Effect of different nanoparticles on thermal decomposition of poly(propylene sebacate)anocomposites: Evaluation of mechanisms using TGA and TG-FTIR-GC/MS

摘要

In the present study poly(propylene sebacate) (PPSeb) nanocomposites containing 2wt% of fumed silica nanoparticles (SiO_2) or multiwalled carbon nanotubes (MWCNTs), or montmorillonite (MMT) were prepared by in situ polymerization. The thermal degradation of nanocomposites was studied using ther-mogravimetric analysis (TGA). It was found that the addition of MWCNTs and MMT enhances the thermal stability of the polymer, while SiO_2 nanoparticles do not affect it. From the variation of the activation energy (E) with increasing degree of conversion it was found that the decomposition of nanocomposites proceeded with a complex reaction mechanism with the participation of at least two different steps. To evaluate the thermal decomposition mechanisms and mainly the effect of nanoparticles on the thermal decomposition of PPSeb, TGA/FTIR and a combination of TG-gas chromatography-mass spectrometry (TG/GC-MS) were used. From mass ions detection of the formed decomposition compounds it was found that the decomposition of PPSeb and its nanocomposites, takes place mainly through β-hydrogen bond scission and, secondarily, through α-hydrogen bond scission. The main decomposition products were aldehydes, alcohols, allyl, diallyl, and carboxylic acids.