NONISOTHERMAL THERMOGRAVIMETRY OF POLYMERS .3. THERMOGRAVIMETRY OF PEPP, PE PMMA AND PP PMMA BLENDS

Polyethylene (PE)/polypropylene (PP), PE/poly(methylmethacrylate) (PMM A) and PP/PMMA blends were examined by nonisothermal thermogravimetry. It was found that in a nitrogen atmosphere the less stable polymer us ually causes destabilization of the more stable polymer. The proposed interpretation is based upon the parallel effects of the products of d ecomposition of the less stable polymer on both the initiation and ter mination reactions of the more stable polymer. The separate TG waves a ttributed to the volatilization of each polymer were characterized by the values of the preexponential factor and apparent activation energy , and the mutual effect of each component of the blend was outlined.