Graft Copolymerization of Styrene on Poly(vinyl chloride) by Cr²⁺-Ethanolamine Complex

Abstract

Graft copolymerization of styrene on PVC by Cr2"-ethanolamine complex Cr2" (EA) was studied in DMF at 50"C. Different rate equations of the copolymerization were obtained in the low and high concentrations of Cr2 (EA), as follows: R, oc[PVC]if2[Cr2 (EA)]Y2[St]t in low conc. [Cr""(EA) about O.8 10 "2 mol.1 ] R, oc[PVC] Cr2"(EA)"i[St]2 in high conc. [Cra"(EA) about 2, 0xlO-2 mol.1-i]
Kinetic study revealed that Cr2" (EA) contributed to the termination reaction of the copolymerization when the of Cr2 (EA) was high. Model compounds of PVC, e. g. n-butyl ehloride, 2, 4-dichloropentane, 2-chloro-2-ethylpentane and allyl chloride combined with Cr (EA) in the polymerization of styrene, and the initiation site along the PVC chain was assumed.
Results of fractionation of obtained polymers showed that the graft eMcieney was very high, almost more than 90%, and a large amount of gel was formed in the graft copolymer. The gel content in the graft copolymer decreased with increasing concentration of Cr2" (EA) which contributed to the termination reaction.