| 摘要 |
Propylene sulfide is polymerized or copolymerized with 3 to 20% by weight of total monomer of an unsaturated aliphatic vicinal episulfide cross-linking agent, the reaction being carried out in an environment substantially free from elemental oxygen and unreacted water in the presence of a catalyst which is the reaction product of diethyl zinc and water or diethyl zinc and hydrogen sulfide. The cross-linking agent may be allylthioglycidyl ether; also referred to are vinyl cyclohexene episulfide and butadiene monoepisulfide. The polymerization may be carried out at temperatures of 20 DEG to 60 DEG C., with or without an inert solvent, for example an aromatic or aliphatic hydrocarbon or chlorinated hydrocarbon. The catalyst is used in amounts from 0.05 to 3% w/w on total monomer, and may be the reaction product of 1 mol of water with 1-3 mols of diethyl zinc or of 1 mol of diethyl zinc with from 0.05 to 1.2 mols of hydrogen sulfide.ALSO:A polymerization catalyst is a reaction product of diethyl zinc and water or diethyl zinc and hydrogen sulfide. The diethyl zinc-water catalyst may be prepared by mixing the dialkyl and water in molar ratio 1:1 to 3:1 in an inert hydrocarbon solvent e.g. benzene or hexane. The molar ratio of diethyl zinc to hydrogen sulfide may be 1:0.5 to 1:1.2. The dialkyl may be dissolved in an inert hydrocarbon solvent and hydrogen sulfide gas bubbled through the solution, or a standard saturated solution of hydrogen sulfide can be mixed in predetermined proportions with a standard solution of diethyl zinc in a hydrocarbon solvent. Both catalysts should be prepared in an environment substantially free from elemental oxygen and water other than that used in forming the catalyst. |
