| 摘要 |
Graft polymers are made by polymerizing styrene or a water-insoluble homologue thereof, e.g. alpha-methylstyrene, in an aqueous solution of a polymeric N-vinyl lactam in the presence of a free-radical polymerization catalyst, e.g. hydrogen peroxide, sodium, potassium, barium and zinc peroxides, perboric, persulphuric and peracetic acids and their alkali metal and ammonium salts, organic peroxides, oxygen, ozone, redox systems and azo catalysts. N-vinyl lactam polymers specified are those of N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone, N-vinyl-6-caprolactam N-vinyl-5-methyl-2-pyrrolidone, N-vinyl-3,3-dimethyl-2-pyrrolidone, N-vinylhexahydrophthalimidine and N-vinylnaphthostyrile. Also present during polymerization may be surface active agents, protective colloids, plasticizers and thickeners. Specifications 380,431, 380,851, 443,559 and 70,181 are referred to. |
