PHOTODIMERISATION AND PHOTOPOLYMERISATION OF BIS-MALEIMIDES

1278780 Photopolymerization of bis-maleimides AGFA-GEVAERT 31 Oct 1969 [24 Dec 1968] 61434/68 Heading C3P [Also in Divi- C2 and G2] A process for the photocyclomerization of bismaleimides comprises exposing to radiation in the range of 3000 to 4000 Š a bis-maleimide of the general formula wherein R is an alkylene group of 2 to 12 carbon atoms, an arylene group or a -CH 2 -Z-CH 2 - group in which Z is O, S or NH, and X and Y are the same or different and are H or Cl atoms or CH 3 groups. Suitably the bis-maleimide is dissolved in an organic solvent such as acetonitrile or dioxan, to which solution is added a sensitizing agent such as benzophenone or Michler's ketone. Examples describe the photocyclomerization of a mixture of a copolymer of styrene and butadiene with hexamethylene bis-maleimide, and the preparation of cyclopolymers having recurring units of the following formulae in which the degree of polymerization is 12, 10 and 14 respectively.