Polypropylene-graft-polyacrylic acid

As was found by microphotometration, the concentration gradient of the grafted PAA inside the membrane and its profile depend very much on the amount of the monomer absorbed. It was also evident that, because of the method used for preparation, polymerization of the acid was initiated mainly by PO radicals formed on polypropylene chains by thermal and redox decomposition of POOH hydroperoxides or POOP peroxides. The homopolymer of polyacrylic acid which was also formed inside the film was later removed by long time elution with methanol. 

ESR spectroscopy has been applied to studies of unsaturation and other structural features in a wide range of homopolymers including polyethylene [101-110], polypropylene [111-121], polybutenes [115], polystyrene [122-124], PVC [125,126], polyvinylidene chloride [127], polymethylmethacrylate [128-137], polyethylene glycol polycarbonates [137-140], polyacrylic acid [136-139, 141, 142], polyphenylenes [143], polyphenylene oxides [143], polybutadiene [144], conjugated dienes [145,146], polyester resins [146], cellophane [143,147] and also to various copolymers including styrene grafted polypropylene [148], ethylene-acroline [149], butadiene-isobutylene [150], vinyl acetate copolymers [151] and vinyl chloride-propylene. 

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