVC Grafted by Gamma Radiation

International Nuclear Information System (INIS)

Manzoli, J.E.; Duarte, C.; Somesari, E.; Silveira, C.; Paes, H.A.; Manzoli, J.E.; Araujo, F.D.C.; Panzarini, L.C.G.A.

2009-01-01

PVC is a useful polymer used for many applications, as packaging of food, blood and in contact with body fluids. The most widely-used plasticizer, to make it flexible, is the phthalate DEHP, and its toxicity is a problem. A special radiation grafting of PVC allows an important reduction of thrombogenic properties, and it could cause changes in the DEHP migration too. In this work it is presented the methodology using gas chromatography and numerical simulation for the measurement of DEHP migration from PVC grafted with monomer DMAEMA. The grafting could be an interesting way to reduce DEHP migration

Radiation graft post-polymerization of sodium styrene sulfonate onto polyethylene

International Nuclear Information System (INIS)

Kitaeva, N.K.; Duflot, V.R.; Ilicheva, N.S.

2013-01-01

Post-irradiation grafting of sodium styrene sulfonate (SSS) in the presence of acrylic acid (AA) has been investigated on polyethylene (PE) pre-exposed to gamma radiation at room temperature in the air. Special attention was paid to the effect of low molecular weight salt additives on the kinetics of graft copolymerization of SSS and AA. The presence of SSS links in the grafted PE copolymers was detected by the methods of UV and FTIR spectroscopy. Based on the FTIR spectroscopy and element analysis data, a mechanism was proposed for graft copolymerization of SSS and AA onto PE. The mechanical properties of the graft copolymers were studied. It was established that PE copolymers grafted with sulfonic acid and carboxyl groups have higher strength characteristics (16.3 MPa) compared to the samples containing only carboxyl groups (11 MPa). (author)

Biodegradability of poly(3-hydroxybutyrate) film grafted with vinyl acetate: Effect of grafting and saponification

Science.gov (United States)

Wada, Yuki; Seko, Noriaki; Nagasawa, Naotsugu; Tamada, Masao; Kasuya, Ken-ichi; Mitomo, Hiroshi

2007-06-01

Radiation-induced graft polymerization of vinyl acetate (VAc) onto poly(3-hydroxybutyrate) (PHB) film was carried out. At a degree of grafting higher than 5%, the grafted films (PHB-g-VAc) completely lost the enzymatic degradability that is characteristic of PHB due to the grafted VAc covering the surface of the PHB film. However, the biodegradability of the PHB-g-VAc films was recovered when the films were saponified in alkali solution under optimum conditions. Graft chains of the PHB-g-VAc film reacted selectively to become biodegradable polyvinyl alcohol (PVA). The biodegradability of the saponified PHB-g-VAc film increased rapidly with time.

Biodegradability of poly(3-hydroxybutyrate) film grafted with vinyl acetate: Effect of grafting and saponification

International Nuclear Information System (INIS)

Wada, Yuki; Seko, Noriaki; Nagasawa, Naotsugu; Tamada, Masao; Kasuya, Ken-ichi; Mitomo, Hiroshi

2007-01-01

Radiation-induced graft polymerization of vinyl acetate (VAc) onto poly(3-hydroxybutyrate) (PHB) film was carried out. At a degree of grafting higher than 5%, the grafted films (PHB-g-VAc) completely lost the enzymatic degradability that is characteristic of PHB due to the grafted VAc covering the surface of the PHB film. However, the biodegradability of the PHB-g-VAc films was recovered when the films were saponified in alkali solution under optimum conditions. Graft chains of the PHB-g-VAc film reacted selectively to become biodegradable polyvinyl alcohol (PVA). The biodegradability of the saponified PHB-g-VAc film increased rapidly with time

Surface treatment of poly(ethylene terephthalate) by gamma-ray induced graft copolymerization of methyl acrylate and its toughening effect on poly(ethylene terephthalate)/elastomer blend

International Nuclear Information System (INIS)

Ma, Liang; Wang, Mozhen; Ge, Xuewu

2013-01-01

To improve the compatibility between ethylene-methyl acrylate-glycidyl methacrylate random terpolymer (E-MA-GMA) elastomer and poly(ethylene terephthalate) (PET), thereby enhance the toughening effect of E-MA-GMA on PET, γ-radiation-induced graft copolymerization technique was used to graft methyl acrylate (MA) monomer onto PET. The produced PET-g-PMA copolymer can be used as a self-compatibilizer in PET/E-MA-GMA blend since the copolymer contains the same segments, respectively, with PET and E-MA-GMA. The impact strength of PET/E-MA-GMA blend increased nearly by 30% in the presence of less than 0.1 wt% PET-g-PMA compared with that of the neat PET/elastomer blend, without loss of the tensile strength of the blends. This work proposed a potential application of radiation-induced grafting copolymerization technique on the in-situ compatibilization of PET/elastomer blends so as to improve the integral mechanical properties of PET based engineering plastic. - Highlights: • PMA was grafted onto PET resins by γ-ray radiation-induced copolymerization. • The obtained PET-g-PMA can improve the compatibility between PET and E-MA-GMA. • A small amount of PET-g-PMA can enhance the impact strength of PET/E-MA-GMA blend

Radiation-grafted hydrogels for biomaterial applications as studied by the ESCA technique

International Nuclear Information System (INIS)

Ratner, B.D.; Weathersby, P.K.; Hoffman, A.S.; Kelly, M.A.; Schrapen, L.H.

1978-01-01

Electron spectroscopy for chemical analysis (ESCA) was used to study the surface composition of several radiation-grafted polymers in both the dry and hydrated (frozen at 160 0 K) states. Poly(2-hydroxyethyl methacrylate) (HEMA) and polyacrylamide, both hydrophilic polymers, were readily detected in the hydrated or dehydrated states when grafted to polethylene substrates. For silicone rubber substrates, both grafts were observed on the hydrated surface but were significantly decreased in surface concentration upon dehydration. For grafts on a polyester-urethane, acrylamide was not a major constituent of either the dry or hydrated surface, while HEMA appeared to increase in abundance upon drying. The amount of the hydrophobic poly(ethyl methacrylate) found on the graft surface depended upon the substrate polymer used, but the surface abundance of poly(ethyl methacrylate) was not affected by drying. These results were considered in terms of polar group orientation, polymer chain mobility, substrate permeability, and the limitations of the ESCA technique. The implications of these results with respect to the use of radiation-grafted hydrophilic polymers for biomedical applications are also discussed

Obtention of graft copolymers by ionizing radiation, characterization and study of hemo-compatible properties

International Nuclear Information System (INIS)

Queiroz, A.A.A. de.

1993-01-01

The present work had as objectives the obtention and characterization of grafting copolymers by radiation induced polymerization and the study of its hemo compatible properties. The relationship between grafting conditions and anti-trombogenicity was examined for the purpose of clearing the necessity of controlling grafting conditions to enhance the copolymers blood compatibility. Two methods were chosen to accomplish the irradiation: mutual and pre-irradiation (peroxidation) of the films in 6O Co source and electron beam accelerator. Primarily grafting parameters were studied in the systems of the monomers N, N-dimethyl acrylamide (DMAA) and acrylic acid (AA) with the polymeric films: poly (tetrafluoroethylene) (PTFE), poly (ethylene-co-tetrafluoroethylene) (PETFE), low density polyethylene (LDPE) and poly (vinyl chloride) (PVC). The simultaneous irradiation was effective in the polymerization of all the substrates above mentioned, although the peroxidation method has given better results for PETFE-DMAA, LDPE-g-DMAA, LDPE-g-AA and PVC-g-AA. In the system AA/LDPE and AA/PVC the homo polymerization was controlled by the addition of the comonomer N, N-dimethyl acrylic acid (DMA). As for the grafting parameters, low dose rate and low irradiation dose, showed to be very effective for the graftability of DMAA and AA on the substrates. (author). 129 refs, 51 figs, 7 tabs

Ion-containing reverse osmosis membranes obtained by radiation grafting method

International Nuclear Information System (INIS)

Hegazy, E.-S.A.; El-Assy, N.B.; Dessouki, A.M.; Shaker, M.M.

1989-01-01

Cationic membranes obtained by radiation grafting of aqueous acrylic acid onto low density polyethylene films followed by alkaline treatment to confer ionic character in the graft chains, were tested for reverse osmosis desalination of saline water. Selected physical properties of such membranes were investigated. The grafted membranes possess good mechanical and electrical properties. Water uptake for the alkali-treated membrane was much higher than that of the alkali-untreated one. The effect of operation time, degree of grafting, applied pressure and feed concentration on the water flux and salt rejection for the grafted membranes was investigated. Such cationic membranes showed good durability, thermal and chemical stability, acceptable water flux and salt rejection which may make them acceptable for practical use in reverse osmosis desalination of sea water. (author)

Radiation-grafting of flame retardants on flax fabrics - A comparison between different flame retardant structures

Science.gov (United States)

Teixeira, Marie; Sonnier, Rodolphe; Otazaghine, Belkacem; Ferry, Laurent; Aubert, Mélanie; Tirri, Teija; Wilén, Carl-Eric; Rouif, Sophie

2018-04-01

Three unsaturated compounds bearing respectively phosphate, aryl bromide and sulfenamide moieties were used as flame retardants (FR) for flax fabrics. Due to the presence of carbon-carbon double bonds, radiation-grafting was considered to covalently bond these FR onto fiber structure. Grafting efficiency and location of FR molecules were investigated by weight measurements and SEM-EDX observations. Flammability and especially self-extinguishment were assessed by thermogravimetric analysis, pyrolysis-combustion flow calorimetry and a non-standardized fire test already used in previous studies. All FRs were able to diffuse into elementary fiber bulk. Nevertheless only the phosphonated monomer (noted FR-P) was significantly grafted onto flax. Self-extinguishment was obtained for fabrics containing at least around 0.5 wt% of phosphorus. On the contrary the FR content of flax fibers after radiation-grafting procedure and washing was negligible for FR-S and FR-Br, evidencing that these molecules have not been grafted upon irradiation. Moreover, the combination of these molecules prevents the radiation-grafting of other molecules which showed good grafting rate when used alone.

Radiation-induced grafting from binary mixture of monomers onto cellulose acetate film and the characterization of the graft copolymer

International Nuclear Information System (INIS)

Bhattacharyya, S.N.; Maldas, D.

1984-01-01

Binary mixtures of styrene and acrylamide in methanol-water were grafted onto cellulose acetate films by taking recourse to preirradiation grafting technique. The extent of total grafting was determined from the measured weight increase. The percent acrylamide residue in the graft copolymer was calculated from the observed nitrogen content but the polystyrene residue in the grafted sample was determined by IR spectral studies. When the specific permeability of water vapour through the grafted films is measured, it is observed that the specific permeability increases with the increase of grafting of acrylamide in all humidities, but in case of styrene which is a nonpolar molecule the permeability is found to show a reversed order. In the case of mixed graft the permeability pattern pertains to that when both styrene and acrylamide have their effective roles to play. (author)

Radiation grafting of various water-soluble monomers on ultra-high molecular weight polyethylene powder. Part II: Thermal, FTIR and morphological characterisation

Science.gov (United States)

Aydınlı, Bahattin; Tin c̡er, Teoman

2001-10-01

Radiation induced grafted polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyacrylamide (PAAm), poly N,N-dimethyl acrylamide (PNDAAm) and poly 1-vinyl-2 pyrrolidone (PVP) on ultra-high molecular weight polyethylene (UHMWPE) were characterised by DSC, FTIR and SEM analysis. While the effect of irradiation on pure UHMWPE was found to increase crystallinity and cause higher enthalpy of crystallisation, grafted UHMWPE powders showed lower crystallinity and enthalpy of crystallisation. In all grafted UHMWPE there existed secondary transitions corresponding to grafting polymers in the first run of DSC above 60°C and they became clearer at a higher grafting level. In the second run of DSC some Tg values appeared to shift to higher temperatures while some were not detected. FTIR analysis indicated the presence of water-soluble polymers in the grafted UHMWPE. The characteristic peaks of water-soluble polymers became sharper in the grafted UHMWPE. SEM analysis revealed that the grafting occurs both on fiber and microparticles of UHMWPE while flowing characteristic of powder is retained.

In-situ radiation grafting of polymer films and degradation studies of monomers for applications in fuel cell membranes

Energy Technology Data Exchange (ETDEWEB)

Mitov, S.

2007-02-15

The present work consists of three parts which deal with the optimization of the properties of polymers finding application as proton exchange membranes in PEMFCs. The focus is the oxidative and photochemical stability of non-fluorinated polymer membranes, as well as the radiation-induced grafting of commercially available fluoropolymer films. The use of the ESR technique is common for the first two parts of the dissertation. ESR spectroscopy is the major method of study, because of its sensitivity and specificity for the detection of radical intermediates. It is a suitable spectroscopic technique to identify the nature of radiation generated radicals in organic polymers, and to monitor their concentration in-situ during the grafting process. The third part comprises the results and discussions of DFT calculations for non-fluorinated and fluorinated fragments.

Radiation grafting of methyl methacrylate onto polyethylene separators for lithium secondary batteries

Science.gov (United States)

Gwon, Sung-Jin; Choi, Jae-Hak; Sohn, Joon-Yong; An, Sung-Jun; Ihm, Young-Eon; Nho, Young-Chang

2008-08-01

Micro-porous polyethylene separator was modified by radiation grafting of methyl methacrylate in order to improve its affinity with a liquid electrolyte. The degree of grafting (DOG) increased with the monomer concentration and grafting time. The morphological change of the modified separator was investigated by scanning electron microscopy. The degree of crystallinity upon grafting was reduced due to the formation of an amorphous PMMA layer. The electrolyte uptake and the ionic conductivity of the separator increased with an increase in the DOG. The ionic conductivity reached 2.0 mS/cm for the grafted polyethylene separator with 127 wt% DOG.

Radiation grafting of methyl methacrylate onto polyethylene separators for lithium secondary batteries

Energy Technology Data Exchange (ETDEWEB)

Gwon, Sung-Jin [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of); Department of Materials Engineering, Chnugnam National University, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Choi, Jae-Hak; Sohn, Joon-Yong; An, Sung-Jun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of); Ihm, Young-Eon [Department of Materials Engineering, Chnugnam National University, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Nho, Young-Chang [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of)], E-mail: ycnho@kaeri.re.kr

2008-08-15

Micro-porous polyethylene separator was modified by radiation grafting of methyl methacrylate in order to improve its affinity with a liquid electrolyte. The degree of grafting (DOG) increased with the monomer concentration and grafting time. The morphological change of the modified separator was investigated by scanning electron microscopy. The degree of crystallinity upon grafting was reduced due to the formation of an amorphous PMMA layer. The electrolyte uptake and the ionic conductivity of the separator increased with an increase in the DOG. The ionic conductivity reached 2.0 mS/cm for the grafted polyethylene separator with 127 wt% DOG.

Immobilized enzymes in blood plasma exchangers via radiation grafting

Science.gov (United States)

Gombotz, Wayne; Hoffman, Allan; Schmer, Gottfried; Uenoyama, Satoshi

The enzyme asparaginase was immobilized onto a porous hollow polypropylene (PP) fiber blood plasma exchange device for the treatment of acute lymphocytic leukemia. The devices were first radiation grafted with polymethacrylic acid (poly(MAAc)). This introduces carboxyl groups onto the surface of the fibers. Several variables were studied in the grafting reaction including the effects of solvent type and monomer concentration. The carboxyl groups were activated with N-hydroxy succinimide (NHS) using carbodiimide chemistry. Asparaginase was then covalently immobilized on the activated surfaces. Quantitative relationships were found relating the percent graft to the amount of immobilized enzyme which was active. The enzyme reactor was tested both in vitro and in vivo using a sheep as an animal model.

Dose Rate Effect on Grafting by Gamma Radiation of DMAEMA onto Flexible PVC

International Nuclear Information System (INIS)

Panzarini, L.C.G.A.; Araujo, F.D.C.; Martinello, V.C.; Somesari, E.; Manzoli, J.E.; Silveira, C.; Paes, H.A.; Moura, E.

2009-01-01

Intravenous tubing, blood bags and catheters stays in contact with blood and body fluids. They are normally made by flexible PVC. The contact of PVC with this fluid is not possible for long periods and there is the necessity of addition of non-thrombogenic substances into blood. This work shows the radiation grafting process to produce copolymer PVC-g-DMAEMA, a new material that allows a future grafting of Heparin on it, and will have the perspective of avoiding undesirable substances additions to blood or body fluid contact. In this preliminary work, only radiation dose rate effect on grafting was studied

Radiation-grafting of acrylamide onto silicone rubber films for diclofenac delivery

Science.gov (United States)

Magaña, Hector; Palomino, Kenia; Cornejo-Bravo, Jose M.; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Bucio, Emilio

2015-02-01

This work focuses on the pre-irradiation grafting of acrylamide (AAm) onto silicone rubber films (SR) and evaluates the effect of gamma-ray radiation conditions on the grafting yield, which in turn may influence the performance of the grafted materials as components of drug-eluting devices. Pristine and modified SR were characterized using FTIR-ATR, DSC, TGA, swelling, and water contact angle analysis in order to elucidate the effects of AAm grafting onto SR. Grafted films with content in AAm ranging from 0.81% to 22.20% showed excellent cytocompatibility against fibroblasts, and capability to uptake the anti-inflammatory drug diclofenac. Amount of drug loaded directly correlated with the grafting degree of the films. Drug release studies were performed at pH 7.4 and 37 °C (physiological conditions). Most grafted films released the drug in a sustained way for at least three hours.

Study on poly-electrolyte membrane of crosslinked PTFE by radiation-grafting

International Nuclear Information System (INIS)

Sato, Kohei; Ikeda, Shigetoshi; Iida, Minoru; Oshima, Akihiro; Tabata, Yoneho; Washio, Masakazu

2003-01-01

Polymer electrolyte fuel cell membrane based on crosslinked polytetrafluoroethylene (PTFE) [RX-PTFE] has been processed by radiation-grafting with reactive styrene monomers by γ-rays under atmospheric circumstances, and the characteristic properties of the obtained membranes have been studied. The grafting yields of styrene monomer onto RX-PTFE, which have various crosslinking densities, were in the range of 5-100%. At the reaction period of 24 h, the grafting yields for RX-PTFE with low crosslinking density, which was reacted at 60 deg. C, achieved 94%. As a tendency, the lower grafting temperature gives higher grafting ratio of styrene onto RX-PTFE. Moreover, the yields of subsequent sulfonation for all samples were close to 100%. Mechanical properties were decreased with increasing grafting yields; especially the membrane with higher grafting yields was brittle. Ion exchange capacity of sulfonated RX-PTFE reached 1.1 meq/g while maintaining the mechanical properties

Pre-irradiation induced emulsion graft polymerization of acrylonitrile onto polyethylene nonwoven fabric

International Nuclear Information System (INIS)

Liu Hanzhou; Yu Ming; Deng Bo; Li Linfan; Jiang Haiqing; Li Jingye

2012-01-01

Acrylonitrile has been widely used in the modification of polymers by graft polymerization. In the present work, pre-irradiation induced emulsion graft polymerization method is used to introduce acrylonitrile onto PE nonwoven fabric instead of the traditional reaction in organic solvents system. The degree of grafting (DG) is measured by gravimetric method and the kinetics of the graft polymerization is studied. The existence of the graft chains is proven by Fourier transform infrared spectroscopy (FT-IR) analysis. Thermal stability of the grafted polymer is measured by Thermogravimetric analysis (TGA). - Highlights: → Acrylonitrile is grafted onto pre-irradiated polyethylene (PE) nonwoven fabrics. → Emulsion system is applied, for the graft polymerization avoids organic solvent. → Kinetic of the pre-irradiation induced graft polymerization is studied. → Optimal condition is determined at the temperature below the b.p. of acrylonitrile.

The γ-radiation induced grafting of unsaturated segmented polyurethanes with N-vinyl pyrrolidone

International Nuclear Information System (INIS)

Egboh, S.H.; George, M.H.; Barrie, J.A.

1984-01-01

Linear unsaturated segmented polyurethanes have been modified by hydrophilic grafting at 40 deg C with N-vinyl pyrrolidone, in N,N-dimethylformamide as solvent, using 60 Cobalt γ-irradiation. Graft copolymers were isolated from homopolymers by selective solvent extraction using a Soxhlet apparatus. The effects of reaction time, total dose, temperature and monomer concentration, on the graft yields have been examined. Relatively high irradiation doses were avoided during the grafting experiments to prevent possible degradation of the segmented polyurethanes and gelation of the homopolymer, poly(N-vinyl pyrrolidone). The ungrafted and grafted copolymers were characterized, and the graft copolymers were shown to be more thermally stable than the original polyurethanes, by thermogravimetric analysis. An explanation for the observed variation of the graft yields with some of the experimental variables is suggested. (author)

Post radiation grafting of vinyl acetate onto low density polyethylene films: preparation and properties of membrane

International Nuclear Information System (INIS)

Dessouki, A.M.

1987-01-01

Reverse osmosis membranes were prepared by the post radiation grafting of vinyl acetate onto low density polyethylene films. The factors affecting the grafting process such as radiation dose, monomer concentration and temperature on the grafting yield were studied. It was found that the dependence of the grafting rate on radiation intensity and monomer concentration was found to be of 0.64 and 1.4 order, respectively. The activation energy for this grafting system was calculated and found to be 4.45 kcal/mol above 30 0 C. Some properties of the grafted films such as specific electric resistance, water uptake, mechanical properties and thermal and chemical stability were investigated. An improvement in these properties was observed which makes possible the use of these membranes in some practical applications. The use of such membranes for reverse osmosis desalination of saline water was tested. The effect of operating time, degree of grafting and applied pressure on the water flux and salt rejection were determined. The results showed salt rejection percent over 90% and a reasonable water flux. A suitable degree of grafting of the membrane was determined as well as the optimum applied pressure. (author)

Preparation of membranes by radiation grafting of acrylic acid onto Teflon-FEP film

International Nuclear Information System (INIS)

Gupta, B.D.

1991-01-01

The grafting of acrylic acid on radiation-peroxidised Teflon-FEP film provides an effective technique to prepare ion-exchange membranes. It was found that the grafted membranes have very high degree of swelling in aqueous KOH. The electric resistance of the film decreases considerably by grafting. An electric resistance of 0.2Ω cm 2 was obtained for a graft level beyond 58%. The hydrophilicity of the film was evaluated in terms of contact angle which shows a decreasing trend with the increasing degree of grafting. (author). 8 refs

Super water absorbent by radiation graft polymerization of acrylic monomers onto cassava starch

International Nuclear Information System (INIS)

Doan Binh

2008-01-01

Water superabsorbent gel has been applying in personal care, agriculture, medical supplies and water purification. In agricultural application, the gel will help to control soil erosion, limit loss of nutrients and slit for plants, decrease irrigation frequency, improve infiltration, and increase water retention in prolonged arid soil and droughts. The gel absorbs many times its weight in available water. The gel from poly(acrylamide) was developed in the 60's to grow plants in the deserts. The other gel from poly(acrylic acid) was used to absorb rapidly in baby diapers, sanitary napkins. These polymers are commonly produced from natural gas, which have recently been introduced as a soil conditioner with great success. Prior to these polymers, peat moss, agro-waste (sugar-cane waste, coffee-shell, etc.), activated kaolin were the alternative soil additives to hold water (20 times its weight), but poly(acrylamide) absorbs 400 times its weight and polyacrylate is capable of absorbing greater amounts of liquid than poly(acrylamide). In addition, starch and cellulose are biodegradable naturally occurring polymers, which are not capable of holding a great amount of water, but their modification by graft polymerization or crosslinking through radiation or chemical initiation techniques, they become the potential superabsorbent polymers. Radiation initiation of chemical reactions has been widely known for making novel materials because the degree of polymerization, grafting and crosslinking process can easily be controlled. Recently, it was shown that the starch and cellulose derivatives such as carboxymethyl starch, carboxymethyl starch can be synthesized by radiation-induced crosslinking at high concentrations. Their utilization in agriculture seems to be appropriately evaluated. In this article, the graft polymerization and crosslinking of acrylic acid onto cassava starch and field trial of its product (GAM-Sorb S) are reported. (author)

Grafting and curing

International Nuclear Information System (INIS)

Garnett, J.L.; Loo-Teck Ng; Visay Viengkhou

1998-01-01

Progress in radiation grafting and curing is briefly reviewed. The two processes are shown to be mechanistically related. The parameters influencing yields are examined particularly for grafting. For ionising radiation grafting systems (EB and gamma ray) these include solvents, substrate and monomer structure, dose and dose-rate, temperature and more recently role of additives. In addition, for UV grafting, the significance of photoinitiators is discussed. Current applications of radiation grafting and curing are outlined. The recent development of photoinitiator free grafting and curing is examined as well as the potential for the new excimer laser sources. The future application of both grafting and curing is considered, especially the significance of the occurrence of concurrent grafting during cure and its relevance in environmental considerations

Adsorption of crude oil from aqueous solution by hydrogel of chitosan based polyacrylamide prepared by radiation induced graft polymerization

Energy Technology Data Exchange (ETDEWEB)

Sokker, H.H., E-mail: hesham_sokkre@yahoo.com [Jazan University, Faculty of Science (Saudi Arabia); National Center for Radiation Research and Technology, Polymer Chemistry Department, P.O. Box 29, Cairo (Egypt); El-Sawy, Naeem M. [National Center for Radiation Research and Technology, Polymer Chemistry Department, P.O. Box 29, Cairo (Egypt); Hassan, M.A. [Scib Company of Paints, Cairo (Egypt); El-Anadouli, Bahgat E. [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt)

2011-06-15

The adsorption of crude oil (initial concentration 0.5-30 g/L) from aqueous solution using hydrogel of chitosan based polyacrylamide (PAM) prepared by radiation induced graft polymerization has been investigated. The prepared hydrogel was characterized by FTIR and SEM micrographs. The experiments were carried out as a function of different initial concentrations of oil residue, acrylamide concentration, contact time and pH to determine the optimum condition for the adsorption of residue oil from aqueous solution and sea water. The results obtained showed that the hydrogel prepared at concentration of 40% acrylamide (AAm) and at a radiation dose of 5 kGy has high removal efficiency of crude oil 2.3 g/g at pH 3. Equilibrium studies have been carried out to determine the capacity of the hydrogel for adsorption of crude oil, Langmuir and Freundlich adsorption models were applied to describe the experimental isotherms and isotherms constants. Equilibrium data were found to fit very well with both Freundlich and Langmuir models. Also the adsorption of oil onto the hydrogel behaves as a pseudo-second-order kinetic models rather than the pseudo-first-order kinetic model.

Development of Less Water-Dependent Radiation Grafted Proton Exchange Membranes for Fuel Cells

Energy Technology Data Exchange (ETDEWEB)

Nasef, M M; Ahmad, A; Saidi, H; Dahlan, K Z.M. [Institute of Hydrogen Economy, Energy Research Alliance (ERA), International Campus, Univeristi Teknologi Malaysia, Jalan Semarak, Kuala Lumpur (Malaysia); Radiation Processing Division, Malaysian Nuclear Agency, Bangi, Kajang (Malaysia)

2012-09-15

The aim of these studies was the development of proton exchange membranes for polymer electrolyte membrane (PEM) fuel cell operated above 100{sup o}C, in order to obtain less water dependent, high quality and cheap electrolyte membrane. Sulfonic acid membranes were prepared by radiation induced grafting (RIG) of sodium styrene sulfonate (SSS) onto electron beam (EB) irradiated poly(vinylidene fluoride) (PVDF) films in a single step reaction for the first time using synergetic effect of acid addition to grafting mixture under various grafting conditions. The fuel cell related properties of the membranes were evaluated and the in situ performance was tested in a single H{sub 2}/O{sub 2} fuel cell under dynamic conditions and compared with a similar sulfonated polystyrene PVDF membrane obtained by two-step conventional RIG method i.e. grafting of styrene and subsequent sulfonation. The newly obtained membrane (degree of grafting, G% = 53) showed an improved performance and higher stability together with a cost reduction mainly as a result of elimination of sulfonation reaction. Acid-base composite membranes were also studied. EB pre-irradiated poly(ethylene-co-tetrafluoroethylene) (ETFE) films were grafted with N-vinyl pyridine (NVP). The effects of monomer concentration, dose, reaction time, film thickness, temperature and film storage time on G% were investigated. The membranes were subsequently doped with phosphoric acid under controlled condition. The proton conductivity of these membranes was investigated under low water conditions in correlation with the variation in G% and temperature (30-130{sup o}C). The performance of 34 and 49% grafted and doped membranes was tested in a single fuel cell at 130{sup o}C under dynamic conditions with 146 and 127 mW/cm{sup 2} power densities. The polarization, power density characteristics and the initial stability of the membrane showed a promising electrolyte candidate for fuel cell operation above 100 deg. C. (author)

A comparative study on the graft copolymerization of acrylic acid onto rayon fibre by a ceric ion redox system and a γ-radiation method.

Science.gov (United States)

Kaur, Inderjeet; Kumar, Raj; Sharma, Neelam

2010-10-13

Functionalization of rayon fibre has been carried out by grafting acrylic acid (AAC) both by a chemical method using a Ce(4+)-HNO(3) redox initiator and by a mutual irradiation (γ-rays) method. The reaction conditions affecting the grafting percentage have been optimized for both methods, and the results are compared. The maximum percentage of grafting (50%) by the chemical method was obtained utilizing 18.24 × 10(-3) moles/L of ceric ammonium nitrate (CAN), 39.68 × 10(-2) moles/L of HNO(3), and 104.08 × 10(-2) moles/L of AAc in 20 mL of water at 45°C for 120 min. For the radiation method, the maximum grafting percentage (60%) was higher, and the product was obtained under milder reaction conditions using a lower concentration of AAc (69.38 × 10(-2) moles/L) in 10 mL of water at an optimum total dose of 0.932 kGy. Swelling studies showed higher swelling for the grafted rayon fibre in water (854.54%) as compared to the pristine fibre (407%), while dye uptake studies revealed poor uptake of the dye (crystal violet) by the grafted fibre in comparison with the pristine fibre. The graft copolymers were characterized by IR, TGA, and scanning electron micrographic methods. Grafted fibre, prepared by the radiation-induced method, showed better thermal behaviour. Comparison of the two methods revealed that the radiation method of grafting of acrylic acid onto rayon fibre is a better method of grafting in comparison with the chemical method. Copyright © 2010 Elsevier Ltd. All rights reserved.

Radiation chemical grafting of vinyl acetate and styrene on nitrocellulose

International Nuclear Information System (INIS)

Chapiro, A.; Foex, M.; Jendrychowska-Bonamour, A.M.

1977-01-01

Vinyl acetate and styrene were grafted onto nitrocellulose using the direct radiation grafting technique with 500 and 3000 Ci 60 Co γ sources. For vinyl acetate, the reaction proceeds homogeneously. The kinetics are dominated by degradative chain transfer to the nitrocellulose. The polymerization of vinyl acetate was examined in the presence of isoamyl nitrate, a model for nitrocellulose; the transfer constant was determined and the results are treated semi-quantitatively. For styrene, grafting occurs in a swollen film irradiated in the presence of excess monomer. The diffusion of styrene into nitrocellulose is extremely slow; methanol was added to the reaction mixture to favour diffusion which was found to obey Fick's law. The diffusion constant and activation energy of diffusion are evaluated. The grafting kinetics are controlled by monomer diffusion, accounting for the increase of dose-rate exponent with temperature. A spontaneous grafting process occurs in the absence of irradiation. It is initiated by macroradicals arising from thermal decomposition of nitrocellulose. (author)

Radiation grafting of various water-soluble monomers on ultra-high molecular weight polyethylene powder. Part II: Thermal, FTIR and morphological characterisation

Energy Technology Data Exchange (ETDEWEB)

Aydinli, Bahattin; Tincer, Teoman E-mail: teotin@metu.edu.tr

2001-10-01

Radiation induced grafted polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyacrylamide (PAAm), poly N,N-dimethyl acrylamide (PNDAAm) and poly 1-vinyl-2 pyrrolidone (PVP) on ultra-high molecular weight polyethylene (UHMWPE) were characterised by DSC, FTIR and SEM analysis. While the effect of irradiation on pure UHMWPE was found to increase crystallinity and cause higher enthalpy of crystallisation, grafted UHMWPE powders showed lower crystallinity and enthalpy of crystallisation. In all grafted UHMWPE there existed secondary transitions corresponding to grafting polymers in the first run of DSC above 60 deg. C and they became clearer at a higher grafting level. In the second run of DSC some T{sub g} values appeared to shift to higher temperatures while some were not detected. FTIR analysis indicated the presence of water-soluble polymers in the grafted UHMWPE. The characteristic peaks of water-soluble polymers became sharper in the grafted UHMWPE. SEM analysis revealed that the grafting occurs both on fiber and microparticles of UHMWPE while flowing characteristic of powder is retained.

Radiation grafting from binary monomer mixtures. II. Vinyl ether of monoethanolamine and N-vinylpyrrolidone

International Nuclear Information System (INIS)

Nurkeeva, Zauresh S.; Abdel Aal, A.-S.; Kupchishin, Anatoliy I.; Khutoryanskiy, Vitaliy V.; Mun, Grigoriy A.; Beksyrgaeva, Aida G.

2003-01-01

Radiation grafting from binary monomer mixtures of vinyl ether of monoethanolamine and N-vinylpyrrolidone onto polyethylene films has been studied. The structure of the grafted films was characterized by FTIR spectroscopy. Water uptake and contact angle measurements confirmed that the grafting leads to a considerable hydrophilization of the films surface. The presence of the more active N-vinylpyrrolidone enhances the grafting of the less active vinyl ether of monoethanolamine. Sorption properties of grafted films with respect to copper (II) ions have been studied

Enhancement of the grafting performance and of the water absorption of cassava starch graft copolymer by gamma radiation

International Nuclear Information System (INIS)

Kiatkamjornwong, Suda; Meechai, Nispa

1997-01-01

Enhancement of the gamma radiation grafting of acrylonitrile onto gelatinized cassava starch was investigated. Infrared spectrometry was used to follow the chemical changes in the grafting reaction and from saponification. The saponified starch-g-PAN (HSPAN) was then characterized in terms of grafting parameters to provide a guide for the optimum total dose (kGy) and the appropriate ratio of starch/acrylonitrile for a fixed dose rate of 2.5 x 10 -1 kGy/min. Other dose rates were also carried out to obtain the appropriate result of grafting copolymerization and of water absorption. A thin aluminium foil, covering the inner wall of the reaction vessel, was found to be far more effective than any other metal films in the enhancement of the grafting reaction and the water absorption as well. Nitric acid in the medium increases the grafting yield and the water absorption. Methyl ether hydroquinone inhibitor was evaluated for its ability to increase homopolymerization and decrease graft reaction. When styrene was used as a comonomer, it hampered the grafting of acrylonitrile onto starch backbone. The water absorption capacity was improved by freeze-drying the HSPAN. The treatment of the HSPAN with aluminium trichloride hexahydrate was found to enhance the degree of wicking, but to decrease the water absorbency. (author)

Radiation-induced crosslinking of polyethylene in the presence of bifunctional vinyl monomers

Energy Technology Data Exchange (ETDEWEB)

Joshi, M.S.

1976-10-06

The apparent crosslinking produced by the radiation grafting of two monomers to polyethylene, acrylic acid and acrylonitrile, was investigated. Evidence is presented to show that covalent crosslinks are not produced during the radiation grafting step; covalent crosslinks are produced by the post-irradiation heat treatment associated with measurements of gel; the enhancement in gel fraction and physical properties arises from true crosslinks rather than chain entanglements; and there may be practical value associated with the sensitization of crosslinking produced by the methods employed in this work. The effect of monomer-solvent composition on the graft and gel yield was studied. Viscoelastic properties of grafted films were determined above the melting point of pure polyethylene. The kinetic data, infrared spectra, and viscoelastic properties are the bases for the following mechanism: (1) Acrylic acid-g-PE: Acrylic acid enters the film in the form of a hydrogen bonded dimer and undergoes a grafting reaction that produces hydrogen-bond crosslinks. The heat treatment during the conventional methods for determining of crosslinks convert them into intermolecular anhydride bonds. (2) Acrylonitrile-g-PE: In this, the post-grafting crosslinking is the result of a thermally induced chain reaction leading to an uninterrupted conjugated sequence. The length of the ring structure increases with time and temperature, and the intensity of color increases with the length of the ring structure.

Radiation-induced crosslinking of polyethylene in the presence of bifunctional vinyl monomers

International Nuclear Information System (INIS)

Joshi, M.S.

1976-01-01

The apparent crosslinking produced by the radiation grafting of two monomers to polyethylene, acrylic acid and acrylonitrile, was investigated. Evidence is presented to show that covalent crosslinks are not produced during the radiation grafting step; covalent crosslinks are produced by the post-irradiation heat treatment associated with measurements of gel; the enhancement in gel fraction and physical properties arises from true crosslinks rather than chain entanglements; and there may be practical value associated with the sensitization of crosslinking produced by the methods employed in this work. The effect of monomer-solvent composition on the graft and gel yield was studied. Viscoelastic properties of grafted films were determined above the melting point of pure polyethylene. The kinetic data, infrared spectra, and viscoelastic properties are the bases for the following mechanism: (1) Acrylic acid-g-PE: Acrylic acid enters the film in the form of a hydrogen bonded dimer and undergoes a grafting reaction that produces hydrogen-bond crosslinks. The heat treatment during the conventional methods for determining of crosslinks convert them into intermolecular anhydride bonds. (2) Acrylonitrile-g-PE: In this, the post-grafting crosslinking is the result of a thermally induced chain reaction leading to an uninterrupted conjugated sequence. The length of the ring structure increases with time and temperature, and the intensity of color increases with the length of the ring structure

Preparation of high water-swelling agricultural starch hydrogels by 60Co γ-radiation grafting

International Nuclear Information System (INIS)

Wang Qingjun; Quan Yiwu; Chen Qingmin

2003-01-01

The starch grafted acrylic acid was used to synthesize water-swelling hydrogels by 60 Co γ-radiation grafting technique. With radiation dose of about 7 kGy, the crosslinking reagent amount of 0.001%-0.1%, the pH value 5-8 and the starch amount of 10%-30%, we can produce 600 times water-swelling hydrogels which are of high performance, low cost and suitable for agriculture

Dendrimer functionalized radiation grafted hydrogels for tissue engineering applications

International Nuclear Information System (INIS)

Higa, Olga Z.; Sakuno, Lilian M.; Queiroz, Alvaro A.A. de

2009-01-01

Low density polyethylene (LDPE) films were modified by γ-ray radiation grafting of 2- hydroxyethylmethacrylate (HEMA). The covalent immobilization of polyglycerol dendrimer (PGLD) on LDPEG- HEMA surface was performed by using dicyclohexyl carbodiimide (DCC)/N,N-dimethylaminopyridine (DMAP) method. The occurrence of grafting polymerization of HEMA and further immobilization of PGLD was quantitatively confirmed by photoelectron spectroscopy (XPS) and fluorescence, respectively. The LDPEG- HEMA surface topography after PGLD coupling was studied by atomic force microscopy (AFM). The hydrophilicity of the LDPE-G-HEMA film was remarkably improved compared to that of the ungrafted LDPE. The core level XPS ESCA spectrum of HEMA-grafted LDPE showed two strong peaks at ∼286.6 eV (from hydroxyl groups and ester groups) and ∼289.1 eV (from ester groups) due to HEMA brushes grafted onto LDPE surfaces. The results from the cell adhesion studies shows that MCT3-E1 cells tended to spread more slowly on LDPE-G-HEMA than on LDPE-G-HEMA-i-PGLD. (author)

Radiation graft copolymerization of n-butyl acrylate on natural rubber latex

International Nuclear Information System (INIS)

Sundardi, F.; Kadariah, S.

1986-01-01

A method of radiation graft copolymerization of n-butyl acrylate (NBA) on natural rubber (NR) latex has been studied. The rate of conversion increases with the increase of NBA in latex. An irradiation dose of about 12 kGy is needed to obtain 90% conversion with 40 phr of NBA in latex. Tensile strength, tear strength, and elongation at break of grafted NR are found to decrease with increasing degree of grafting. The physical strength of a vulcanizate prepared from a mixture of NR and ply-NBA was found to be better than that of NBA-NR graft copolymer vulcanizate. The graft copolymerization reaction takes place in the outer layer of NR particles, and because the secondary bonds between poly-NBA molecules may be weaker than those between NR molecules, the existence of a poly-NBA layer in NR particles will decrease its physical strength

Modification on liquid retention property of cassava starch by radiation grafting with acrylonitrile: Pt. 1

International Nuclear Information System (INIS)

Kiatkamjornwong, S.; Nakason, C.; Chvajarempun, J.

1993-01-01

Radiation modification on liquid retention properties of native cassava starch, gelatinized at 85 o C, by graft copolymerization with acrylonitrile was carried out by mutual irradiation to gamma-rays. A thin aluminium foil was used to cover the inner wall of the reaction vessel, so that the homopolymer concentration was reduced to be less than 1.0% with a distilled water retention value of 665 g/g of the dry weight of the saponified grafted product. Confirmation of graft copolymerization and saponification reactions was made by the infrared spectrophotometric technique. The combined effect of radiation parameters in terms of an irradiation time and a dose rate to the total dose on the extent of the grafting reaction expressed in terms of grafting parameters which directly influenced liquid retention values was evaluated in conjunction with statistical analysis. (author)

Subacute radiation dermatitis: a histologic imitator of acute cutaneous graft-versus-host disease

International Nuclear Information System (INIS)

LeBoit, P.E.

1989-01-01

The histopathologic changes of radiation dermatitis have been classified either as early effects (necrotic keratinocytes, fibrin thrombi, and hemorrhage) or as late effects (vacuolar changes at the dermal-epidermal junction, atypical radiation fibroblasts, and fibrosis). Two patients, one exposed to radiation therapeutically and one accidentally, are described. Skin biopsy specimens showed an interface dermatitis characterized by numerous dyskeratotic epidermal cells with lymphocytes in close apposition (satellite cell necrosis); that is, the epidermal changes were similar to those in acute graft-versus-host disease. Because recipients of bone marrow transplants frequently receive total body irradiation as part of their preparatory regimen, the ability of radiation to cause persistent epidermal changes similar to those in acute graft-versus-host disease could complicate the interpretation of posttransplant skin biopsy specimens

Surface modification of silica nanoparticles by UV-induced graft polymerization of methyl methacrylate.

Science.gov (United States)

Kim, Sooyeon; Kim, Eunhye; Kim, Sungsoo; Kim, Woosik

2005-12-01

In this study we modified the surface of silica nanoparticles with methyl methacrylate by UV-induced graft polymerization. It is a surface-initiated polymerization reaction induced by ultraviolet irradiation. The resulting organic-inorganic nanocomposites were near-monodisperse and fabricated without homopolymerization of the monomer. Substantial increase in mean particle size was observed by SEM image analysis after UV-induced grafting of methyl methacrylate onto pure silica particles. FT-Raman spectroscopy and X-ray photoelectron spectroscopy studies of these materials revealed the successful grafting of methyl methacrylate onto the silica surface. The formation of a covalent bond between the grafted PMMA chains and silica surface was indicated by FT-Raman spectra. Thermogravimetric analysis of the PMMA-grafted silica particles indicated the polymer contents in good agreement with SEM photographs.

Localized surface grafting reactions on carbon nanofibers induced by gamma and e-beam irradiation

Energy Technology Data Exchange (ETDEWEB)

Evora, M.C., E-mail: cecilia@ieav.cta.br [Institute for Advanced Studies-IEAV/DCTA, Av. Cel Jose Alberto Albano do Amarante, 1-Putim, 12228-001 São Jose dos Campos, SP (Brazil); Araujo, J.R., E-mail: jraraujo@inmetro.gov.br [Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias, RJ (Brazil); Ferreira, E.H.M. [Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias, RJ (Brazil); Strohmeier, B.R. [Thermo Fisher Scientific, 5225 Verona Road, Madison, WI 53711 (United States); Silva, L.G.A., E-mail: lgasilva@ipen.br [Institute for Nuclear and Energy Research- IPEN, Av. Prof lineu Prestes, 2242- Cidade Universitaria, 05508-000 SP (Brazil); Achete, C.A. [Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias, RJ (Brazil)

2015-04-30

Graphical abstract: - Highlights: • Methodology for the functionalization of carbon nanofibers was investigated. • Two radiation sources were used to promote grafting reactions: gamma and electron beam. • We report the optimum inhibitor concentration to achieve the functionalization. • Surface of carbon nanofibers showed an increase of oxygen content after irradiation. • The radiation-induced graphitization did not damage the overall sp{sup 2} structure. - Abstract: Electron beam and gamma-ray irradiation have potential application to modify the carbon fiber nanostructures in order to produce useful defects in the graphitic structure and create reactive sites. In this study, the methodology to functionalize carbon nanofiber (CNF), via a radiation process and using acrylic acid as a source of oxygen functional groups, was investigated. The samples were submitted to a direct grafting radiation process with electron beam and gamma-ray source. Several parameters were changed such as: acrylic acid concentration, radiation dose and percentage of inhibitor necessary to achieve functionalization, with higher percentage of oxygen functional groups on CNF surface, and better dispersion. The better results achieved were when mixing CNF in a solution of acrylic acid with 6% of inhibitor (FeSO{sub 4}·7H{sub 2}O) and irradiated at 100 kGy. The samples were characterized by X-ray photoelectron spectroscopy and the surface composition (atomic%) showed a significant increase of oxygen content for the samples after irradiation. Also, the dispersion of the functionalized CNF in water was stable during months which may be a good indication that the functionalization process of CNF via ionizing radiation was successful.

Localized surface grafting reactions on carbon nanofibers induced by gamma and e-beam irradiation

International Nuclear Information System (INIS)

Evora, M.C.; Araujo, J.R.; Ferreira, E.H.M.; Strohmeier, B.R.; Silva, L.G.A.; Achete, C.A.

2015-01-01

Graphical abstract: - Highlights: • Methodology for the functionalization of carbon nanofibers was investigated. • Two radiation sources were used to promote grafting reactions: gamma and electron beam. • We report the optimum inhibitor concentration to achieve the functionalization. • Surface of carbon nanofibers showed an increase of oxygen content after irradiation. • The radiation-induced graphitization did not damage the overall sp 2 structure. - Abstract: Electron beam and gamma-ray irradiation have potential application to modify the carbon fiber nanostructures in order to produce useful defects in the graphitic structure and create reactive sites. In this study, the methodology to functionalize carbon nanofiber (CNF), via a radiation process and using acrylic acid as a source of oxygen functional groups, was investigated. The samples were submitted to a direct grafting radiation process with electron beam and gamma-ray source. Several parameters were changed such as: acrylic acid concentration, radiation dose and percentage of inhibitor necessary to achieve functionalization, with higher percentage of oxygen functional groups on CNF surface, and better dispersion. The better results achieved were when mixing CNF in a solution of acrylic acid with 6% of inhibitor (FeSO 4 ·7H 2 O) and irradiated at 100 kGy. The samples were characterized by X-ray photoelectron spectroscopy and the surface composition (atomic%) showed a significant increase of oxygen content for the samples after irradiation. Also, the dispersion of the functionalized CNF in water was stable during months which may be a good indication that the functionalization process of CNF via ionizing radiation was successful

Basic and engineering studies of radiation induced reactions in the liquid phase. Final technical report, June 1, 1970-May 31, 1974

International Nuclear Information System (INIS)

1978-06-01

Laboratory studies reported on are ionic polymerization under superdry conditions, emulsion polymerization, and vinyl chloride polymerization. Engineering studies include the effect of moisture level on radiation-induced solution polymerization, effect of dose rate on radiation-induced emulsion polymerization of styrene, the effect of soap exchange in styrene emulsion polymerization, pilot plant studies of radiation induced emulsion polymerization of vinyl chloride, pilot plant studies of radiation-induced emulsion copolymerization of vinyl chloride with vinyl acetate, pilot plant study of radiation-induced graft emulsion polymerization of styrene onto polyvinyl chloride and poly(vinyl chloride-vinyl acetate), and radiation-induced precipitation polymerization of vinyl chloride in a flow reactor

Radiation-grafting of acrylamide onto silicone rubber films for diclofenac delivery

International Nuclear Information System (INIS)

Magaña, Hector; Palomino, Kenia; Cornejo-Bravo, Jose M.; Alvarez- Lorenzo, Carmen; Concheiro, Angel; Bucio, Emilio

2015-01-01

This work focuses on the pre-irradiation grafting of acrylamide (AAm) onto silicone rubber films (SR) and evaluates the effect of gamma-ray radiation conditions on the grafting yield, which in turn may influence the performance of the grafted materials as components of drug-eluting devices. Pristine and modified SR were characterized using FTIR-ATR, DSC, TGA, swelling, and water contact angle analysis in order to elucidate the effects of AAm grafting onto SR. Grafted films with content in AAm ranging from 0.81% to 22.20% showed excellent cytocompatibility against fibroblasts, and capability to uptake the anti-inflammatory drug diclofenac. Amount of drug loaded directly correlated with the grafting degree of the films. Drug release studies were performed at pH 7.4 and 37 °C (physiological conditions). Most grafted films released the drug in a sustained way for at least three hours. - Highlights: • SR–g-AAm depends on dose, monomer concentration, and reaction time and temperature. • Diclofenac sodium salt is loaded and released in a sustained way from SR–g-AAm films. • SR–g-AAm films are cytocompatible and have potential as components of drug–device

Some investigations on the post radiation grafting of acrylamide onto polyethylene films

International Nuclear Information System (INIS)

Hegazy, E-S.A.; El-Dessouky, M.M.; El-Sharabasy, S.A.

1986-01-01

A study has been made on the post radiation grafting of aqueous acrylamide onto low density polyethylene film. It was found that the addition of 0.05 wt % Mohr's salt reduced effectively the homopolymerization of acrylamide and the grafting process was successfully achieved. The dependence of the grafting rate on the preirradiation dose and monomer concentration was found to be of 1.43 and 1.4 order, respectively. The overall activation energy for the graft polymerization was found to be 13.5 and 1.95 Kcal/mol below and above 45 0 C, respectively. Some properties of the graft co-polymer such as swelling behaviour, electrical conductivity, and reverse osmosis desalination of saline water (water flux and salt rejection), were also investigated and the possibility of its uses in the practical applications was discussed. (author)

Mechanical properties of human bone-tendon-bone grafts preserved by different methods and radiation sterilised

International Nuclear Information System (INIS)

Kaminski, A.; Gut, G.

2008-01-01

Full text: Patellar tendon auto and allografts are commonly used in orthopaedic surgery for reconstruction of the anterior crucial ligaments (ACL). Autografts are mainly used for primary reconstruction, while allografts are useful for revision surgery. To avoid the risk of infection diseases transmission allografts should be radiation-sterilised. As radiation-sterilisation is supposed to decrease the mechanical strength of tendon tissue, it is important to establish methods of allografts preservation and sterilisation resulting in their best quality and safety. Therefore, the purpose of the study was to compare the tensile strength of the central one third of human patellar tendon (as used for ACL reconstruction), preserved by different methods (deep fresh freezing, lyophilisation) and subsequently radiation-sterilised with doses of 0 (control), 25, 50 or 100 kGy. Bone-tendon-bone grafts were prepared from cadaveric human patella tendon with both patellar and tibial attachments. BTB grafts were preserved by deep freezing, glicerolisation or lyophilisation and radiation-sterilised with doses of 0 (control), 25, 50 or 100 kGy. To estimate mechanical properties all samples were subjected to tensile tests to failure using Instron system. Before these tests all lyophilised grafts were rehydrated. We found decrease of tensile strength of irradiated grafts compared to non-irradiated controls. Obtained results of the mechanical testing of studied grafts indicate their potential usefulness for clinical applications.(Author)

Immobilization of enzymes and antibodies to radiation grafted polymers for therapeutic and diagnostic applications

Energy Technology Data Exchange (ETDEWEB)

Hoffman, A.S.; Gombotz, W.R.; Uenoyama, S.; Dong, L.C.; Schmer, G.

1986-01-01

Pre-irradiation and mutual radiation grafting were employed to produce poly(methacrylic acid) (MAAc) hydrogels on polypropylene/polyethylene (PP/PE) copolymer films, and porous PP fibers of a plasma filter. A diphenyl picryl hydrazyl (DPPH) assay was developed to measure the surface peroxide concentration of the pre-irradiated PP/PE films prior to grafting. Mutually grafted porous PP fibers were used for subsequent immobilization of L-asparaginase while the mutually grafted PP/PE films were used to immobilize a schistosoma monoclonal antibody.

Radiation induced graft copolymerization of acrylonitrile on natural rubber

International Nuclear Information System (INIS)

Claramma, N.M.; Mathew, N.M.; Thomas, E.V.

1989-01-01

Acrylonitrile graft natural rubber was prepared by initiating the polymerization of acrylonitrile in natural rubber field latex using γ-rays. The reaction was carried out at different rubber-monomer concentrations and the properties of the modified rubbers were compared with those of natural rubber and nitrile rubber. (author)

Study of Radiation Induced Radicals in HAP and β-TCP Based Bone Graft Materials by ERP Spectroscopy

International Nuclear Information System (INIS)

Maltar-Strmecki, N.; Matkovic, I.

2013-01-01

Calcium phosphates such as beta-tricalcium phosphate (β-TCP) and hydroxyapatite (HAP) are frequently used as dental implants due to proven excellent biocompatibility. Because of their resorption in the body and direct contact with tissues, in order to inactivate bacteria, fungal spores and viruses, they are usually sterilized by γ-irradiation. However, literature provides little information about effects of γ-irradiation on the formation and stability of the free radicals in the bone graft materials during and after sterilization procedure. In this study EPR (electron paramagnetic resonance) spectroscopy was used to investigate HAP and β-TCP based dental implants present on the market. Eight dental graft materials present on the market were investigated: Bioresorb R Macropore, Poresorb R -TCP, Easy-Graft T M and Cerasorb R synthetic β-tricalcium phosphates, Easy-Graft T M crystal and Ossceram R two phase synthetic CaP consisting of 60 % HAP and 40 % β-TCP, and Dexabone R and Bio-Oss R bone graft material of bovine origin. EPR study shows that this is the only technique for characterization of free radicals that can simultaneously determine not only the presence and content, but also the position and the structure of free radicals formed by γ-sterilization in the investigated materials, as well as the paramagnetic substitutions incorporated in the materials during the synthesis (such as Mn 2+ , Fe 3+ or Cr 2+ ). Additionally, EPR provides information on stability of irradiation-induced radicals (CO 2 - , trapped H-atoms, NO 3 2 etc.) and processes for reducing them. Results show that EPR should be considered as a valuable technique in improving the quality of bone graft materials, which must be sterile, and to offer the high quality, efficacy and reliable materials to the patients.(author)

Survey Study of Trunk Materials for Direct ATRP Grafting

Energy Technology Data Exchange (ETDEWEB)

Saito, Tomonori [ORNL; Chatterjee, Sabornie [ORNL; Johnson, Joseph C. [ORNL; Dai, Sheng [ORNL; Brown, Suree [ORNL

2015-02-01

In previous study, we demonstrated a new method to prepare polymeric fiber adsorbents via a chemical-grafting method, namely atom-transfer radical polymerization (ATRP), and identified parameters affecting their uranium adsorption capacity. However, ATRP chemical grafting in the previous study still utilized conventional radiation-induced graft polymerization (RIGP) to introduce initiation sites on fibers. Therefore, the objective of the present study is to perform survey study of trunk fiber materials for direct ATRP chemical grafting method without RIGP for the preparation of fiber adsorbents for uranium recovery from seawater.

[Evaluation of Radiation Dose during Stent-graft Treatment Using a Hybrid Operating Room System].

Science.gov (United States)

Haga, Yoshihiro; Chida, Kouichi; Kaga, Yuji; Saitou, Kazuhisa; Arai, Takeshi; Suzuki, Shinichi; Iwaya, Yoshimi; Kumasaka, Eriko; Kataoka, Nozomi; Satou, Naoto; Abe, Mitsuya

2015-12-01

In recent years, aortic aneurysm treatment with stent graft grafting in the X-ray fluoroscopy is increasing. This is an endovascular therapy, because it is a treatment which includes the risk of radiation damage, having to deal with radiation damage, to know in advance is important. In this study, in order to grasp the trend of exposure stent graft implantation in a hybrid operating room (OR) system, focusing on clinical data (entrance skin dose and fluoroscopy time), was to count the total. In TEVAR and EVAR, fluoroscopy time became 13.40 ± 7.27 minutes, 23.67 ± 11.76 minutes, ESD became 0.87 ± 0.41 mGy, 1.11 ± 0.57 mGy. (fluoroscopy time of EVAR was 2.0 times than TEVAR. DAP of EVAR was 1.2 times than TEVAR.) When using the device, adapted lesions and usage are different. This means that care changes in exposure-related factors. In this study, exposure trends of the stent graft implantation was able to grasp. It can be a helpful way to reduce/optimize the radiation dose in a hybrid OR system.

Evaluation of radiation dose during sent-graft treatment using a hybrid operating room system

International Nuclear Information System (INIS)

Haga, Yoshihiro; Kaga, Yuji; Chida, Koichi

2015-01-01

In recent years, aortic aneurysm treatment with stent graft grafting in the X-ray fluoroscopy is increasing. This is an endovascular therapy, because it is a treatment which includes the risk of radiation damage, having to deal with radiation damage, to know in advance is important. In this study, in order to grasp the trend of exposure stent graft implantation in a hybrid operating room (OR) system, focusing on clinical data (entrance skin dose and fluoroscopy time), was to count the total. In TEVAR and EVAR, fluoroscopy time became 13.40 ± 7.27 minutes, 23.67 ± 11.76 minutes, ESD became 0.87 ± 0.41 mGy, 1.11 ± 0.57 mGy. (fluoroscopy time of EVAR was 2.0 times than TEVAR. DAP of EVAR was 1.2 times than TEVAR). When using the device, adapted lesions and usage are different. This means that care changes in exposure-related factors. In this study, exposure trends of the stent graft implantation was able to grasp. It can be a helpful way to reduce/optimize the radiation dose in a hybrid OR system. (author)

Molecular analysis of radiation-induced experimental tumors in mice

International Nuclear Information System (INIS)

Niwa, O.; Muto, M.; Suzuki, F.

1992-01-01

Molecular analysis was made on mouse tumors induced by radiation and chemicals. Expression of oncogenes was studied in 12 types of 178 mouse tumors. Southern blotting was done on tumors in which overexpression of oncogenes was noted. Amplification of the myc oncogene was found in chemically induced sarcomas, but not those induced by radiations. Radiogenic thymomas were studied in detail. These thymomas were induced in two different ways. The first was thymomas induced by direct irradiation of F1 mice between C57BL/6NxC3H/He. Southern analysis of DNA revealed deletion of specific minisatellite bands in these tumors. DNA from directly induced thymomas induced focus formation when transfected into normal Golden hamster cells. The mouse K-ras oncogene was detected in these transformants. The second type of thymomas was induced by X-irradiation of thymectomized B10.thy1.2 mice in which normal thymus from congenic B10,thy1.1. mice was grafted. Thymomas of the donor origin was analysed by transfection and the transformants by DNA from those indirectly induced thymomas did not contain activated ras oncogenes. (author)

Improvement of antithrombogenicity of a fluoro polymer by radiation-induced grafting of hydrophilic monomer

International Nuclear Information System (INIS)

Otsuhata, Kazushige; Razzak, M.T.; Tabata, Yoneho; Ohashi, Fumito; Takeuchi, Atsushi.

1985-01-01

Fluoro polymers have been used as biomaterials in medical field since they have good compatibility with both tissue and blood, and their biomaterial application are of variety. Blood compatibility of fluoro polymers, however, are not always enough for every applications. Especially, there is a large difficulty in the application for artificial vessel with small radius below than 4 mm. In the present study, grafting of a hydrophilic monomer onto a fluoro polymer has been carried out to improve blood compatibility of the fluoro polymer. The technique of grafting employed here was simultaneous irradiation method of gamma rays from a 60 Co source. The fluoro polymer and the hydrophilic monomer used in the experiment were alternative copolymer of ethylene and tetrafluoethylene(AFLON) and N,N-dimethylacry lamide(DMAA), respectively. After grafting, it was found by in vitro tests that antithrombogenicity of AFLON was improved by grafting of DMAA. It was, however, also found that degree of the improvement is affected by grafting conditions. When ethyl acetate was used as a solvent for the graft copolymerization, the improvement was affected by dose rate. Blood compatibility of DMAA-g-AFLON obtained at a higher dose rate of 1 x 10 5 rad/h was not improved, while it was improved in the sample of DMAA-g-AFLON obtained at a lower dose rate of 1 x 10 4 rad/h. On the other hand, when acetone was used as a solvent for the grafting, the degree of grafting gave a significant effect on the improvement. Blood compatibility of all samples with grafting percent more than 20 % was improved by grafting of DMAA. (author)

Development of deodorizing materials by radiation graft polymerization

International Nuclear Information System (INIS)

Sugo, Takanobu; Okamoto, Jiro; Fujiwara, Kunio; Sekiguchi, Hideo.

1989-01-01

With the development of society, the countermeasures for service water and sewerage in large cities and the environment preservation in industrial districts become difficult as their scale becomes larger. There are many unsolved problems, for example photochemical smog due to harmful gases, exhaust gas from automobiles, and smell of toilets and home waste water. The deodorizing materials used so far are mainly inorganic substances, and their ability of adsorbing harmful gases is very low. Besides, those are mostly granular, and limited in the formability. Therefore, it is expected to develop the fibrous adsorbent which has large adsorbing surface area and is easy to make filters. The chemical structures of the compounds having smell are shown. Eight legal bad smell substances which exert large influence to environment even in very small amount are designated. In this paper, the method of introducing functional radicals into existing fiber materials by the application of radiation graft polymerization process and the test of removing smelling compositions by using the obtained resin are reported. The experimental method, and the results of radiation graft polymerization, the adsorption of basic gases and acid gases, and gas flow test are described. (K.I.)

Synthesis of ion-exchange membranes by radiation-induced multiple grafting of methyl α,β,β-trifluoroacrylate

International Nuclear Information System (INIS)

Omichi, H.; Okamoto, J.

1982-01-01

Methyl α,β,β-trifluoroacrylate (MTFA) was grafted onto polymer films with the multiple grafting technique initiated by γ-rays: the yields were similar to those of the single-step grafting procedure with any irradiation dose. Grafted polymer obtained in the single-step experiments were distributed mainly near the film surface, whereas graft polymer from the multiple grafting experiments were distributed uniformly in the film at graft yields greater than 20%. The electric resistance of the hydrolyzed multiple graft polymer film in a 2N NaOH solution was much lower than that of one-step graft film at the same graft yield

Dependence of crystallinity degree with induced grafting by gamma radiation of N,N'-dimethyl acrylamide

International Nuclear Information System (INIS)

Queiroz, A.A.A.; Higa, O.Z.; Barrak, E.R.; Giolito, I.

1991-01-01

N,N' -dimethyl acrylamide (DMAA) graft copolymerization onto polyethylene films was carried out, using a organic solvent as a reaction medium and gamma rays from a 60 Co source for surface activation. Thermal analysis revealed the crystallinity and the grafting inversely proportional. The DSC curves fusion peaks decreased with grafting rate increase, the peak almost disappearing in the curve of PE 440% grafted. It was concluded that the graft occurs not only on the surface but also in the substrate bulk, being the PE absorption of DMAA an important factor for build up of grafted mass. (author)

Application of controlled radiation-induced degradation in polymers: less exploited aspect of radiation processing of polymers

International Nuclear Information System (INIS)

Haji Saeid, M.; Guven, O.

