Kinetics and mechanism of grafting of oleic acid onto acrylonitrile-butadiene-styrene terpolymer

The graft copolymerization of oleic acid onto acrylonitrile-butadiene-styre ne (ABS) terpolymer was initiated by benzoyl peroxide (BPO) in 1,2-dichloro ethane solution. The infrared spectra confirmed that oleic acid was success fully grafted onto ABS backbone. The influences of the concentration of ole ic acid, BPO and ABS on grafting were studied. The grafting occurred at the butadiene region of ABS. A reaction mechanism has been proposed; grafting most probably took place by cross-termination of oleic acid radicals with A BS macroradicals. Monomer cage effect on grafting was observed to depend on the 1.3 power of monomer concentration from the experimental results of in itial rate of graft copolymerization. The initial rate of graft copolymeriz ation (R-p) could be written as: R-p = 1.61x 10(-4)[M](2.3) [P][I-2]/([M](2 .3) + 0.53 [P])(2), where [M], [P], [I-2] denote the concentration of monom er, polymer and initiator, respectively. (C) 2001 Elsevier Science Ltd. All rights reserved.