The thermal degradation of polystyrene.

McWalter, Ian Thomson

Abstract

A review is made of the thermal degradation of polystyrene. In a theoretical study the importance of intramolecular transfer during degradation is emphasized in the formation of oligomeric volatiles. To account for past experimental results a mechanism is proposed involving biradical cage combination. The presence of weak links in thermally-initiated polystyrenes cannot be accounted for in terms of peroxidic links incorporated into the polymer chains. However such links do reduce the thermal stability of the polymer. The degradation pattern of polystyrenes containing initiator fragments at the chain-ends is different from that of thermally-initiated or anionic samples. The results are explained in terms of the relative strengths of the chain-end and internal chain bonds. The presence in the polymer of the inhibitor diaminoanthraquinone supports the explanations for the behaviour of thermally- and benzoyl peroxide-initiated polystyrenes. A significant degree of recombinations is shown to take place after chain scission. The volatilisation behaviours of a thermal polystyrene and low RMM benzoyl peroxide-initiated polymer are studied. The loss of carbonyl-containing structures from the polymer residue is correlated with the gain of these structures in the volatiles. Comparisons are made throughout of the thermal stabilities of the various groups of polystyrenes used. Also the assumptions of the theory used to relate intrinsic viscosity to degree of degradation are shown to be essentially correct. Finally some suggestions are made for further work.

Citation

MCWALTER, I.T. 1977. The thermal degradation of polystyrene. Robert Gordon's Institute of Technology, PhD thesis. Hosted on OpenAIR [online]. Available from: https://doi.org/10.48526/rgu-wt-1993252

• Thesis Type: Thesis
• Deposit Date: Oct 18, 2024
• Publicly Available Date: Oct 18, 2024
• DOI: https://doi.org/10.48526/rgu-wt-1993252
• Public URL: https://rgu-repository.worktribe.com/output/1993252
• Award Date: Oct 31, 1977