Sample records for spirtovykh rastvorakh galogenovodorodov
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Energy Technology Data Exchange (ETDEWEB)
Kholmuminov, A A [AS RU, Institute of Polymer Chemistry and Physics, Tashkent (Uzbekistan)
2008-06-15
Key words:silk fibroin, dissolution, solution's model systems, gelation, orientational crystallization, optical polarization, longitudinal stream, {alpha} - {beta} transition, structure formation, phase transformations, relaxation, anisotropy of swelling and desorption, thermo- and biodegradation. Subjects of the inquiry: silk fibroin is the main subject of investigation. Fibroin's solutions were obtained on the base of water and organic solvents, containing salts. Comparative investigations were carried out by using biosolution - secretion of silkworm, solutions of silk sericin, cotton cellulose, methylcellulose, polystyrene and (co) polycrylonitrile. Aim of the inquiry: the elucidation of the regularities of silk fibroin anisotropic structures formation in the direct generation of orientational ordering in solutions taking into account of influences of its the molecular structures, configuration information, {alpha} - {beta} conformational transformations, and development jointly using polarization-optical and hydrodynamic methods to control of structure formation. And also definition of possibility fields for use biopolymers anisotropic structure formation principles. Method of inquiry: birefringence, dispersion optical rotation, circular dichroism, polarization- ultramicroscope, ultracentrifuge, viscosimetry, potentiometry, differential thermal analysis, chromatography, x-ray analysis, spectroscopy. The results achieved and their novelty: the physical regularity amorphous-crystalline fibroin dissolutions in salt-containing solvents based on chains melting, distribution and redistribution were recognized; fibroin statistical parameters, molecular-mass and conformational characteristics were established; It was shown that fibroin molecules turned into fully uncoiled and oriented state with the breakdown decay of {alpha}-spiral chain sections by I type phase transition mechanism, but in oriented state with {alpha}-spiral conservation by II type transition; the presence of longitudinal field on the boundary 'reservoir - withdrawing capillary' of gland, initiating the transition of {alpha}-spiral in {beta}-structures as well as phase separation of fibroin and sericin in stream were discovered; the phase diagram of liquidus for secret in the framework of polymers orientation crystallization conception were suggested; the mechanism of fibroin orientational crystallization under the longitudinal flow of solutions and gels was conformed experimentally; the scientific principles of oriented-crystallized fibrillar biopolymer materials receipt were established on the base of fibroin model solutions with properties of anisotropy of moisture absorption, swelling, desorption, thermo- and biodegradation; the approach of jointly using polarization-optical and hydrodynamic methods to the investigation of fibrillar biopolymers structure formation and phase transformations in solution was developed. Practical value - the elucidated physical regularities of fibroin solution allow to formulate a new idea on fibrillar biopolymer solutions formation and to get on their late model systems for practical use; the established scientific principles of orientational structure-formation and phase transformation of fibroin will be the base for development of original methods of anisotropic biopolymer materials from solutions of the polarization-optical and developed hydrodynamic methods can be used for the investigation of structure and phase transformations of wide range of fibrillar biopolymer samples. Sphere of usage: physics of anisotropic polymer systems, macromolecular compounds solutions, gels, crystals, biopolymers materials science, optical polarization and hydrodynamics. (author)
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Energy Technology Data Exchange (ETDEWEB)
Ditrikh, I V; Makhno, A Ya [Donetskij Gosudarstvennyj Univ., Donetsk (Ukraine)
1997-12-31
Conditions of vanadium(5) heteropolycompounds formation in aqueous solutions containing aluminium(3) have been studied. By the methods of potentiometry and conductometry in solutions of Al(NO{sub 3}){sub 3}-NaVO{sub 3} salt mixture the formation of complexes with the ratios [Al{sup 3+}]:[V{sup 5+}]=1:3, 1:6 and 1:12 has been ascertained. A salt of gross formula 3NaO {center_dot} (Al{sub 2}){sub 3} {center_dot} 12V{sub 2}O{sub 5} {center_dot} 67H{sub 2}O has been isolated. 3 refs.; 2 figs.
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Energy Technology Data Exchange (ETDEWEB)
Dubinina, L K; Shejkkh, M A; Ospanov, Kh K; Gemanova, L N [Kazakhskij Gosudarstvennyj Univ., Alma-Ata (Kazakhstan)
1995-01-01
Zinc and cadmium interaction with sodium 2,3-dimercaptopropane sulfonate in aqueous solution is studied by means of physicochemical analysis techniques (pH-metry, conductometry, viscosimetry, volumetry). Cadmium is determined to form 1:1 and 1:2 composition complex compounds. Formation constants of complex ions are determined. Mechanism of interaction of initial reagents is suggested. 7 refs.; 1 fig.
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Energy Technology Data Exchange (ETDEWEB)
Okamura, S; Manabe, T; Higashimura, T; Oishi, Y; Futami, S
1960-07-15
styrolene amorcee au moyen de rayons gamma dans une solution de dichlorure de methylene a basse temperature. Le rapport direct constate entre la vitesse de polymerisation et l'intensite repond a une caracteristique du mecanisme de polymerisation ionique. La composition du copolymere obtenu avec le methacrylate de methyle vient egalement a l'appui de cette hypothese. (author) [Spanish] Observando la extincion de la luminiscencia del terienilo inducida por los rayos gamma, se ha estudiado el proceso de transmision de la energia de excitacion en soluciones bencenicas de monomeros, polimeros y copolimeros. La facilidad con que la energia se transmite del benceno a los diversos monomeros responde al siguiente orden decreciente: monomeros conjugados > monomeros no conjugados > compuestos saturados correspondientes. Tambien se realizaron experimentos sobre la extincion de la luminiscencia utilizando polimeros disueltos en benceno. El poder de extincion de los polimeros disminuye con arreglo al siguiente orden: caucho natural > poliestireno > acetato de polivinilo > polimeros acrilicos. Los resultados obtenidos al emplear un copolimero de estireno-metacrilato de metilo indicaron que el poder extintor especifico de los grupos estireno del copolimero es inferior al observado en el caso del homopolimero. La polimerizacion inducida por rayos gamma del estireno disuelto en diclorometileno tambien se estudio a bajas temperaturas. Los resultados obtenidos en lo que se refiere a la relacion existente entre la velocidad de polimerizacion y la intensidad de irradiacion parecen indicar que el mecanismo es de naturaleza ionica. La composicion del copolimero obtenido a partir de metacrilato de metilo tambien corrobora esta opinion. (author) [Russian] Peredacha ehnergii vozbuzhdeniya v benzol'nykh rastvorakh monomerov, polimerov i sopolimerov izuchayutsya putem nablyudeniya kvenchinga trifinil'noj fluorestsentsii, poluchaemogo v rezul'tate gamma-oblucheniya. Sposobnost' peredachi ehnergii ot
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Energy Technology Data Exchange (ETDEWEB)
Plakhotnik, V N; Sukhaya, E M; Mishustin, A I
1995-10-01
Lithium hexafluorophosphate solutions in propylencarbonate and {gamma}-butyrolactone are investigated in a wide ranges of concentrations and temperatures using conductometry, viscosimetry, densimetry methods and measurements of lithium-7 nucleus spin-lattice relaxation rates. Absence of correlations between solution conductivity and ionization ability of solvents, which is conditioned by the prevailing viscosity effect, is shown. Notable effect of ion-dipole interaction on the formation of Li{sup +} ion electric field gradient is ascertained within the framework of ion association model. 15 refs.; 2 figs.; 1 tab.
