摘要:

AbstractDie beschriebene Methode verschafft einen Überblick über die Zusammensetzung der Copolymerisate von Propylen und Äthylen. Sie ermöglicht die grobquantitative Bestimmung von homopolymerem Äthylen und isotaktischem Polypropylen bis zu Gehalten von weniger als 2%. Außerdem kann der Gesamtpolypropylengehalt der Copolymerisate mit Hilfe einer Verhältnisrechnung aus den IR‐Absorptionen bei 8,6 (1163) und 13,9 · (719 cm−1) mit einem Fehler von rund 10% bestimmt werden. Ataktisches Polypropylen ist neben dem Propylenanteil des Copolymerisats nicht erkennbar und wird in dessen Gesamtpropylengehal

ISSN:0025-116X    

DOI:10.1002/macp.1960.020420101

出版商:Hüthig&Wepf Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractSome metal ketyls (mono‐alkali metal complex of non‐enolizable ketone) were found to induce the polymerization of vinyl compounds such as acrylonitrile and methylmethacrylate. Styrene was not polymerized by the ketyls. On the other hand, the di‐alkali metal complex of the ketone had a greater activity than the ketyl. By the dimetal complex. styrene was also polymerized readily to a quantitative yield, even at low temperature. In the polymerization of styrene, the formation of living polymer was observed. A study on the copolymerization by the ketyl or the dimetal complex showed the polymerization to be anionic. Variation in the kind of ketone and metal component of the ketyl or the kind of solvent, appreciably affected the catalytic activity of the ketyl. No effect of solvent, however, was found on the copolymer composition. Some samples of polymethyl methacrylate obtained by ketyl or dimetal complex were proved to have the same infrared absorption spectrum as that of the type‐F crystallizable polymer. Consideration was made on the possible mechanism of the polymer

ISSN:0025-116X    

DOI:10.1002/macp.1960.020420102

出版商:Hüthig&Wepf Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractMercuric chloride polymerized diketene at low temperature. The molecular weight of the acetone‐insoluble and dioxane‐soluble fraction of the polymer was 1630.From the alcoholysis of the polymer and the infrared spectrum of the polymer, the molecular structure of the polymer was considered to be the open chain polymer of vinylaceto‐β‐lactone. Consequently, the molecular structure of diketene was also believed to be vinylaceto‐β‐lactone, although the assignments of the five strong bands in the doublebond region still remai

ISSN:0025-116X    

DOI:10.1002/macp.1960.020420103

出版商:Hüthig&Wepf Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractThe acceleration of the polymerisations of γ‐irradiated styrene and vinyl acetate by added polymethyl methacrylate has been examined. G values of 0.46 radicals/100eV. for pure styrene and 5.7 for pure vinyl acetate are in agreement with those of previous workers. It was shown that styrene does not exert any significant “aromatic protection” over irradiated polymethyl methacrylate.Radiochemical assays of the methyl methacrylate content of the block‐copolymers formed in irradiated solutions of polymethyl methacrylate in vinylacetate showed that ca. 70% arose from main chain scission of polymethyl methacrylate with the growing vinyl acetate chains terminating by disproportionation or transfer. The remainder could have arisen from vinyl acetate chains terminating by combination, grafting to the polymethyl methacrylate or side chain

ISSN:0025-116X    

DOI:10.1002/macp.1960.020420104

出版商:Hüthig&Wepf Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractUntersuchungen der magnetischen Kernresonanzabsorption wurden an einem 6,12‐Polyamid im Temperaturbereich zwischen —75 und 160°C durchgeführt. Das Kernresonanzsignal besteht sowohl beim vollkommen trockenen als auch beim wasserhaltigen (35 Mol‐%) Polyamid oberhalb der jeweiligen Glastemperatur aus zwei Komponenteu. Die schmale Komponente kommt durch die mikro‐BROWNsche Bewegung der Molekülsegmente in den amorphen Bereichen oberhalb der Glastemperatur zustande. Die breite Komponente gehört zu den unbeweglicheren Protonen der kristallinen Bereiche. Eine Abnahme der Linienbreite oberhalb TGwird durch Rotationen der Methylengruppen in den Kristalliten erklärt.Dynamisch mechanische Untersuchungen an trockenem 6,12‐Polyamid unterschiedlicher thermischer Vorbehandlung im Bereich zwischen 20°C und dem Schmelzpunkt bei einer Frequenz von 1 Hz lassen keine Modifikationsumwandlung erkennen. Bei einem kurz unterhalb des Schmelzpunktes in der Temperaturabhängigkeit des mechanischen Verlustfaktors tg δ auftretenden α‐Maximum handelt es sich nicht um einen neuen Relaxationsprozeß. In der Temperaturabhängigkeit der physikalisch durchsichtigeren Größe G

