Thermal oxidative degradation of poly(4-methyl-1-pentene). I. Identification of products and mechanisms

Abstract

SynopsisIsotactic and atactic poly(4-methyl-1-pentene) powders were degraded in the presence of pure oxygen at temperatures of 145O and 175OC. The functional groups present in the nonvolatile products were identified using infrared spectroscopy. The volatile products that formed were identified by means of a relativly new technique which combines gas chromatography and mass spectroscopy. In this study, seventeen yolatile products were detected and identified and their relative abundance estimated. The results obtained could readily be reproduced. Various oxidation mechanisms for these products are postulated.

The degradation of TPX components by oxygen, elevated temperature, and ionizing radiation

“…This mechanism is based on a series of chain reactions that involve the following free radicals: R, HO;, ROY, RO, and HO. It is noteworthy that the infrared data of Gabbay, Stivala, and Reich [6,7] are completely consistent with the earlier results obtained by Zitomer and DiEdwardo 121.…”

“…In another publication, Babbay, Stivala, and Reich discuss the thermal oxidative degradation of atactic and isotactic PMP powders in the presence of pure, dry oxygen at 145 and 175°C [6,7]. The formation of nonvolatile products (NVPs) were studied with infrared (IR) spectroscopy, while gas chromatography with mass spectroscopy (GCMS) was used to identify volatile products (VPs).…”

Effect of Annealing Poly(4-Methylpentene) and of Oxidative Degradation during Annealing

“…[1] Besides high transparency, poly(4-methylpentene) has a high melting point, up to 235 • C. These characteristics let poly(4-methylpentene) be practically used as heat-resistant transparent engineering plastics, and a number of research reports have been published on this polymer. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Like other polyolefins, poly(4-methylpentene) may suffer from degradation at high temperatures. [4,5,14] For long-term applications at high temperatures, the properties of poly(4-methylpentene) may be affected by degradation.…”