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Energy Technology Data Exchange (ETDEWEB)
Dahl, J B; Birkelund, O R [Institutt for Atomenergi, Kjeller, Lillestrom (Norway)
1962-01-15
nastoyashchem doklade dayutsya svedeniya otnositel'no khimicheskogo sostoyaniya fosfora-32 v vodnykh rastvorakh na razlichnykh stadiyakh prinyatogo v praktike protsessa polucheniya ehtogo ehlementa. Byli rassmotreny takzhe izmeneniya khimicheskogo sostoyaniya slozhnykh soedine- nij fosfora-32 v konechnykh produktakh v funktsii ot vremeni khraneniya. Bylo obnaruzheno, chto glavnym sostavlyayushchim veshchestvom yavlyaetsya fosfor-32, svyazan- nyj v vide ortofosfata. Po mere khimicheskoj obrabotki kolichestvo ortofosfata uvelichi- los' priblizitel'no s 70% pri nachale izvlecheniya i priblizitel'no do 98% v konechnom produkte svobodnogo ot nositelya fosfora-32. Ostatok sostoyal iz smesi piro-, tri-, tetra- i polifosfatov s dlinnoj tsep'yu (chislo P {>=} 5). Ni vo vremya obrazovaniya, ni vo vremya khraneniya v rastvorakh ne bylo obnaruzheno (kol'tseobraznykh) metafosfatov. EHti rezul'taty pokazyvayut, chto polifosfornye slozhnye soedineniya obrazovalis' v materiale misheni vo vremya oblucheniya. Osoboe vnimanie bylo obrashcheno na adsorbtsiyu svobodnogo ot nositelya fosfora-32 steklyannoj laboratornoj posudoj pri sushchestvuyushchikh ehksperimental'nykh usloviyakh. (author)
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Energy Technology Data Exchange (ETDEWEB)
Okamura, S; Iwasaki, T; Kobayashi, Y; Hayashi, K
1960-07-15
injerto cuando la irradiacion se efectua con dosis especificas del orden de los 10{sup 5} roentgens/hora . (author) [Russian] V rezul'tate oblucheniya nejlonovogo volokna v azotnoj srede sozdaetsya poperechnaya svyaz', togda kak pri obluchenii v vozdushnoj srede proiskhodit reaktsiya, vedushchaya k umen'sheniyu velichiny molekul. Proiskhodyashchie pod vliyaniem oblucheniya izmeneniya byli izucheny posredstvom izmereniya vyazkosti volokna, obluchennogo v rastvorakh sernoj kisloty. Prochnost' na rastyazhenie byla izuchena takzhe v vozdushnoj srede. Pri obluchenii v azotnoj srede pogruzhennogo v vodnyj rastvor akrilamida nejlonovogo volokna narashchivanie imeet mesto lish' na poverkhnosti. Esli zhe predvaritel'noe obluchenie proizvodilos' v vozdushnoj srede, to narashchivanie proiskhodit i vo vnutrennikh sloyakh volokna. Stepen' narashchivaniya tsellyuloznykh volokon pri pomoshchi stirola iz metanolovogo rastvora znachitel'no povyshaetsya, esli voloknu dat' nabukhnut' v 5-10 protsentnom rastvore formamida v metanole. Bylo izucheno vliyanie kontsentratsii formamida i stirola v rastvorakh metanola, prichem bylo ustanovleno, chto maksimal'noe narashchivanie proiskhodit v 5-protsentnom rastvore formamida i 70-protsentnoj kontsentratsii stirola. Pri moshchnosti dozy priblizitel'no v 10{sup 5} r/chas ustanovleno, chto skorost' narashchivaniya opredelyaetsya diffuziej. (author)
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Energy Technology Data Exchange (ETDEWEB)
Kulyukhin, S A; Majorov, A V; Kamenskaya, A N; Mikheev, N B
1989-01-01
Using cocrystallization and conductometry methods Sr{sup 2+} and Eu{sup 2+} complexing with 18-crown-6 in aqueous-ethanolic solutions at (H{sub 2}O)=10 mol/l is studied. Stability constants of Sr{sup 2+} and Eu{sup 2+} complexes with 18-crown-6 in C{sub 2}H{sub 5}OH, for which lg{beta} is equal to (4.76{plus minus}0.12) and (4.72{plus minus}0.13) respectively, are determined. Comparison of the investigated elements features during complexing with 18-crown-6 in aqueous and aqueous-ethanolic solutions is carried out. It is shown that both in water and in C{sub 2}H{sub 5}OH -10 mol/l H{sub 2}O system under Sr{sup 2+} and Eu{sup 2+} complexing with 18-crown-6 the differences in properties of these elements are not detected.
