| 摘要 |
Improved free radical bulk, soln., suspension or emulsion polymerisation of monomer comprises contacting monomer (I) with initiator (II), solvent and suspending or emulsifying agent, in the presence of a molecular wt. control agent (III) which is a cobalt chelate chain transfer agent of formulae (a) or (b). In formulae, R is phenyl or 1-12C alkyl where each alpha-C contains 2 H atoms, or R and R on adjacent C atoms, taken together is 5-8C cycloalkylene unsubstd. in alpha-position (4 gps. are listed); R2 is H or CxH2x+1, x is 1-12; each R4 is R2, or both R4 gps. taken together are -O-Z---O-; n is 2 or 3; z is BF2, BCl2, BBr2, BR2(2); and X(-) is NO3(-), Cl(-), BF4(-) (8 are listed). - Specifically, bulk or soln. polymerisation is carried out at 50-150 deg.C, and emulsion polymerisation at 25-90 deg.C.
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