Neue photoreaktive Polymere mit seitenständigen Dimethylmaleinimid-Gruppen. I. Radikalische homo-und copolymerisation von N-(5-methyl-3-oxa-4-oxo-hexen-5-yl)-dimethylmaleinimid

The homopolymerisation of N-(5-methyl-3-oxo-4-oxo-hexen-5-yl)-dimethylmaleimide (DMI-MA) leads to linear poly(methylmethyacrylates) with pendant lightsensitive dimethylmaleimide groups. Due to steric hindrance of the methyl substitutents, the carbon-double bond is not involved in the reaction, even at conversions of over 90%. The reaction velocity constant for the homopolymerisation is k_p/k = 2,0 – 2,2.10^?2 (65°C, toluene, AIBN) and the activation energy E_a = 62,36 ± 2 KJ/mol^?1. Measurement of the copolymerisation reactivity ratios for the monomer pairs DMI-MA/methacrylic acid (MAS), DMI-MA/methylmethacrylate (MMA) and DMI-MA/ethylacrylate (EA) gave the following values: DMI-MA (r₁): MAS (r₂) = 1,36 ±0,06 : 0,77: ± 0,06; DMI-MA (r₁) : MMA (r₂) = 1,16 ± 0,17:0,475 ± 0,17 and DMI-MA (r₁): EA(r₂) = 1,60 ± 0,15: 0,44 ± 0,15.