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Energy Technology Data Exchange (ETDEWEB)
Kambara, T.; Yamaguchi, K.; Yasuba, S. [Shizuoka University, Shizuoka City (Japan)
1965-10-15
The exchange reaction of Sb{sup III} - Sb{sup V} in solutions of low HCl concentrations was studied using {sup 124}Sb as a tracer. The effects of HCl concentrations and chemical forms of antimony on the exchange rate were investigated. The HCl concentrations of the antimony solutions ((Sb{sup III}) =(Sb{sup V}) = 6.8 x 10{sup -4}M) were changed from 0.8 to 4.0M and the half-time for the exchange was measured by plotting log (1 - F) versus time t to calculate the exchange rate assuming the second-ordet reaction. It was found that the exchange rate was sharply increased with the increase of HCl concentrations (at 25 Degree-Sign C, from 0.8 to 2.0M) and at 2.0M HCl concentration the rate reached the maximum, from which the rate was decreased with the increase of HCl concentrations (at 25 Degree-Sign C, from 2.0 to 4.0M). Two sorts of Sb{sup V} species were used for our investigations, i.e. one was used directly after the dilution of 10M HCl Sb{sup V} solution with water and the other was used after 24 hours standing at room temperature from the dilution. (The Sb{sup III} species were also kept standing after preparation from 10M HCl Sb{sup III} solution.) In both cases the maximum rates were found to exist at 2.0M HCl concentration. The rate R{sub 1} for the former (directly after dilution) was 4.5 x 10{sup -6} mole litre{sup -1} min{sup -1} and the rate R{sub 2} for the latter (24 hours standing) was 1.2 x 10{sup -}{sub 6} mole litre. Also the activation energy for these cases was found to be 12.2 kcal/mole and 19.1 kcal/mole. By spectrophotometric studies, the Sb{sup V} species of the former type were found to be mainly consisting of SbCl{sup -}{sub 6} and the species of the latter type to be of SbCl{sub 4}(OH){sup -}{sub 2}, etc. Besides these facts the form of Sb{sup III} species was found to have no influence on the exchange rate. A much sharper increase of the exchange rate was observed when the HCl concentration of the antimony solution was fixed at 0.8M and the chloride concentration was increased to 3.0M by an addition of LiCl. It is noteworthy that an almost linear and sharp increase of the rate was observed until 2.0M chloride concentration. The above fact obtained at a constant hydrogen ion concentration suggests that the chloride atoms act as bridge formation atoms of the intermediate compound for the antimony exchange. To summarize these results, the existence of the maximum exchange rate at about 2.0M HCl concentration in a low HCl concentration region is thought to be well explained. (author) [French] En utilisant {sup 124}Sb comme radioindicateur, les auteurs ont etudie l'echange Sb{sup III} - Sb{sup V} dans des solutions diluees de HCl, notamment les effets de la concentration en HCl et de la forme chimique de l'antimoine sur la vitesse d'echange. Ils ont fait varier la concentration en HCl des solutions d'antimoine ((Sb{sup III}) =(Sb{sup V}) = 6.8 x 10{sup -4}M) de 0,8 a 4,0M et ils ont mesure le temps de demi-echange en tracant la courbe de log(1 - F) en fonction du temps t, en vue de calculer la vitesse d'echange, la reaction etant supposee du deuxieme ordre. Les auteurs ont constate que la vitesse d'echange augmentait fortement avec l'accroissement de la concentration en HCl (a 25 Degree-Sign C, de 0,8 a 2,0M); le maximum a ete atteint pour une concentration de 2,0M, apres quoi la vitesse a diminue avec l'augmentation de la concentration en HCl (a 25 