Thermoset plastics decomposition temperature

Attempts to give a quantitative analysis of plastisol extrusion were undertaken only in a few published papers. They were based on the analysis of plastisol viscosity as a function of temperature and time. If in the processing of thermosetting plastics their viscosity is assumed as practically independent of time (except of materials sensitive to structural and chemical transformation in temperature and stress fields which are accompanied by thermo-mechanical decomposition and cross-linking of macromolecular chains, the extent of the larter being influenced by the time of exposure to thermal and mechanical loads 18-21)), then at extrusion of plastisols, in view of their gelatination, the additional condition should be satisfield ... 

A thermoset plastic is a solid polymer that cannot be dissolved or heated to sufficiently high temperatures to permitcontinuousdeformation, because chemical decomposition intervenes at lower temperatures. Vulcanized rubber is an example. 

Thermoset plastics, such as Bakelite, which stay hard once set and do not soften or melt with increasing temperature. At very high temperatures molecules in a thermoset decompose with evolution of gas, and after complete decomposition a solid residue remains. Hence, the response of thermosets to heat is irreversible. 

Thermosetting plastics (thermosets) are polymer materials that irreversibly cure, to a chemically crosslinked stronger form [1]. Once formed and cooled they cannot be reprocessed and will decompose before they can melt. Thermoset materials are generally stronger than thermoplastic materials due to their rigid three-dimensional network of bonds and are also better suited to high-temperature applications up to the decomposition temperature of the material, see Figure 3.1. 

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