Radical Polymerization Method Performed in the Presence of Disulfide Compounds

Title Radical Polymerization Method Performed in the Presence of Disulfide Compounds 

A method for preparing isolatable and re-activatable polymethyl methacrylate using the chain transfer agent bis(ethoxythiocarbonyl)disulfane with 2,2 -azobis(isobutyr-onitrile) is described. Reactivation of this macroinitiator with 2,2 -azobisisobutyr-onitrile was then used to prepare block copolymers. 

A reaction vessel was charged with 50 ml of benzene solution containing methyl methacrylate (0.236 mol), bis(ethoxythiocarbonyl)disulfane (1.53 mmol), 2,2 -azo-bisisobutyronitrile (1.18 mmol), and l,l -azobis(cyclohexanecarbonitrile) (1 mmol). The mixture was heated for 4 hours at 80°C and cooled, and the polymer was 

Preparation of Poly(Methyl Methacrylate-6/ocfe-Vinyl Acetate) 

The Step 1 product (8 g) was dissolved in 50 ml of benzene and then treated with 2,2 -azobisisobutyronitrile (14.6 mg) and 13.8 g of vinyl acetate and heated to 60°C for 72 hours. The mixture was cooled, and the polymer was precipitated in heptane. After drying the block copolymer was isolated in 47.8% yield having aM of21,500 daltons and a polydispersity index of 1.6. 

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