Degree-Sign C, de 2,0 J 4,0M). Dans leurs recherches, les auteurs ont eu recours a deux Sb{sup V}; ils ont utilise le premier aussitot apres dilution dans l'eau d'une solution de Sb{sup V} dans HCl 10M, et la seconde apres avoir laisse reposer 24 heures a la temperature ambiante. (On a aussi laisse reposer les especes de Sb{sup III} apres les avoir preparees a partir d'une solution de Sb{sup III} dans HCl 10M). Dans les deux cas, les maximums ont ete atteints pour une concentration de 2,0M. Dans le premier cas (aussitot apres dilution), la vitesse R{sub 1} etait de 4,5 * 10{sup -6} mole * l{sup -1}; dans le deuxieme (apres 24 heures de repos), R{sub 2} etait de 1,2 * 10{sup -6} mole * l{sup -1} * min{sup -1}. L'energie d'activation etait respectivement de 12,2 kcal/mole et 19,1 kcal/mole. Les etudes spectrophotometriques ont permis d'etablir que les SbV du premier type etait constitues principalement par SbCl{sub 6}{sup -} et ceux du deuxieme type, par SbCl{sub 4}(OH){sub 2}{sup -}, etc. En dehors de ces faits, les auteurs n'ont releve aucune influence de la forme de Sb{sup III} sur la vitesse d'echange. Une augmentation beaucoup plus forte de la vitesse d'echange a ete observee lorsque la concentration en HCl de la solution d'antimoine etait 0,8M et la concentration en chlorure etait portee a 3.0M par addition de LiCl. Il est a noter qu'une augmentation forte et quasi lineaire de la vitesse a ete observee pour des concentrations en chlorure allant jusqu'a 2,0M. Etant donne que ce phenomene a ete observe pour une concentration constante en ions hydrogene, on peut penser que les atomes de chlorure interviennent comme atomes de pontage du compose intermediaire en vue de l'echange d'antimoine. (author) [Spanish] Empleando {sup 124}Sb como indicador, los autores estudiaron la reaccion de intercambio Sb{sup III} - Sb{sup V} en soluciones diluidas de HCl y en particular los efectos de la concentracion de HCl y de la forma quimica del Sb sobre la velocidad de intercambio. La concentracion de HCl de las soluciones de antimonio ((Sb{sup III}) =(Sb{sup V}) = 6.8 x 10{sup -4}M) se modifico entre 0,8 y 4,0M y el tiempo de semi-intercambio se midio trazando la curva representativa de log(1 - F) en funcion del tiempo t, con el fin de calcular la velocidad de intercambio suponiendo que se trata de una reaccion de segundo orden. Se comprobo que la velocidad de intercambio aumentaba netamente al elevar la concentracion de HCl (de 0,8 a 2,0M a 25 Degree-Sign C) y alcanzaba un valor maximo a 2,0M a partir del cual volvia a diminuir si la concentracion de HCl seguia aumentado (de 2,0 a 4, OM a 25 Degree-Sign C). Se emplearon en la investigacion dos especies SbV, Una de las cuales se utilizo inmediatamente despues de diluir con agua la solucion 10M de HCl; y la otra despues de dejarla reposar a temperatura ambiente durante 24 h contadas a partir de la dilucion. (La especie Sb{sup III} tambien se dejo en reposo despues de prepararla partiendo de la solucion de Sb{sup III} en HCl 10M. ) En ambos casos, los maximos se determinaron para una concentracion de HCl 2,0M. La velocidad Rj correspondiente a la primera (inmediatamente despues de la dilucion) fue 4,5 * 10{sup -6} mol * l{sup -1} min{sup -1}, la velocidad R{sub 2} de la segunda (al cabo de 24 h de reposo), 1,2 * 10{sup -6} mol * l{sup -1} min{sup -1}. Las energias de activacion fueron en estos casos 12,2 kcal/mol y 19,1 kcal/mol, respectivamente. Mediante estudios espectrofotometricos, se determino que la especie Sb{sup V} del primer tipo consistia principalmente en SbCl{sub 6}{sup -} y la del segundo tipo, en SbCl{sub 4}(OH){sub 2}{sup -}, etc. Fuera de estos hechos, no se observo ninguna influencia de la forma del Sb{sup III} sobre la velocidad de intercambio. Se comprobo un aumento mucho mas marcado de la velocidad de intercambio cuando la concentracion de HCl en la solucion de antimonio se fijo en 0,8M y la concentracion de cloruro se aumento hasta 3,0M agregando LiCl. Cabe destacar que se registro un aumento marcado y casi lineal de la velocidad hasta llegar una concentracion de cloruro igual a 2,0M. Este resultado, obtenido con una concentracion constante de iones hidrogeno, sugiere que los atomos de cloruro intervienen como puentes en el compuesto intermedia con miras al intercambio de antimonio. (author) [Russian] Izuchalas' reakcija obmena Sb{sup III} - Sb{sup V} v rastvorah s nizkoj koncentraciej HCl s primeneniem Sb{sup 124} v kachestve indikatora. Issledovany vlijanie koncentracii HCl i himicheskih form sur'my na skorost' obmena. Koncentracija HCl v rastvorah sur'my ((Sb{sup III}) = (Sb{sup V}) = 6,8 * 10{sup -4} M) menjalas' ot 0,8 do 4,0 M, i period poluobmena byl izmeren putem vyvedenija logarifma (1-F) po otnosheniju ko vremeni dlja rascheta skorosti obmena v predpolozhenii reakcii vtorogo porjadka. Bylo obnaruzheno, chto skorost' obmena rezko vozrastaet s vozrastaniem koncentracii HCl (pri 25 Degree-Sign S ot 0,8 do 2,0 M) i pri 2,0 M koncentracii HCl skorost' dostigaet maksimuma, posle kotorogo skorost' padaet s uvelicheniem koncentracii HCl (pri 25 Degree-Sign S ot 2,0 do 4,0 M). Pri issledovanijah byli ispol'zovany dve raznovidnosti Sbv, to est' odna byla ispol'zovana neposredstvenno posle razvedenija rastvora 10 M HCl Sbv vodoj i drugaja - posle 24 chasov otstaivanija pri komnatnoj temperature iz rastvora. V oboih sluchajah maksimal'nye sko- rosti byli obnaruzheny pri koncentracii 2,0 M HCl. Skorost' R{sub 1} dlja pervoj (neposred- stvenno posle razbavlenija) sostavila 4,5 * 10{sup -6} mol' litr{sup -1} min{sup -1}, i skorost' R{sub 2} dlja vtoroj (otstaivalas' v techenie 24 chasov) byla 1,2 * 10{sup -6} mol' litr{sup -1} min{sup -1} . Energija aktivacii dlja ukazannyh sluchaev ravnjalas' 12,2 kkal/mol' i 19,1 kkal/mol'. Pri pomoshhi spektrofoto- metricheskih issledovanij bylo obnaruzheno, chto raznovidnosti Sb{sup V} pervogo tipa sostojat glavnym obrazom,iz SbClg, a raznovidnosti vtorogo tipa - iz SbCl(OH){sup -}{sub 2} i t . d . Pomimo jetih faktov bylo obnaruzheno, chto forma raznovidnostej Sb{sup III} ne okazyvaet nikakogo vlijanija na skorost' obmena. Bolee rezkoe vozrastanie skorosti obmena otmechalos', kogda koncentracija HCl v ras- tvore sur'my byla 0,8 M, a koncentracija hlorida byla uvelichena do 3,0 M s dobavleniem LiCl. Primechatel'no, chto pochti linejnoe i rezkoe uvelichenie skorosti otmechalos' do kon- centracii hlorida 2,0 M. Jeti fakty, poluchennye pri postojannoj koncentracii vodorodnyh ionov, navodjat na mysl', chto atomy hlorida igrajut rol' mostikovyh atomov v obrazovanii promezhutochnyh soedinenij pri obmene sur'my. Summiruja vysheupomjanutye rezul'taty, mozhno skazat', chto sushhestvovanie maksimal'noj skorosti obmena pri koncentracii HCl okolo 2,0 M v oblasti nizkoj koncentracii HCl mozhet byt', po-vidimomu, prekrasno ob'jasneno. (author)
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Energy Technology Data Exchange (ETDEWEB)
Kudahl, J N; Fremlin, J H; Hardwick, J L [Department of Physics, University of Birmingham (United Kingdom)
1962-01-15
