摘要:

AbstractIn molten non‐crystallising polymers we find normal random coil conformations of the molecules. This is inferred from the theoretically predicted and experimentally observed relationships between the properties of solutions (relaxational modulus, viscosity, osmotic pressure and specific volume) and melts. It is also derived from the intrinsic viscosities (η) and the diffusion constants of molecules with a very high molecular weight in polymeric solvents (M= 104−105) of the same chemical constitution. Moreover the properties of melts (relaxational modulus, flow curve, viscosity) depend on chemical structure and long chain branching in the manner predicted assuming a random coil conformation.At the glass temperatureTgthe conformation resembles that in the melt as the temperature dependence of the conformation atT>Tgshows ((η) in polymeric solvents, diameters of the domains in block copolymers). However, on cooling belowTgan irreversible volume shrinking process may lead to an inhomogeneous distribution of densities and possibly to an extended conformation of molecules in grain boundaries. Experiments show that only strong deviations from random coil conformations decrease the ultimate strength of a

ISSN:0007-1641    

DOI:10.1002/pi.4980060502

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractReaction variables of the interfacial condensation of Cp2TiCl2with diamidoximes is presented. At 1:1 Cp2TiCl2: diamidoxime ratios and less the product is found to contain predominately units of form I. It is tentatively concluded that the disubstituted product, form II, is formed at Cp2TiCl2:diamidoxime ratios>1. Sodium hydroxide and triethylamine are both found to be adequate added bases for the reaction.High concentrations of Cp2TiCl2and low concentrations of diamidoxime favour a more rapid reaction.Thermal degradation of the products in air and nitrogen occur via identical pathways.

ISSN:0007-1641    

DOI:10.1002/pi.4980060503

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe reaction between styrene or a styrene derivative and an alkali metal is the first stage in the synthesis of regular copolymers. The kinetics of the reaction of 1,1‐diphenyl ethylene in tetrahydrofuran at a sodium metal surface has been studied using a rotating sodium disc. It has been established that the reaction is transport controlled and first order in 1,1‐diphenyl ethylene concentrat

ISSN:0007-1641    

DOI:10.1002/pi.4980060504

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980060505

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980060506

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980060501

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY