ing group, and X is an alkenyl group or an ethylenically unsaturated acyl group; said PX monomer comprising from about 0.025% to about 0.5% by weight of the resultant copolymer and the degree of polymerization of said copolymer being such that said copolymer has an inherent viscosity of from about 0.5 dl/g to about 1.4 dl/g; (b) coating at least a portion of the surface of said support member with