Graft copolymerization of acrylonitrile onto poly(vinyl alcohol) in presence of air using ceric ammonium nitrate-natural gums

In an attempt to overcome the problem of polymerization of vinyl monomers i n presence of oxygen, polymerization was done by using some plant gums. The effect of some plant gums were studied on the graft copolymerization of ac rylonitrile (AN) on to poly(vinyl alcohol) using eerie ammonium nitrate (CA N) as initiator in presence of air. Percent of grafting was determined as a function of nitric acid, concentration of monomer, time, and temperature. The rate of polymerization and maximum grafting (151%) were high compared w ith those in absence of the gum both in air of even in an inert atmosphere. Thus, it was definitely observed that the graft copolymerization is affect ed by the gum. From the differential scanning calorimetric (DSC) studies th e glass-transition temperature Tg of polyacrylonitrile (PAN) is found to be 56 degrees C, Thermal stabilities were checked by thermogravimetric analys is (TGA) and this indicated that the grafted copolymers were resistant to m oisture absorption. (C) 2000 John Wiley & Sons, Inc.