| 摘要 |
1,243,702. Termination of anionic polymerization. DOW CHEMICAL CO. 24 June, 1969, No. 31894/69. Heading C3P. Unsaturated monomers (a) are polymerized in the presence of a polymerization initiator (b), suitably in a solvent (c), at 0‹ to - 80‹ C., and the polymerization terminated by adding an external terminating agent (d) while at least 80% of the polymer chain ends are still active. The monomers (a) are conjugated acyclic diolefins, methacrylate esters or an o-halostyrene. In examples, the following are employed: (a) butadiene, 2,3-dimethyl- or 1- methoxy-butadiene, piperylene, butylmethacrylate, o - bromo - and o - chloro - styrene, and 2,6 - dichlorostyrene; (b) n - butyl lithium and sodium-alpha-methylstyrene complex; (c) tetrahydrofuran which may be mixed with toluene; and (d) n-butyl bromide, carbon dioxide followed by hydrogen chloride, water, and ethylene oxide. |
