The Synthesis of Macromolecular Compounds by Radiation Polymerisation

Abstract

Diffuse neutron scattering measurements have been made on single crystals of Ndo SPbo ,Mn03 in the temperature range 5-295 K. It is found that Nd, sPbo ,Mn03 begins to order magnetically at a temperature T, = 184 K, this being accompanied by an anomalous change in electrical conductivity. Above T, the conductivity is of the activated hopping type and below T, it is metallic. Neutron scattering measurements show that below T, there are well defined magnon branches which soften as T approaches T,. Temperature-dependent coherent diffuse quasi-elastic scattering occurs around some Bragg peaks above T,. This diffuse scattering is magnetic in origin and its energy width is consistent with the activation energy derived from the conductivity, suggesting magnetic polaron formation. Diffuse scattering due to lattice polarons has not been observed.

A study on the chemical structure of phenyl acetylene radiopolymer

“…In agreement with the results of the electronic spectra, we may observe that cis ‐rich Rh‐PPA has a molecular weight M w ranging from 50 000 to 260 000 g mol −1 and even more24 while γ‐PPA has a molecular weight of the order of magnitude of 10 3 g mol −1 19. The solubility of γ‐PPA in many solvents again suggests a low molecular weight and also the absence of crosslinks between adjacent chains.…”

“…Radiation‐induced polymerization of alkynes is a convenient method of synthesis in the absence of any catalyst and impurity, but this approach has received limited attention 19. 20 The purpose of this work is to study the chemical structure of polyphenylacetylene prepared by radiation‐induced polymerization.…”

60Co γ-rays irradiation modified p-diethynylbenzene as prepolymers to prepare polyarylacetylene with excellent heat resistance

“…Radiation-induced polymerization of alkynes is a convenient synthesis in the absence of any catalyst and impurity, but this approach has received limited attentions [19,25,26]. El Fadl F. I.…”