S.V. Vinogradova

Thermal decomposition of polyarylates of 1,2-bis-(p-carboxyphenyl)-o-barene — [1,2-bis-(p-carboxyphenyl) dicarbaklosododecarborane]☆

Wv, have previously given information about the synthesis and some properties of polyarylates containing barene (carborane) groups in the polymer chain [1]. I t has been noted, in particular, that during thermal oxidizing decomposition of these polymers studied by TGA, when heated to 900 ° an unusually high coke residue (up to ~ 8 0 ~ ) was obtained. Conventional polyarylates under similar conditions in air undergo complete combustion at 650-700 ° .

The ageing of polyarylates containing carborane groups

A comparative study of the thermal degradation of polyarylates from 9,9-bis-(p-hydroxyphenyl)fluorene and terephthalic acid (D9), 1,2- and 1,7-bis-(p-carboxyphenyl)carborane (o-BP and m-BP) has shown that the carborane nucleus affects the thermal stability of the ester bond, and that thermal decomposition of polyarylate o-BP involves two mechanisms. Up to 450° the reaction is predominantly heterolytic and at higher temperatures it is a free-radical chain reaction.

A study of the formation of iron tricarbonyl π-Complexes with block copolymers☆

Abstract Iron tricarbonyl π-complexes with poly(styrene-butadiene) block copolymers were prepared. The characteristics of the formation of these complexes were studied. It was shown that the degree of complex formation depends on the ratio of the reagents and on the polymer concentration in the solution. The dependence of the polymer molar mass characteristics on the conditions of their preparation were investigated.

Study using NMR of polyarylates derived from bisphenols substituted in the ring

The structural formulae of secondary radicals R, the designations of the polymers and their characteristics are given in Table 1. The ~rMR spectra were observed in a labora tory apparatus with a frequency of 24 Me/s at temperatures ranging from -196 to 330 ° as a derivat ive of the absorpt ion signal, Pr ior to measurement, the samples were evacuated at 100 ° and a pressure of 2 × 10 -~ mmHg for 2-3 hr and sealed in a glass ampoule.

Influence of carborane-containing compounds on the oxidative stability of products of pyrolysis of network polymers☆

Abstract A study has been made of the influence of o -carborane and its aryl derivatives on the oxidative stability of the products of pyrolysis of synthetic thermoreactive polymers. It is shown that o -carborane increases the oxidative stability of the pyrolysis products more efficiently that phenyl- or diphenyl- o -carborane.

Polyimides with o- and m-diphenylcarborane fragments in the chain

Polyimides (PIs) have been prepared from 1·2- and 1·7-bis-(3·4-dicarboxyphenyl) carborane dianhydrides and aromatic diamines. It is shown that PIs containing o-carborane groups can be synthesized by two-stage polycondensation with thermal cyclization in the second stage. Synthesis of PIs containing m-carborane groups can also be achieved by chemical cyclization in two-stage polycondensation and by one stage, high temperature polycyclization in solution. Some properties of the polymers have been investigated.