2007-01-01

Industrial use of ionizing radiation treatment has been most successful in applications related to polymeric materials. The polymer, plastics and rubber industries have benefited from the unique advantages of ionizing radiation since its inception as an industrial tool to modify their properties and manufacture novel materials with value addition to the end product. The established and emerging applications of electron beam processing of polymers are based on the well known ultimate effects of ionizing radiation on polymers namely, crosslinking, curing, grafting and chain scissioning. Radiation-induced crosslinking dominates most applications, whereas the chain scissioning effect is much less explored and currently limited to radiation-induced degradation of Teflon, cellulose and polypropylene. The controlling of radiation-induced degradation for achieving a target average molecular weight or distribution has been evaluated for some polysaccharides, biopolymers and waste inner tubes whereas mitigation of the degradative effects of radiation has been analyzed from the point of view of using certain stabilizers, copolymers and annealing at an appropriate temperature. Several new or highly specialized techniques such as positron annihilation lifetime spectroscopy. Rutherford backscattering, elastic recoil detection analysis and solid waste NMR spectroscopy and gas chromatography-mass spectroscopy have been applied to the study or radiation-induced degradation. New information has been collected on the morphological changes associated with radiation-induced degradation processes, including chain scission, oxidation and free volume alteration. The IAEA coordinated research project (CRP) on Controlling of Degradation Effects in Radiation Processing of Polymers dealt with the role and importance of using ionizing radiation in controlling properties of natural and synthetic polymers through its degradative effect. This paper provides a summary of most important results

Radiation grafting of styrene and maleic anhydride onto PTFE membranes and sequent sulfonation for applications of vanadium redox battery

International Nuclear Information System (INIS)

Qiu Jingyi; Ni Jiangfeng; Zhai Maolin; Peng Jing; Zhou Henghui; Li Jiuqiang; Wei Genshuan

2007-01-01

Using γ-radiation technique, poly(tetrafluoroethylene) (PTFE) membrane was grafted with styrene (St) (PTFE-graft-PS) or binary monomers of St and maleic anhydride (MAn) (PTFE-graft-PS-co-PMAn), respectively. Then grafted membranes were further sulfonated with chlorosulfonic acid into ion-exchange membranes (denoted as PTFE-graft-PSSA and PTFE-graft-PSSA-co-PMAc, respectively) for application of vanadium redox battery (VRB). Micro-FTIR analysis indicated that PTFE was successfully grafted and sulfonated at the above two different conditions. However, a higher degree of grafting (DOG) was obtained in St/MAn binary system at the same dose due to a synergistic effect. Comparing with PTFE-graft-PSSA, PTFE-graft-PSSA-co-PMAc membrane showed higher water uptake and ion-exchange capacity (IEC) and lower area resistance (AR) at the same DOG. In addition, PTFE-graft-PSSA-co-PMAc with 6% DOG also showed a higher IEC and higher conductivity compared to Nafion membrane. Radiation grafting of PTFE in St/MAn binary system and sequent sulfonation is an appropriate method for preparing ion-exchange membrane of VRB

Post irradiation effects on the graft of poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA) films

International Nuclear Information System (INIS)

Geraldes, Adriana N.; Zen, Heloisa A.; Ribeiro, Geise; Ferreira, Henrique P.; Souza, Camila P.; Parra, Duclerc F.; Lugao, Ademar B.

2009-01-01

Radiation induced grafting of monomers into fluorinated polymers was designed as an alternative route to polymer modification. In this work, grafting of styrene onto poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA) was studied. Radiation-induced grafting of styrene onto PFA films was investigated after simultaneous irradiation (in post-irradiation condition) using a 60 Co source. The films of PFA were irradiated at 20, 40, 80 and 100 kGy doses at room temperature and chemical changes were monitored after contact with styrene for grafting. The post-irradiation time was established between 7 and 28 days when films of PFA were maintained in styrene/toluene 1:1 v/v solution at room temperature. After these periods the grafting degrees were evaluated in the samples. The highest degree of grafting was achieved after 14 days. Chemical modifications were evaluated by infrared spectroscopic analysis (FTIR), thermogravimetry (TG), differential scanning calorimetry (DSC) and also by scanning electron microscopy (SEM). The degree of grafting (DOG) was determined gravimetrically. The results showed that irradiated PFA films at 100 kGy exhibited higher grafting degree. Surface analysis by SEM technique of irradiated, grafted and original films have presented an homogeneous surface. (author)

Radiation grafting on natural films

Science.gov (United States)

Lacroix, M.; Khan, R.; Senna, M.; Sharmin, N.; Salmieri, S.; Safrany, A.

2014-01-01

Different methods of polymer grafting using gamma irradiation are reported in the present study for the preparation of newly functionalized biodegradable films, and some important properties related to their mechanical and barrier properties are described. Biodegradable films composed of zein and poly(vinyl alcohol) (PVA) were gamma-irradiated in presence of different ratios of acrylic acid (AAc) monomer for compatibilization purpose. Resulting grafted films (zein/PVA-g-AAc) had their puncture strength (PS=37-40 N mm-1) and puncture deformation (PD=6.5-9.8 mm) improved for 30% and 50% PVA in blend, with 5% AAc under 20 kGy. Methylcellulose (MC)-based films were irradiated in the presence of 2-hydroxyethyl methacrylate (HEMA) or silane, in order to determine the effect of monomer grafting on the mechanical properties of films. It was found that grafted films (MC-g-HEMA and MC-g-silane) using 35% monomer performed higher mechanical properties with PS values of 282-296 N mm-1 and PD of 5.0-5.5 mm under 10 kGy. Compatibilized polycaprolactone (PCL)/chitosan composites were developed via grafting silane in chitosan films. Resulting trilayer grafted composite film (PCL/chitosan-g-silane/PCL) presented superior tensile strength (TS=22 MPa) via possible improvement of interfacial adhesion (PCL/chitosan) when using 25% silane under 10 kGy. Finally, MC-based films containing crystalline nanocellulose (CNC) as a filling agent were prepared and irradiated in presence of trimethylolpropane trimethacrylate (TMPTMA) as a grafted plasticizer. Grafted films (MC-g-TMPTMA) presented superior mechanical properties with a TS of 47.9 MPa and a tensile modulus (TM) of 1792 MPa, possibly due to high yield formation of radicals to promote TMPTMA grafting during irradiation. The addition of CNC led to an additional improvement of the barrier properties, with a significant 25% reduction of water vapor permeability (WVP) of grafted films.

Study on radiation grafting of NASI on sephadex and conjugation of the copolymer with BSA

International Nuclear Information System (INIS)

Yi Min; Li Jun; Wei Jinshan; Ha Hongfei

1997-01-01

N-acryloxysuccinimide (NASI) with a function ester group is grafted on Sephadex G75 and Sephadex G50 separately by radiation technology. The radiation grafting conditions including absorbed dose, dose rate, monomer concentration in solvent are investigated. The conjugation reactions between the grafted copolymers Sephadex G75-NASI, and bovine serum albumin (BSA) or Sephadex G50-NASI and bovine serum albumin (BSA) are followed. The experiment results show that the conjugate of Sephadex G75-NASI with larger holes and BSA (M r = 6.6 x 10 4 ) is obtained successfully, however, the Sephadex G50 with small holes can be only conjugated with neutral red (M r = 2.58 x 10 2 )

Synthesis and characterization of superabsorbent polymer prepared by radiation-induced graft copolymerization of acrylamide onto carboxymethyl cellulose for controlled release of agrochemicals

Science.gov (United States)

Hemvichian, Kasinee; Chanthawong, Auraruk; Suwanmala, Phiriyatorn

2014-10-01

Superabsorbent polymer (SAP) was synthesized by radiation-induced grafting of acrylamide (AM) onto carboxymethyl cellulose (CMC) in the presence of a crosslinking agent, N,N‧-methylenebisacrylamide (MBA). The effects of various parameters, such as dose, the amount of CMC, AM, MBA and ionic strength on the swelling ratio were investigated. In order to evaluate its controlled release potential, SAP was loaded with potassium nitrate (KNO3) as an agrochemical model and its potential for controlled release of KNO3 was studied. The amount of released KNO3 was analyzed by an inductively coupled plasma mass spectrometry (ICP-MS). The results from controlled release experiment agreed very well with the results from swelling experiment. The synthesized SAP was characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The obtained SAP exhibited a swelling ratio of 190 g/g of dry gel.

Chemical structure of chromium(III) crosslinked collagen-poly(methyl methacrylate) copolymers in radiation grafting

International Nuclear Information System (INIS)

Pietrucha, K.

1991-01-01

Upon γ-irradiation of aqueous emulsions of methyl methacrylate embedded into chrome tanned skin, the formation of graft copolymers is observed. The number-average molecular weight of the grafted poly(methyl methacrylate) side chains was in the range of 430000 (for a dose of 10 kGy) and practically independent of grafting degree. However, the number of branches per graft copolymer molecule increases from 0.3 to 0.8 when the degree of grafting increases from 32% to 88%. Similarly, the radiation yield, i.e. the number of branches formed per 100 eV of energy absorbed in the substrate polymer increases from 0.75 to 1.94. The value and meaning of molecular weight of graft copolymer is discussed along with the mechanism of polymer chain termination. (author) 14 refs.; 3 figs.; 4 tabs

Optimization of process parameter for graft copolymerization of glycidyl methacrylate onto delignified banana fibers

International Nuclear Information System (INIS)

Selambakkannu, S.; Nor Azillah Fatimah Othman; Siti Fatahiyah Mohamad

2016-01-01

This paper focused on pre-treated banana fibers as a trunk polymer for optimization of radiation-induced graft copolymerization process parameters. Pre-treated banana fiber was grafted with glycidyl methacrylate (GMA) via electron beam irradiation. Optimization of grafting parameters in term of grafting yield was analyzed at numerous radiation dose, monomer concentration and reaction time. Grafting yield had been calculated gravimetrically against all the process parameters. The grafting yield at 40 kGy had increases from 14 % to 22.5 % at 1 h and 24 h of reaction time respectively. Grafting yield at 1 % of GMA was about 58 % and it increases to 187 % at 3 % GMA. The grafting of GMA onto pre-treated banana fibers confirmed with the characterization using FTIR, SEM and TGA. Grafting of GMA onto pre-treated fibers was successfully carried out and it was confirmed by the results obtained via the characterization. (author)

Repair of the radiation induced rectovaginal fistulas without or with interposition of the bulbocavernosus muscle (Martius procedure)

Energy Technology Data Exchange (ETDEWEB)

Aartsen, E.J.; Sindram, I.S.

1988-04-01

Two local repair procedures, one without (9) and the other with (14) a bulbocavernosus muscle graft were performed on 20 patients with a radiation induced rectovaginal fistula. Four patients had two procedures successively. The initial success rate of both procedures was 7/9 and 14/14 respectively. Though the initial result of the bulbocavernosus graft was obviously better, in many of the local repair procedures, subclinical radiation damage progressed, resulting in recurrence of rectovaginal fistula (5), rectovesical fistula (4), pararectal abscess (2) etc. After a mean follow up of around 10 years, the success rate of fistula repair decreased to 5/9 and 13/14 and only 2/9 and 6/14 finally remained without a colostomy. A local repair operation should be restricted to carefully selected cases. The musculus gracilis is proposed as a better vascular graft. If the general condition of the patient does not allow more aggressive reconstructive procedures, fistula repair is better cancelled because there is a high risk of subsequent radiation damage.

Facial reconstruction for radiation-induced skin cancer

International Nuclear Information System (INIS)

Panje, W.R.; Dobleman, T.J.

1990-01-01

Radiation-induced skin cancers can be difficult to diagnose and treat. Typically, a patient who has received orthovoltage radiotherapy for disorders such as acne, eczema, tinea capitis, skin tuberculosis, and skin cancer can expect that aggressive skin cancers and chronic radiodermatitis may develop subsequently. Cryptic facial cancers can lead to metastases and death. Prophylactic widefield excision of previously irradiated facial skin that has been subject to multiple recurrent skin cancers is suggested as a method of deterring future cutaneous malignancy and metastases. The use of tissue expanders and full-thickness skin grafts offers an expedient and successful method of subsequent reconstruction

Preparation and characterization of intrinsically coloured polymers using high energy radiation induced processes

International Nuclear Information System (INIS)

Guthrie, J.T.

1978-07-01

Information on the development in research is given in the utilization of high energy radiation sources in polymerizations and on polymer characterization in the following three areas: studies on the nitrile-styrene system, studies on the radiation induced polymerization of 2-vinyl anthraquinone and the graft polymerization of vinyl monomers onto cellulose in the DMSO/HCHO/cellulose system. Within the framework of research in radiation induced polymerization, samples of 2-vinyl anthraquinone were subjected to X-ray diffraction and e.s.r. examinations and the kinetics and mechanism of γ-ray induced solution polymerization of 2-vinyl anthraquinone in methylene chloride and dimethyl sulfoxide was investigated. Methylene chloride was found to be an efficient solvent for poly(2-vinyl anthraquinone). The rate of polymerization in methylene chloride was 10 3 times greater than that obtained using dimethyl sulfoxide as solvent

The synthesis of a new type adsorbent for the removal of toxic gas by radiation-induced graft polymerization

International Nuclear Information System (INIS)

Okamoto, Jiro; Sugo, Takanobu

1990-01-01

A new type of adsorbent containing sulfuric acid group for the removal of ammonia gas was synthesized by radiation-induced graft polymerization of styrene onto fibrous and nonwoven type polypropylene followed by sulufonation with chlorosulfonic acid. The rate of the adsorption of ammonia gas by H-type adsorbent is independent of the ion-exchange capacity. The amount of ammonia gas adsorbed by the chemical adsorption was dependent on the ion-exchange capacity of H-type fibrous adsorbent and was kept constant value in spite of the equilibrium pressure of ammonia gas. Cu(II)- and Ni(II)-types fibrous adsorbent were prepared by the ion exchange reaction of Na-type fibrous adsorbent with metal nitrate solutions. Although, the rate of adsorption of ammonia gas by metal-type fibrous adsorbent is lower than that of H-type adsorbent, the amount of ammonia gas adsorbed increases compared to H-type adsorbent with the same ion exchange capacity. It was related to the highest coordination number of metal ion. The ratio of the number of ammonia molecules adsorbed chemically and the number of metal ion adsorbed in fibrous adsorbent was 4 for Cu-type and 6 for Ni-type fibrous adsorbent, respectively. (author)

Swelling, ion uptake and biodegradation studies of PE film modified through radiation induced graft copolymerization

Energy Technology Data Exchange (ETDEWEB)

Kaur, Inderjeet, E-mail: ij_kaur@hotmail.com [Department Chemistry, HPU Shimla 171005 (India); Gupta, Nitika; Kumari, Vandna [Department Chemistry, HPU Shimla 171005 (India)

2011-09-15

An attempt to develop biodegradable polyethylene film grafting of mixture of hydrophilic monomers methacrylic acid (MAAc) and acrylamide (AAm) onto PE film has been carried out by preirradiation method using benzoyl peroxide as the radical initiator. Since ether linkages are susceptible to easy cleavage during degradation process, PE film was irradiated before the grafting reactions by {gamma}-rays to introduce peroxidic linkages (PE-OO-PE) that offer sites for grafting. The effect of irradiation dose, monomer concentration, initiator concentration, temperature, time and amount of water on the grafting percent was determined. Maximum percentage of grafting of binary mixture (MAAc+AAm), (1792%) was obtained at a total concentration of binary monomer mixture=204.6x10{sup -2} mol/L ([MAAc]=176.5x10{sup -2} mol/L, [AAm]=28.1x10{sup -2} mol/L), [BPO]=8.3x10{sup -2} mol/L at 100 deg. C in 70 min. The grafted PE film was characterized by the Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA) and Scanning Electron Microscopic (SEM) methods. Some selective properties of grafted films such as swelling studies, ion uptake and biodegradation studies have been investigated. The grafted films show good swelling in water, ion uptake studies shows promising results for desalination of brackish water and the soil burial test shows that PE film grafted with binary monomer mixture degrades up to 47% within 50 days. - Highlights: > Binary mixture of methacrylic acid (MAAc) and acrylamide (AAm) onto PE film by preirradiation method was carried out. > Graft copolymers of MAAc+AAm and PE film were characterized by FTIR, TGA and SEM studies and was found to be thermally stable. > Grafting of MAAc+AAm improved swelling behavior giving maximum swelling (485.71%) in water as against PE with 0% swelling. > The grafted PE-g-poly (MAAc-co-AAm) behaves as an excellent material for ion separation. > Biodegradation studies by soil burial test showed 47.19% of

Abaca/polyester nonwoven fabric functionalization for metal ion adsorbent synthesis via electron beam-induced emulsion grafting

International Nuclear Information System (INIS)

Madrid, Jordan F.; Ueki, Yuji; Seko, Noriaki

2013-01-01

A metal ion adsorbent was developed from a nonwoven fabric trunk material composed of both natural and synthetic polymers. A pre-irradiation technique was used for emulsion grafting of glycidyl methacrylate (GMA) onto an electron beam irradiated abaca/polyester nonwoven fabric (APNWF). The dependence of degree of grafting (Dg), calculated from the weight of APNWF before and after grafting, on absorbed dose, reaction time and monomer concentration were evaluated. After 50 kGy irradiation with 2 MeV electron beam and subsequent 3 h reaction with an emulsion consisting of 5% GMA and 0.5% polyoxyethylene sorbitan monolaurate (Tween 20) surfactant in deionized water at 40 °C, a grafted APNWF with a Dg greater than 150% was obtained. The GMA-grafted APNWF was further modified by reaction with ethylenediamine (EDA) in isopropyl alcohol at 60 °C to introduce amine functional groups. After a 3 h reaction with 50% EDA, an amine group density of 2.7 mmole/gram adsorbent was achieved based from elemental analysis. Batch adsorption experiments were performed using Cu 2+ and Ni 2+ ions in aqueous solutions with initial pH of 5 at 30 °C. Results show that the adsorption capacity of the grafted adsorbent for Cu 2+ is four times higher than Ni 2+ ions. - Highlights: • An amine type adsorbent from abaca/polyester nonwoven fabric was synthesized. • Pre-irradiation method was used in grafting glycidyl methacrylate on nonwoven fabric. • Radiation-induced grafting was performed with monomer in emulsion state. • The calculated adsorption capacity for Cu 2+ is four times higher than Ni 2+ ions. • Grafted adsorbent can remove Cu 2+ faster than a chemically similar commercial resin

Oxidative degradation property of the proton-exchange membranes based on fluorinated polymer using radiation-induced grafting

International Nuclear Information System (INIS)

Mitani, N.; Muto, F.; Fujii, K.; Sato, Y.; Kakigi, T.; Matsuura, A.; Li Jingye; Miura, T.; Oshima, A.; Washio, M.

2006-01-01

To grow popularity of polymer electrolyte fuel cells (PEFCs), it is important that the life-time of FC will be evaluated. In the PEFCs operation, the oxygenated water would be produced by fuel gases crossover reaction. Moreover, the metal ions such as Fe 2+ would dissolve from piping and humidification bubblers in FC systems. As the results, the dissolved metal ions catalyze with oxygenated water, and then active oxidative radicals such as hydroxy and hydroperoxy radicals are induced by Fenton reaction. The oxidative radicals have considered one of the reasons of deterioration of FC performance. In our previous study, the partial-fluorinated sulfonic acid membranes based on crosslinked PTFE (sulfonated RX-PTFE) have been fabricated by pre EB-grafting method. In this study, in order to evaluate the chemical durability exerted on the PEFC performance of sulfonated RX-PTFE, we carried out the accelerated degradation test by Fenton reaction. The test conditions were 6 vol% H 2 O 2 with 5 ppm Fe 2+ solution at 60 degree C. The properties of sulfonated RX-PTFE before and after degradation tests were measured by means of X-ray photoelectron spectroscopy (XPS) and other methods. According to oxidative degradation test, the sulfonated RX-PTFE with higher crosslinking density of main chain became hard to deteriorate. On the contrary, the higher grafting yields became easy to degrade. It is suggested that the oxidative degradation would be greatly influenced to the grafted chain length and crosslinking density of main chain. From XPS after Fenton treated sulfonated RX-PTFE, the signal of S 2p and S 2s was disappeared. And also, by TGA and TG-MS analysis, it was found that the reduction of grafted chains was taken place. Furthermore, the crosslinked PTFE chains may be degraded through the reduction of grafted chain. The PEFC operation tests of sulfonated RX-PTFE before and after degradation tests were carried out. When the weight loss of sulfonated RX-PTFE was almost the same

Manual of radiation processing of cassava starch hydrogel

International Nuclear Information System (INIS)

Sonsuk, Manit

2007-01-01

The radiation processing of natural cassava starch (CS) is described for the improvement of its properties. A series of hydrogels were prepared from gelatinized CS and vinylpyrrolidone by radiation-induced graft copolymerization. Hydrogels were also synthesized from radiation-induced crosslinking of carboxymethyl CS. The optimum condition for the swelling ratio and gel fraction of the obtained hydrogels is irradiation at low dose. The polymeric chelating resins containing the hydroxamic acid groups were synthesized from the polymethyl acrylate (PMA)-grafted CS via gamma radiation. (M.H.)

Radiation grafting on natural films

International Nuclear Information System (INIS)

Lacroix, M.; Khan, R.; Senna, M.; Sharmin, N.; Salmieri, S.; Safrany, A.

2014-01-01

Different methods of polymer grafting using gamma irradiation are reported in the present study for the preparation of newly functionalized biodegradable films, and some important properties related to their mechanical and barrier properties are described. Biodegradable films composed of zein and poly(vinyl alcohol) (PVA) were gamma-irradiated in presence of different ratios of acrylic acid (AAc) monomer for compatibilization purpose. Resulting grafted films (zein/PVA-g-AAc) had their puncture strength (PS=37–40 N mm −1 ) and puncture deformation (PD=6.5–9.8 mm) improved for 30% and 50% PVA in blend, with 5% AAc under 20 kGy. Methylcellulose (MC)-based films were irradiated in the presence of 2-hydroxyethyl methacrylate (HEMA) or silane, in order to determine the effect of monomer grafting on the mechanical properties of films. It was found that grafted films (MC-g-HEMA and MC-g-silane) using 35% monomer performed higher mechanical properties with PS values of 282–296 N mm −1 and PD of 5.0–5.5 mm under 10 kGy. Compatibilized polycaprolactone (PCL)/chitosan composites were developed via grafting silane in chitosan films. Resulting trilayer grafted composite film (PCL/chitosan-g-silane/PCL) presented superior tensile strength (TS=22 MPa) via possible improvement of interfacial adhesion (PCL/chitosan) when using 25% silane under 10 kGy. Finally, MC-based films containing crystalline nanocellulose (CNC) as a filling agent were prepared and irradiated in presence of trimethylolpropane trimethacrylate (TMPTMA) as a grafted plasticizer. Grafted films (MC-g-TMPTMA) presented superior mechanical properties with a TS of 47.9 MPa and a tensile modulus (TM) of 1792 MPa, possibly due to high yield formation of radicals to promote TMPTMA grafting during irradiation. The addition of CNC led to an additional improvement of the barrier properties, with a significant 25% reduction of water vapor permeability (WVP) of grafted films. - Highlights: • Irradiation of zein

Radiation graft copolymerization of styrene with m/e and styrene with acrylic acid at highthyl methacryl dose rate

International Nuclear Information System (INIS)

Aliev, R.Eh.; Kabanov, B.Ya.

1984-01-01

Comparative investigation of radiation graft copolymerization of styrene with methyl methacrylate (MMA) and styrene with acrylic acid (AA) is carried out at considerably differing radiation dose rates. The monomer mixture was grafted to PE low density films at dose rates of 0.16, 0.25 Gy/s (1 MeV electron acceleration). The value of graft was 3-6 and 5-10%, respectively, for the styrene-MMA and styrene-AA systems. An essential difference in the dependences of the formed copolymer composition on initial monomer mixture composition is noticed. Difference in composition of graft polymers prepared at different dose rates is less for the systems with AA, than for systems with MMA. It is shown that at high dose rates in difference with low ones not only radical graft copolymerization of the styrene mixture with AA takes place, but a contribution of the graft styrene polymerization according to cation mechanism as well

Radiation sterilisation dose determination for lyophilised amnion membranes and lyophilised bone grafts

International Nuclear Information System (INIS)

Hilmy, N.; Basril, A.; Febrida, A.

1999-01-01

Radiation sterilisation of medical products is now well established in commercial scale and at present there are more than two hundred irradiation facilities in operation throughout the world. It is a cold sterilisation process without toxic chemical residues, high degree of safety and easy to control, so that it is a safe technology to sterilise human tissue grafts. According to ISO (International Organisation of Standard) No. 11137, radiation sterilisation dose should be established based on the number of product's bioburden (number of product's contaminated microbes before irradiation). Bioburden of lyophilised amnion membranes and lyophilised bone grafts produced by Batan Research Tissue Bank (BRTB) have been determined since 1990 and 1994 consecutively by using 100 up to 120 pieces of samples per year. Results show that the average bioburden of the amnion membranes were 1.4 ( 0.2 x 103; 1.2 (0.2 x 103; 1.2 ( 1.2 x 103; 4.5 ( 0.5 x 102; 1.8 ( 0.9 x 102; 2.4 ( 2.3 x 102; 1.7(l.5 x 102; 1.5 ( 1.7 x 102 cells per sample, calculated in 1990 to 1997 consecutively and the average bioburden of the bonegrafts were 1.5 (0.4x 101; 0.25 (0.12 x 101; 0; 0 cells per sample, calculated in 1994 to 1997 consecutively. Morphological of those contaminants were found to be Gram positive coccoid forms (98%) and Gram positive vegetative rod (2%) with the D10 - values of 0.25 to 0.50 kGy. No spore forming bacteria and Gram negative bacteria were found in those contaminations. The highest bioburden of lyophilised amnion membranes and lyophilised bone grafts were found to be 4900 and 80 cells per sample consecutively, and the lowest was found to be 0 cell per sample in both of materials observed. According to ISO 11137 radiation sterilisation doses for amnion membranes were ranging between 21 to 25 kGy and for bone grafts was around 15 kGy with the Sterility Assurance Level (SAL) of 106. Since 1990, radiation sterilisation dose used for lyophilised amnion membranes produced by BRTB

Allogeneic bone marrow grafts in genotyped swine

International Nuclear Information System (INIS)

Vaiman, M.

1974-01-01

The proof of a major histocompatibility complex (MHC) called SL-A enabled to promote bone marrow allografts. A study of the response to that kind of graft in irradiated pig states a number of interesting points. Bone marrow allografting complies with the rule of tissular compatibility with the major histocompatibility complex. The taking of SL-A incompatible bone marrow allografts could not be achieved under the experimental conditions. In spite of the high doses of radiation, 950 to 1050 rads, higher than 1.5 LD 100%, recipients were capable of rejecting their grafts, regularly. SL-A identify ensured 100%, initial achievement. However, animals developed regular fatal disease within a fairly short time. This development could by no means, be ascribed to the sole sequealae of radiation sickness since autografted animals at equal or even higher doses, showed none of the symptome. Assumption of a chronic graft-vs-host reactions, induced by the minor histocompatible systems, was put foreward, but should be confirmed histopathologically [fr

Radiation Synthesis of Poly(N-Vinyl Pyrrolidone) Nanogels and Nanoscale Grafting of Poly(Acrylic Acid) from Cellulose

Energy Technology Data Exchange (ETDEWEB)

Guven, Olgun; Isik, Semiha Duygu; Barsbay, Murat [Hacettepe University, Department of Chemistry, 06800 Ankara (Turkey)

2010-07-01

Ionizing radiation has long been known to be a very useful tool for the preparation of nanogels. Although preparation is straightforward, the control of the sizes of nanogels has been a challenging issue. This report shows the results of our work on using radiation for the synthesis of PVP nanogels in the range of 40-200nm by making use of the principles of solution thermodynamics of aqueous polymer solutions. Nanoscale grafting of responsive polymers however has been of scientific and industrial importance due to fine control of the molecular weight and molecular weight distribution of grafted polymers. The second part of this report deals with the grafting of poly(acrylic acid) onto the surface of cellulose, thus imparting pH response to the substrate. The use of radiation as a constant source of radical generation and Reversible-Addition-Fragmentation-Chain transfer agents for the control of free radical polymerization provided a full control over the molecular weight and distribution of poly(acrylic acid) grafts on cellulose. (author)

Radiation Synthesis of Poly(N-Vinyl Pyrrolidone) Nanogels and Nanoscale Grafting of Poly(Acrylic Acid) from Cellulose

International Nuclear Information System (INIS)

Guven, Olgun; Isik, Semiha Duygu; Barsbay, Murat

2010-01-01

Ionizing radiation has long been known to be a very useful tool for the preparation of nanogels. Although preparation is straightforward, the control of the sizes of nanogels has been a challenging issue. This report shows the results of our work on using radiation for the synthesis of PVP nanogels in the range of 40-200nm by making use of the principles of solution thermodynamics of aqueous polymer solutions. Nanoscale grafting of responsive polymers however has been of scientific and industrial importance due to fine control of the molecular weight and molecular weight distribution of grafted polymers. The second part of this report deals with the grafting of poly(acrylic acid) onto the surface of cellulose, thus imparting pH response to the substrate. The use of radiation as a constant source of radical generation and Reversible-Addition-Fragmentation-Chain transfer agents for the control of free radical polymerization provided a full control over the molecular weight and distribution of poly(acrylic acid) grafts on cellulose. (author)

Effect of auto-skin grafting on bacterial infection of wound in rats inflicted with combined radiation-burn injury

International Nuclear Information System (INIS)

Ran Xinze; Yan Yongtang; Wei Shuqing

1992-01-01

Rats were exposed to 6 Gy whole body γ-ray irradiation from a 60 Co source followed by light radiation burn (15% TBSA, full thickness burn) from a 5 kw bromo-tungsten lamp. The effect of auto-skin grafting on invasive bacterial infection of wound in the rats with combined radiation-burn injury was studied, In the control group inflicted with combined radiation-burn injury but without skin grafting, bacteria were found on and in the eschars at 24th hour after injury, and in the subeschar tissue on 3rd day. Tremendous bacterial multiplication occurred from 7th to 15th day, and the amount of bacteria in the internal organs increased along with the increase of subeschar infection. At the same time, no bacterial infection was found in internal organs in auto-skin grafted group at 24th hour after injury. The results show that skin grafting can decrease or prevent bacterial infection in both subeschar tissue and internal organs

Radiation grafting of acrylamide and maleic acid on chitosan and effective application for removal of Co(II) from aqueous solutions

Science.gov (United States)

Saleh, Alaaeldine Sh.; Ibrahim, Ahmed G.; Elsharma, Emad M.; Metwally, Essam; Siyam, Tharwat

2018-03-01

The graft copolymerization has been proven as a superior polymerization technique because it combines the functional advantages of the grafted and base polymers. In this work, the radiation-induced grafting of acrylamide (AAm) and maleic acid (MA) onto chitosan (CTS) was developed and optimized by determining the grafting percentage and efficiency as a function of grafting conditions such as AAm, MA, and CTS concentrations, and absorbed dose. Fourier transform infrared spectroscopic analysis (FTIR) confirmed the graft copolymerization. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) further characterized the grafted copolymers and showed their high thermal stability. Using batch sorption experiments and 60Co as a radiotracer, poly(CTS-AAm) and poly(CTS-MA) were evaluated for Co(II) removal from aqueous solutions. The Co(II) removal increases with increasing time, pH, polymer, and Co(II) concentrations. Experimentally, P(CTS-AAm) and P(CTS-MA) show high sorption capacities of Co(II), i.e. 150 mg g-1 and 421 mg g-1, respectively, which makes them potential sorbents of Co(II) for water and wastewater treatment. Finally, the Co(II) sorption was examined using sorption isotherm and kinetic models. The sorption was best fitted to Langmuir model which suggests the sorption is of chemisorption type. On the other hand, the sorption kinetics was best represented by Elovich model which also indicates the chemical nature of Co(II) sorption on P(CTS-AAm) and P(CTS-MA).

Characterisation of Microbial Cellulose Modified by Graft Copolymerization Technique

International Nuclear Information System (INIS)

Tita Puspitasari; Cynthia Linaya Radiman

2008-01-01

Chemical and phisycal modifications of polymer can be carried out by radiation induced graft copolymerization. This research was carried out to study the morphology and crystallinity of microbial cellulose copolymer grafted by acrylic acid (MC-g-AAC). The SEM microstructural analysis proved that the acrylic acid could diffuse into the microbial celullose and resulted a dense structure. Crystallinity measurement showded that the crystalinity of microbial cellulose increase from 50 % to 53 % after modification. (author)

Radiation degradation of methyl methacrylate grafted natural rubber

International Nuclear Information System (INIS)

Perera, M.C.S.

1998-01-01

M G rubber is a mixture consisting of the graft copolymer and two home polymers. Natural rubber is known to undergo crosslinking during exposure to high energy radiation where as poly methyl methacrylate is a polymer where high energy radiation causes chain scission. It is interesting to determine how this partially miscible blend of scission and crosslinking polymers will behave under high energy radiation. Dynamic Mechanical Analysis (DMA) was used to study the variations in the glass transition regions during high energy treatment of the polymers. Another techniques that is available to obtain motional information and miscibility of blends is Nuclear Magnetic Resonance Spectroscopy (NMR).The present study is aimed at understanding the changes in the molecular structure of rubber when exposed to high energy radiation. The changes in the dynamic mechanical properties in the glass transition region and solid state NMR were made used of for this investigation. The data obtained from the DMA results were analysed to calculate the radiation chemical yields. The local dynamics were investigated with measurement of carbon relaxation times and molecular structure was studied with focus on the level of intermolecular mixing by proton relaxation times

Development of an amine-type adsorbent by electron beam-induced emulsion grafting of glycidyl methacrylate onto a nonwoven fabric

International Nuclear Information System (INIS)

Madrid, Jordan; Ueki, Yuji; Seko, Noriaki

2013-01-01

In the recent years, radiation-induced graft polymerization of various monomers onto different types of trunk polymers have been extensively used for researchers on adsorbents for cations, anions and different compounds, battery separators, antibacterial bandages, protein separators, and fuel cell applications. Some of these technologies were transferred to end-users and eventually commercialized. In most of these studies, a post-grafting reaction is performed to introduced chemical groups that impart functionality to the grafted material. In this paper, pre-irradiation technique was used for emulsion grafting of glycidyl methacrylate (GMA) onto an electron beam irradiated abaca-polyester nonwoven fabric (APNWF). The dependence of degree of grafting (Dg), calculated from the weight of APNWF before and after grafting, on irradiation dose, reaction time and monomer concentration were studies. After 50 kGy irradiation with 2 MeV electron beam and subsequent 3-hour reaction with an emulsion consisting of 5% GMA and 0.5% polyoxyethylene sorbitan monolaurate (Tween 20) surfactant in deionized water at 40 degree centegrade, a grafted APNWF with a Dg greater than 150% was obtained. The GMA grafted APNWF was further modified by reaction with ethylenediamine (EDA) in isopropyl alcohol at 60 degree centegrade to introduce amine functional groups. A 3-hour reaction with 50% EDA resulted to an amine group density of 2.7 mmole/gram-adsorbent. Preliminary batch adsorption experiments using Cu 2+ and Ni 2+ ions in aqueous solutions show that the adsorption capacity of the grafted adsorbent is four times greater for Cu 2+ ions compared to Ni 2+ ions. (author)

Grafting study of polysulfone polymeric membranes by gamma ray irradiation

International Nuclear Information System (INIS)

Furtado Filho, Acacio A.M.; Gomes, Ailton de S.

2011-01-01

Radiation-induced grafting of styrene poli sulfone films were investigated by simultaneous method in solution using gamma-ray from a radio nuclide 60 Co source. The gamma-ray energy of high intensity induced breaking of chemical bonds leading to free radical formation. The radical start a conventional polymerization sequence comparable with that obtained with a chemical catalyst acting as initiator. The effects of grafting conditions such as irradiation total dose, dose rate and addition of cross linking agent, were studied by means of morphology analysis, thermal degradation and crystallinity. After the grafting reaction, the membranes were submitted to an exhaustive extraction with solvent to remove the polystyrene homopolymer formed. The degree of grafting (DOG) was analyzed by percentage of weight increase. As a result, the reaction always follows the same pattern: DOG increases rapidly initially whilst propagation is the main reaction, then more slowly as termination becomes more frequent. (author)

Materials of 4. Spring School of Radiation Sterilization of Medical Materials, Grafts, Pharmaceutics and Cosmetics

International Nuclear Information System (INIS)

1997-01-01

The state of art in well developed in Poland radiation technologies has been done. The legal and economical aspects have been discussed for radiation sterilization of health care products, drugs, biomaterials and grafts. Industrial plants and radiation procedures have been described. The perspectives for further development and other industrial applications have been also discussed

Radiation-assisted grafting of vinylidene chloride onto high-density polyethylene

Science.gov (United States)

Nagesh, N.; Dokhale, P. A.; Bhoraskar, V. N.

1999-06-01

6 MeV electrons and Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays were used for grafting vinylidene chloride (VDC) onto high-density polyethylene (HDPE) samples. The HDPE samples were immersed in vinylidene chloride and irradiated either with Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays or with 6 MeV electrons. In both cases, the radiation dose was varied in the range 1.25-7.5 kGy. The grafted samples were characterized by IR spectroscopy to obtain information about the chemical bonds and with the 14 MeV neutron activation analysis technique for estimating the number of chlorine atoms. The formation of stable bonds between the VDC molecules and the polymer chains could be achieved either with 6 MeV electrons or with Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays. Both the number of chlorine atoms and the sample-surface conductivity increased with the radiation dose but the increases achieved with 6 MeV electrons were greater than those achieved with Co-60 icons/Journals/Common/gamma" ALT="gamma" ALIGN="TOP"/>-rays.

The study on grafting comonomer of n-butyl acrylate and styrene onto poly(ethylene terephthalate) film by gamma-ray induced graft copolymerization

Energy Technology Data Exchange (ETDEWEB)

Ping Xiang; Wang Mozhen [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Ge Xuewu, E-mail: xwge@ustc.edu.c [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2010-09-15

Poly(ethylene terephthalate) (PET) film was successfully grafted with n-butyl acrylate and styrene comonomer through gamma-ray induced graft copolymerization. The degree of grafting (DG) and the composition of grafted side chain were characterized by {sup 1}H NMR. It was found that St can inhibit the homopolymerization of BA effectively and increase the DG when the concentration of comonomer mixture is kept constant. The proportion of St to BA in grafted side chain has a positive dependence on the feed ratio of St, which ultimately approaches the feed ratio. The thermal properties of poly(ethylene terephthalate)-graft-poly(n-butyl acrylate-co-styrene) (PET-g-P(BA-co-St)) films were investigated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The T{sub g} of PET decreases with the DG, indicating that the grafted P(BA-co-St) copolymer has good compatibility with PET backbone.

Introduction of various amine groups onto polyethylene bead prepared by radiation-induced polymerization

International Nuclear Information System (INIS)

Kim, M.S.; Choi, S.H.; Lee, K.P.

2002-01-01

Complete text of publication follows. Radiation-induced graft polymerization is a good method for modification of chemical and physical properties of polymeric materials because it can endow properties such as membrane quality, ion exchange, blood compatibility, dyeability, protein adsorption, and immobilization of bioactive materials. Polyethylene microbead is very useful material due to the following advantages; low price, simple purchase, high sensitivity, and simple analysis. On the other hand, the epoxy group of the glycidyl methacrylate (GMA) can easily be converted to the various functional groups such as amines, alcohols, phosphoric acid, sulfonic acid, and amino acid, etc. Cyclodextrin have been applied universally in various industries such as foods, cosmetics, pharmaceutical industry, analytical chemistry, and chemical industry. In order to obtain cyclodextrins, polyethylene microbead with the epoxy group were prepared by radiation-induced graft polymerization of GMA onto polyethylene microbead. The physical and chemical properties of the GMA-induced polyethylene microbeads were investigated by IR, thermal analysis (TGA/DSC), and SEM, respectively. Subsequently, the various amine groups such as diethylamine. diethylenetriamine, triethylamine, triethylenetetramine, and 1,6-hexanediamine were induced onto the epoxy group in polyethylene microbead. Finally, cyclodextrin glucanotransferase were immobilized onto polyethylene microbead with various amines under the various experimental conditions, such as pH, amin content, immobilization time, and etc. The activity of CGTase-immobilized polyethylene microbead was determined by Phenolphthein method. The production of the cyclodextrins from starch is in progress

Intensifying radiation induced grafting of 4-vinylpyridine/glycidyl methacrylate mixtures onto poly(ethylene-co-tetrafluoroethylene) films using ultrasound

International Nuclear Information System (INIS)

Nasef, Mohamed Mahmoud; Sithambaranathan, Paveswari; Ahmad, Arshad; Abouzari-lotf, Ebrahim

2017-01-01

A new ultrasound-aided method was used to enhance grafting of 4-vinylpyridine (4-VP) and glycidyl methacrylate (GMA) monomers mixtures onto electron beam (EB) irradiated poly(ethylene-co-tetrafluoroethylene) (ETFE) film for the first time. The effects of reaction parameters such as absorbed dose, monomer concentration, reaction time on both of degree of grafting (DG) and grafting efficiency (GE) were investigated under sonication and conventional grafting at similar temperatures. Fourier transform infrared (FTIR) and atomic force microscopy (AFM) were used to monitor the impact of the applied ultrasound on composition and surfaces of the grafted films whereas 1 H-NMR was used to investigate composition of the grafting residues. The ultrasound-aided grafting of 4-VP/GMA was found to enhance both of DG% and GE remarkably. Moreover, it produced grafted ETFE films having smoother surfaces without homopolymer contamination compared to grafted films obtained from conventional grafting. The results of this study suggest that the use of ultrasound is a promising way for intensifying grafting process and improving its economy. - Highlights: • Grafting of 4-VP/GMA onto ETFE films was carried out with the aid of ultrasound. • Degree of grafting was found to be strongly dependent on reaction parameters. • Sonication remarkably enhanced the reaction kinetics and grafting efficiency. • Grafted films with smoother surfaces without homopolymer contamination were obtained. • Ultrasound aided grafting is superior to conventional one and promotes intensification.

Industrial application of electron beams for grafting and vulcanization

Energy Technology Data Exchange (ETDEWEB)

Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

1994-12-31

The topics discussed are radiation graft polymerization; industrial application of radiation grafting - ion exchange membrane for a battery separator, ammonia adsorbent, non-flammable PE (polyethylene) foam; R and D on radiation grafting, radiation vulcanization of natural rubber.

Industrial application of electron beams for grafting and vulcanization

International Nuclear Information System (INIS)

Keizo Makuuchi

1994-01-01

The topics discussed are radiation graft polymerization; industrial application of radiation grafting - ion exchange membrane for a battery separator, ammonia adsorbent, non-flammable PE (polyethylene) foam; R and D on radiation grafting, radiation vulcanization of natural rubber

Adsorption of Heavy Metals From Industrial Wastes Using Membranes Prepared by Radiation Grafting

International Nuclear Information System (INIS)

Hegazy, E. A.; Kamal, H.; Maziad, N.; Dessouki, A.M.; Aly, H.F.

1999-01-01

Preparation of synthetic membranes using simultaneous radiation grafting of acrylic acid (AAc) and styrene (Sty) individually and in a binary monomers mixture onto polypropylene (PP) has been carried out. The effect of preparation conditions such as irradiation dose, monomer and inhibitor concentration, comonomer composition on the grafting yield was investigated. The thermal stability and mechanical properties were also investigated as a function of degree of grafting. Accordingly the possibility of its practical use in industrial waste treatment is determined. The prepared cation-exchange membranes possess good mechanical properties, high thermal stability and good characteristics for separation processes. These membranes have also good affinity toward the adsorption or chelation with Fe 3+ , Pb 2+ , and Cd 2+ ions either in a mixture or exists alone in the solution

Synthesis of ion exchange membrane by radiation grafting of acrylic acid onto polyethylene

International Nuclear Information System (INIS)

Ishigaki, I.; Sugo, T.; Senoo, K.; Takayama, T.; Machi, S.; Okamoto, J.; Okada, T.

1981-01-01

Radiation grafting of vinyl monomers onto polymer films has been extensively studied by many workers. In the preirradiation method of grafting a polymer substrate is activated by irradiation (either in the presence or absence of oxygen) and subsequently allowed to react with a monomer. The preirradiation method was utilized in this study to synthesize an ion exchange membrane useful for a battery separator by grafting acrylic acid onto polyethylene film. The battery separator should be chemically and thermally stable, sufficiently durable in electrolyte as well as highly electrically conductive. Membranes made from regenerated cellulose, e.g., cellophane, have long been used as a separator in the batteries with alkaline electrolyte, such as silver oxide primary cell. However, it has poor durability, as short as one year, due to breakdown of the membrane during operation or storing. The acrylic acid-grafted polyethylene film was found to be quite useful for a separator in the alkaline batteries. This membrane has a high electric conductivity and an excellent durability. (author)

Kinetic investigations of emulsion- and solvent-mediated radiation induced graft copolymerization of glycidyl methacrylate onto nylon-6 fibres

International Nuclear Information System (INIS)

Teo Ming Ting; Paveswari Sithambaranathan

2017-01-01

Kinetic behaviour of graft copolymerisation of glycidyl methacrylate onto nylon-6 fibres in solvent- and emulsion- media was investigated. The order for the dependence of the initial rate of grafting on the monomer concentration for solvent and emulsion grafting systems were found to be 1.65 and 1.57, respectively. The order of dependence of the initial rate of grafting on the absorbed dose was found to be 1.55 for solvent and 0.62 emulsion grafting systems. The results showed that grafting in both systems is controlled by diffusion mechanism and the degree of grafting can be effectively tuned by variation of the grafting parameters. (author)

Radiation effects on biodegradable polyesters

International Nuclear Information System (INIS)

Hiroshi Mitomo; Darmawan Darwis; Fumio Yoshii; Keizo Makuuchi

1999-01-01

Poly(3-hydroxybutyrate) [P(3HB)] and its copolymer poly(3-hydroxybutyrate-co-3hydroxyvalerate) [P(3HB-co-3HV)] are microbial biodegradable polyesters produced by many types of bacteria. Poly(butylene succinate) (PBS) and poly(E-caprolactone) (PCL) are also biodegradable synthetic polyesters which have been commercialized. These thermoplastics are expected for wide usage in environmental protection and blocompatible applications. Radiation grafting of hydrophilic monomers onto many polymers, e.g., polyethylene and polypropylene has been studied mainly for biomedical applications. In the present study, radiation-induced graft polymerization of vinyl monomers onto PHB and P(3HB-co-3HV) was carried out and improvement of their properties was studied. Changes in the properties and biodegradability were compared with the degree of grafting. Radiation-induced crosslinking of PBS and PCL which relatively show thermal and irradiation stability was also carried out to improve their thermal stability or processability. Irradiation to PBS and PCL mainly resulted in crosslinking and characterization of these crosslinked polyesters was investigated

Radiation-induced erectile dysfunction: Recent advances and future directions

Directory of Open Access Journals (Sweden)

Javed Mahmood, PhD

2016-07-01

Full Text Available Prostate cancer is one of the most prevalent cancers and the second leading cause of cancer-related deaths in men in the United States. A large number of patients undergo radiation therapy (RT as a standard care of treatment; however, RT causes erectile dysfunction (radiation-induced erectile dysfunction; RiED because of late side effects after RT that significantly affects quality of life of prostate cancer patients. Within 5 years of RT, approximately 50% of patients could develop RiED. Based on the past and current research findings and number of publications from our group, the precise mechanism of RiED is under exploration in detail. Recent investigations have shown prostate RT induces significant morphologic arterial damage with aberrant alterations in internal pudendal arterial tone. Prostatic RT also reduces motor function in the cavernous nerve which may attribute to axonal degeneration may contributing to RiED. Furthermore, the advances in radiogenomics such as radiation induced somatic mutation identification, copy number variation and genome-wide association studies has significantly facilitated identification of biomarkers that could be used to monitoring radiation-induced late toxicity and damage to the nerves; thus, genomic- and proteomic-based biomarkers could greatly improve treatment and minimize arterial tissue and nerve damage. Further, advanced technologies such as proton beam therapy that precisely target tumor and significantly reduce off-target damage to vital organs and healthy tissues. In this review, we summarize recent advances in RiED research and novel treatment modalities for RiED. We also discuss the possible molecular mechanism involved in the development of RiED in prostate cancer patients. Further, we discuss various readily available methods as well as novel strategies such as stem cell therapies, shockwave therapy, nerve grafting with tissue engineering, and nutritional supplementations might be used to

Investigations to increase the efficiency of fluorine and boron removal from groundwater using radiation-induced graft polymerization adsorbent

International Nuclear Information System (INIS)

Iyatomi, Yosuke; Shimada, Akiomi; Ogata, Nobuhisa; Sugihara, Kozo; Hoshina, Hiroyuki; Seko, Noriaki; Kasai, Noboru; Ueki, Yuji; Tamada, Masao

2010-01-01

The Japan Atomic Energy Agency is performing a research project in the Mizunami Underground Research Laboratory (MIU) to build a firm scientific and technological basis for the studies of the deep underground environment in crystalline rock. In the project, it is necessary to reduce the fluorine and boron concentrations in groundwater pumped from the MIU shafts to levels below the environmental standards. This is done at the MIU water treatment facility using coagulation and ion exchange treatment for fluorine and boron, respectively. In addition, in 2006, research started on the efficient treatment of groundwater for removal of fluorine and boron using a radiation-induced graft polymerization adsorbent. The adsorbent removed boron at a flow rate (space velocity (SV)=120 h -1 ) higher than that of a general ion exchange resin (SV=10 h -1 ) and the adsorbent could be used repeatedly. It was also apparent that the pH of groundwater had an influence on adsorption performance. With respect to fluorine removal, more than 90% of fluorine was removed. However, the adsorbent for fluorine showed a lower adsorption capacity than that for boron. The reason for this difference is considered to be related to the initial concentration difference between fluorine and boron in the groundwater. Therefore, it is necessary to define the initial concentrations of dissolved materials, which can be used as better indicators of the performance of the adsorbent. (author)

Radiation-Induced Grafting for the Synthesis of Adsorbents for Phosphate and Chromate Removal from Aqueous Systems

Energy Technology Data Exchange (ETDEWEB)

Kavakli, P A; Kavakli, C; Guven, O [Department of Chemistry, Hacettepe University, Beytepe, 06800, Ankara (Turkey)

2012-09-15

Nonwoven fabrics made of PE coated PP fibres were irradiated by accelerated electrons in inert atmospheres for grafting of two different monomers, glycidyl methacrylate and dimethylaminoethyl methacrylate. Grafting conditions were optimized by a systematic investigation of the effects of absorbed dose, monomer concentration, grafting reaction temperature and duration. 150% grafted copolymers were later modified by protonation and quaternization of poly(dimethylaminoethyl methacrylate) chains and by Cu(II) loading of dipyridyl amine modified poly(glycidyl methacrylate) graft chains. The PE/PP based adsorbents thus prepared were used for their suitability of removing phosphate and chromate ions from aqueous systems. Adsorption/removal studies were carried out in both batch and continuous flow type systems. The selectivity of adsorption of phosphate ions in the presence of other competing anions were also checked showing the enhanced selectivity for phosphate ions. (author)

UV-Induced [2+2] Grafting-To Reactions for Polymer Modification of Cellulose.

Science.gov (United States)

Conradi, Matthias; Ramakers, Gijs; Junkers, Thomas

2016-01-01

Benzaldehyde-functional cellulose paper sheets have been synthesized via tosylation of cellulose (Whatman No 5) followed by addition of p-hydroxy benzaldehyde. Via UV-induced Paterno-Büchi [2+2] cycloaddition reactions, these aldehyde functional surfaces are grafted with triallylcyanurate, trimethylolpropane allyl ether, and vinyl chloroacetate. In the following, allyl-functional polymers (poly(butyl acrylate), pBA, Mn = 6990 g mol(-1) , Đ = 1.12 and poly(N-isopropyl acrylamide), pNIPAAm, Mn = 9500 g mol(-1) , Đ = 1.16) synthesized via reversible addition fragmentation chain transfer polymerization are conjugated to the celloluse surface in a UV-induced grafting-to approach. With pBA, hydrophobic cellulose sheets are obtained (water contact angle 116°), while grafting of pNIPAAm allows for generation of "smart" surfaces, which are hydrophilic at room temperature, but that become hydrophobic when heated above the characteristic lower critical solution temperature (93° contact angle). The Paterno-Büchi reaction has been shown to be a versatile synthetic tool that also performs well in grafting-to approaches whereby its overall performance seems to be close to that of radical thiol-ene reactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Capturing of staphylococcus aureus onto an interface containing graft chains

International Nuclear Information System (INIS)

Lee, W.; Furusaki, Shintaro; Saito, Kyoichi; Sugo, Takanobu; Makuuchi, Keizo.

1995-01-01

A microbial-cell-capturing material was prepared by radiation-induced grafting of glycidyl methacrylate onto a polyethylene-based fiber before the introduction of diethylamine. The prepared fiber was tested against a Staphylococcus aureus and Escherichia coli solution. The results showed that the grafted-type fiber had a capturing rate constant 1000-fold higher than the commercial crosslinked-type bead for S. aureus and that an activation energy of 39 kJ/mol was obtained for the microbial-cell-capturing action. (author)

Solvent and irradiation doses effects on the ion exchange capacity of sulfonated styrene grafted PVDF

International Nuclear Information System (INIS)

Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B.

2011-01-01

Polymers exhibiting ion exchange capacity are studied for many years due to their application in several fields, such as membranes for proton exchange fuel cells, filtration membranes, heavy ions recovery and artificial muscles and sensors. Radiation induced grafting followed by sulfonation is a well-known way to obtain ion exchange polymers. Fluorinated polymers are frequently used as polymeric matrix for grafting due to their excellent physicochemical properties. Radiation induced grafting of styrene into poly (vinylidene fluoride) (PVDF) by simultaneous method in 1:1 styrene/toluene or styrene/N,N-dimethylformamide solutions was studied. Irradiations were performed under nitrogen atmosphere, room temperature and at doses of 5, 10 and 20 kGy with dose rate of 5 kGy.h -1 from a 60 Co gamma source. After washing, grafted materials were sulfonated in 10% chlorosulfonic acid/1,2-dichloroethane solutions for 4 h at room temperature. Characterization shows that increasing irradiation dose corresponds to increases in the grafting yield (GY %) gravimetrically calculated and these different solvents shows different grafting behaviors. Toluene allows no more than 3 % of grafting while DMF allows up to 55 % of grafting in the same condition. Grafting in toluene solution occurs on the surface and in DMF solution it occurs in the bulk, as confirmed by SEM. Both irradiation doses and solvent used have direct effects in the ion exchange capacities (calculated after titrations). FT-IR spectra exhibit new peaks after grafting and after sulfonation, attributed to grafted monomer and sulfonic groups attached to the styrene. DSC shows differences in thermal behavior of the polymer before and after each step. (author)

Solvent and irradiation doses effects on the ion exchange capacity of sulfonated styrene grafted PVDF

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2011-07-01

Polymers exhibiting ion exchange capacity are studied for many years due to their application in several fields, such as membranes for proton exchange fuel cells, filtration membranes, heavy ions recovery and artificial muscles and sensors. Radiation induced grafting followed by sulfonation is a well-known way to obtain ion exchange polymers. Fluorinated polymers are frequently used as polymeric matrix for grafting due to their excellent physicochemical properties. Radiation induced grafting of styrene into poly (vinylidene fluoride) (PVDF) by simultaneous method in 1:1 styrene/toluene or styrene/N,N-dimethylformamide solutions was studied. Irradiations were performed under nitrogen atmosphere, room temperature and at doses of 5, 10 and 20 kGy with dose rate of 5 kGy.h{sup -1} from a {sup 60}Co gamma source. After washing, grafted materials were sulfonated in 10% chlorosulfonic acid/1,2-dichloroethane solutions for 4 h at room temperature. Characterization shows that increasing irradiation dose corresponds to increases in the grafting yield (GY %) gravimetrically calculated and these different solvents shows different grafting behaviors. Toluene allows no more than 3 % of grafting while DMF allows up to 55 % of grafting in the same condition. Grafting in toluene solution occurs on the surface and in DMF solution it occurs in the bulk, as confirmed by SEM. Both irradiation doses and solvent used have direct effects in the ion exchange capacities (calculated after titrations). FT-IR spectra exhibit new peaks after grafting and after sulfonation, attributed to grafted monomer and sulfonic groups attached to the styrene. DSC shows differences in thermal behavior of the polymer before and after each step. (author)

Allogeneic radiation chimeras induced in SPF mice

International Nuclear Information System (INIS)

Sado, Toshihiko; Kamisaku, Hitoko

1977-01-01

During the past two decades much has been learned concerning the immunobiology of bone marrow chimeras induced in experimental animals as well as in man. However, from the basic as well as clinical points of view, there still remain many unsolved questions yet to be resolved. In this presentation, we discussed some of our recent results on the immunobiology of radiation chimeras induced in specific-pathogen-free (SPF) mice. These included the following: (a) contribution of graft versus host reaction (GVHR) as well non- GVHR mediated immunologic mechanism(s) to the expression of immunologic dysfunctions observed in allogeneic and certain semiallogeneic chimeras, (b) existence of immunoregulatory mechanism as a basis for the apparent lack of immunologic reactivity (tolerance) to the host- as well as to the donor-type alloantigens in situ in successful allogeneic bone marrow chimeras, and (c) the effect of microflora of the environment on the stability of such immunoregulatory mechanisms and its possible mechanism of action. (auth.)

Electron-beam-induced post-grafting polymerization of acrylic acid onto the surface of Kevlar fibers

Science.gov (United States)

Xu, Lu; Hu, Jiangtao; Ma, Hongjuan; Wu, Guozhong

2018-04-01

The surface of Kevlar fibers was successfully modified by electron beam (EB)-induced post-grafting of acrylic acid (AA). The generation of radicals in the fibers was confirmed by electron spin resonance (ESR) measurements, and the concentration of radicals was shown to increase as the absorbed dose increased, but decrease with increasing temperature. The influence of the synthesis conditions on the degree of grafting was also investigated. The surface microstructure and chemical composition of the modified Kevlar fibers were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The SEM images revealed that the surface of the grafted fibers was rougher than those of the pristine and irradiated fibers. XPS analysis confirmed an increase in C(O)OH groups on the surface of the Kevlar fibers, suggesting successful grafting of AA. These results indicate that EB-induced post-grafting polymerization is effective for modifying the surface properties of Kevlar fibers.

Effect of gamma radiation on the mechanical and barrier properties of HEMA grafted chitosan-based films

International Nuclear Information System (INIS)

Khan, Avik; Huq, Tanzina; Khan, Ruhul A.; Dussault, Dominic; Salmieri, Stephane; Lacroix, Monique

2012-01-01

Chitosan films were prepared by dissolving 1% (w/v) chitosan powder in 2% (w/v) aqueous acetic acid solution. Chitosan films were prepared by solution casting. The values of puncture strength (PS), viscoelasticity coefficient and water vapor permeability (WVP) of the films were found to be 565 N/mm, 35%, and 3.30 g mm/m 2 day kPa, respectively. Chitosan solution was exposed to gamma irradiation (0.1–5 kGy) and it was revealed that PS values were reduced significantly (p≤0.05) after 1 kGy dose and it was not possible to form films after 5 kGy. Monomer, 2-hydroxyethyl methacrylate (HEMA) solution (0.1–1%, w/v) was incorporated into the chitosan solution and the formulation was exposed to gamma irradiation (0.3 kGy). A 0.1% (w/v) HEMA concentration at 0.3 kGy dose was found optimal-based on PS values for chitosan grafting. Then radiation dose (0.1–5 kGy) was optimized for HEMA grafting. The highest PS values (672 N/mm) were found at 0.7 kGy. The WVP of the grafted films improved significantly (p≤0.05) with the rise of radiation dose. - highlights: ► HEMA and Silane monomer were incorporated into the MC-based formulation and films. ► Films were exposed to gamma radiation. ► HEMA containing films showed the highest PS values. ► Surface morphology of the grafted films suggested better appearance.

Structural, thermal and ion transport properties of radiation grafted lithium conductive polymer electrolytes

Energy Technology Data Exchange (ETDEWEB)

Nasef, Mohamed Mahmoud [Business and Advanced Technology Centre (BATC), Universiti Teknologi Malaysia, Jalan Semarak, 54100 Kuala Lumpur (Malaysia)]. E-mail: mahmoudeithar@mailcity.com; Saidi, Hamdani [Business and Advanced Technology Centre (BATC), Universiti Teknologi Malaysia, Jalan Semarak, 54100 Kuala Lumpur (Malaysia)

2006-10-10

Structural, thermal and ion transport properties of lithium conductive polymer electrolytes prepared by radiation-induced grafting of styrene onto poly(vinylidene fluoride) (PVDF) films and subsequent activation with LiPH{sub 6}/EC/DEC liquid electrolyte were investigated in correlation with the content of the grafted polystyrene (Y%). The changes in the structure were studied using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Thermal gravimetric analysis (TGA) was used to evaluate the thermal stability. The ionic conductivity was measured by means of ac impedance spectroscopy at various temperatures. The polymer electrolytes were found to undergo considerable structural and morphological changes that resulted in a noticeable increase in their ionic conductivity with the increase in Y% at various temperatures (25-65 deg. C). The ionic conductivity achieved a value of 1.61 x 10{sup -3} S cm{sup -1} when Y of the polymer electrolyte reached 50% and at 25 deg. C. The polymer electrolytes also showed a multi-step degradation behaviour and thermal stability up to 120 deg. C, which suits normal lithium battery operation temperature range. The overall results of this work suggest that the structural changes took place in PVDF matrix during the preparation of these polymer electrolytes have a strong impact on their various properties.

Raman spectroscopy of poly (3-hydroxybutyrate) modified with poly (vinyl acetate) by radiation- induced copolymerization

International Nuclear Information System (INIS)

Gonzalez, Maykel; Galego Fernandez, Norma; Ortiz del Toro, Pedro; Rapado, Manuel; Paredes

2007-01-01

Poly (3-hydroxybutyrate) (PHB) is an important material used in the field of medicine. However in common conditions, PHB has some deficiencies. It is very brittle and slightly hydrophobic polymer. This somewhat limit its applications. Radiation chemistry can be used to improve its chemical properties. In the present study, the substrate, modified by radiation-induced graft copolymerization with vinyl acetate (VAc), was characterized using FTIR and Raman spectroscopy. FTIR spectroscopy did not reveal any significant bands but Raman spectroscopy revealed the formation of a new band that characterize the material

Development and Characterization of Photoinduced Acrylamide-Grafted Polylactide Films for Biomedical Applications

Directory of Open Access Journals (Sweden)

Mijanur Rahman

2017-01-01

Full Text Available Surface grafting of biodegradable/biocompatible polylactide (PLA films by a UV-assisted reaction has been developed by employing a hydrophilic acrylamide (Am monomer, an N,N′-methylenebisacrylamide (MBAm cross-linker, and a camphorquinone (CQ/N,N′-dimethylaminoethylmethacrylate (DMAEMA photoinitiator/coinitiator system. The accomplishment of the process is confirmed by FTIR and XPS analyses. Physicochemical changes of the grafted PLA films are evaluated in terms of chemical structures, radiation-induced degradation followed by crystallization, morphology, thermal properties, and mechanical behavior. The results reveal that a low degree of PLA degradation through chain scission is observed in both blank and grafted PLA films. This generates more polar chain ends that can further induce crystallization. Results from contact angle measurements indicate that the grafted films have higher hydrophilicity and pH-responsive behavior. The incorporation of PAm on the film’s surface and the induced crystallization lead to improvements in certain aspects of mechanical properties of the films. The materials have high potential for use in biomedical and environmental applications, such as cell culture substrates or scaffolds or pH-sensitive absorbents.

Effect of solubility parameter of monomers on electron beam induced graft-polymerization onto polyethylene films

International Nuclear Information System (INIS)

Mori, Koji; Koshiishi, Kenji; Masuhara, Ken-ichi

1991-01-01

Electron beam induced graft-polymerization by the mutual irradiation technique of monomers with different solubility parameters δ onto low density polyethylene films (LDPE) and high density polyethylene films (HDPE) were investigated at high dose rates (25 Mrad per second). Graft-polymerization mechanisms were discussed on the basis of grafting rates, surface tensions, atomic ratios of surface by XPS, and SEM images of the grafted films. Grafting rates decreased with increasing δ of monomers, and grafting rates onto LDPE were larger than those onto HDPE. Graft chain contents on surface, which were evaluated in terms of surface tensions and atomic ratios of the surface, increased with increasing δ of monomers, and graft chain contents on surface of HDPE were higher than those of LDPE. It is assumed that mutual solubility of PE and monomers, i.e., infiltration of monomers into PE during graft-polymerization influence grafting rates and graft sites in films. In case of high mutual solubility, grafting rates were large and graft sites spread from the surface into bulk. On the other hand, in case of low mutual solubility, grafting rates were small and graft sites localized on the surface of films. (author)

Radiation-induced mouse chimeras: a cellular analysis of the major lymphoid compartments, factors affecting lethal graft versus host disease and host-tumor interactions

International Nuclear Information System (INIS)

Almaraz, R.

