| 摘要 |
1286600 Polymethyl methacrylate E I DU PONT DE NEMOURS & CO 22 Dec 1970 [22 Dec 1969] 60877/70 Heading C3P The continuous flow polymerization of methyl methacrylate is effected by mixing monomer with a syrup comprising methyl methacrylate polymer (e.g. recycle), an initiator and a chain transfer agent, the mixture containing 30-80% by weight of monomer feeding the mixture at 120-170‹ C. and advancing it through a reaction zone under adiabatic conditions resulting in a uniform temperature rise of 10-30‹ C. along the reaction zone and withdrawing polymer syrup containing 25-75% of polymer. Preferably the monomer contains 1-25% of ethyl acrylate. Exemplified initiators are tbutyl perbenzoate, dimethylhexyl dihydroperoxide and dimethyl di-t-butylperoxy hexane. The chain transfer agent is t-amyl mercaptan or butyl mercaptan. |