ISSN:0025-116X    

DOI:10.1002/macp.1960.020420105

出版商:Hüthig&Wepf Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractThe solubility of water in molten polyhexamethylene adipamide (nylon 66) has been measured in order to investigate the equilibrium in the system of nylon 66 and water. The solubility of water nw(mole/mole of fundamental structural unit) increases with the rise of the vapour pressure p (mm. Hg) of water and HENRY's law holds well within the range of water contents of less than 0.1%. The following equation is obtained.Under the same vapour pressure of water, the number of amino groups in the polymer increases markedly with the rise of temperature, while that of carboxyl groups decreases. The equilibrium constant K of the condensation reaction between the linear polymers can be expressed in the following equation.The relationship between the number average degree of polymerization P̄nand p can be expressed as follows

ISSN:0025-116X    

DOI:10.1002/macp.1960.020420106

出版商:Hüthig&Wepf Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractIn conjunction with a more extensive investigation of cellulose xanthate decomposition (viscose ripening), xanthates of two synthetic polyalcohols, polyvinyl alcohol (PVA) and polyallyl alcohol (PAA), respectively, have been prepared and studied. The xanthation was made with a four‐fold excess of carbon disulfide as an emulsion in 5.3 N NaOH for six hours at 27°C. A high degree of xanthation (DS of 0.5 and 0.9 for PVA and PAA. respectively) was obtained. The PVA xanthate was almost completely soluble in 1.3‐N NaOH while about 50 per cent of PAA xanthate was separated as a gel which could not be dissolved in 1.3 to 5.3‐N NaOH.The decomposition of the two xanthate solutions in 1.3 N NaOH at 18°C. was measured spectrophotometrically (UV) as described by DUX and PHIFER5after removal of the impurities using a NaOH saturated ion exchange resin (IRA–400). After an initial period (3–4 days) of rapid and gradually decreasing rate of decomposition, the reaction was of the first order for the following two weeks. The PVA xanthate, however, decomposed at a rate (k1= 2.11· 10−6sec.−1) which was about 13 times that of the PAA xanthate (k1= 0.162· 10−6sec.−1).The probable reaction mechanisms of xanthate decomposition in acid and alkaline solutions, the difference in rate for xanthates of primary and secondary alcohols, and the nature of the initial rapid reactions, have been discussed and tentatively interpreted. The results are of special interest in relation to the technical viscose, i. e., caustic soda solutions of cellulose xanthates, containing one primary and two secondary alcohol groups on each gluc

ISSN:0025-116X    

DOI:10.1002/macp.1960.020420107

出版商:Hüthig&Wepf Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractA sample of thymus sodium deoxyribonucleate has been irradiated with high‐speed electrons and with γ‐rays in the dry state. Solutions of DNA were irradiated with γ‐rays. Higher doses of irradiation in the dry state produced marked reduction in S 020. At the low doses of electrons and γ‐rays, there was an increase in S 020over the control. This was explained as compensatory. When DNA was irradiated in solution with γ‐rays, there was a gradual decrease in S 020. The decrease in S 020was greatest when the DNA was irradiated in solution. The decrease in S 020was greater when DNA was irradiated in the dry state with electrons than when irradiated with γ‐rays. The concentration dependence of S20of DNA was greatly reduced both with irradiation in the dry state with electrons and with γ‐rays. In solution with γ‐rays, the effect was greater.There was an over‐all decrease in intrinsic viscosity with irradiation in the dry state with electrons and with γ‐rays. The effect was somewhat greater with electrons for an equivalent dose.Light‐scattering measurements indicated the formation of aggregates. In the case of irradiation with γ‐rays in the dry state, the maximum formation of aggregates was at 5·106r. At 20·106r., the molecular weight was less than at

ISSN:0025-116X    

DOI:10.1002/macp.1960.020420108

出版商:Hüthig&Wepf Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractStyrol kann mit linearen Lithiumalkylen in aliphatischen Kohlenwasserstoffen bei tiefen Temperaturen stereospezifisch polymerisiert werden; mit verzweigten Lithiumalkylen entstehen dagegen nur ataktische Polymerisate. Es wird angenommen, daß die stereospezifische Polymerisation von Assoziaten der lithiumorganischen Verbindungen aus initiiert wird

ISSN:0025-116X    

DOI:10.1002/macp.1960.020420109

出版商:Hüthig&Wepf Verlag    

年代:1960

数据来源: WILEY

摘要:

AbstractThe polymerization of styrene was carried out in benzene at 30°C. As initiator, a system of benzoyl peroxide – di‐n‐alkylaniline was applied. It was found that the initial rate of polymerization was proportional to the square root of the initial concentrations of both benzoyl peroxide and di‐n‐alkylaniline. The decomposition of benzoyl peroxide with di‐n‐alkylaniline was also carried out in the presence of styrene and it was found that the initial rate of decomposition was proportional to the initial concentrations of benzoyl peroxide and di‐n‐alkylaniline. The plots of the initial rate constant of the polymerization of styrene and that of decomposition of the benzoyl peroxide vs. the number of carbons of the alkyl group of di‐n‐alkylaniline showed a similar trend as those obtained in the previous paper. From the relationship between the initial rates of polymerization of styrene and that of the decomposition of benzoyl peroxide, the values of the initiator ef

ISSN:0025-116X    

DOI:10.1002/macp.1960.020420110

出版商:Hüthig&Wepf Verlag    

年代:1960

数据来源: WILEY