pomeshchayutsya na opredelennuyu ploshchad' stekla, to nekotoroe kolichestvo F{sup 18} adsorbiruetsya i po ustanovlenii sostoyaniya ravnovesiya mozhet byt' zakrepleno posredstvom uvelicheniya pH. Radioaktivnost' stekla mozhet sluzhit' meroj obshchego kolichestva ftora na stekle i ehta mera mozhet byt' ispol'zovana dlya postroeniya izotermy adsorbtsii, iz kotoroj mozhno vyvesti soderzhanie ftora v neizvestnom rastvore dannoj serii. Bylo izucheno vliyanie pokazatelya rN i prisutstvie ionov kal'tsiya i fosfata i pokazano, chto organicheskie materialy mozhno szhigat' bez kakoj-libo opasnosti, esli oni soderzhat iony kal'tsiya i magniya. Tochnost' ehtogo metoda ne zavisit ot kontsentratsii ftora v rastvorakh, krepost' kotorykh mozhet vyrazhat'sya menee, chem v odnu chast' na million. (author)
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Energy Technology Data Exchange (ETDEWEB)
Medvedev, S S; Abkin, A D; Khomikovsky, P M [Fiziko-khimicheskij institut im. Karpova, SSSR, Moscow, Union of Soviet Socialist Republics (Russian Federation)
1960-07-15
presion del etileno (50-300 atmosferas), la dosis especifica (20-160 roentgens/segundo) y la temperatura (0-50{sup o}C). La velocidad del proceso, el rendimiento quimico obtenido por radioinduccion y el peso molecular medio de los polimeros aumentan considerablement e con la presion (entre 50 y 200 atmosferas, la velocidad de polimerizacion es proporcional a la cuarta potencia de la concentracion de etileno). La velocidad de polimerizacion depende poco de la dosis especifica, siendo proporcional a la intensidad de irradiacion elevada a la potencia 0,3, en tanto que el rendimiento quimico obtenido por radioinduccion y el peso molecular medio de los polimeros aumentan a medida que la dosis especifica disminuye. La velocidad del proceso y el peso molecular aumentan ligeramente al crecer la temperatura. Los autores estudian las posibles explicaciones de las leyes cineticas observadas. El polietileno obtenido por irradiacion se distingue del polimero producido a presiones elevadas por su mayor densidad y grado de cristalizacion. En lo que se refiere a sus propiedades mecanicas, el polimero de viscosidad intrinseca superior a la unidad (obtenido a presiones comprendidas entre 100 y 200 atmosferas) se asemeja al polietileno producido a presiones elevadas. (author) [Russian] Issledovan protsess radiatsionnoj polimerizatsii ehtilena. S tsel'yu uvelicheniya skorosti initsiirovaniya provedeno izuchenie polimerizatsii ztilena v rastvorakh organicheskikh veshchestv (spirty, atseton, alifaticheskie uglevodorody) i pokazano, chto pri postoyannom davlenii (50 atm) i komnatnoj temperature skorost' protsessa v rastvore v 10-15 raz vyshe, chem v gazovoj faze. Detal'no izuchen protsess polimerizatsii ehtilena pod vliyaniem izlucheniya kobal'ta{sup -60} v gaze v zavisimosti ot davleniya ehtilena (50-300 atm), moshchnosti dozy (20-160 rentg/sek) i temperatury (0-50{sup o}C). Skorost' protsessa, radiatsionno-khimicheskij vykhod i srednij molekulyarnyj ves polimerov rezko vozrastayut s davleniem
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Energy Technology Data Exchange (ETDEWEB)
Rosinger, S.; Mullner, S. [Farbwerke Hoechst AG, Hoechst (Germany)
1963-11-15
vestigios de oxigeno. La cantidad de polimero formada es proporcional a la dosis absorbida, para una intensidad de dosis constante. La variacion del rendimiento en funcion de l a intensidad de dosis, o sea J, es igual a J{sup 0,5-0,6}. Eliintervalo optimo de temperaturas es el comprendido entre 20 y 30{sup o}C. Por debajo de 0{sup o}C, la reaccion deja de verificarse. La velocidad de agitacion no influye en el rendimiento. El peso especifico de los productos es del orden de 0,94g/cm{sup 3}; se han observado puntos de fusion que oscilan entre 126 y 131{sup o}C. El analisis