High pressure copolymerisation of maleic anhydride with cyclic olefins and substituted ethylenes

The pressure effect on the rate of maleic anhydride copolymerisations with various substituted ethylenes was found to be considerable, leading to high negative values of the activation volume, especially when the comonomer is crowded with bulky substituents. No significant variation of the polymer composition was observed and the reactivity ratios were found to be less affected by pressure than rates and generally decrease slightly with increasing pressure. Pressure influences also the e‐value of the monomers.