effect of some additives on degradation of poly (vinyl chloride- co- vinyl

the thermal decomposition of 86 % vinyl chloride 14 % vinyl acetate copolymer wasstudied by the conductometry technique in the presence of nitrogen. the kinetics of stability andthermal degradation of vinyl chloride- co- vinyl acetate (pvc- co- pvac) copolymer withcopper, copper oxide and tricalcium dicitrate (st) were investigated at various temperatures (150-180 oc ) in solution. the rate coefficients for the degradation of the copolymer were determined.the energies of activation, determined from the temperature dependence of the rate coefficientsfor copolymer alone was 63.536 kj mol-1 and in the presence of copper, copper oxide andtricalcium dicitrate were 44.224, 55.594 and 110.332 kj mol-1, respectively. the results showthat thermal stability was increased in the presence of tricalcium dicitrate, but its thermalstability was decreased in the presence of copper and copper oxide.