Maleic Anhydride by Stable Free Radical Polymerization

A stable free radical polymerization using 2,2,6,6-tetramethyl-l-piperidinyloxy with maleic anhydride and styrene was used to prepared moderate molecular weight copolymers with polydispersities less than 1.5. Thermal re-activation of these copolymers in the presence of other monomers produced block polymers. 

A 1-liter reaction vessel was charged with 425 ml of styrene, maleic anhydride (100.2 g), and 2,2,6,6-tetramethyl-l-piperidinyloxy (0.0205 moles) and then treated dropwise with a mixture of 72 ml of styrene and 2,2,6,6-tetramethyl-1 -piperidinyloxy (0.0782 moles). The reaction was heated to 135°C for 45 minutes and cooled, and the mixture was dissolved in 500 ml of THE The polymer was precipitated in 3 liter of hexane, and 125.3 g solid product were isolated having a M of 3523 daltons and a polydispersity of 1.48. 

Preparation of Poly(Styrene-co-Maleic Anhydride-b-Styrene-co-Acrylonitrile) 

The Step 1 product was dissolved in 118 ml of styrene and 47 ml of acrylonitrile and then heated to 135°Cfor 100 minutes and cooled. After the workup described in Step 1, the product was isolated having a Mj, of 62,000 daltons with a polydispersity of 1.41. 

Additional free radical polymerization regulating agents were provided by Anderson [1], (I)-(ni). 

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Title Copolymers of Maleic Anhydride by Stable Free Radical Polymerization... 

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