| 摘要 |
FIELD: polymerization processes. ^ SUBSTANCE: invention relates to methods of controlled free-radical vinyl chloride polymerization or copolymerization at temperatures within a range of 40 to 95°C and pressure between 5 and 30 bar in presence of stable nitroxyl free radicals. Stable nitroxyl radicals are used as vinyl chloride free-radical polymerization regulators. Source of nitroxyl radicals is polyvinylchloride macroinitiator containing thermally unstable nitroxyl group bound through oxygen atom. Upon heating, macroinitiator splits releasing polyvinylchloride radical and nitroxyl radical. Presence of the latter at relatively high temperatures allows production of high-molecular polymers with low polydispersity. ^ EFFECT: increased homogeneity of polyvinylchloride product. ^ 19 cl, 6 tbl, 23 ex |