1981-01-01

The major lymphoid compartments of allogeneic bone marrow chimeras were evaluated for the extent of cell chimerism and distribution of Thy 1 and la bearing cells. These chimeras contained lymphoid cell primarily of donor origin. The bone marrow compartment was a mixture of host and donor origin cells. The distribution of Thy 1 and la bearing cells was similar as in normal mice. The effect of adult thymectomy alone or followed by whole-body irradiation and bone marrow reconstitution on the distribution of the Thy 1 positive cells was also investigated. Thymectomy with or without WBI and bone marrow reconstitution significantly lowered the number of Thy 1 bearing cells in the blood and spleen. The number of la bearing cells did not appear to be affected by thymectomy. The role of circulating lymphoid cells in the incidence of lethal graft versus host disease (GVHD) in radiation induced fully allogeneic mouse chimeras was studied. Mice reconstituted with allogeneic bone marrow from bled donors had a statistically lower incidence of GVHD than those reconstituted with bone marrow from unbled donors. Addition of mature peripheral lymphocytes from blood to the reconstituting bone marrow cells from bled donors reduplicated the high incidence of lethal GVHD. It was demonstrated that the bone marrow of mice not exsanguinated prior to harvesting of bone marrow contained significant numbers of peripheral contaminating cells in the harvested bone marrow. The role of suppressor cell elimination in resisting tumor growth was investigated using radiation induced mouse chimeras. Local effects of irradiation alone at the site of tumor inoculation could account for this lack of growth

Effect of solubility parameter of solvents on electron beam induced graft-polymerization onto polyethylene films

International Nuclear Information System (INIS)

Mori, Koji; Koshiishi, Kenji; Masuhara, Ken-ichi

1992-01-01

Electron beam induced graft-polymerization by the mutual irradiation technique of methyl methacrylate (MMA) and methacrylic acid (MAAc) blended with solvents, which have different solubility parameters δ, onto high density polyethylene films (PE) were investigated at high dose rates (25 Mrad per second). Graft-polymerization mechanisms were discussed on the basis of grafting rates, surface tensions, atomic rations on the surface by XPS, and SEM images of the grafted films. Grafting rates decreased with increasing δ of solvents, and grafting rates for MMA were larger than those for MAAc. Graft chain contents on the surface, which were evaluated in terms of surface tensions and atomic ratios on the surface, increased with increasing δ of solvents, and graft chain contents on the surface of MAAc grafted PE were higher than those of MMA grafted PE. It is assumed that mutual solubility of PE and solvents (monomer solutions), i.e., infiltration of monomer solutions into PE during graft-polymerization, influenced grafting rates and graft sites in films. In case of high mutual solubility, grafting rates were large and graft sites spread from the surface into bulk. On the other hand, in case of low mutual solubility, grafting rates were small and graft sites localized on the surface of films. (author)

A proton-exchange membrane prepared by the radiation grafting of styrene and silica into polytetrafluoroethylene films

Science.gov (United States)

Yu, Hongyan; Shi, Jianheng; Zeng, Xinmiao; Bao, Mao; Zhao, Xinqing

2009-07-01

A polytetrafluoroethylene (PTFE) based organic-inorganic hybrid proton-exchange membrane was prepared from simultaneous radiation grafting of styrene (St) into porous PTFE membrane with the in situ sol-gel reaction of tetraethoxysilane (TEOS) followed by sulfonation in fuming sulfonic acid. The effect of radiation on the sol-gel reaction was studied. The results show that radiation promotes the sol-gel reaction with the help of St at room temperature. Incorporated silica gel helps to produce higher degree of grafting (DOG). SEM analysis was conducted to confirm that the inorganic silicon oxide was introduced to produce hybrid membrane in this work. The proton conductivity of membrane evaluated using electrochemical impedance spectroscopy is much higher (14.3×10 -2 S cm -1) than that of Nafion ® 117 at temperature of 80 °C with acceptable water uptake 51 wt%.

Preliminary studies on 1-vinyl-2-pyrrolidone grafting onto cellulose by pre-irradiation method

Energy Technology Data Exchange (ETDEWEB)

Severich, Patrick; Dutra, Rodrigo da Costa; Kodama, Yasko, E-mail: ykodama@ipen.br, E-mail: patrick.severich@ipen.br, E-mail: rodrigo.dutra@ipen.br [Instituto de Pesquisas Energética s e Nucleares (IPEN-CNEN/SP), São Paulo, SP (Brazil)

2017-07-01

Cellulose is considered a renewable biopolymer most abundant in nature. Better functional surfaces can be Obtained by modifying cellulose. On the other hand, poly vinyl pyrrolidone, PVP, is a synthetic nontoxic, water-soluble polymer frequently used in an extensive variety of applications including several pharmaceutical applications. Grafting 1-vinyl-2-pyrrolidone, NVP, onto polymeric cellulose can be obtained by ionizing radiation. Ionizing radiation grafting can be affected by several factors as environment, solvent, monomer concentration, temperature of graft reaction. Grafting by ionizing radiation can be performed by three methods, pre-irradiation, oxidation by peroxide and simultaneous irradiation. In this study, it was used pre-irradiation method of cellulose. Paper filter without ash, NVP without purification was used in this study. Paper samples were exposed to electron beam from Dynamitron Accelerator with radiation absorbed dose of 25 kGy. Influence of NVP concentration, temperature of reaction after irradiation on degree of grafting (DG) was studied. Also, cellulose radicals of grafted paper samples was studied by electron paramagnetic resonance using a Bruker X-band ESR at room temperature just after heating reaction. Small decrease of cellulose radicals was observed with increasing reaction temperature. It was observed DG small increase with increasing concentration of monomer in solution of water ethanol 50-50 v:v and rising temperature of reaction. Further tests using simultaneous method of grafting of NVP in cellulose paper, in water:ethanol 75:25 v:v solution, induced by gamma irradiation were performed. It was observed homopolymerization forming PVP with increasing monomer concentration. (author)

Preliminary studies on 1-vinyl-2-pyrrolidone grafting onto cellulose by pre-irradiation method

International Nuclear Information System (INIS)

Severich, Patrick; Dutra, Rodrigo da Costa; Kodama, Yasko

2017-01-01

Cellulose is considered a renewable biopolymer most abundant in nature. Better functional surfaces can be Obtained by modifying cellulose. On the other hand, poly vinyl pyrrolidone, PVP, is a synthetic nontoxic, water-soluble polymer frequently used in an extensive variety of applications including several pharmaceutical applications. Grafting 1-vinyl-2-pyrrolidone, NVP, onto polymeric cellulose can be obtained by ionizing radiation. Ionizing radiation grafting can be affected by several factors as environment, solvent, monomer concentration, temperature of graft reaction. Grafting by ionizing radiation can be performed by three methods, pre-irradiation, oxidation by peroxide and simultaneous irradiation. In this study, it was used pre-irradiation method of cellulose. Paper filter without ash, NVP without purification was used in this study. Paper samples were exposed to electron beam from Dynamitron Accelerator with radiation absorbed dose of 25 kGy. Influence of NVP concentration, temperature of reaction after irradiation on degree of grafting (DG) was studied. Also, cellulose radicals of grafted paper samples was studied by electron paramagnetic resonance using a Bruker X-band ESR at room temperature just after heating reaction. Small decrease of cellulose radicals was observed with increasing reaction temperature. It was observed DG small increase with increasing concentration of monomer in solution of water ethanol 50-50 v:v and rising temperature of reaction. Further tests using simultaneous method of grafting of NVP in cellulose paper, in water:ethanol 75:25 v:v solution, induced by gamma irradiation were performed. It was observed homopolymerization forming PVP with increasing monomer concentration. (author)

Radiation Graft Copolymerization of Butyl methacrylate and Acrylamide onto Low density polyethylene and polypropylene films and its application in wastewater treatment

International Nuclear Information System (INIS)

Abdel Ghaffar, A.M.; El-Arnaouty, M.B.; Aboulfotouh, M.E.; Taher, N.H.

2012-01-01

Butyl methacrylate and Acrylamide (BMA/AAm) comonomer were grafted onto Low density polyethylene and polypropylene films using direct gamma radiation by grafting technique. The influences of grafting conditions such as solvent, monomer concentration, monomer composition, and irradiation dose on the grafting yield were determined. It was found that, using DMF as a solvent enhanced the copolymerization process. The grafting yield increases with comonomer concentration up to 60 %. . Also it was found that, the degree of grafting of (BMA/AAm) onto LDPE and PP films increases as the AAm content increases till optimum value at (50:50) %. The grafting yield of the comonomer found to be increased with increasing radiation dose. It was observed that the degree of grafting of polyethylene films is higher than that for polypropylene films. Some selected properties of the graft copolymers, such as water uptake and thermal properties determined by using thermogravimetric analysis (TGA) has been carried out. The morphology and structure of grafted films was investigated by using SEM, IR and X-ray diffraction. The improvement in such properties of the prepared copolymers was observed which makes possible uses in some practical applications such as in the removal of some heavy metals from wastewater. It was found that the maximum metal uptake by the copolymer is ordered in the sequence of Cu 2+ > CO 2+ > Ni 2+ ions.

Aluminum uptake from natural waters by a radiation-grafted membrane

Energy Technology Data Exchange (ETDEWEB)

Bazante-Yamaguishi, Renata; Moura, Eduardo; Manzoli, Jose E.; Geraldo, Aurea B.C., E-mail: ageraldo@ipen.br, E-mail: ryamaguishi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2013-07-01

Styrene grafted, chemically modified polymeric membranes were used to carry off aluminum of drinking water from wells located at Billings dam region. The membranes comprised polymeric substrates of PVC (polyvinylchloride) and PP (polypropylene), which were mutually grafted with gamma radiation. The chemical modification included three basic reaction paths: Friedel-Crafts acylation, 2-methylanisole coupling and a final oxidation; this modification enables aluminum selectivity on the membrane. This chemical process inserts a salicylated derivative bonded onto the aromatic ring of styrene; such molecular arrangement is responsible for complexation of aluminum ions. The aluminum sorption capacity of these membranes was evaluated firstly from an aluminum control solution, where parameters like the ideal pH value for aluminum sorption and the interfering species were studied and correlated to know the best conditions for aluminum uptake. Later, the membranes were used for aluminum remediation of natural waters (real-life samples). The applicability results and limits are then discussed. (author)

Aluminum uptake from natural waters by a radiation-grafted membrane

International Nuclear Information System (INIS)

Bazante-Yamaguishi, Renata; Moura, Eduardo; Manzoli, Jose E.; Geraldo, Aurea B.C.

2013-01-01

Styrene grafted, chemically modified polymeric membranes were used to carry off aluminum of drinking water from wells located at Billings dam region. The membranes comprised polymeric substrates of PVC (polyvinylchloride) and PP (polypropylene), which were mutually grafted with gamma radiation. The chemical modification included three basic reaction paths: Friedel-Crafts acylation, 2-methylanisole coupling and a final oxidation; this modification enables aluminum selectivity on the membrane. This chemical process inserts a salicylated derivative bonded onto the aromatic ring of styrene; such molecular arrangement is responsible for complexation of aluminum ions. The aluminum sorption capacity of these membranes was evaluated firstly from an aluminum control solution, where parameters like the ideal pH value for aluminum sorption and the interfering species were studied and correlated to know the best conditions for aluminum uptake. Later, the membranes were used for aluminum remediation of natural waters (real-life samples). The applicability results and limits are then discussed. (author)

The fate of allogenic radiation sterilized bone grafts controlled by the electron spin resonance spectrometry

International Nuclear Information System (INIS)

Ostrowski, K.; Dziedzic-Goclawska, A.

1981-01-01

The normal fate of bone grafts is their resorption and substitution by the own host's bone tissue. This phenomenon described as creeping substitution process was controlled using biopsies from the grafted region in allogenic experimental system. Electron spin resonance (ESR) spectrometry was used for independent evaluation of resorption and substitution processes. The measurements were based on the process of induction in the hydroxyapatite (HA) crystals of bone mineral of stable paramagnetic centers which can be detected by ESR spectrometry. The loss of total amount of spins connected with the paramagnetic centers expressed in percent describes the kinetics of resorption. The changes in the concentration of spins due to the ''dilution'' of spins implanted with the graft by the nonirradiated ingrowing host's own bone describe the kinetics of the substitution process. Allogenic bone of calvaria was grafted orthotopically into rabbits after lyophilization and radiation sterilization with a dose of 3.5 Mrads. The process of graft's rebuilding was evaluated using the described ESR method. The application of the described technique in the human clinic is possible. (author)

Models for radiation-induced tissue degeneration and conceptualization of rehabilitation of irradiated tissue by cell therapy

International Nuclear Information System (INIS)

Phulpin, Berengere

2011-01-01

Radiation therapy induced acute and late sequelae within healthy tissue included in the irradiated area. In general, lesions are characterized by ischemia, cell apoptosis and fibrosis. In this context, cell therapy using bone marrow mesenchymal stem cells (BMSC) might represent an attractive new therapeutic approach, based partly on their angiogenic ability and their involvement in the natural processes of tissue repair. The first part of this work consisted in the development of experimental mouse model of radio-induced tissue degeneration similar to that occurring after radiotherapy. The aim was to better understand the physiopathological mechanisms of radiation-induced tissue damage and to determine the best treatment strategy. The second part of this work investigated the feasibility of autologous BMSC therapy on the murine model of radiation previously established with emphasis on two pre-requisites: the retention of the injected cells within the target tissue and the evaluation of the graft on bone metabolism. This preclinical investigation in a mouse model constitutes an essential step allowing an evaluation of the benefit of cell therapy for the treatment of radiation-induced tissue injury. Data from these studies could allow the proposal of clinical studies [fr

Radiation-induced apoptosis

International Nuclear Information System (INIS)

Ohyama, Harumi

1995-01-01

Apoptosis is an active process of gene-directed cellular self-destruction that can be induced in many cell types via numerous physiological and pathological stimuli. We found that interphasedeath of thymocytes is a typical apoptosis showing the characteristic features of apoptosis including cell shrinkage, chromatin condensation and DNA degradation. Moderate dose of radiation induces extensive apoptosis in rapidly proliferating cell population such as the epithelium of intestinal crypt. Recent reports indicate that the ultimate form of radiation-induced mitotic death in several cells is also apoptosis. One of the hallmarks of apoptosis is the enzymatic internucleosomal degradation of chromatin DNA. We identified an endonuclease responsible for the radiation-induced DNA degradation in rat thymocytes. The death-sparing effects of interrupting RNA and protein synthesis suggested a cell genetic program for apoptosis. Apoptosis of thymocytes initiated by DNA damage, such as radiation and radio mimetic substance, absolutely requires the protein of p53 cancer suppresser gene. The cell death induced by glucocorticoid, or aging, has no such requirement. Expression of oncogene bcl-2 rescues cells from the apoptosis. Massive apoptosis in radiosensitive cells induced by higher dose radiation may be fatal. It is suggested that selective apoptotic elimination of cells would play an important role for protection against carcinogenesis and malformation through removal of cells with unrepaired radiation-induced DNA damages. Data to evaluate the significance of apoptosis in the radiation risk are still poor. Further research should be done in order to clarify the roles of the cell death on the acute and late effects of irradiation. (author)

Highly hydrophilic ultra-high molecular weight polyethylene powder and film prepared by radiation grafting of acrylic acid

Energy Technology Data Exchange (ETDEWEB)

Wang, Honglong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xu, Lu; Li, Rong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Pang, Lijuan [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Hu, Jiangtao; Wang, Mouhua [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Wu, Guozhong, E-mail: wuguozhong@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

2016-09-30

Highlights: • Hydrophilic UHMWPE powder and film were obtained by γ-ray pre-irradiation grafting of AA. • A low concentration of AA solution was used for surface modification of UHMWPE. • A small grafting yield of AA sufficiently improved hydrophilicity of UHMWPE powder and film. - Abstract: The surface properties of ultra-high molecular weight polyethylene (UHMWPE) are very important for its use in engineering or composites. In this work, hydrophilic UHMWPE powder and film were prepared by γ-ray pre-irradiation grafting of acrylic acid (AA) and further neutralization with sodium hydroxide solution. Variations in the chemical structure, grafting yield and hydrophilicity were investigated and compared. FT-IR and XPS analysis results showed that AA was successfully grafted onto UHMWPE powder and film; the powder was more suitable for the grafting reaction in 1 wt% AA solution than the film. Given a dose of 300 kGy, the grafting yield of AA was ∼5.7% for the powder but ∼0.8% for the film under identical conditions. Radiation grafting of a small amount of AA significantly improved the hydrophilicity of UHMWPE. The water contact angle of the UHMWPE-g-PAA powder with a grafting yield of AA at ∼5.7% decreased from 110.2° to 68.2°. Moreover, the grafting powder (UHMWPE-g-PAA) exhibited good dispersion ability in water.

Experiment of radiation-resistant materials for nuclear powers generating station

International Nuclear Information System (INIS)

Choe, J.H.; Lee, C.K.; Kong, Y.K.; Chang, H.S.

1981-01-01

The properties of polyethylene materials exhibit good insulation and radiation resistance, but exhibit poor flame resistance. Flame retardant properties of the polyethylene were improved by the radiation induced grafting, coating or cross-linking. When the various flame retardants were fixed onto polyethylene, the amount of fixation in grafting or coating was increased with the increase of radiation dosages. In the case of grafting, it is necessary for high grafting yield that the polyethylene films were swelled before irradiation with γ-rays or electron beams. It is the suitable method for the fixation of flame retardant that polyethylene samples were blended with various flame retardants at 125 0 C and then blended polymers were crosslinked by the electron beams at room temperature

Enhanced interfacial radiation-induced reaction for improving the interfacial adhesion of incompatible polymer blend PP/BR

International Nuclear Information System (INIS)

Liu Changhai; Yang Huili; Xu Jun

1995-01-01

γ-radiation induced interfacial changes of incompatible polymer isotactic polypropylene (PP) and cis1,4-polybutadiene (BR) blends containing polyfunctional monomer (PFM) triallyl isocyanurate (TAIC) were investigated. The results of the study are as following: PP is incompatible with BR; TAIC is hardly dissolved in both PP and BR; when blended with PP/BR, the concentration of TAIC in the interfacial region is higher than that in dispersion phase of BR or matrix of PP. The crosslinking and/or grafting of which TAIC occurred under radiation in the interfacial region anchored the dispersed BR phase to PP matrix. The interaction between adjacent phases is changed from sole van der Waals force to co-action of both chemical bond and molecular forces. Crosslinking between adjacent phases links the dispersed phase with PP matrix, and grafting in the boundary regions increases the thickness of interface. These result in a good interfacial adhesion between dispersed phase and matrix. (author)

Functionalization of polypropylene by radiation grafting of acryloyl chloride and sterification with disperse red

International Nuclear Information System (INIS)

Bucio, E.; Burillo, G.; Carreon, M.P.; Ogawa, T.

2002-01-01

Complete text of publication follows. A practical method for obtaining films containing functional groups on the surface, is the gamma ray-induced grafting of acryloyl or methacryloyl chloride on the films, followed by the reaction of hydroxy or amino groups of the functional compounds. Direct grafting of acrylates or methacrylates with bulky functional groups onto films of polyethylene, polypropylene, polycarbonate, etc, is often encounter difficulty in polymerization of bulky monomers, loss due to homopolymerization, etc. In this work, polypropylene (PP) films were irradiated by gamma rays of Co-60 (Gamma Beam 651 PT source) and grafted with acryloyl chloride; grafting was carried out by direct and phase vapor direct method, at a dose rate of 5.1 kGy/h, different acryloyl concentration on toluene, and doses from 1 to 5 kGy, at room temperature. The unreacted acryloyl chloride and its homopolymer were removed by chloroform extraction. The grafted poly(acryloyl chloride) was then reacted with Disperse Red 1,2-[4-(4-nitrophenylazo)-N-ethylphenylamino] ethanol. The grafted films were characterized by NMR, FTIR-ATR, Visible Spectroscopy, DSC, X-ray diffractometry, SEM, AFM, NMR of solids and Elemental Analysis. Scanning electron micrographs of fractured surfaces indicated that grafting took place not only on the surface of PP film, but the grafted polymer penetrated into the PP films. Thermochromic properties of the films were observed by FTIR and UV-VIS spectrophotometers at different temperatures. AFM showed depth profiles and average rough for samples with different percentage of graft

Radiation crosslinking of poly(butyl acrylate) during polymerization and grafted copolymerization with Cr(III) crosslinked collagen

International Nuclear Information System (INIS)

Pietrucha, K.; Kroh, J.

1984-01-01

Enhanced crosslinking of synthetic polymer simultaneous with grafting and homopolymerization processes have been observed in irradiated leather tanned with Cr(III) and embedded with aqueous emulsions of butyl acrylate. Extent of poly(butyl acrylate) crosslinking during copolymerization was found to be approximately one order higher than in the case of radiation polymerization of butyl acrylate in emulsion. New method for isolation of grafted copolymer based on degradation of collagen has been developed. The extent of crosslinking was calculated from the swelling data. (author)

Preparation and Characterization of PLA-Starch Biodegradable Composites Via Radiation Processing

Energy Technology Data Exchange (ETDEWEB)

Hemvichian, K.; Suwanmala, P. [Thailand Institute of Nuclear Technology (TINT) (Thailand); Kungsumrith, W. [Department of Industrial Engineering, Faculty of Engineering, Thammasat University (TU) (Thailand); Pongprayoon, T. [Department of Chemical Engineering, Faculty of Engineering, King Mongkut’s University of Technology North Bangkok (KMUTNB), Bangkok (Thailand)

2011-07-01

This research project aims to apply the use of radiation processing to prepare biodegradable composites from poly(lactic acid) or polylactide (PLA) and cassava starch. Cassava starch, a natural polymer that is inexpensive and abundant, especially in Thailand, will be used as starting material. Functional group of cassava starch will be modified first in order to render starch more compatible with PLA. The monomer with desired functional groups will be grafted onto the backbone of starch via radiation-induced grafting polymerization. Different parameters will be examined to determine the optimum conditions for the grafting polymerization. The modified starch will subsequently be blended with PLA, with and without clay, to form biodegradable composites. In order to further improve the thermal properties, the blends and their composites will be subjected to radiation to induce crosslinking between the molecules of PLA and starch derivatives. (author)

Preparation and Characterization of PLA-Starch Biodegradable Composites Via Radiation Processing

International Nuclear Information System (INIS)

Hemvichian, K.; Suwanmala, P.; Kungsumrith, W.; Pongprayoon, T.

2011-01-01

This research project aims to apply the use of radiation processing to prepare biodegradable composites from poly(lactic acid) or polylactide (PLA) and cassava starch. Cassava starch, a natural polymer that is inexpensive and abundant, especially in Thailand, will be used as starting material. Functional group of cassava starch will be modified first in order to render starch more compatible with PLA. The monomer with desired functional groups will be grafted onto the backbone of starch via radiation-induced grafting polymerization. Different parameters will be examined to determine the optimum conditions for the grafting polymerization. The modified starch will subsequently be blended with PLA, with and without clay, to form biodegradable composites. In order to further improve the thermal properties, the blends and their composites will be subjected to radiation to induce crosslinking between the molecules of PLA and starch derivatives. (author)

Hemocompatible control of sulfobetaine-grafted polypropylene fibrous membranes in human whole blood via plasma-induced surface zwitterionization.

Science.gov (United States)

Chen, Sheng-Han; Chang, Yung; Lee, Kueir-Rarn; Wei, Ta-Chin; Higuchi, Akon; Ho, Feng-Ming; Tsou, Chia-Chun; Ho, Hsin-Tsung; Lai, Juin-Yih

2012-12-21

In this work, the hemocompatibility of zwitterionic polypropylene (PP) fibrous membranes with varying grafting coverage of poly(sulfobetaine methacrylate) (PSBMA) via plasma-induced surface polymerization was studied. Charge neutrality of PSBMA-grafted layers on PP membrane surfaces was controlled by the low-pressure and atmospheric plasma treatment in this study. The effects of grafting composition, surface hydrophilicity, and hydration capability on blood compatibility of the membranes were determined. Protein adsorption onto the different PSBMA-grafted PP membranes from human fibrinogen solutions was measured by enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies. Blood platelet adhesion and plasma clotting time measurements from a recalcified platelet-rich plasma solution were used to determine if platelet activation depends on the charge bias of the grafted PSBMA layer. The charge bias of PSBMA layer deviated from the electrical balance of positively and negatively charged moieties can be well-controlled via atmospheric plasma-induced interfacial zwitterionization and was further tested with human whole blood. The optimized PSBMA surface graft layer in overall charge neutrality has a high hydration capability and keeps its original blood-inert property of antifouling, anticoagulant, and antithrmbogenic activities when it comes into contact with human blood. This work suggests that the hemocompatible nature of grafted PSBMA polymers by controlling grafting quality via atmospheric plasma treatment gives a great potential in the surface zwitterionization of hydrophobic membranes for use in human whole blood.

A case of radiation induced cancer

Energy Technology Data Exchange (ETDEWEB)

Ozawa, Kazuyoshi; Tsuchikawa, Kohzo; Sato, Akira; Kato, Joji (Nippon Dental Univ., Niigata (Japan). School of Dentistry at Niigata)

1994-06-01

A case of carcinoma on the right buccal mucosa is presented. The case was suspected to have been induced by irradiation therapy for a carcinoma on the left buccal mucosa. An external radiotherapy, 6-MeV Linac, had been done for the carcinoma on the left buccal mucosa in a 55-year-old female, with single lateral direction from the left to the right in 1977. In 1985, a papillary lesion on the right buccal mucosa was detected, and histological examination revealed a papilloma without atypism. In 1991, as an ulcer on the right upper buccal fold as well as three papillary lesions in the central portion of the right buccal mucosa were found, the patient was referred to our clinic. Microscopical findings were consistent with the early invasive carcinomas. A surgical excision of these whole lesions and skin graft were completed. The criteria of this case for the suspicion of radiation-induced carcinoma were as follows. There was a long latent period of 14 years. The previous dose of irradiation, 60 Gy, was sufficient. The right buccal mucosa was involved in the radiation field. A severe scar on the left cheek resulted from the previous irradiation. Anatomically, there is no evidence of the secondary carcinoma on the right buccal mucosa with the primary carcinoma on the left buccal mucosa. No evidence for recurrence of the tumors on both sides of buccal mucosa has been detected so far. Further observations will be necessary to detect other tumors in the irradiated field later on. (author).

Radiation crosslinking of poly(butyl acrylate) during polymerization and grafted copolymerization with Cr(III) crosslinked collagen

International Nuclear Information System (INIS)

Pietrucha, K.; Kroh, J.

1986-01-01

Enhanced crosslinking of synthetic polymer simultaneously with grafting and homopolymerization processes has been observed in irradiated leather tanned with Cr(III) and embedded with aqueous emulsions of butyl acrylate. The extent of poly(butyl acrylate) crosslinking during copolymerization was found to be approximately one order higher than in the case of radiation polymerization of butyl acrylate in emulsion. A new method for isolation of grafted copolymer based on degradation of collagen has been developed. The extent of crosslinking was calculated from the swelling data. (author)

Radiation-induced aftertreatment of textiles

International Nuclear Information System (INIS)

Okada, Toshio

1978-01-01

Techniques to improve the properties of textiles by graft polymerization of acrylic acid, metacrylic acid, etc. on natural and synthetic fibers by irradiation of electron beam or γ ray were developed and put into practical use. Such graft polymerization by irradiation is effective technique to give synthetic fibers hydrophilic property, heat-shrinkage resistance, dye affinity, static electricity prevention, combustion resistance, etc.. Irradiation is also applied for adhesion of nonwoven fabric, coating processing of textiles, and printing processing of fabrics. Thus, the processing of textiles by radiation, especially electron beam, is effective to give new properties to textiles, but its importance has been also recognized as energy saving and public nuisance-avoiding processes. A great deal of energy reduction can be expected by electron beam irradiation method. (Kobatake, H.)

Electron beam induced graft-polymerization of methyl methacrylate onto polyethylene films at high dose rates

International Nuclear Information System (INIS)

Mori, Koji; Koshiishi, Kenji; Masuhara, Ken-ichi

1991-01-01

Electron beam induced graft-polymerization by the mutual irradiation technique of methyl methacrylate on the surface of low density polyethylene films (LD) and high density polyethylene films (HD) was investigated at high dose rates over 10 Mrad per second. Graft-polymerization mechanisms were discussed on the basis of O 2 permeability, tensile strength, elongation at break, and surface tension of the grafted films. As the degree of grafting increased, the O 2 permeability of LD decreased, while that of HD little changed at the grafting up to 4 ∼ 5 %. This indicates that the grafting occurred in the amorphous regions for LD and occurred in the amorphous regions in the neighborhood of crystalline regions for HD. For HD, when the degree of the grafting surpassed 4 ∼ 5 %, the O 2 permeability, tensile strength, elongation at break, and surface tension decreased with an increase in the degree of grafting. It was assumed that rapid grafting in the amorphous regions in the neighborhood of crystalline regions caused the increase in local temperature by the heat of polymerization, and the viscosity of polyethylene in the amorphous regions decreased with an increase in temperature. As a result, the graft chains, which formed micro domain structure, condensed in the amorphous regions and the domain increased in size. (author)

Electrospun silk fibroin/poly (L-lactide-ε-caplacton) graft with platelet-rich growth factor for inducing smooth muscle cell growth and infiltration.

Science.gov (United States)

Yin, Anlin; Bowlin, Gary L; Luo, Rifang; Zhang, Xingdong; Wang, Yunbing; Mo, Xiumei

2016-12-01

The construction of a smooth muscle layer for blood vessel through electrospinning method plays a key role in vascular tissue engineering. However, smooth muscle cells (SMCs) penetration into the electrospun graft to form a smooth muscle layer is limited due to the dense packing of fibers and lack of inducing factors. In this paper, silk fibroin/poly (L-lactide-ε-caplacton) (SF/PLLA-CL) vascular graft loaded with platelet-rich growth factor (PRGF) was fabricated by electrospinning. The in vitro results showed that SMCs cultured in the graft grew fast, and the incorporation of PRGF could induce deeper SMCs infiltrating compared to the SF/PLLA-CL graft alone. Mechanical properties measurement showed that PRGF-incorporated graft had proper tensile stress, suture retention strength, burst pressure and compliance which could match the demand of native blood vessel. The success in the fabrication of PRGF-incorporated SF/PLLA-CL graft to induce fast SMCs growth and their strong penetration into graft has important application for tissue-engineered blood vessels.

Bone grafts in dentistry

Directory of Open Access Journals (Sweden)

Prasanna Kumar

2013-01-01

Full Text Available Bone grafts are used as a filler and scaffold to facilitate bone formation and promote wound healing. These grafts are bioresorbable and have no antigen-antibody reaction. These bone grafts act as a mineral reservoir which induces new bone formation.

Preparation of permselective membranes by means of radiation induced grafting. Part of a coordinated programme on radiation modified polymers for biomedical and biochemical applications

International Nuclear Information System (INIS)

Lee, C.K.

1982-09-01

Styrene grafting to cellulose acetate membrane was studied to prepare a cellulose acetate reverse osmosis membrane with improved dimensional stability. The combination of cross-linking agents such as divinylbenzene or trimethyl propane triacrylate was found to increase the percentage of grafting. For the grafting of styrene:4-vinylpyridine:benzoyl peroxide mixture to cellulose acetate, the activation energy was determined to be 21.8 Kcal/mole over the range of 55-80 deg. C. The initial rate of grafting in % per hour was proportional to 0.76 power of dose intensities

Effect of grafting cellulose acetate and methylmethacrylate as compatibilizer onto NBR/SBR blends

International Nuclear Information System (INIS)

Khalf, A.I.; Nashar, D.E.El.; Maziad, N.A.

2010-01-01

Compatibilizer is used for improving of processability, interfacial interaction and mechanical properties of polymer blends. In this study acrylonitrile butadiene rubber (NBR) and styrene-butadiene rubber (SBR) blends were compatibilized by a graft copolymer of acrylonitrile butadiene rubber (NBR) grafted with cellulose acetate (CA) i.e. (NBR-g-CA) and acrylonitrile butadiene rubber (NBR) grafted with methylmethacrylate i.e. (NBR-g-MMA). Compatibilizers were prepared by gamma radiation induced grafting of NBR with cellulose acetate (CA) and methylmethacrylate (MMA) were added with different ratios to NBR/SBR (50/50) blend. The compatibilized blends were evaluated by rheometric characteristics, physico-mechanical properties, swelling behavior, scanning electron microscope (SEM) and thermal analysis. The results showed that, the blends with graft copolymer effect greatly on the rheological characteristics [optimum cure time (Tc 90 ), scorch time (Ts 2 ), and the cure rate index (CRI)]. The physico-mechanical properties of the investigated blends were enhanced by the incorporation of these graft copolymers, while the resistance to swelling in toluene became higher. SEM photographs confirm that, these compatibilizers improve the interfacial adhesion between NBR/SBR (50/50) blend which induce compatibilization in the immiscible blends. The efficiency of the compatibilizer was also evaluated by studying the thermogravimetric analysis.

