Synthesis of polyacrylamide with pendant poly(n-octyl acrylate) chains using macromer technique and studies on their properties

An amphiphilic graft copolymer of polyacrylamide (PAM) with uniform poly(n‐octyl acrylate) (POA) grafts was synthesized by copolymerization of AM with POA macromer in solution using azobisisobutyronitrile as the initiator. The macromer was synthesized by free radical polymerization of octyl acrylate in the presence of different amounts of thioglycolic acid as the chain transfer agent, followed by termination with glycidyl methacrylate. The reactivity ratio and effects of copolymerization conditions on the conversion of macromer or grafting efficiency were studied. The crude products were purified by extraction with toluene and water successively. The purified graft copolymer was characterized by IR, DSC, and TEM. PAM‐g‐POA can bring about microphase separation and exhibits good emulsifying properties and water absorbency. PAM‐g‐POA exhibits a very good compatibilizing effect on the acrylic rubber/poly(vinyl chloride) blends. About 2–3% of the graft copolymer is enough for enhancing the tensile strength of the blends. The tensile strength of the blends is more than twice that without the compatibilizer. DSC and SEM demonstrated the enhancement of compatibility in the presence of the graft copolymer. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers