Stabilizing poly(vinyl chloride) using its blends with poly(methyl methacarylate): pyrolysis GC/MS studies.

Binary blends of poly(vinyl chloride) (PVC) with poly(methyl methacarylate) (PMMA) of various compositions were prepared through solution blending. Thermogravimetric and pyrolysis studies of these blends were carried out and the volatile products were separated and quantitatively analyzed by GC/MS. Harmful pyrolysis products from PVC like HCl and different aromatic hydrocarbons are significantly suppressed in presence of a small amount of PMMA. The stabilization effect on PVC was found to be the most significant with 10 wt.%. PMMA contents in the matrix. Mechanism of the stabilization has been explained by the interaction of micro- and macro-radicals resulting from PMMA with PVC, which stabilize the unzipping of polymer chains by a reversible blocking mechanism and increase the amount of cross-linked residue retained above 500 °C.