Microfiltration membranes prepared from polyethersulfone powder grafted with acrylic acid by simultaneous irradiation and their pH dependence

International Nuclear Information System (INIS)

Deng Bo; Li Jingye; Hou Zhengchi; Yao Side; Shi Liuqing; Liang Guoming; Sheng Kanglong

2008-01-01

Polyethersulfone (PES) powder was grafted with acrylic acid (AAc) by simultaneous γ-ray irradiation. The kinetics of the radiation induced graft polymerization was studied and the grafted PES powder was characterized. Then, microfiltration (MF) membranes were prepared from PES-g-PAAc powder with different degrees of grafting (DG) under phase inversion method. The swelling behavior and the mean pore size of MF membranes were measured, and the filtration property was tested. The results showed that the pore size and the flux of MF membranes increased with the increase in DG. And, MF membranes' properties were dependent on the pH value

Study on immobilization enzyme using radiation grafting and condensation covalent

International Nuclear Information System (INIS)

Cao Jin; Su Zongxian; Gao Jianfeng

1989-01-01

The immobilization of gluecose oxidase (GOD) on polyethylene and F 46 is described by radiation grafting and condensation covalent. The GOD on polyethylene film is characterized with IR-spectrum. The results show that the enzyme activity on F 46 film is high when dose rate and covalent yield are low. When covalent yield is 4.3% the enzyme relative activity achieves the greatest value for F 46 film. The experiment also demonstrates that acrylic acid affects the relative activity of enzyme and the method of IR-pectrum character is convenient and efficient for GOD on polyethylene film

Radiation grafting of methacrylate onto carbon nanofiber surface

International Nuclear Information System (INIS)

Evora, M.C.; Klosterman, D.; Lafdi, K.; Li, L.

2011-01-01

Radiation can be used to modify and improve the properties of materials. Electron beam irradiation has potential application in modifying the structure of carbon fibers in order to produce useful defects in the graphite structure and create reactive sites. In this study, vapor grown carbon nano fibers (VGCF) were irradiated with a high energy (3 MeV) electron beam in air to dose of 1000 kGy to create active sites and added to methyl methacrylate (MMA) dissolved in water/methanol (50% V). The irradiated samples were analyzed by X-Ray Photoelectron Spectroscopy (XPS) and Raman spectroscopy to assess the impact on surface and bulk properties. Oxygen was readily incorporated enhancing the dispersion of VGCF. Raman spectroscopy analyses indicated that the sample irradiated and preirradiated grafted sample with MMA had the intensity ratio increased. (author)

An Engineering Scale Study on Radiation Grafting of Polymeric Adsorbents for Recovery of Heavy Metal Ions from Seawater

International Nuclear Information System (INIS)

Prasad, Tl; Saxena, Ak; Tewari, Pk; Sathiyamoorthy, D

2009-01-01

The ocean contains around eighty elements of the periodic table and uranium is also one among them, with a uniform concentration of 3.3 ppb and a relative abundance factor of 23. With a large coastline, India has a large stake in exploiting the 4 billion tonnes of uranium locked in seawater. The development of radiation grafting techniques, which are useful in incorporating the required functional groups, has led to more efficient adsorbent preparations in various geometrical configurations. Separation based on a polymeric adsorbent is becoming an increasingly popular technique for the extraction of trace heavy metals from seawater. Radiation grafting has provided definite advantages over chemical grafting. Studies related to thermally bonded non woven porous polypropylene fiber sheet substrate characterization and parameters to incorporate specific groups such as acrylonitrile (AN) into polymer back bones have been investigated. The grafted polyacrylonitrile chains were chemically modified to convert acrylonitrile group into an amidoxime group, a chelating group responsible for heavy metal uptake from seawater/brine. The present work has been undertaken to concentrate heavy metal ions from lean solutions from constant potential sources only. A scheme was designed and developed for investigation of the recovery of heavy metal ions such as uranium and vanadium from seawater

Poly-electrolyte fuel cell membrane based on crosslinked polytetrafluoroethylene by radiation-grafting

International Nuclear Information System (INIS)

Ichizuri, Shogo; Asano, Saneto; Li, Jingye

2004-01-01

Poly-electrolyte fuel cell (PEFC) membranes based on crosslinked Polytetrafluoroethylene (RX-PTFE) have been fabricated by radiation-grafting with reactive styrene monomers using γ-ray irradiation in air at room temperature / electron beam irradiation under N 2 gas atmosphere at room temperature. The characteristic properties of obtained materials have been measured by DSC, TGA and FT-IR spectroscopy, and so on. Ion exchange capacity of sulfonated crosslinked PTFE has been achieved 2.8meq/g. (author)

Radiation grafting of hydrophilic monomers on to plasticized poly(vinyl chloride) sheets: Pt. 1

International Nuclear Information System (INIS)

Kalliyana Krishnan, V.; Jayakrishnan, A.; Francis, J.D.

1990-01-01

Medical-grade plasticized polyvinyl chloride (PVC) sheets were surface modified using gamma-radiation grafting of a combination of hydrophilic monomers based on 2-hydroxyethyl methacrylate (HEMA) and N-vinyl pyrrolidone (NVP). The properties of the modified surfaces were evaluated using contact angle measurements, phase-contrast photomicroscopy and scanning electron microscopy. Surface energy calculations indicated that the surfaces became highly hydrophilic when grafted with even a 1% (v/v) solution of HEMA-NVP combination in the presence of 0.005 M CuSO 4 . Migration of the plasticizer di(2-ethylhexyl phthalate) from the grafted sheets was examined in hydrocarbon solvents such as n-hexane, n-heptane and n-octane and in extractant media such as cotton seed oil and polyethylene glycol-400 (PEG-400). The migration was found to be 0 C over a period of 5 h. Accelerated leaching studies in cotton seed oil and PEG-400 demonstrated that virtually no plasticizer migrated out in the former over a period of 96 h whereas the rate of migration in the latter medium showed only a mild reduction. The migration behaviour was Fickian in nature for grafted sheets. The method described may be useful as a simple, versatile technique for preventing plasticizer migration from plasticized PVC for medical applications. (author)

Synthesis of Functional Materials by Radiation

International Nuclear Information System (INIS)

Noh, Y. C.; Kang, P. H.; Choi, J. H.

2006-06-01

The radiation crosslinking, grafting, curing and degradation can be easily adjusted and is easily reproducible by controlling the radiation dose. These studies aim to develop new biomaterials such as wound healing, tissue engineering and antiadhesion barrier. The effect of thermal treatment and irradiation on the physico-chemical properties of ultra-high molecular weight polyethylene (UHMWPE) used in orthopedic implants was investigated. If a large amount of polymer radicals remain trapped after the irradiation of ultra-high molecular weight polyethylene (UHMWPE), the radicals may significantly alter the physical properties of UHMWPE during long shelf storage and implantation for a long time period. UHMWPE irradiated in the molten state had a higher crosslinking extent and a lower wear rate than one irradiated in the room temperature. The radiation grafting technology can develop membrane of fuel cell and Li secondary battery and heavy metal absorbents. Proton exchange membranes were prepared by γ-irradiation-induced grafting of styrene into fluorinated polymer films and subsequent sulfonation. Results of the present work suggest that radiation induced-graft polymerization can be used as alternative method to blending to prepare polymer electrolyte membranes for lithium battery applications. The polypropylene-based compatibilizers, polypropylene-g-maleic anhydride (PP-MAH), polypropylene-g-maleic anhydride/styrene (PP-St/MAH), and polypropylene-g-acrylic acid (PP-AA), were prepared by a high energy irradiation method. The compatibilizing effect of newly prepared graft copolymers on immiscible PP/Nylon6 blends has been studied by means of UTM, SEM, and DSC techniques. The results indicate that PP-MAH and PP-St/MAH are more effective compatibilizers for PP/Nylon6 blends than PP-AA showing more than 30 % increase in impact strength, and the compatibilizing effect on PP/Nylon6 blends depends on molecular structure of the compatibilizers and the composition of the

Preparation of poly(vinylbenzyl chloride)-grafted PFA film by a simultaneous irradiation grafting method

International Nuclear Information System (INIS)

Fei, Geng; Shin, Jun Hwa; Nho, Young Chang; Lee, Youn Sik

2009-01-01

In this study, PFA-g-PVBC films were prepared by a radiation grafting of vinylbenzyl chloride (VBC) monomer onto poly(tetrafluoroethylene-co-perfluoro propyl vinyl ether) (PFA) films by simultaneous irradiation method. IR, TGA, and SEM-EDX instruments were utilized to confirm the successful preparation of the grafted film. The effects of several irradiation conditions, including the dose, VBC concentration, and film thickness on the degree of grafting of PFA-g-PVBC film were investigated

Study of energy transfer to solvent in radiation graft polymerization of styrene onto polyethylene

International Nuclear Information System (INIS)

Rabie, A.; Odian, G.

1977-01-01

The radiation-initiated graft polymerization of styrene onto polyethylene was studied to determine whether energy transfer to diluent was responsible for the previously observed high orders of dependence of the grafting rate on monomer concentration. n-Octane was used as the diluent instead of benzene. If energy transfer from excited polyethylene to benzene were present, it should not be with n-octane. The percent swelling of polyethylene by various n-octane--styrene mixtures was determined. The compositions of various n-octane--styrene mixtures absorbed inside polyethylene were determined by ultraviolet and refractive index measurements and found to be richer in styrene than the corresponding mixtures in which the polyethylene had been placed. The graft polymerization rates were determined at 0.000761, 0.0371, and 0.213 Mrad/hr and plotted against the inside styrene concentrations on a log-log scale to yield the kinetic orders of dependence of rate on monomer as 2, 3, and 3, respectively. It was concluded that energy transfer to diluent was not responsible for the high-order dependence observed

Zwitterionic sulfobetaine-grafted poly(vinylidene fluoride) membrane with highly effective blood compatibility via atmospheric plasma-induced surface copolymerization.

Science.gov (United States)

Chang, Yung; Chang, Wan-Ju; Shih, Yu-Ju; Wei, Ta-Chin; Hsiue, Ging-Ho

2011-04-01

Development of nonfouling membranes to prevent nonspecific protein adsorption and platelet adhesion is critical for many biomedical applications. It is always a challenge to control the surface graft copolymerization of a highly polar monomer from the highly hydrophobic surface of a fluoropolymer membrane. In this work, the blood compatibility of poly(vinylidene fluoride) (PVDF) membranes with surface-grafted electrically neutral zwitterionic poly(sulfobetaine methacrylate) (PSBMA), from atmospheric plasma-induced surface copolymerization, was studied. The effect of surface composition and graft morphology, electrical neutrality, hydrophilicity and hydration capability on blood compatibility of the membranes were determined. Blood compatibility of the zwitterionic PVDF membranes was systematically evaluated by plasma protein adsorption, platelet adhesion, plasma-clotting time, and blood cell hemolysis. It was found that the nonfouling nature and hydration capability of grafted PSBMA polymers can be effectively controlled by regulating the grafting coverage and charge balance of the PSBMA layer on the PVDF membrane surface. Even a slight charge bias in the grafted zwitterionic PSBMA layer can induce electrostatic interactions between proteins and the membrane surfaces, leading to surface protein adsorption, platelet activation, plasma clotting and blood cell hemolysis. Thus, the optimized PSBMA surface graft layer in overall charge neutrality has a high hydration capability and the best antifouling, anticoagulant, and antihemolytic activities when comes into contact with human blood. © 2011 American Chemical Society

Graft irradiation abrogates graft-versus-host disease in combined pancreas-spleen transplantation

International Nuclear Information System (INIS)

Schulak, J.A.; Sharp, W.J.

1986-01-01

A model of combined pancreas-spleen transplantation (PST) was studied in LBN F1 recipients of Lewis grafts in order to evaluate the efficacy of pretransplant graft irradiation in preventing lethal graft-versus-host disease (GVHD). Recipients of unmodified PST uniformly developed severe GVHD and died (MST = 16.7 +/- 3.8 days). Whole body donor irradiation with either 500 or 250 rad prevented lethal GVHD. Similarly, ex vivo graft irradiation with either 1000 or 500 rad also resulted in normal weight gain, graft function, and host survival for the 6-week study period. Conversely, delay of graft irradiation until 3 days after transplantation failed to prevent this complication (MST = 15.8 +/- 3.7 days). Recipients of irradiated grafts displayed glucose tolerance tests that were identical to those in the control group indicating that the doses of radiation employed in these experiments were not deleterious to islet function. Irradiated spleen grafts appeared histologically normal at 6 weeks after transplantation. Cells derived from these grafts failed to stimulate lymph node enlargement in a popliteal lymph node assay for GVHD, suggesting that these spleens may have become repopulated with host cells. These experiments confirm that PST has the potential to cause lethal GVHD and suggest that pretransplant graft irradiation may be used to prevent its occurrence

Radiation-induced microenvironments - The molecular basis for free flap complications in the pre-irradiated field?

International Nuclear Information System (INIS)

Mueller, Cornelia Katharina; Schultze-Mosgau, Stefan

2009-01-01

Background and purpose: The effect of preoperative radio- or radiochemotherapy on the survival of free flaps used for head and neck reconstruction is reported in a contradictory way. Although there is a lot of knowledge on radiation-induced wound healing disorders from animal models there are no investigations on human patients so far. Our prospective study aimed at clarifying the effect of radiotherapy on clinically apparent free flap complications and on correlating them with radiation-induced extracellular matrix (ECM) remodeling. Materials and methods: Healing of 114 free flaps was monitored in a prospective study and correlated with different anamnestic features, such as diabetes and radio- or radiochemotherapy using multivariate regression. During the operation connective tissue biopsies were harvested from the graft beds and analyzed for Transforming Growth Factor (TGF)-β 1 -expression by means of Western blotting as well as Tissue Inhibitor of Matrix-Metallo-Proteinase (TIMP)-1 and Matrix-Metallo-Proteinase (MMP)-1 by immunohistochemistry. Results: History of radio- or radiochemotherapy was the only factor significantly predicting free flap complications. Radiochemotherapy resulted in a significant increase in TGF-β 1 - and TIMP-1-expression, while MMP-1-expression was not significantly altered. Radiotherapy alone significantly increased TIMP-1-expression without detectable effects on TGF-β 1 and MMP-1. Conclusions: Radio- and radiochemotherapy alter graft bed ECM organization prior to surgery. This alteration impacts significantly on free flap survival in the pre-irradiated field.

Obtention of graft copolymers by ionizing radiation, characterization and study of hemo-compatible properties; Obtencao de copolimeros de enxerto via radiacao ionizante, caracterizacao e estudo de suas propriedades hemocompativeis

Energy Technology Data Exchange (ETDEWEB)

Queiroz, A A.A. de

1994-12-31

The present work had as objectives the obtention and characterization of grafting copolymers by radiation induced polymerization and the study of its hemo compatible properties. The relationship between grafting conditions and anti-trombogenicity was examined for the purpose of clearing the necessity of controlling grafting conditions to enhance the copolymers blood compatibility. Two methods were chosen to accomplish the irradiation: mutual and pre-irradiation (peroxidation) of the films in {sup 6O} Co source and electron beam accelerator. Primarily grafting parameters were studied in the systems of the monomers N, N-dimethyl acrylamide (DMAA) and acrylic acid (AA) with the polymeric films: poly (tetrafluoroethylene) (PTFE), poly (ethylene-co-tetrafluoroethylene) (PETFE), low density polyethylene (LDPE) and poly (vinyl chloride) (PVC). The simultaneous irradiation was effective in the polymerization of all the substrates above mentioned, although the peroxidation method has given better results for PETFE-DMAA, LDPE-g-DMAA, LDPE-g-AA and PVC-g-AA. In the system AA/LDPE and AA/PVC the homo polymerization was controlled by the addition of the comonomer N, N-dimethyl acrylic acid (DMA). As for the grafting parameters, low dose rate and low irradiation dose, showed to be very effective for the graftability of DMAA and AA on the substrates. (author). 129 refs, 51 figs, 7 tabs.

Radiation-induced thermoacoustic imaging

International Nuclear Information System (INIS)

Bowen, T.

1984-01-01

This invention provides a new technique for obtaining information non-invasively on the composition and structures of a material or body by detecting radiation-induced thermoacoustic image features. This is accomplished by utilizing the acoustic wave generated by sudden thermal stress. The sudden thermal stress is induced by a pulse of radiation which deposits energy causing a rapid, but very small, rise of temperature (typically, ΔT approximately 10sup(-6) - 10sup(-5) deg C). The radiation may be ionizing radiation, such as high energy electrons, photons (x-rays), neutrons, or other charged particles or it may be non-ionizing radiation, such as R.F. and microwave electromagnetic radiation and ultrasonic radiation. The choice of radiation depends on the nature of the body to be imaged and the type of information desired

Amputation of congo red dye from waste water using microwave induced grafted Luffa cylindrica cellulosic fiber.

Science.gov (United States)

Gupta, Vinod Kumar; Pathania, Deepak; Agarwal, Shilpi; Sharma, Shikha

2014-10-13

The present study deals with the surface modification of Luffa cylindrica fiber through graft copolymerization of methyl acrylate/acrylamide (MA/AAm) via microwave radiation without the use of initiator. Various reaction parameters effecting grafting yield were optimized and physico-chemical properties were evaluated. The grafted Luffa cylindrica fiber showed morphological transformations, thermal stability and chemical resistance. The adsorption potential of modified fiber was investigated using adsorption isotherms for hazardous congo red dye removal from aqueous system. The maximum adsorption capacity of dye onto grafted Luffa cylindrica fiber was found to be 17.39 mg/g with best fit for Langmuir adsorption isotherm. The values of thermodynamic parameters such as enthalpy change, ΔH(0) (21.27 kJ/mol), entropy change, ΔS(0) (64.71 J/mol K) and free energy change, ΔG(0) (-139.52 kJ/mol) were also calculated. Adsorption process was found spontaneous and endothermic in nature. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of groundwater treatment method using radiation-induced graft polymerization adsorbent at the Mizunami Underground Research Laboratory. Annual report on 2007 fiscal year (Joint research)

International Nuclear Information System (INIS)

Iyatomi, Yosuke; Shimada, Akiomi; Ogata, Nobuhisa; Sugihara, Kozo; Seko, Noriaki; Kasai, Noboru; Hoshina, Hiroyuki; Ueki, Yuji; Tamada, Masao

2009-11-01

The concentrations of fluorine (7.2-10mg/L) and boron (0.8-1.5mg/L) dissolved in groundwater pumped from shafts during excavation at the Mizunami Underground Research Laboratory (MIU), Tono Geoscience Centre, must be reduced to the levels below the environmental standards (fluorine:0.8mg/L, boron:1mg/L). Coagulation treatment and ion exchange treatment are applied for fluorine and boron at a current water treatment facility in MIU, respectively. A collaborative research on groundwater treatment for fluorine and boron was started by the Environment and Industrial Materials Research Division, Quantum Beam Science Directorate and the Tono Geoscientific Research Unit, Geological Isolation Research and Development Directorate in 2006. This is because the Quantum Beam Science Directorate has synthesized fibrous adsorbents with radiation-induced graft polymerization and applied them to collect rare metals dissolved in hot springs and sea water. Boron adsorbent synthesized by grafting showed higher removal rate than that of the ion-exchange resin. Additionally, the durability and the repetitive use of the boron adsorbent were evaluated to estimate the capacity of the boron adsorption. Therefore we produced a test equipment to do scale-up test of the adsorbent. Effects of flow rate and the repetitive use on the adsorption capacity of boron were investigated. As a result, it concluded that the adsorption capacity of the boron adsorbent did not change even when the flow rate increased from SV 50h -1 to 100h -1 . In addition, enough durability was confirmed for the repetitive use of the adsorbent. The adsorption capacity of the adsorbent was affected by pH of the groundwater especially in high alkaline range above a pH of 10. (author)

Effects of ionizing radiation on the hematopoietic niche and treatment of acute radiation syndrome by gene therapy in highly-irradiated monkeys

International Nuclear Information System (INIS)

Garrigou, Ph.

2011-01-01

The hematopoietic stem cell niche represents a complex radiosensitive compartment whose protection is required for recovery from radiation-induced myelosuppression. We initially studied RI effects on endothelial and mesenchymal progenitors by an evaluating radiosensitivity and cell death. Then, we have proposed a new gene therapy strategy based on local and short term secretion of Sonic hedgehog morphogen to favour vascular niche repair and to stimulate residual hematopoietic stem and progenitor cells. We investigated the hematopoietic response of 8-Gy gamma irradiated monkeys to a single intra-osseous injection of xenogeneic multipotent mesenchymal stem cells transduced with a Shh pIRES2 plasmid. Thrombocytopenia and neutropenia duration were significantly reduced in grafted animals and clonogenics normalized from day 42. Areas under the curve of PLTs and ANCs between day 0 and day 30 were significantly higher in treated animals than in controls. Grafting Matrigel TM colonized or not with ASC in immunocompromised mice demonstrated a notable pro-angiogenic activity for Shh-ASC. Long term follow up (180-300 days) confirmed a durable recovery in the four grafted monkeys. Globally this study suggests that grafting Shh-multipotent stem cells may represent a new strategy to cure radiation-induced niche damage. (author)

Synthesis of functional materials by radiation

Energy Technology Data Exchange (ETDEWEB)

Nho, Young Chang; Kim, Ki Yup; Kang, Phil Hyun and others

2000-04-01

The radiation can induce chemical reaction to modify polymer under even the solid condition or in the low temperature. Therefore, the radiation processing is used as the means to develop the high functional polymer and new material which is impossible by chemical process. The radiation grafting process has the advantage to endow the adsorption function to the existing materials such as polymer membrane, fabric, non-fabric, non-woven fabric and film. Radiation crosslinking is effected with no pressure and is performed at low temperatures. Thus, temperature sensitive additives can be used in radiation crosslinking. The radiation crosslinking and grafting can be easily adjusted and is easily reproducible by controlling the radiation dose. The finished product contains no residuals of substances required to initiate the chemical crosslinking and grafting which can restrict the application possibilities, or can increase the failure rate. In these studies, radiation grafting and crosslinking were used to develop the toxic gas adsorbent, blood compatible polymer, acetabular cup of artificial joint, urokinase adsorbent, hydrogel, hollow fiber membrane adsorbing the heavy metals, and battery separator membrane. Because cable in nuclear power plant is directly related to safe operation, the life assessment of the cable system is an important issue. To assess the degradation and life time of cable is complicated owing to the various types and the different formulation of cable. In order to make an estimate the long term degradation occurring in a material, it is necessary to carry out the accelerated aging studies and to establish the appropriate test method to characterize the degradation. These studies are aimed at the evaluation technique on radiation degradation of polymer material and applying these results to nuclear equipment qualification.

Synthesis of functional materials by radiation

International Nuclear Information System (INIS)

Nho, Young Chang; Kim, Ki Yup; Kang, Phil Hyun and others

2000-04-01

The radiation can induce chemical reaction to modify polymer under even the solid condition or in the low temperature. Therefore, the radiation processing is used as the means to develop the high functional polymer and new material which is impossible by chemical process. The radiation grafting process has the advantage to endow the adsorption function to the existing materials such as polymer membrane, fabric, non-fabric, non-woven fabric and film. Radiation crosslinking is effected with no pressure and is performed at low temperatures. Thus, temperature sensitive additives can be used in radiation crosslinking. The radiation crosslinking and grafting can be easily adjusted and is easily reproducible by controlling the radiation dose. The finished product contains no residuals of substances required to initiate the chemical crosslinking and grafting which can restrict the application possibilities, or can increase the failure rate. In these studies, radiation grafting and crosslinking were used to develop the toxic gas adsorbent, blood compatible polymer, acetabular cup of artificial joint, urokinase adsorbent, hydrogel, hollow fiber membrane adsorbing the heavy metals, and battery separator membrane. Because cable in nuclear power plant is directly related to safe operation, the life assessment of the cable system is an important issue. To assess the degradation and life time of cable is complicated owing to the various types and the different formulation of cable. In order to make an estimate the long term degradation occurring in a material, it is necessary to carry out the accelerated aging studies and to establish the appropriate test method to characterize the degradation. These studies are aimed at the evaluation technique on radiation degradation of polymer material and applying these results to nuclear equipment qualification

Radiation-grafting of 2-hydroxyethylmethacrylate and oligo (ethylene glycol) methyl ether methacrylate onto polypropylene films by one step method

Energy Technology Data Exchange (ETDEWEB)

Ramirez-Jimenez, Alejandro [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Alvarez-Lorenzo, Carmen; Concheiro, Angel [Departamento de Farmacia y Tecnologia Farmaceutica, Universidad de Santiago de Compostela, 15782-Santiago de Compostela (Spain); Bucio, Emilio, E-mail: ebucio@nucleares.unam.mx [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico)

2012-01-15

Polypropylene films were modified with 2-hydroxyethylmethacrylate (HEMA) and oligo (ethylene glycol) methyl ether methacrylate (OEGMA) using the pre-irradiation method with gamma-rays (one step method). The effect of absorbed dose from 10 to 100 kGy, temperature (50, 60, and 70 {sup o}C), monomer concentration between 12.5% and 62.5%, monomers ratio from 10% to 90% and reaction time from 5 to 50 h; on the degree of grafting was determined. The grafted samples were analyzed by FTIR-ATR, TGA, DSC, swelling, and contact angle. Grafts onto polymeric films between 3% and 109% were obtained at doses from 10 to 100 kGy and a dose rate around 7.4 kGy/h. The graft percent increased with the content in HEMA in the HEMA:OEGMA feed mixture, which indicates a lower reactivity of OEGMA compared to HEMA. The hydrogel layer grafted on the polypropylene substrate increases the hydrophilicity of the surface and also provides certain temperature-responsiveness, which may be of interest for biomedical applications. - Highlights: > PP was grafted with a hydrogel layer applying the {gamma}-ray pre-irradiation method. > Effects of radiation dose, time, temperature and monomers concentration were evaluated. > Grafted layer increases the hydrophilicity of PP films. > HEMA and OEGMA grafted onto PP may be of interest for biomedical applications.

Graft copolymerization of glycidyl methacrylate onto delignified kenaf fibers through pre-irradiation technique

International Nuclear Information System (INIS)

Sharif, Jamaliah; Mohamad, Siti Fatahiyah; Fatimah Othman, Nor Azilah; Bakaruddin, Nurul Azra; Osman, Hasnul Nizam; Güven, Olgun

2013-01-01

Glycidyl methacrylate grafted kenaf (GMA-g-Kenaf) was prepared by pre-irradiation grafting technique. Kenaf fibers were treated with different concentration of sodium chlorite solution before used as trunk polymer. Treated kenaf fibers were irradiated by electron beam followed by grafting reaction in GMA/water emulsion system. The degree of grafting was determined as a function of absorbed dose, reaction time, reaction temperature and concentration of monomer. The results showed that the lignin content was decreased from 14.3% to as low as 3.3% with the increased of sodium chlorite concentration. This was evidenced by SEM pictures which show the surface of treated kenaf fibers was cleaner and smoother compared to that of untreated one. The degree of grafting increased with the increase of absorbed dose, reaction temperature, reaction time and monomer concentration as well as with decreasing lignin content. Formation of graft copolymer was confirmed with SEM, FTIR analysis. The structural investigation by XRD showed that degree of crystallinity of graft copolymers decreased with the increase in degree of grafting. - Highlights: • We used kenaf fibers for radiation induce graft copolymerization with GMA. • Kenaf fibers was treated to remove lignin in order to increase grafting yield. • Treated kenaf fibers were graft copolymerize through preirradiation technique. • Optimum conditions for graft copolymerization of kenaf fibers were established. • Formation of graft copolymer is also confirmed with SEM, FTIR and XRD

Interaction of blood with radiation-grafted materials

International Nuclear Information System (INIS)

Ikada, Y.; Suzuki, M.; Taniguchi, M.; Iwata, H.; Taki, W.; Miyake, H.; Yonekawa, Y.; Handa, H.

1981-01-01

Extensive works on blood compatibility of polymeric materials have revealed that it is strongly governed by their surface structure and properties. Among them are roughness, hydrophobic-hydrophilic balance, ionic species, and water content in the surface layer. In the present work, low and high density polyethylenes as well as heat-treated poly(vinyl) alcohol are grafted with acrylamide (and acrylic acid for comparison) by a pre-irradiation technique to convert the rigid hydrophobic surface into a soft hydrogel with high water contents. The surface modification of materials with grafted polyacrylamide chains will be confirmed from the contact angle measurement which is one of the best methods for assessing the hydrophilicity of surfaces. Blood compatibility of the resulting surfaces will be evaluated from in vivo experiments by anastomosing the surface-grafted tubes of small diameter with the carotid artery of rat. (author)

Solvent effect on post-irradiation grafting of styrene onto poly(ethylene-alt-tetrafluoroethylene) (ETFE) films

Science.gov (United States)

Napoleão Geraldes, Adriana; Augusto Zen, Heloísa; Ribeiro, Geise; Fernandes Parra, Duclerc; Benévolo Lugão, Ademar

2013-03-01

Radiation-induced grafting of styrene onto ETFE films in different solvent was investigated after simultaneous irradiation (in post-irradiation condition) using a 60Co source. Grafting of styrene followed by sulfonation onto poly(ethylene-alt-tetrafluoroethylene) (ETFE) are currently studied for synthesis of ion exchange membranes. The ETFE films were immersed in styrene/toluene, styrene/methanol and styrene/isopropyl alcohol and irradiated at 20 and 100 kGy doses at room temperature. The post-irradiation time was established at 14 day and the grafting degree was evaluated. The grafted films were sulfonated using chlorosulfonic acid and 1,2-dichloroethane 20:80 (v/v) at room temperature for 5 h. The degree of grafting (DOG) was determined gravimetrically and physical or chemical changes were evaluated by differential scanning calorimeter analysis (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The ion exchange capacity (IEC) values showed the best performance of sulfonation for ETFE membranes grafted in toluene solvent. Surface images of the grafted films by SEM technique have presented a strong effect of the solvents on the films morphology.

Fundamental radiation effect on polymers energy transfer from radiation to polymer

International Nuclear Information System (INIS)

Seguchi, T.

2007-01-01

Polymer modification as cross-link, chain scission, and graft-polymerization by radiation is initiated by the quantum energy transferred from radiation to polymers. The active species for chemical reactions are produced through ionization or activation of polymer molecules for any radiation source. The energy transfer occurs mainly by ionic interaction between radiation and polymer molecule, and the contribution from the collision interaction is miner. The radiation of electromagnetic wave as X-ray or γ-ray generates the energetic electron which induces ionic interaction with polymer molecule. The energy loss profile along the penetration to polymer material is much different among the radiation sources of EB, γ-ray, and ion beams in the macroscopic mechanism. In this article, the behavior of single event, that is, the event induced by one electron, γ-ray, ion, and neutron is described by the macroscopic mechanism and by the microscopic mechanism. (authors)

Facile graft polystyrene onto multi-walled carbon nanotubes via in situ thermo-induced radical polymerization

International Nuclear Information System (INIS)

Liu Peng

2009-01-01

A facile procedure was developed for the grafting of polystyrene onto the surfaces of multi-walled carbon nanotubes (MWNTs) via the in situ thermo-induced bulk radical polymerization of styrene at the different polymerizing temperatures, in the presence of MWNTs without any initiator added. The grafting products were validated by the dispersibility, TEM, TGA, FT-IR, and Raman analysis. The TGA results also showed the lower polymerizing temperature was propitious to the free radical addition reactions.

Preparation of thermal-responsive chitosan-graft-N-isopropylacrylamide membranes via γ-ray irradiation

International Nuclear Information System (INIS)

Mu Qing; Fang Yue'e

2006-01-01

Poly(N-isopropylacrylamide) (PNIPAAm) has been attracting increasing attention because of its thermosensitivity. Many authors have studied the reaction of chitosan with NIPAAm, with most of the interest being focused on hydrogels. Few research programs, however, were about chitosan membranes grafted with NIPAAm monomer. In this study, a novel thermo-sensitive switching membrane was prepared by radiation-induced simultaneous grafting of NIPAAm onto chitosan membrane. Fourier transform infrared spectroscopy (FT-IR) was used to identify structure of the grafted membranes. Compared to FT-IR spectra of pristine chitosan, the new band at 1535 cm-1 in the grafted membrane was attributed to amide II of PNIPAAm. This indicated that NIPAAm was introduced onto the chitosan membrane. Surface morphology of the grafted membrane was different from the pristine chitosan membrane. The SEM images revealed cypress leaf-like structures adhered tightly to the grafted membrane surface, in comparison to smooth surface of the pristine chitosan membrane. Pure water flux measurements showed that the grafted membrane decreased with the increasing temperature, while water flux of pristine chitosan membrane was constant. It was found that the grafted membrane was sensitive to temperature. The effects of dose, dose rate and the concentration of NIPAAm on the grafting percentage were discussed. The graft yield increased with the monomer concentration and the absorbed dose. (authors)

Radiation-induced centers in inorganic glasses

International Nuclear Information System (INIS)

Brekhovskikh, S.M.; Tyul'nin, V.A.

