TG-FTIR-QMS analysis of more environmentally friendly poly(geranyl methacrylate)-co-poly(cyclohexyl methacrylate) copolymers

The pyrolysis and thermal oxidation course of new, more environmentally friendly copolymers, not described in the literature so far, was systematically investigated by the TG/FTIR/QMS technique. New materials were obtained in the UV polymerization process of geranyl methacrylate, a monomer synthesized on the basis of natural, terpene alcohol (geraniol), and cyclohexyl methacrylate using a variable percentage of individual monomers. As confirmed, the copolymers were characterized by excellent resistance to solvents and chemical environment as well as T-g in the range 34.5-53.8 degrees C. The TG/DTG analyses proved their high thermal stability in an inert atmosphere and satisfactory thermal resistance in an oxidizing atmosphere. The thermal resistances of the copolymers were directly dependent on the percentage of individual monomers. The simultaneous TG/DTG coupled with the FTIR and QMS analyses confirmed that the decomposition course of the tested materials was complex, in both atmospheres. The pyrolysis process included two main stages. In the first stage, depolymerization, random cleavage of the C-C and C-O bonds and decarboxylation were the main processes. These led to the emission of methacrylate monomers, myrcene, geraniol, citral, propene, methacrylic acid and other structure low molecular saturated and unsaturated compounds, as the main products of pyrolysis. In the second stage, the secondary reactions between intermediate volatiles and the formed residues were expected. Under oxidative conditions, the decomposition mechanism was more complicated. The depolymerization, random cleavage of the C-C and C-O bonds, decarboxylation and additional reactions of the intermediates with oxygen led to the emission of methacrylate monomers, myrcene, geraniol, citral, propene, methacrylic acid and other structure low molecular saturated and unsaturated compounds and more oxidized gaseous products.

Automated summary

The pyrolysis and thermal oxidation processes of new environmentally friendly copolymers have been examined using TG/FTIR/QMS technique. The obtained copolymers demonstrated excellent resistance to solvents and chemical environment as well as high thermal stability. The composition of the copolymers directly affected their thermal resistance. The decomposition course of tested materials was complex, with depolymerization and additional reactions leading to the emission of various compounds.