por absorcion de rayos infrarrojos no indica la existencia de dobles enlaces C=C ni de grupos C-O-H o C=O; se ha detectado un pequeno numero de enlaces C-O-C. El contenido de grupos metilo es del 0,3%. Los polimeros estan probablemente constituidos por largas cadenas ramificadas y presentan viscosidades comprendidas entre 5 y 10. (author) [Russian] Ehtilen, ehtilen-propilenovye smesi i propilen polimerizovali pod oblucheniem v vodnykh rastvorakh serebryanykh solej pri umerennom davlenii. V to vremya kak iz propilena poluchali masla ili voski, ehtilen daval tverdye polimery s vysokim molekulyarnym vesom. Vykhod prevysil 25 g poliehtilena na 1 litr v chas. Pri moshchnosti dozy 7,1 x 10{sup 3} rad/chas ehto sootvetstvuet znacheniyu G (chislo molekul, proreagirovavshikh na kazhdye 100 ehv pogloshchennoj ehnergii), ravnomu 0,6 x 10{sup 5} pri uchete vsej sistemy i prevyshaet 0,5 x 10{sup 6} pri uchete rastvorennogo ehtilena. Obrazovanie polimera rastet pri uvelichenii davleniya i kontsentratsii serebryanoj soli. Rastvor serebryanoj soli mozhno ispol'zovat' povtorno, ne umen'shaya vykhoda polimera. Reaktsiyu ingibiruyut sledy kisloroda. Vykhod polimera proportsionalen pogloshchennoj doze pri postoyanstve moshchnosti dozy. Izmenenie vykhoda v za- visimosti ot moshchnosti dozy (J) ravno J{sup o,5-o,6}. Optimum temperatury lezhit v intervale 20 - 30{sup o}C. Nizhe 0{sup o}C reaktsiya pochti ne idet. Skorost
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Energy Technology Data Exchange (ETDEWEB)
Harris, Gordon M [Department of Chemistry, University of Buffalo, Buffalo 14, NY (United States)
1962-03-15
estado de equilibrio, efectuada en la reaccion de intercambio de carbonatos. De la misma manera, los datos relativos al efecto cinetico de los isotopos en la hidratacion del ion Co(NH{sub 3}){sub 4}CO{sub 3}{sup +} catalizada por acidos han corroborado las teorias sobre el caracter de la fase de ruptura de enlaces, que determina la velocidad de estas reacciones. Por ultimo, los experimentos con trazadores radiactivos facilitan frecuentemente el estudio de las posiciones sucesivas de ciertos atomos o radicales en las reacciones inorganicas para las que existen diversas explicaciones teoricamente posibles. Como ejemplo puede citarse la demostracion de que en la oxidacion del ion tiocianato por peroxido de hidrogeno, el cianuro no es un producto intermedio que sufre un intercambio rapido a pesar de que constituye uno de los principales productos finales. (author) [Russian] Ispol'zovanie radioizotopov okazyvaet neotsenimye uslugi pri issledovanii khimicheskikh neorganicheskikh reaktsij samykh raznoobraznykh vidov i, v chastnosti, reaktsij so slozhnymi ionizirovannymi veshchestvami v vodnykh rastvorakh. Odnim iz vazhnykh metodov sluzhit izuchenie skorosti i mekhanizma protsessov izotopnogo obmena. Tak, naprimer, byl proveden ryad issledovanij obmen a mezhdu t.n. ''svobodnym'' karbonatom, mechennym uglerodom-14, i svyazyvayushchim karbonatom oktaehdral'nykh slozhnykh ionov tipa CoA{sub 2}CO{sub 3}{sup +}, gde A = 2 NH{sub 3}, ehtilendiamin (en), propilendiamin (pn) ili trimetilendiamin (tn). EHti issledovaniya priveli k dovol'no tochnomu ponimaniyu kharaktera reaktsij ehtogo roda po zamene svyazi, a takzhe roli v ehtoj reaktsii neuchastvuyushchikh v obmene svyazyvayushchikh aminovykh zven'ev. Analogichnye issledovaniya obmena oksalatov, provedennye so slozhnymi trioaksalatami tipa M (C{sub 2}O{sub 4}){sub 3}{sup -3}, gde M=Co (III), Cr (III) ili Br (III), dali stol' zhe plodotvornye rezul'taty. Drugim metodom, primenimym tol'ko v sluchae ispol'zovaniya radioizotopov s malym