1988-01-01

The nature, structure and formation mechanisms of radiation-induced colour centers, EPR, luminescence, generated ionizing radiation in nonorganic oxide glasses are considered. Experimental material covering both fundamental aspects of radiation physics and glass chemistry, and aspects intimately connected with the creation of new materials with the given radiation-spectral characteristics, with possibilities to prepare radiation-stable and radiation-sensitive glasses is systematized and generalized. Considerable attention is paid to the detection of radiation-induced center binding with composition, glass structures redox conditions for their synthesis. Some new possibilities of practical application of glasses with radiation-induced centers, in particular, to record optical information are reflected in the paper

Radiation grafting from binary mixtures of vinyl ether of mono ethanol amine with N-vinylpyrrolidone and vinyl ether of ethylene glycol onto polyolefins films and metallization of obtained films

International Nuclear Information System (INIS)

Al'-Saed Abdel' Aal'; Nurkeeva, Z.; Khutoryanskij, V.; Mun, G.; Sangajlo, M.

2003-01-01

Radiation grafting from binary mixtures of vinyl ether of mono ethanol amine with N-vinylpyrrolidone and vinyl ether of ethylene glycol onto polyolefins films using γ-radiation and accelerated electrons has been studied. IR-spectroscopy is used to confirm the structure of grafted films. A combination of and metallization of obtained films. A combination of gravimetric and potentiometric techniques is applied to determine the fraction of each monomer in graft copolymer. Water uptake and contact angle measurements confirmed that the grafting process improve the hydrophilic properties of obtained films. The obtained materials are metallized by electroless copper plating. The metallized films have good electro conductive properties. (author)

Immune competence in /sup 90/Sr-exposed, adult thymectomized and antilymphocyteglobulin-treated CBA mice. Pt. 1. Allogenic skin graft reaction

Energy Technology Data Exchange (ETDEWEB)

Bierke, P.

1989-01-01

CBA mice subjected to either adult thymectomy, internal exposure to /sup 90/Sr or antilymphocyteglobulin treatment separately, or to combinations of the three were tested for cellular immune competence using their reaction to allogenic skin grafts. Peripheral blood white cell counts did not reveal any obvious correlation between the degree of mononuclear cell depletion and the ability to accept grafts, suggesting that the particular treatments depleted specific fractions of mononuclear cells, differing in their extent of involvement in the rejection process. No single treatment alone induced a significant prolongation in the time elapsed before graft rejection. Adult thymectomy followed by appropriate antilymphocyteglobulin treatment induced severe lymphocytopenia and a profound suppression of the cell-mediate immune system, as evidenced by the acceptance of allogenic skin grafts. When applied to /sup 90/Sr-preexposed mice the same treatment induced lifelong acceptance of grafts, indicating a similar, though weaker immunosuppressive impact of /sup 90/Sr. Hence it was possible to significantly enhance immunosuppression in /sup 90/Sr-exposed mice. This in vivo model should be useful when investigating the role of immunological responsiveness in radiation carcinogenesis. (orig.).

Nuclear accidents and bone marrow graft

International Nuclear Information System (INIS)

Bernard, J.

1988-01-01

In case of serious contamination, the only efficacious treatment is the bone marrow grafts. The graft types and conditions have been explained. To restrict the nuclear accidents consequences, it is recommended to: - take osseous medulla of the personnel exposed to radiations and preserve it , that permits to carry out rapidly the auto-graft in case of accidents; - determine, beforehand, the HLA group of the personnel; - to register the voluntary donors names and addresses, and their HLA group, that permits to find easily a compatible donar in case of allo-graft. (author)

Hydrophil diaphragms on the basis of perfluorated copolymers FEP and polyacryl nitrile: Manufacture by radiation- initiated grafting and their use for pervaporation

International Nuclear Information System (INIS)

Scholz, H.

1986-01-01

The radiation-initiated grafting copolymerisation of hydrophil monomers to FEP, a copolymer of tetrafluorethene and hexafluorpropene and to polyacryl nitrile (PAN) was examined in this dissertation. The grafted products were used as diaphragms for the separation of water-ethanol mixtures by pervaporation. Water was separated through the diaphragm from the mixture in the pervaporation experiments. It was shown how the mechanical properties of the basic polymer affect the interaction between basic polymer and grafted polymer and how the grafting conditions affect the diaphragm properties. By grafting acrylic acid on to the basic polymers FEP and PAN, very good results were achieved for the water-ethanol separation, if the diaphragms were used in the K form. The selectivity of PAN-g-acrylic acid-K for water reached values of α > 1000. (orig./RB) [de

Application of radiation grafted media for lectin affinity separation and urease immobilization: a novel approach to tumor therapy and renal disease diagnosis

International Nuclear Information System (INIS)

Mueller-Schulte, D.; Daschek, W.

1995-01-01

Carriers modified by synergistic radiation grafting are used as affinity media for the separation of a lectin from a mistletoe extract. The grafted supports show distinctly superior properties when compared to conventional affinity media. The application of these carriers as urease immobilization support incorporated in a conductimetric bioreactor for urea analysis as potential diagnostic device in renal diseases is also described. (Author)

Preparation of vinyl acetate grafted natural rubber by irradiation method

Energy Technology Data Exchange (ETDEWEB)

Porntrairat, A.; Pattamaprom, C. [Center of Excellence on Natural Rubber Technology, Department of Chemical Engineering, Faculty of Engineering, Thammasat University, Pathumthani 12120 (Thailand)

2016-03-09

Improvement in properties of natural rubber could be done by several methods. In this research, gamma radiation technique, which is simple, accurate, easy to control and clean, was applied to enhance the properties of natural rubber (NR) in latex state. The purpose of this research is to study the appropriate condition for preparing grafted natural rubber latex by using irradiation method. Vinyl acetate monomers (VAc) were grafted onto natural rubber latex (NR-g-PVAc) at 0-10 kGys by gamma radiation from Cobalt-60 source at room temperature. Physical properties of grafted natural rubber such as chloroform number, swelling ratio and gel content were measured. The VAc content of NR-g-PVAc was investigated by titration and visualized by FTIR spectroscopy. The FTIR spectra of NR-g-PVAc prepared at 0-10 kGys showed characteristic peaks of the vinyl acetate confirming that VAc could be grafted onto natural rubber molecular chains effectively under appropriate irradiation conditions. From the result, radiation grafting was found to be a useful technique for grafting of vinyl acetate onto natural rubber.

Radiation-induced camptocormia and dropped head syndrome. Review and case report of radiation-induced movement disorders

International Nuclear Information System (INIS)

Seidel, Clemens; Kuhnt, Thomas; Kortmann, Rolf-Dieter; Hering, Kathrin

2015-01-01

In recent years, camptocormia and dropped head syndrome (DHS) have gained attention as particular forms of movement disorders. Camptocormia presents with involuntary forward flexion of the thoracolumbar spine that typically increases during walking or standing and may severely impede walking ability. DHS is characterized by weakness of the neck extensors and a consecutive inability to extend the neck; in severe cases the head is fixed in a ''chin to chest position.'' Many diseases may underlie these conditions, and there have been some reports about radiation-induced camptocormia and DHS. A PubMed search with the keywords ''camptocormia,'' ''dropped head syndrome,'' ''radiation-induced myopathy,'' ''radiation-induced neuropathy,'' and ''radiation-induced movement disorder'' was carried out to better characterize radiation-induced movement disorders and the radiation techniques involved. In addition, the case of a patient developing camptocormia 23 years after radiation therapy of a non-Hodgkin's lymphoma of the abdomen is described. In total, nine case series of radiation-induced DHS (n = 45 patients) and - including our case - three case reports (n = 3 patients) about radiogenic camptocormia were retrieved. Most cases (40/45 patients) occurred less than 15 years after radiotherapy involving extended fields for Hodgkin's disease. The use of wide radiation fields including many spinal segments with paraspinal muscles may lead to radiation-induced movement disorders. If paraspinal muscles and the thoracolumbar spine are involved, the clinical presentation can be that of camptocormia. DHS may result if there is involvement of the cervical spine. To prevent these disorders, sparing of the spine and paraspinal muscles is desirable. (orig.) [de

In Vitro Antioxidant-Activity Evaluation of Gallic-Acid-Grafted Chitosan Conjugate Synthesized by Free-Radical-Induced Grafting Method.

Science.gov (United States)

Hu, Qiaobin; Wang, Taoran; Zhou, Mingyong; Xue, Jingyi; Luo, Yangchao

2016-07-27

The major objective of this work was to develop a green and facile process to prepare gallic acid-chitosan conjugate and comprehensively evaluate the physicochemical properties and biological activities of an as-prepared water-soluble chitosan derivative. A free-radical-induced grafting approach using an ascorbic acid-hydrogen peroxide redox pair was adopted. The obtained conjugate was characterized by Fourier transform infrared spectroscopy, UV-vis, X-ray diffraction, and pKa analysis. The antioxidant activities were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6)-sulphonic acid (ABTS), reducing power, and oxygen-radical antioxidant-capacity assays. The results showed that the mass ratio of gallic acid to chitosan played a vital role in determining the grafting degree and ζ potential of the conjugates, with the ratio of 0.5:1 being the optimal ratio that resulted in the highest grafting degree. The antioxidant assays demonstrated that conjugation significantly improved the antioxidant activities, being dramatically higher than that of free chitosan. It was notable that the DPPH- and ABTS-scavenging activities of conjugate at 0.4 mg/mL reached the same level as the free gallic acid at the equivalent concentration. Our study demonstrated a green and facile synthesis approach to preparing a novel water-soluble chitosan derivative that may have promising potentials in the food industry.

Contribution of radiation-induced, nitric oxide-mediated bystander effect to radiation-induced adaptive response.

Science.gov (United States)

Matsumoto, H.; Ohnishi, T.

There has been a recent upsurge of interest in radiation-induced adaptive response and bystander effect which are specific modes in stress response to low-dose low-dose rate radiation Recently we found that the accumulation of inducible nitric oxide NO synthase iNOS in wt p53 cells was induced by chronic irradiation with gamma rays followed by acute irradiation with X-rays but not by each one resulting in an increase in nitrite concentrations of medium It is suggested that the accumulation of iNOS may be due to the depression of acute irradiation-induced p53 functions by pre-chronic irradiation In addition we found that the radiosensitivity of wt p53 cells against acute irradiation with X-rays was reduced after chronic irradiation with gamma rays This reduction of radiosensitivity of wt p53 cells was nearly completely suppressed by the addition of NO scavenger carboxy-PTIO to the medium This reduction of radiosensitivity of wt p53 cells is just radiation-induced adaptive response suggesting that NO-mediated bystander effect may considerably contribute to adaptive response induced by radiation

Mixed allogeneic reconstitution (A+B----A) to induce donor-specific transplantation tolerance. Permanent acceptance of a simultaneous donor skin graft

International Nuclear Information System (INIS)

Ildstad, S.T.; Wren, S.M.; Oh, E.; Hronakes, M.L.

1991-01-01

Mixed allogeneic reconstitution, in which a mixture of T-cell-depleted bone marrow of syngeneic host and allogeneic donor type is transplanted into a lethally irradiated recipient (A+B----A), results in mixed lymphopoietic chimerism with engraftment of a mixture of both host and donor bone marrow elements. Recipients are specifically tolerant to donor both in vitro and in vivo. Donor-specific skin grafts survive indefinitely when they are placed after full bone marrow repopulation at 28 days, while third-party grafts are rapidly rejected. To determine whether a delay of a month or more for full bone marrow repopulation is required before a donor-specific graft can be placed, we have now examined whether tolerance induction can be achieved if a graft is placed at the time of bone marrow transplantation. Permanent acceptance of donor-specific B10.BR skin grafts occurred when mixed allogeneic chimerism (B10+B10.BR----B10) was induced and a simultaneous allogeneic donor graft placed. In vitro, mixed reconstituted recipients were specifically tolerant to the B10.BR donor lymphoid cells but fully reactive to MHC-disparate third-party (BALB/c; H-2dd) when assessed by mixed lymphocyte reaction (MLR) and cell-mediated lympholysis (CML) assays. These data therefore indicate that a donor-specific graft placed at the time of mixed allogeneic reconstitution is permanently accepted without rejection. To determine whether an allogeneic skin graft alone without allogeneic bone marrow would be sufficient to induce tolerance, syngeneic reconstitution (B10----B10) was carried out, and a simultaneous B10.BR allogeneic skin graft placed. Although skin grafts were prolonged in all recipients, all grafts rejected when full lymphopoietic repopulation occurred at 28 days

Some remarks on applied radiation chemistry

International Nuclear Information System (INIS)

Sakurada, I.

1979-01-01

Radiation induced polymerization and grafting are two important reactions in the processing. Numerous reports concerning these subjects have appeared in the literature. There are, however, still many problems which have been left unsolved or neglected. Several problems will be taken up in this paper and discussed on experiments carried out in Osaka Laboratory for Radiation Chemistry and Department of Polymer Chemistry of Kyoto University. (author)

Radiation grafting of pH and thermosensitive N-isopropylacrylamide and acrylic acid onto PTFE films by two-steps process

International Nuclear Information System (INIS)

Bucio, E.; Burillo, G.

2007-01-01

Polytetrafluoroethylene (PTFE) was grafted (g) with acrylic acid (AAc) by γ-ray pre-irradiation method to get PTFE-g-AAc films, then N-isopropylacrylamide (NIPAAm) was grafted onto PTFE-g-AAc films with γ-ray to get (PTFE-g-AAc)-g-NIPAAm. PTFE films were irradiated in air at a dose rate of 3.0 kGy h -1 and different radiation dose. The irradiated films were placed in glass ampoules, which contained aqueous solutions with different monomer concentration (AAc), and then they were heated at different temperatures and reaction time. NIPAAm onto PTFE-g-AAc was carried out with the same procedure with monomer concentration of 1 mol L -1 . The thermosensitivity of the samples was defined and calculated as the ratio of the grafted samples swelling at 28 and 35 o C, and pH sensitivity defined as the ratio of the grafted samples swelling at pH 2 and 8

Radiation-induced instability of human genome

International Nuclear Information System (INIS)

Ryabchenko, N.N.; Demina, Eh.A.

2014-01-01

A brief review is dedicated to the phenomenon of radiation-induced genomic instability where the increased level of genomic changes in the offspring of irradiated cells is characteristic. Particular attention is paid to the problems of genomic instability induced by the low-dose radiation, role of the bystander effect in formation of radiation-induced instability, and its relationship with individual radiosensitivity. We believe that in accordance with the paradigm of modern radiobiology the increased human individual radiosensitivity can be formed due to the genome instability onset and is a significant risk factor for radiation-induced cancer

New CO2 adsorbent containing aminated poly(glycidyl methacrylate) grafted onto irradiated PE-PP nonwoven sheet

Science.gov (United States)

Mahmoud Nasef, Mohamed; Abbasi, Ali; Ting, T. M.

2014-10-01

A new CO2 adsorbent containing triethylamine (TEA) was prepared by radiation induced grafting of glycidyl methacrylate (GMA) onto polyethylene coated polypropylene (PE-PP) non-woven sheet followed by amination reaction. The degree of grafting (DOG%) was controlled by variation of monomer concentration and absorbed dose. The incorporation of aminated poly(GMA) was investigated by Fourier transform infrared (FTIR) and scanning electron microscope (SEM). The adsorbent with DOG of 350% and amination yield of 60% exhibited CO2 adsorption capacity of 4.52 mol/kg at ambient temperature and pressure.

Salt-Induced Control of the Grafting Density in Poly(ethylene glycol) Brush Layers by a Grafting-to Approach

DEFF Research Database (Denmark)

Ortiz, Roberto; Olsen, Stefan; Thormann, Esben

2018-01-01

In this work, a method to obtain control of the grafting density during the formation of polymer brush layers by the grafting-to method of thiolated poly(ethylene glycol) onto gold is presented. The grafting density of the polymer chains was adjusted by adding Na2SO4 in concentrations between 0.......2 and 0.9 M to the aqueous polymer solution during the grafting process. The obtained grafting densities ranged from 0.26 to 1.60 chains nm-2, as determined by surface plasmon resonance. The kinetics of the grafting process were studied in situ by a quartz crystal microbalance with dissipation......, and a mushroom to brush conformational transition was observed when the polymer was grafted in the presence of Na2SO4. The transition from mushroom to brush was only observed for long periods of grafting, highlighting the importance of time to obtain high grafting densities. Finally, the prepared brush layer...

Radiation grafting of pH-sensitive acrylic acid and 4-vinyl pyridine onto nylon-6 using one- and two-step methods

International Nuclear Information System (INIS)

Ortega, Alejandra; Alarcón, Darío; Muñoz-Muñoz, Franklin; Garzón-Fontecha, Angélica; Burillo, Guillermina

2015-01-01

Acrylic acid (AAc) and 4-vinyl pyridine (4VP) were γ-ray grafted onto nylon-6 (Ny 6 ) films via pre-irradiation oxidative method. These monomers were grafted using a one-step method to render Ny 6 -g–(AAc/4VP). A two-step or sequential method was used to render (Ny 6 -g–AAc)-g–4VP. Random copolymer branches were obtained when the grafting was carried out via one-step method using the two monomers together. The two-step method was applied to graft chains of 4VP on both Ny 6 substrate and previously grafted AAc chains (Ny 6 -g–AAc). The two types of binary copolymers synthesized were characterized to determine the amount of grafted polymers, the thermal behavior (DSC and TGA), the surface composition (XPS), and the pH responsiveness. In the two-step process, it is possible to achieve a higher graft yield, better control of the amount of each monomer, good reversibility in the swelling/deswelling process and shorter time to achieve equilibrium swelling. - Highlights: • A new binary graft of 4VP and AAc onto Ny 6 films was synthesized by γ-radiation. • The binary grafted material has potential application for heavy ion retention. • The two-step method shows better conditions in swelling and reversibility properties. • Surface distribution of monomers was evaluate by XPS characterization

Synthesis and characterization of radiation grafted films for removal of arsenic and some heavy metals from contaminated water

International Nuclear Information System (INIS)

Chowdhury, M.N.K.; Khan, M.W.; Mina, M.F.; Beg, M.D.H.; Khan, Maksudur R.; Alam, A.K.M.M.

2012-01-01

Grafting of styrene/maleic anhydride and methyl methacrylate/maleic anhydride binary monomers onto the low density polyethylene film was performed using the γ-ray irradiation technique. Then, the synthesized grafted films were treated with different ammonia derivatives for developing chelating functionalization. These chelating products were characterized by the gravimetric method as well as by the Fourier transformed infrared spectroscopic method, and were used for removal of arsenic and some heavy metals from aqueous solutions. The optimum absorbed dose of 30 kGy reveals the graft yielding of about 325% in the films. Uptake of arsenic and some heavy-metal ions (Cr(III), Mn(II), Fe(III), Ni(II), Cu(II) and Pb(II)) from contaminated water by the chelating functionalized films (CFF) was examined by an atomic absorption spectrophotometer. The maximum arsenic removal capacity of 5062 mg/kg has been observed for the film treated with hydroxylamine hydrochloride. The CFF prepared by semicarbazide and thiol analogs show affinity toward the metal ions with an order: Cu(II)>Fe(III)>Mn(II) etc. The results obtained from this study indicate that the functionalized films show good chelating and ion-exchange property for metal ions. - Highlights: ► Optimization of radiation dose for grafting reaction of polyethylene with binary monomers. ► Chelating functionalization of grafted film with various amine compounds. ► Characterization of both grafted and chelating functionalized films. ► Proposed mechanism for both grafting and chelating functionalization reaction. ► Application of the synthesized films for the removal of arsenic and some heavy metals from contaminated water.

Comparison with adsorption of Re (VII) by two different γ-radiation synthesized silica-grafting of vinylimidazole/4-vinylpyridine adsorbents

Energy Technology Data Exchange (ETDEWEB)

Xiao, Pu [Beijing Key Laboratory for Solid Waste Utilization and Management, Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871,China (China); Han, Dong; Zhai, Maolin [Beijing National Laboratory for Molecular Sciences, Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, The Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Xu, Ling, E-mail: lingxu@pku.edu.cn [Beijing Key Laboratory for Solid Waste Utilization and Management, Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871,China (China); Li, Huibo, E-mail: hb0012@sina.com [China Institute of Atomic Energy, P.O. Box 275-26, Beijing 102413 (China)

2017-02-15

Highlights: • Two Re adsorbents were synthesized by grafting of vinylimidazole and vinylpyridine onto silanized silica gel via γ-radiation. • The Re adsorption capacities of SS-MPTS-VIMH and SS-MPTS-VPQ were 145.99 mg g{sup −1} and 71.08 mg g{sup −1}, respectively. • Both the adsorbents had fast adsorption kinetics, and could be used for column adsorption. • SS-MPTS-VPQ had good anti-interference abilities, and might be used for the disposal of Tc in the future. - Abstract: Two silica gel based adsorbents for Re (VII), i.e. SS-MPTS-VIMH and SS-MPTS-VPQ, were synthesised. Silica gel was used as the matrix for γ-radiation grafting, and the monomer of 1-vinyl imidazole (VIM) and 4-vinylpyridine (4-VP) was grafted onto the silica silanized by methacryloxy propyl trimethoxyl silane, respectively. A VIM concentration of 2 mol L{sup −1} and an absorbed dose of 30 kGy were the optimal grafting conditions for adsorbent SS-MPTS-VIM, and a 4-VP concentration of 4 mol L{sup −1} and an absorbed dose of 40 kGy were the optimal grafting conditions for adsorbent SS-MPTS-VP. At the certain condition, the grafting yield of SS-MPTS-VIM was 30.1% and that of SS-MPTS-VP was 21.0%. The adsorption capacity of adsorbent SS-MPTS-VIMH was 145.99 mg g{sup −1} and that of SS-MPTS-VPQ was 71.08 mg g{sup −1} according to the Langmuir model. The adsorbent SS-MPTS-VPQ had better adsorption properties of acid resistance and anti-interference than SS-MPTS-VIMH. Dynamic column experiments showed that protonated adsorbent SS-MTPS-VIMH could be recycled with good performance while quaternized adsorbent SS-MPTS-VPQ could not. The adsorbent SS-MPTS-VIMH belongs to weak anion exchange adsorbent and SS-MPTS-VPQ belongs to strong anion exchange adsorbent. This study paves a way to the synthesis and application of a novel silica base adsorbents for Re (VII).

Polymerization by radiation. Application

International Nuclear Information System (INIS)

Romero, M.; Fernandez Miranda, J.

1997-01-01

Achieved results of the research work done in the field of radiation polymerization are summarized. Developing new chromatographic matrices, the radiation grafting of Glycidyl methacrylate on the surface of Low Density Polyethylene beads was studied. The dependence of both, the grafted degree and width of the grafted layer, with the radiation dose applied, is presented

Antimicrobial and Thermal Properties of Metal Complexes of Grafted Fabrics with Acrylic Acid by Gamma Irradiation

International Nuclear Information System (INIS)

Hassan, M.S.; Attia, R.M.; Zohdy, M.H.

2008-01-01

Cotton, cotton/PET blend and PET fabrics were treated against microbial effect by radiation - induced grafting of acrylic acid followed by metal complexation with some divalent transition metal ions Co (II), Ni (II) and Cu (II). The microbial resistance was evaluated by testing the mechanical properties of the treated fabrics after burring for one and two weeks in a moist soil reach with microorganisms. Also, the growth of microorganisms was examined by scanning electron microscope (SEM). Moreover, the effect of this treatment on the thermal decomposition behavior was investigated by thermogravimetric analysis (TGA). On the basis of microbial studies, it was found that the metal complexation of the grafted fabrics with acrylic acid enhanced the antimicrobial resistance of the fabrics and the antimicrobial resistance could be arranged according to the metal ions as follows: copper> nickel> cobalt. Also, the thermal stability of different fabrics could be arranged as follow: grafted fabrics complexed with Cu (II) > grafted fabrics complexed with Ni (II) > grafted fabrics complexed with Co (II)

Radiation-induced heart injury

International Nuclear Information System (INIS)

Suzuki, Yoshihiko; Niibe, Hideo

1975-01-01

In order to identify radiation-induced heart injury and to differentiate it from heart disease, an attempt was made to clarify post-irradiation heart injury by investigating the histological changes which occur during the internal between the irradiation and the time of demonstrable histological changes. A study was made of 83 autopsies in which most of the primary neoplasms were breast cancers, lung cancers and mediastinal tumors. In 43 of these autopsies the heart had been irradiated. Sixty eight dd-strain mice were also used for microautoradiographic study. Histological changes in the heart were observed in 27 of the 43 cases receiving irradiation. The limit of the tolerance dose to the heart for indicating histological changes was 1220 ret in humans. The latent period without histological changes was 2.7 months after initiation of radiation therapy. Greater heart injury was observed after re-irradiation or after the combined therapy of radiation and chemotherapy especially mitomycin (MMC). The histological findings after treatment with MMC were similar to those of radiation-induced heart injury. Results of the study indicate that the damage is secondary to radiation-induced changes of the vascula connective tissue. (Evans, G.)

Prospect of radiation application in industry and agriculture

International Nuclear Information System (INIS)

Kume, Tamikazu

2007-01-01

The prospect of radiation application in industry and agriculture are described. In industry, the radiation-induced crosslinking of polymers and radiation-induced graft polymerization improved many chemical and physical properties and new functional materials were created using ion beams. In agriculture, the food irradiation improved the food hygiene and killed insect pest of fruits and vegetables. Furthermore, the sterile insect technique, mutation breeding of plants, positron imaging system for plant, sterilization of medical products, environmental conservation due to purification of flue gas and wastewater, and upgrading of natural polymer (polysaccharide etc.) have been performed. Radiation process is a clean one without use of chemical reagents. The electron beam radiation is expected to reduce the cost of radiation process compared with the gamma-ray radiation. (M.H.)

Development and Application of Chlorinated, Fluorinated and Technological Polymer Films Modified by Grafting Process Using Electron Beam and Gamma Radiation

Energy Technology Data Exchange (ETDEWEB)

Manzoli, J E [Nuclear Energy National Commission, Nuclear and Energetic Research Institute, Sao Paulo (Brazil); Universidade Sao Judas Tadeu, Sao Paulo (Brazil); Geraldo, A B.C.; Moura, E; Somesari, E S.R.; Silveira, C G; Oikawa, H; Moreira, N S; Forbicini, C [Nuclear Energy National Commission, Nuclear and Energetic Research Institute, Sao Paulo (Brazil); Tenorio, E [FATEC, Tatui (Brazil); Augusto, C G [IFSP, Sao Paulo (Brazil); Universidade Sao Judas Tadeu, Sao Paulo (Brazil); Panzarini, L C.G.A. [FEI, Sao Bernardo do Campo (Brazil)

2012-09-15

The ionizing irradiation (electron beam and gamma irradiation) induced grafting to fluorinated and chlorinated polymeric films were studied. Styrene grafting onto fluorinated and perfluorinated polymers and their ulterior sulfonation constitute a process to produce ionomers for many applications. The modification of polyvinylchloride with dimethylaminethylmethacrylate-heparin grafting attempt for the fact that grafting can be applied in packaging industry as an alternative for decreasing of plasticizer or another chemical species migration, in many cases nocivus contaminant for human health, and, in the specific study of this project, to obtain a less thrombogenic polymer surface to be used in medical applications. The results indicate mutual styrene grafting performed by industrial EB accelerator can be a fast alternative to produce ionomers that can compete in market. The numerical method to simulate diffusion process evolved is simple and fast and applied to fit experimental results. (author)

Radiation-induced gene expression in human subcutaneous fibroblasts is predictive of radiation-induced fibrosis

DEFF Research Database (Denmark)

Rødningen, Olaug Kristin; Børresen-Dale, Anne-Lise; Alsner, Jan

2008-01-01

BACKGROUND AND PURPOSE: Breast cancer patients show a large variation in normal tissue reactions after ionizing radiation (IR) therapy. One of the most common long-term adverse effects of ionizing radiotherapy is radiation-induced fibrosis (RIF), and several attempts have been made over the last...... years to develop predictive assays for RIF. Our aim was to identify basal and radiation-induced transcriptional profiles in fibroblasts from breast cancer patients that might be related to the individual risk of RIF in these patients. MATERIALS AND METHODS: Fibroblast cell lines from 31 individuals......-treated fibroblasts. Transcriptional differences in basal and radiation-induced gene expression profiles were investigated using 15K cDNA microarrays, and results analyzed by both SAM and PAM. RESULTS: Sixty differentially expressed genes were identified by applying SAM on 10 patients with the highest risk of RIF...

On the influence of X-ray surface radiation of the donor or recipient site on the revascularisation of autologous free full thickness skin grafts

International Nuclear Information System (INIS)

Lange, R.

1972-01-01

Experimental X-ray injuries of the skin were created on guineapigs with contact therapy conditions with a total dose of 14,000 or 12,000R. Measurements of the skin temperature and heat release of the skin show that regardless of whether the donor or recipient site was injured, a reproduction of the plethora and a reduction of the blood circulation of antologous, free full thickness skin grafts was brought about compared to control grafts if the operation was performed 2 - 3 weeks after ending irradiation. Extensively corresponding results were obtained if the operation was performed 5 months after terminating irradiation; however, an increased blood circulation was detected on the 7th post-operative day with the pre-injury of the graft bed. Corresponding measurements on 10 human full thickness skin grafts with radiation-injured graft bed and 15 comparison grafts also showed a negative influence of the revascularisation by the X-ray injury of the graft bed. (orig./LH) [de

Radiation-grafting of N-vinylimidazole onto silicone rubber for antimicrobial properties

Science.gov (United States)

Meléndez-Ortiz, H. Iván; Alvarez-Lorenzo, Carmen; Burillo, Guillermina; Magariños, Beatriz; Concheiro, Angel; Bucio, Emilio

2015-05-01

Poly(N-vinylimidazole) (PVIm) was grafted numbers onto silicone rubber (SR) with the aim of providing antimicrobial properties. The grafting was carried out by means of gamma rays using the direct method. The influence on the grafting yield of absorbed dose, monomer concentration, addition of FeSO4 salt, composition and type of solvent (H2O, MeOH, THF, and acetone) was investigated. Grafts onto SR between 10% and 90% were obtained at doses from 20 to 100 kGy and a dose rate 10.9 kGy h-1; grafting yield increased with monomer concentration and dose. The new graft copolymers were confirmed by Fourier transform infrared spectroscopy (FT-IR). Differential scanning calorimeter (DSC) showed glass transition at 149 and 159 °C for 38% and 88% grafting respectively. Thermogravimetry analysis (TGA) presented two decomposition temperatures for SR-g-VIm at 380 (PVIm) and 440 °C (SR). SR-g-VIm showed antibacterial activity against Pseudomonas aeruginosa.

Proceedings of 3. autumn school of radiation sterilization of medical utensils and grafts; 3. jesiennea szkola sterylizacji radiacyjnej sprzetu medycznego i przeszczepow

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

The Polish experience and review of worldwide development of radiation techniques and technologies have been presented and discussed in the field of radiation sterilization of medical supplies and grafts as well as for food processing. These problems have found now in Poland industrial or pilot plant solutions. Also some technologies connected with medical utensils production from with polymeric material resistant for radiation have been developed in Poland.

Proceedings of 3. autumn school of radiation sterilization of medical utensils and grafts; 3. jesiennea szkola sterylizacji radiacyjnej sprzetu medycznego i przeszczepow

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-31

The Polish experience and review of worldwide development of radiation techniques and technologies have been presented and discussed in the field of radiation sterilization of medical supplies and grafts as well as for food processing. These problems have found now in Poland industrial or pilot plant solutions. Also some technologies connected with medical utensils production from with polymeric material resistant for radiation have been developed in Poland.

Application of radiation-induced apoptosis in radiation oncology and radiation protection

International Nuclear Information System (INIS)

Crompton, N.E.A.; Emery, G.C.; Ozsahin, M.; Menz, R.; Knesplova, L.; Larsson, B.

1997-01-01

A rapid assay of the ability of lymphocytes to respond to radiation-induced damage is presented. Age and genetic dependence of radiation response have been quantified. The assay is sensitive to low doses of radiation. Its ability to assess the cytotoxic response of blood capillaries to radiation has been evaluated. (author)

Radiation-induced pneumothorax

International Nuclear Information System (INIS)

Epstein, D.M.; Littman, P.; Gefter, W.B.; Miller, W.T.; Raney, R.B. Jr.

