A detail study on the mechanism for the thermal decomposition
of polymers is proposed by Cullis and Hirschler [78]. The four
different mechanisms proposed are: (1) End-chain scission or
unzipping, (2) Random-chain scission/fragmentation, (3) Chainstripping/elimination
of side chain, (4) Cross-linking. The decomposition
mode mainly depends on the type of polymer (the
molecular structure).The following Table 3 describes the reaction
pattern of different thermoplastics where first three types of
mechanism is being followed [77]. This has been shown as below