ROLE OF ACRYLIC ACID IN INITIATION REACTION OF GRAFT POLYMERIZATION ONTO 6-NYLON IN CaCl2-METHANOL SOLUTION

The role of acrylic acid (AA) in the initiation reaction of graft copolymerization of methyl acrylate (MA) and AA onto 6-nylon was investigated using AIBN_??_ as initiator in CaCl2-MeOH solution. Graft efficiency was not influenced by the amount of AIBN, but increased with increases in the concentration of CaCl2 and in the ratio of AA/MA. The efficiency was 23% regardless of the reaction time, except for the initial stage at which it was very high. With benzoylperoxide (BPO) as initiator, poor efficiency resulted due to the presence of CaCl2. However, a redox system, cumene hydroperoxide-l-ascorbic acid and 4, 4′-azobis (4-cyanopentanoic acid) also yielded 23% of graft efficiency. It was concluded from these results that the graft copolymerization is initiated by the extraction of a hydrogen on 6-nylon not by the initiator radicals, but by the primary radicals or the growing polymer radicals predominantly containing AA produced by the attack of initiator radicals to AA. _??_ azobisisobutyronitrile (AIBN)