N-(Substituted Phenyl) Itaconimides as Organic Stabilizers for Plasticized

Poly(vinyl chloride) against Photo-Degradation

Mona Mohamed Fahmi, Nadia Ahmed Mohamed

Department of Chemistry, Faculty of Science, Cairo University, Giza, Egypt

Abstract

Several N-(substituted phenyl)itaconimide derivatives, N-(RPh)II, (R: -NO2, -COOH, -H, -OH, -OMe, -Me, -Cl, or -Br) have been investigated as organic photo-stabilizers for poly(vinyl chloride) (PVC) plasticized with dioctyl phthalate (DOP). Their stabilizing efficiencies are evaluated by measuring the length of the induction period (Ts), the period during which no detectable amounts of hydrogen chloride gas could be observed, and also from the rate of dehydrochlorination as measured by continuous potentiometric determination on the one hand, and the extent of discoloration of the degraded polymer on the other. The efficiencies are also evaluated by determining the amount of gel formation as well as the intrinsic viscosity of the insoluble and the soluble fractions of the degraded polymer, respectively. The results have proved the greater stabilizing efficiency of the N-(RPh)II derivatives relative to that of the phenyl salicylate UV absorber which is a commonly used industrial stabilizer. A radical mechanism is proposed to account for the stabilizing action of the investigated products.