1983-01-01

Pneumothorax is an uncommon complication of radiation therapy to the chest. The proposed pathogenesis is radiation-induced fibrosis promoting subpleural bleb formation that ruptures resulting in pneumothorax. We report on two young patients with primary sarcomas without pulmonary metastases who developed spontaneous pneumothorax after irradiation. Neither patient had antecedent radiographic evidence of pulmonary fibrosis

Radiation induced sarcomas of bone following therapeutic radiation

International Nuclear Information System (INIS)

Kim, J.H.; Chu, F.C.H.; Woodward, H.Q.; Huvos, A.

1983-01-01

Because of new therapeutic trends of multi-modality and the importance of late effects, we have updated our series of radiation induced bone sarcomas seen at Memorial Sloan-Kettering Cancer Center over the past four decades. A total of 37 cases of bone sarcoma arising from normal bone in the irradiated field was analyzed. The median for latent period from irradiation to diagnosis of bone sarcoma was 11 years with a minimum latent period of four years. The median radiation dose for the bone sarcoma was 6000 rad in 6 weeks with a minimum total radiation dose of 3000 rad in 3 weeks. We have found nine patients who developed bone sarcomas in the radiation field after successful treatment of Hodgkin's disease. Criteria for radiation induced bone sarcomas and the magnitude of the risk of bone sarcomas are briefly discussed

Biofunctional polymers prepared by ionizing radiation; Polimeros biofuncionais preparados pela radiacao ionizante

Energy Technology Data Exchange (ETDEWEB)

Martellini, Flavia; Rodas, Andrea C.D.; Higa, Olga Z. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Queiroz, Alvaro A.A. de [Escola Federal de Engenharia de Itajuba, MG (Brazil)

1995-12-31

Polymeric systems with biomedical and biochemical properties can be obtained by radiation induced polymerization. Those systems exhibit a pharmaceutical or biocatalytic activity if drugs or enzymes are immobilized in the polymer matrices. This work deals with the synthesis by gamma radiation of acrylic monomers and paracetamol, a drug with analgesic and anti thermic action, which can be used as medication in drug delivery systems. Besides, polyethylene and polypropylene radiation grafted with a hydrogel containing carboxylic groups (acrylic acid), showed to be a suitable substrate for the enzyme coupling, such as urease and glucose oxidase. The grafted matrices allow the immobilization of any biocomponent with protein structure. (author). 8 refs., 4 figs.

Radiation-induced bone neoplasma in facial cranium

Energy Technology Data Exchange (ETDEWEB)

Zomer-Drozda, J; Buraczewska-Lipinska, H; Buraczewski, J [Instytut Onkologii, Warsaw (Poland)

1976-01-01

Radiation-induced bone neoplasms in the region of facial cranium account for about 40% of all radiation-induced tumours of bones, although the number of cases with lesions irradiated in this area is proportionally much lower than the number of cases treated with radiotherapy in other parts of the body. Four personal cases of radiation-induced tumours with complicated course are reported. Attention is called to the value of radiological investigations in the diagnosis of bone diseases and in differential diagnosis of radiation-induced tumours of bones.

The morphological effect of electron irradiation on the healing of skin wounds and skin grafts in the rat

International Nuclear Information System (INIS)

Wang, Q.

1995-01-01

this study is the the first to investigate skin grafting combined with radiation of the wound bed, it is noteworthy that while this procedure induces a delay in the healing of skin autografts, it does not appear to present any obvious clinical complications during early healing stages, at least in the rat model. Further irradiation studies in this area should be undertaken at higher dose levels. (author)

The morphological effect of electron irradiation on the healing of skin wounds and skin grafts in the rat

Energy Technology Data Exchange (ETDEWEB)

Wang, Q

1995-07-01

this study is the the first to investigate skin grafting combined with radiation of the wound bed, it is noteworthy that while this procedure induces a delay in the healing of skin autografts, it does not appear to present any obvious clinical complications during early healing stages, at least in the rat model. Further irradiation studies in this area should be undertaken at higher dose levels. (author)

Radiation syntheses and characteristics of PTFE-g-PSSA ion exchange membranes for applications in vanadium redox battery

International Nuclear Information System (INIS)

Peng Jinfen; Qiu Jinyi; Zhai Maolin; Xu Peng; Peng Jing; Li Jiuqiang; Wei Genshuan

2006-01-01

Radiation-induced grafting of styrene onto polyterafluorothylene (PTFE) films was studied by simultaneous irradiation technique. The grafting was induced by 60 Co γ-rays at room temperatures. Effects of the solvent, absorbed dose, dose rate, atmosphere and initial monomer concentration on the grafting yield were investigated and optimal grafting conditions were obtained. Subsequently, sulphonation of the grafted PTFE films (PTFE-g-PS) was investigated and a series of ion exchange membranes (PTFE-g-PSSA) was prepared. FTIR, TGA, XRD and SEM measurements showed that grafting and sulfonation of the PTFE films were successfully carried out; moreover, grafting of styrene mainly occurred in the pores of PTFE films and crystallization degree of the PTFE films decreased with increase grafting yield. Water uptake, ion exchange capacity (IEC) and conductivity of the PTFE-g-PSSA membrane increased with the grafting yield. The results indicated that by 20 kGy irradiation, ion exchange membrane which was suitable for vanadium redox battery can be prepared. (authors)

The radiation grafting of vinyl monomers to cotton fabrics

International Nuclear Information System (INIS)

Shiraishi, N.; Williams, J.L.; Stannett, V.

1982-01-01

Cobalt 60 γ and electron beam radiation were used to graft diethylphosphatoethyl methacrylate, pure and in 90:10 methanol solution, to cotton cloth. This monomer, with an 11.64% phosphorus content, was especially developed by the Scott Paper Co. to develop fire retardancy. A simple pad and squeeze application followed by direct irradiation under a nitrogen atmosphere was used. Although excess monomer could be removed by washing with water, no solvent for the polymer was found so only the total 'add-ons' could be measured. With 60 Co irradiation, total polymerization was obtained with more than 1 Mrad but with electron beam irradiation only about 50% conversion was obtained even with 10 Mrad. No acceleration in the rates could be achieved with the viscous pure monomer as opposed to in solution. Yields adequate to impart reasonable fire retardancy could, however, be obtained with about 3 Mrad with electrons. No noticeable degradation of the polymer occurred at the doses used. (author)

Preparation of porous adsorbers and supports most favorable for separation by using radiation-induced graft polymerization

International Nuclear Information System (INIS)

Saito, Kyoichi

2014-01-01

Various functional groups such as chelate-forming and ion-exchange groups were introduced into the poly-glycidyl methacrylate chain grafted onto a commercially available porous hollow-fiber membrane with a thickness of approximately 1 mm, an average pore size of 0.4 µm, and a porosity of 70%. Permeation of a target metal-ion or protein solution driven by a transmembrane pressure enables us to minimize the diffusional mass-transfer resistance of metal ions or proteins to the functional groups. Considerable degree of GMA grafting and molar conversion of the epoxy group into the functional group provide a higher functional group density of the porous hollow-fiber membrane than for conventional adsorbents. First, metal ions and proteins were transported to the chelating and ion-exchange groups, respectively, of the graft chain. The higher the permeation rate of the target solution is, the higher the overall adsorption rate of the target ions or proteins onto the modified porous hollow-fiber membrane becomes. In addition, proteins were bound to the ion-exchange polymer brush in multilayers because the polymer brush extends from the pore surface towards the pore interior due to its mutual electrostatic repulsion. Second, replacement adsorption was observed in a binary system of metal ions or proteins during the permeation of the solution through the membrane with a membrane thickness of approximately 1 mm. Third, chiral resolution of DL-tryptophan was demonstrated using albumin-multilayered porous hollow-fiber membranes. (author)

Regulation of radiation-induced protein kinase Cδ activation in radiation-induced apoptosis differs between radiosensitive and radioresistant mouse thymic lymphoma cell lines

International Nuclear Information System (INIS)

Nakajima, Tetsuo; Yukawa, Osami; Tsuji, Hideo; Ohyama, Harumi; Wang, Bing; Tatsumi, Kouichi; Hayata, Isamu; Hama-Inaba, Hiroko

2006-01-01

Protein kinase Cδ (PKCδ) has an important role in radiation-induced apoptosis. The expression and function of PKCδ in radiation-induced apoptosis were assessed in a radiation-sensitive mouse thymic lymphoma cell line, 3SBH5, and its radioresistant variant, XR223. Rottlerin, a PKCδ-specific inhibitor, completely abolished radiation-induced apoptosis in 3SBH5. Radiation-induced PKCδ activation correlated with the degradation of PKCδ, indicating that PKCδ activation through degradation is involved in radiation-induced apoptosis in radiosensitive 3SBH5. In radioresistant XR223, radiation-induced PKCδ activation was lower than that in radiosensitive 3SBH5. Cytosol PKCδ levels in 3SBH5 decreased markedly after irradiation, while those in XR223 did not. There was no apparent change after irradiation in the membrane fractions of either cell type. In addition, basal cytosol PKCδ levels in XR223 were higher than those in 3SBH5. These results suggest that the radioresistance in XR223 to radiation-induced apoptosis is due to a difference in the regulation of radiation-induced PKCδ activation compared to that of 3SBH5. On the other hand, Atm -/- mouse thymic lymphoma cells were more radioresistant to radiation-induced apoptosis than wild-type mouse thymic lymphoma cells. Irradiated wild-type cells, but not Atm -/- cells, had decreased PKCδ levels, indicating that the Atm protein is involved in radiation-induced apoptosis through the induction of PKCδ degradation. The decreased Atm protein levels induced by treatment with Atm small interfering RNA had no effect on radiation-induced apoptosis in 3SBH5 cells. These results suggest that the regulation of radiation-induced PKCδ activation, which is distinct from the Atm-mediated cascade, determines radiation sensitivity in radiosensitive 3SBH5 cells

Surface Modifications of Polymers Induced by Heavy Ions Grafting

Energy Technology Data Exchange (ETDEWEB)

Mazzei, R O; Lombardo, J; Camporotondi, D; Tadey, D; Bermudez, G G [National Atomic Energy Commission, Ezeiza Atomic Centre, Ezeiza (Argentina)

2012-09-15

Polymer surfaces are modified by the application of swift heavy ions etching and grafting procedures. The residual active sites produced by heavy ion beams, remaining after the etching process, were used to start the grafting process. In order to produce tracks on foils of poly(vinylidene fluoride) (PVDF) they were irradiated with {sup 208}Pb of 25.62 MeV/n or with 115 MeV Cl ions. Moreover, foils of polypropylene (PP) were irradiated with {sup 208}Pb of 25.62 MeV/n. Then, they were etched and grafted with N-isopropylacrylamide (NIPAAm) monomers or with acrylic acid (AAc) monomers, respectively. The replica method allowed the observation of the shape of the grafted tracks using transmission electron microscopy (TEM). In addition NIPAAm grafted foils were analyzed using Fourier transform infrared spectroscopy (FTIR). The sulfonation procedure (methodology previously described for perfluorated polymers) was applied on grafted PVDF. A new method is described to produce a thin layer of poly-acrylic-acid (membranes) that grows on the surface of PVDF foils implanted by an Ar{sup +} beam with energies between 30-150 keV. Different combinations of monomers in water solutions were used such as: acrylic acid (AAc); acrylic acid-glycidyl methacrylate (AAc-GMA); acrylic acid-styrene (AAc-S); acrylic acid-N-isopropyl acrylamide (AAc-NIPAAm) and acrylic acid-N-isopropyl acrylamide - glycidyl methacrylate (AAc-NIPAAm-GMA). The experimental results show that for particular values of: ion fluence and energy, AAc concentration, sulphuric acid and PVDF polymorphous (alpha or beta) a huge percentage of grafting was obtained. At certain point of the grafting process the development of the PolyAAc-Xmonomer produce a detachment from the irradiated substrate and continue its grafting outside it. This method produces a membrane that is an increased replica of the original implanted surface. Finally, PVDF films implanted by an Ar{sup +} beam with energies about 100 keV and a fluence of 10

Skin graft influence in human tissue radiated in nude mice regeneration

International Nuclear Information System (INIS)

Miranda, Jurandir Tomaz de

2016-01-01

Over the last few years it has increased the interest in the human skin grafts radio sterilized for application mainly in extensive and deep burns. Because these grafts quickly grip and present antigenic lower potential, compared with other treatments used. The purpose of this study was to evaluate the histoarchitecture of human skin grafts irradiated with doses 25 kGy, 50 kGy and non-irradiated during the repair tissue process in nude mice submitted by skin grafting in the dorsal region. Three groups of animals received irradiated human skin grafts (25 kGy and 50 kGy) and non-irradiated and were euthanized on the 3 rd , 7 th and 21 th day after the surgery. Indeed, routine histologic procedures, tissue samples were stained with hematoxylin and eosin (HE) for quantification of keratinocytes, fibroblasts, immune cells and blood vessels and immunofluorescence (IF) was performed to determine the expression human collagen type I and collagen type I and III mouse. Therefore, quantification of both the cells and the collagen types was performed by image analysis using Image-Pro Plus 6.0 software. Histologic results demonstrated at a dose of 25 kGy that human skin irradiation when grafted influences the increase in the number of cells in wound site over time and it provides better dispersion of these cells. In addition, on the 21 st day, three groups of animals with human skin graft were embedded part of the graft in the healing process. On the other hand, the group not irradiated showed greater incorporation of the graft (43 %), but less production of collagen type III mouse (22 %). Since the groups irradiated skin graft showed lower graft incorporation (6 and 15%), but with greater production of collagen type III mice (35 % and 28 % to 25 kGy and 50 kGy, respectively). In conclusion, this study presented that the group irradiated to 25 kGy and it has a higher cell proliferation and vessel formation, and better remodeling of the healing area. (author)

Gamma radiation grafting process for preparing separator membranes for electrochemical cells

International Nuclear Information System (INIS)

Agostino, V.F. D'; Lee, J.Y.

1982-01-01

An irradiation grafting process for preparing separator membranes for use in electrochemical cells, comprises contacting a polymeric base film with an aqueous solution of a hydrophilic monomer and a polymerization retardant; and irradiating said contacted film to form a graft membrane having low electrical resistivity and having monomer molecules uniformly grafted thereon. In the examples (meth) acrylic acid is grafted on to polyethylene, polypropylene and polytetrafluoroethylene in the presence of ferrous sulphate or cupric sulphate as polymerization retardants. (author)

3 cases of radiation-induced sarcoma

International Nuclear Information System (INIS)

Shiba, Keiichiro; Fukuma, Hisatoshi; Beppu, Yasuo; Hirota, Teruyuki; Shinohara, Norio.

1982-01-01

Criteria for the diagnosis of radiation-induced sarcoma have been previously described. All cases must have a history of irradiation and the second neoplasm must have arisen in the area of the radiation field. A latent period of several years must have elapsed after irradiation before clinical evidence of a second malignant neoplasm. Most important thing is that, all suspected cases must have been proved histologically. We have experienced 3 cases of radiation-induced sarcoma, they were 42-years-old man who developed an osteosarcoma of the lumbar spine at the field of postoperative irradiation for seminoma 7 years previously, 69-years-old woman who developed a malignant fibrous histiocytoma of the buttock at the field of radical radiation for uterine carcinoma 7 years previously and 59-years-old woman who developed an extraskeletal osteosarcoma of the abdominal wall at the field of postoperative irradiation for uterine sarcoma 7 years previously. The last case is very rare and only 8 cases of radiation-induced extraskeletal osteosarcoma have been reported. Since there has been a definite trend in the treatment of cancer toward employing radiation for more favorable cases, in addition to technical improvements in the administration of radiotherapy and more modern equipment, survival data may have been altered considerably in many malignant tumors. Accordingly, more radiation-induced tumors may be encountered in the future. The clinical presentation and histopathology of these radiation-induced sarcomas are presented with a review of the literature. (author)

Use of gamma and UV radiation in grafting hydrogel polymers to membranes

International Nuclear Information System (INIS)

Baker, L.; Hill, D.J.T.; Whittaker, A.; Hunter, D.; Davis, T.P.

1998-01-01

Full text: Dimethylacrylamide and N-isopropylacrylamide hydrogels are useful for their ability to absorb large amounts of water and for their thermotropic response. However as membranes they do not have the mechanical properties to be applicable in industry. Therefore these hydrogels have been grafted to polyvinylidinedifluoride (PVDF) membranes using radiation. Both UV and gamma irradiation were used. In the first method the PVDF membranes were first hydroxylated by immersion in a aqueous solution of potassium peroxydisulfate (10% w/v), with nitrogen purging for two hours at 80 deg C. This was followed by immersion in an aqueous solution of riboflavine (4mg/L) and monomer (10% v/v), degassing with nitrogen and irradiation under a Mercury UV light (wavelength 240 nm) at room temperature for 15 minutes. Membranes were washed by soxhlet extraction in distilled water and oven dried. The second method of grafting hydrogels to membranes involved immersing the membrane in 10 mL of distilled water containing monomer and CuSO 4 to prevent homopolymerisation. The solution was degassed with N 2 for 3 minutes then irradiated under nitrogen using a 60 Co source for various time periods. The effect of varying monomer and CuSO 4 concentration as well as dose rate and dose were studied. Membranes were rinsed in distilled water for 24 hours and dried in an oven before characterisation. Grafting was characterised by mass change (Mettler AC 100 balance), XPS (PHI Model 560 XPS/SAM/SIMA1 multitechnique surface analysis system), SEM (Hitachi S-900 Field Emission SEM) and FTIR-ATR (Perkn Elmer System 2000 FTIR with MIRMCT detector)

Blood compatibility assessment of graft copolymer (NR-g-DMAA) tubes

International Nuclear Information System (INIS)

Razzak, M.T.; Otsuhata, Kazushige; Tabata, Yoneho; Ohashi, Fumio; Takeuchi, Atsuki

1992-01-01

Graft copolymer (NR-g-DMAA) tubes have been prepared using simultaneous radiation induced grafting of N,N-dimethyl-acrylamide, (DMAA) onto natural rubber (NR) tubes. The blood compatibility of the NR-g-DMAA tubes was assessed with three methods, namely in vitro test, ex vivo once through test and ex vivo loops test. In the case of the in vitro test, a simple whole blood contacting procedure has been employed. The ex vivo once through test involves the exposing of NR-g-DMAA tubes with once through flow of fresh canine blood and then it was inspected for any evidence of clot. In the case of ex vivo loops test, the NR-g-DMAA tube was implanted at external jugular vein of a mongrel canine and the blood flow in the NR-g-DMAA tube was detected with an ultrasonic flow meter. It was found that the blood compatibility of NR-g-DMAA tubes is improved significantly with the increasing degree of grafting. All the NR-g-DMAA tubes having a degree of grafting of about 30 wt% or more exhibit good blood compatibility. It was found that the blood compatibility of the NR-g-DMAA tube is better than that of a medical grade silicon rubber (SiR) tube. (Author)

Radiation-induced radical ions in calcium sulfite

Science.gov (United States)

Bogushevich, S. E.

2006-07-01

We have used EPR to study the effect of γ radiation on calcium sulfite. We have observed and identified the radiation-induced radical ions SO 2 - (iso) with g = 2.0055 and SO 2 - (orth-1) with g1 = 2.0093, g2 = 2.0051, g3 = 2.0020, identical to the initial and thermally induced SO 2 - respectively, SO 3 - (iso) with g = 2.0031 and SO 3 - (axial) with g⊥ = 2.0040, g∥ = 2.0023, identical to mechanically induced SO 3 - . We have established the participation of radiation-induced radical ions SO 3 - in formation of post-radiation SO 2 - .

Radiation- induced aneuploidy in mammalian germ cells

International Nuclear Information System (INIS)

Tease, C.

1989-01-01

The ability of ionizing radiation to induce aneuploidy in mammalian germ cells has been investigated experimentally in the laboratory mouse using a variety of cytogenetic and genetic methods. These studies have provided unambiguous evidence of induced nondisjunction in both male and female germ cells when the effect of irradiation is screened in meiotic cells or preimplantation embryos. In contrast, however, cytogenetic analyses of post-implantation embryos and genetic assays for induced chromosome gains have not found a significant radiation effect. These apparently contradictory findings may be reconciled if (a) radiation induces tertiary rather than primary trisomy, or (b) induces embryo-lethal genetic damage, such as deletions, in addition to numerical anomalies. Either or both of these explanations may account for the apparent loss during gestation of radiation-induced trisomic embryos. Extrapolating from the information so far available, it seems unlikely that environmental exposure to low doses if low dose rate radiation will result in a detectable increase in the rate of aneuploidy in the human population. (author)

Radiation-chemical synthesis of polypropylene fabrics with sulfonic acid functional groups

Energy Technology Data Exchange (ETDEWEB)

Cho, Hyun Kug; Park, Jung Soo; Han, Do Hung, E-mail: dhhan@yumail.ac.kr; Bondar, Iuliia, E-mail: juliavad@yahoo.co

2011-04-01

A sorption-active material carrying sulfonic acid groups was synthesized by the radiation-induced graft polymerization of styrene monomer onto the surface of non-woven polypropylene fabric, followed by sulfonation of the grafted polystyrene chains. The effect of the main experimental parameters (absorbed dose, monomer concentration, reaction time) on the styrene degree of grafting was investigated. The sulfonation process with 5% chlorosulfonic acid at room temperature was investigated in detail and the optimal sulfonation conditions for the samples with a medium degree of grafting (70-140%) were determined. Densities of 3.5-5 meq/g were obtained by applying those sorption-active PP fabrics with a sulfonic acid group.

Radiation-induced camptocormia and dropped head syndrome. Review and case report of radiation-induced movement disorders

Energy Technology Data Exchange (ETDEWEB)

Seidel, Clemens; Kuhnt, Thomas; Kortmann, Rolf-Dieter; Hering, Kathrin [Leipzig University, Department of Radiotherapy and Radiation Oncology, Leipzig (Germany)

2015-10-15

In recent years, camptocormia and dropped head syndrome (DHS) have gained attention as particular forms of movement disorders. Camptocormia presents with involuntary forward flexion of the thoracolumbar spine that typically increases during walking or standing and may severely impede walking ability. DHS is characterized by weakness of the neck extensors and a consecutive inability to extend the neck; in severe cases the head is fixed in a ''chin to chest position.'' Many diseases may underlie these conditions, and there have been some reports about radiation-induced camptocormia and DHS. A PubMed search with the keywords ''camptocormia,'' ''dropped head syndrome,'' ''radiation-induced myopathy,'' ''radiation-induced neuropathy,'' and ''radiation-induced movement disorder'' was carried out to better characterize radiation-induced movement disorders and the radiation techniques involved. In addition, the case of a patient developing camptocormia 23 years after radiation therapy of a non-Hodgkin's lymphoma of the abdomen is described. In total, nine case series of radiation-induced DHS (n = 45 patients) and - including our case - three case reports (n = 3 patients) about radiogenic camptocormia were retrieved. Most cases (40/45 patients) occurred less than 15 years after radiotherapy involving extended fields for Hodgkin's disease. The use of wide radiation fields including many spinal segments with paraspinal muscles may lead to radiation-induced movement disorders. If paraspinal muscles and the thoracolumbar spine are involved, the clinical presentation can be that of camptocormia. DHS may result if there is involvement of the cervical spine. To prevent these disorders, sparing of the spine and paraspinal muscles is desirable. (orig.) [German] In den letzten Jahren haben Bewegungsstoerungen von Wirbelsaeule und paraspinaler Muskulatur in

UV-induced graft polymerization of acrylic acid in the sub-micronchannels of oxidized PET track-etched membrane

Science.gov (United States)

Korolkov, Ilya V.; Mashentseva, Anastassiya A.; Güven, Olgun; Taltenov, Abzal A.

2015-12-01

In this article, we report on functionalization of track-etched membrane based on poly(ethylene terephthalate) (PET TeMs) oxidized by advanced oxidation systems and by grafting of acrylic acid using photochemical initiation technique for the purpose of increasing functionality thus expanding its practical application. Among advanced oxidation processes (H2O2/UV) system had been chosen to introduce maximum concentration of carboxylic acid groups. Benzophenone (BP) photo-initiator was first immobilized on the surfaces of cylindrical pores which were later filled with aq. acrylic acid solution. UV-irradiation from both sides of PET TeMs has led to the formation of grafted poly(acrylic acid) (PAA) chains inside the membrane sub-micronchannels. Effect of oxygen-rich surface of PET TeMs on BP adsorption and subsequent process of photo-induced graft polymerization of acrylic acid (AA) were studied by ESR. The surface of oxidized and AA grafted PET TeMs was characterized by UV-vis, ATR-FTIR, XPS spectroscopies and by SEM.

Removal of phosphate using copper-loaded polymeric ligand exchanger prepared by radiation grafting of polypropylene/polyethylene (PP/PE) nonwoven fabric

Science.gov (United States)

Barsbay, Murat; Kavaklı, Pınar Akkaş; Güven, Olgun

2010-03-01

A novel polymeric ligand exchanger (PLE) was prepared for the removal of phosphate ions from water. 2,2'-dipyridylamine (DPA), a bidentate ligand forming compound with high coordination capacity with a variety of metal ions was bound to glycidyl methacrylate (GMA) grafted polypropylene/polyethylene (PP/PE) nonwoven fabric synthesized by radiation-induced grafting technique. DPA attachment on epoxy ring of GMA units was tested in different solvents, i.e. methanol, ethanol, dioxane and dimethylsulfoxide (DMSO). The highest amount of modification was achieved in dioxane. In order to prepare the corresponding PLE for the removal of phosphate, DPA-immobilized fabric was loaded with Cu(II) ions. Phosphate adsorption experiments were performed in batch mode at different pH (5-9) and phosphate concentrations. The fabric was found to be effective for the removal of phosphate ions. At every stage of preparation and use, the nonwoven fabric was characterized by thermal (i.e. DSC and TGA) and spectroscopic (FTIR) methods. Competitive adsorption experiments were also carried out using two solutions with different concentration levels at pH 7 to see the effect of competing ions. Phosphate adsorption was found to be effective and selective from solutions having trace amounts of competitive anions. It is expected that the novel PLE synthesized can be used for the removal of phosphate ions in low concentrations over a large range of pH.

Radiation-induced myelopathy

Energy Technology Data Exchange (ETDEWEB)

Gaenshirt, H [Heidelberg Univ. (F.R. Germany). Neurologische Klinik

1975-10-01

12 cases of radiation-induced myelopathy after /sup 60/Co teletherapy are reported on. Among these were 10 thoracal lesions, one cerviothoracal lesion, and one lesion of the medulla oblongata. In 9 cases, Hodgkin's disease had been the primary disease, tow patients had been irradiated because of suspected vertebral metastases of cancer of the breast, and one patient had suffered from a glomus tumour of the petrous bone. The spinal doses had exceeded the tolerance doses recommended in the relevant literature. There was no close correlation between the radiation dose and the course of the disease. The latency periods between the end of the radiotherapy and the onset of the neurological symptons varied from 6 to 16 mouths and were very constant in 7 cases with 6 to 9 months. The segmental height of the lesion corresponded to the level of irradiation. The presenting symptons of radiation-induced myelopathy are buruing dysaesthesias and Brown-Sequard's paralysis which may develop into transverse lesion of the cord with paraplegia still accompanied by dissociated perception disorders. The disease developed intermittently. Disturbances of the bladder function are frequent. The fluid is normal in most cases. Myelographic examinations were made in 8 cases. 3 cases developed into stationary cases exhibiting. Brown-Sequard syndrome, while 9 patients developed transverse lesion of the cord with paraplegia. 3 patients have died; antopsy findings are given for two of these. In the pathogenesis of radiation-induced myelopathy, the vascular factor is assumed to be of decisive importance.

Effect of storage conditions on graft of polypropylene non-woven fabric induced by electron beam

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Young; Jeun, Joon Pyo; Kang, Phil Hyun [Radiation Research Dvision for Industry and Environment, Korea Atomic Energy Research Institute, Jeongeup(Korea, Republic of)

2015-05-15

In this study, we fabricated effect of storage conditions on graft of polypropylene (PP) non-woven fabric induced by electron beam. The electron beam irradiations on PP non-woven fabric were carried out over a range of irradiation doses from 25 to 100 kGy to make free radicals on fabric surface. The radical measurement was established by electron spin resonance (ESR) for confirming the changes of the alkyl radical and peroxy radical according to effect of storage time, storage temperature and atmosphere. It was observed that the free radicals were increased with irradiation dose and decreased with storage time due to the continuous oxidation. However, the radical extinction was significantly delayed due to reduced mobility of radicals at extremely low temperature. The degree of graft based on the analysis of ESR was investigated. The conditions of graft reaction were set at a temperature: 60 degrees Celcius, reaction time: 6 hours and styrene monomer concentration: 20 wt%.

Thermal degradation kinetics and estimation of lifetime of radiation grafted polypropylene films

International Nuclear Information System (INIS)

Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Bhalla, Vinod Kumar

2017-01-01

In this research work, thermal stability and degradation behavior of acrylic acid grafted polypropylene (PP-g-PAAc) films were investigated by using thermogravimetric (TGA) analysis at four different heating rates 5, 10, 15 and 20 °C/min over a temperature range of 40–550 °C in nitrogen atmosphere. The kinetic parameters namely activation energy (E a ), reaction order (n) and frequency factor (Z) were calculated by three multiple heating rate methods. The thermal stability of PP-g-PAAc films is found to decrease with increase in degree of grafting. The TGA data and thermal kinetic parameters were also used to predict the lifetime of grafted PP films. The estimated lifetime of neat PP as well as grafted PP decreased with increase in temperature by all the three methods. Studies also indicated that E a and lifetime of PP-g-PAAc films decreased with increase in degree of grafting, which may also be helpful in biodegradation of grafted PP films. - Highlights: • Thermal stability of grafted polypropylene films have been observed lower than for neat polypropylene film. • Multiple heating rate methods have been used for determination of activation energy. • Activation energies of grafted polypropylene films were lower than polypropylene film. • The lifetimes of grafted polypropylene films were shorter than for neat polypropylene film.

Stabilization of colour of woolenized jute by radiation chemical treatment

International Nuclear Information System (INIS)

Al-Siddique, F.R.

1978-09-01

The radiation-induced graft polymerization of methyl methacrylate, ethyl acrylate, acrylonitrile, and venylacetate onto jute to prevent yellowing of the jute by light is reported. Samples were irradiated with a 5000 C; gamma-source at 0.1 Mrad per hour

Radiation-induced genomic instability and bystander effects: related inflammatory-type responses to radiation-induced stress and injury? A review.

Science.gov (United States)

Lorimore, S A; Wright, E G

2003-01-01

To review studies of radiation responses in the haemopoietic system in the context of radiation-induced genomic instability, bystander effects and inflammatory-type processes. There is considerable evidence that cells that themselves are not exposed to ionizing radiation but are the progeny of cells irradiated many cell divisions previously may express a high frequency of gene mutations, chromosomal aberrations and cell death. These effects are collectively known as radiation-induced genomic instability. A second untargeted effect results in non-irradiated cells exhibiting responses typically associated with direct radiation exposure but occurs as a consequence of contact with irradiated cells or by receiving soluble signals from irradiated cells. These effects are collectively known as radiation-induced bystander effects. Reported effects include increases or decreases in damage-inducible and stress-related proteins; increases or decreases in reactive oxygen species, cell death or cell proliferation, and induction of mutations and chromosome aberrations. This array of responses is reminiscent of effects mediated by cytokines and other similar regulatory factors that may involve, but do not necessarily require, gap junction-mediated transfer, have multiple inducers and a variety of context-dependent consequences in different cell systems. That chromosomal instability in haemopoietic cells can be induced by an indirect bystander-type mechanism both in vitro and in vivo provides a potential link between these two untargeted effects and there are radiation responses in vivo consistent with the microenvironment contributing secondary cell damage as a consequence of an inflammatory-type response to radiation-induced injury. Intercellular signalling, production of cytokines and free radicals are features of inflammatory responses that have the potential for both bystander-mediated and persisting damage as well as for conferring a predisposition to malignancy. The

Arterial Blood Pressure Induces Transient C4b-Binding Protein in Human Saphenous Vein Grafts.

Science.gov (United States)

Kupreishvili, Koba; Meischl, Christof; Vonk, Alexander B A; Stooker, Wim; Eijsman, Leon; Blom, Anna M; Quax, Paul H A; van Hinsbergh, Victor W M; Niessen, Hans W M; Krijnen, Paul A J

2017-05-01