摘要:

AbstractMeasurements of dynamic properties of a series of polyvinylchloride‐rubber blends at temperatures of −60 to +100°C and frequencies of 0.3–3.0 Hz have been carried out by means of the free vibration method. The dynamic data have been compared to the results of impact resistance Charpy‐experiments. The linear correlation obtained between the dynamic shear modulus at −10°C (G′−10) and the impact resistance at 20°C indicated that the valueG′−10has to be decreased compared to that of unmodified PVC to increase the resistance of compatible as well as incompatible PVC‐rubber blends. The impact resistance increases with higher decrease ofG′−10. The correlation given and the breaking characteristics of the samples investigated show that, ductile fracture, relieving the deformational stress mainly by developing cracks, occurs in blends withG′−10in the range of 12.0–7.5 × 108N/m2. This is valid for compatible as well

ISSN:0449-2994    

DOI:10.1002/polc.5070160803

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

ISSN:0449-2994    

DOI:10.1002/polc.5070160804

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

ISSN:0449-2994    

DOI:10.1002/polc.5070160805

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractBeside the usual reactants, the reaction medium of polymerization contains two inert compounds IMand IC, which act as internal standards of concentration corresponding, respectively, to the monomer M and the organometallic catalyst RMe. At given time intervals, small liquid samples are picked up and injected into a vaporization cell together with small amounts of water or alcohol. Then a part of the gaseous mixture is analyzed by gas chromatography. The consumption of the monomer and of the catalyst are obtained from the measurements of the ratios of the areas under the peaks M and IM, and RH and IC. Some results are given for the polymerizations of vinyl chloride with an organomagnesium catalyst and of isoprene withn‐butyllithiu

ISSN:0449-2994    

DOI:10.1002/polc.5070160806

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractSix new polymers based on ferrocene and its derivatives have been synthesized and their electrophysical properties investigated. The polymers were prepared by various methods. In polymerization of acetylferrocene oxime and difulvene of 1,1′‐diacetyl‐ferrocene the yield of polymers was 90%. In the direct interaction of ferrocene and hexamethylene diisocyanate, poly(ferrocenylene polyamide) resulted in 73% yield. The polycondensation of ferrocene both with phthalic anhydride and with carbamyl chloride, and that of acetylferrocene with ammonium bicarbonate, in the presence of zinc chloride gave new ferrocenic polymers with a system of conjugated bonds. All produced polymers were coloured powders partly soluble in organic solvents. In the direct interaction of ferrocene and carbamyl chloride (in the form of a complex with zinc chloride) (poly‐(ferrocenyl nitrile), not described previously, has been obtained. By polycondensation of acetylferrocene and ammonium bicarbonate the insoluble polymers and oligomer of molecular weight 480 and m.p. 145‐150°C. containing two hydroxy groups have been prepared. The presence of CN bonds in poly(ferrocenyl nitrile) and the products of polycondensation of acetyl‐ and 1,1,‐diacetylferrocene with ammonium bicarbonate has been confirmed by the complexing effect of CN bonds with a silver salt. Silver extraction due to the complex formation has been 0.62 g./g. of the polymer. The prepared polymers produced a narrow one‐component signal in the ESR spectrum at spin concentration of 10−7–1019spins/g. which confirms the presence of conjugated double bonds in the polymers. The electrical conductivity temperature plot obeyed the exponential law. The values of conductivities were 11−12to 10−8ohm−1‐cm.−1, and

ISSN:0449-2994    

DOI:10.1002/polc.5070160807

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractThe diamagnetic susceptibility of differently prepared polyethylene samples was measured. The application of an expression for the molecular susceptibility based on Pascal's additivity law permits the calculation of intermolecular constants associated with different physical states. Treatments such as hot and cold drawing or crystallization from the melt or solution give rise to susceptibility values χ corresponding to intermediate degrees of order between those of the pure “gaseous” and the pure “crystalline” state. Chain folding does not affect the χ values. Chain branching provokes an increase of χ, indicative of a decreas

ISSN:0449-2994    

DOI:10.1002/polc.5070160808

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractThe increase in integral width of (110), (220) and (330) reflections of linear polyethylene single crystals crystallized from 0.05%n‐xylene solution demonstrates the existence of paracrystalline lattice defects in crystalline regions. The g value describing the statistical distance fluctuations of (110) planes isg= 1.88% and 2.14%, the particle size vertical to the chain directionD= 299 and 331 A., respectively, for Hostalen G and Lupolen 6011‐H, respectively, the two polyethylene materials investigated. It is not possible to explain the increase in line width by the occurrence of lattice stra

ISSN:0449-2994    

DOI:10.1002/polc.5070160809

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractThe study of annealed polyethylene oxide crystals grown from solution has been carried out in the molecular weight range where the transition from the extended chain conformation to the folded chain conformation was expected to occur. Both the variation of the long period with chain length and the chain orientation with respect to the vertical direction to the crystal lamellae plane have been investigated. The value of the long period for crystals grown inp‐xylene closely corresponds to that calculated for a 72helix. During annealing no change of the long period takes place due to the effect of hydrogen bonds of the endgroup

ISSN:0449-2994    

DOI:10.1002/polc.5070160810

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractA radioactive tracer method for distinguishing between cationic and anionic polymerization mechanism is described. The evaluation of the mechanism involves the terminating of polymerization by alkoxyl‐labeled or oxygen‐tritiated alcohols and carboxylation of active sites. The limitations of the technique were estimated by applying it to catalysts of established cationic and anionic activity. The TiI4—AlR3was demonstrated to initiate a coordinated anionic polymerization of butadiene, whereas soluble cobalt complexes catalyze a coordinated cationic propagation. The discrepancies in results of previous studies applying alcohol termination to cobalt catalysts are interpreted. Applying the Cl36‐labeled AlR2Cl and/or CoCl2the chlorine was demonstrated to incorporate into the polymer chain in the course of polymerization, and a mechanism is suggested involving a secondary cationic process catalyzed by excess

ISSN:0449-2994    

DOI:10.1002/polc.5070160811

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY

摘要:

AbstractStereospecific polymerization of butadiene with different rhodium compounds in water medium has been studied using the tracer method. Water is shown to play an active part in both the initiation and termination stages as evidenced by the presence of groups in polymers. The OH−, Cl−polar groups of the polymer are found to be allylic. It has been shown for the case of rhodium‐acetate complex, using the kinetic isotope effect method that termination of polymer chains occurs through water proton addition. A coordinated mechanism through π‐allylic complexes has been proposed for the polymerization of butadiene with rhodium catalysts. It has been assumed that the initiation stage is a π‐allylic complex forming reaction, propagation of polymer chains occurring through the monomer molecules introduction between a metal atom and org

ISSN:0449-2994    

DOI:10.1002/polc.5070160812

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1967

数据来源: WILEY