Pyrolysis Kinetics for Uniform Repetitive Polymers

Thermal decomposition of uniform repetitive polymers was extensively studied in literature [17-19] in relation to the thermal stability of synthetic polymers. A kinetics equation has been developed based on the study of the steps occurring during pyrolysis involving a free radical chain mechanism [17]. For some natural polymers such as rubber, this theory is directly applicable. However, for non-repetitive polymers, or for polymers with more complex decomposition pathways, the theory does not provide appropriate kinetics equations. 

The pyrolytic process of a repetitive polymer frequently takes place with the formation of small volatile molecules and has a polymeric chain scission mechanism, as described in Section 2.6. Considering a polymer with a degree of polymerization (DP) n, the end scission reaction can be described by the chemical equation  

The kinetics equation obtained by considering all reactions (3), with r = 2, 3. .. will be 

It should also be noted that in the chemical reactions (1) and (3) only the macromolecules with the DP = n were considered, but the polymer does not consist of molecules with only one degree of polymerization. This fact will be considered later. 

After the radical formation, intermolecular chain transfer reactions take place. A special case of chain transfer is the propagation reaction (see Section 2.1) of the type  

---

Pyrolysis kinetics for uniform repetitive polymers with a voiatile monomer... 

---