Crosslinking photoaddition reaction

Polymerization and Crosslinking by the Benzene-Bismaleimide Photoaddition Reaction... 

Photoreactions of MA with 1,2-polybutadiene, 1,4-polybutadiene, poly(styrene-co-butadiene), poly(styrene-co-isoprene), polystyrene, and poly(styrene-co-methyl methacrylate) have been studied in air. " In homogeneous solutions, MA addition to the polymers proceeds efficiently by a chain mechanism, where the quantum yield of the photoaddition was greater than unity under irradiation at A >310 nm. From the effects of solvent and photosensitizers and spectroscopic data, a radical chain mechanism was proposed to account for addition and crosslinking of the polymers by MA molecules. The photoaddition reaction was applied to the surface of polymer films. The photoreactions were conducted at the interphase between solid polymer and acetone solution of anhydride and also at the interphase between solid polymer and gaseous anhydride. Irradiation with a 300-W high-pressure lamp brought about considerable surface modification, as shown by wettability and dyeability properties. 

A logical extension of maleimide photoaddition is the light-catalyzed cyclopolymerization reaction of bismaleimides with benzene or alkylbenzenes to form polyimides. This reaction, and the application of bismaleimide photoaddition to polystyrene crosslinking, are discussed in the following sections. 

---