Improvements in and relating to the production of acrylonitrile copolymers

摘要

Acrylonitrile is polymerized according to the process of the parent Specification with the modification that one of the comonomers is methallyl sulphonic acid or a salt thereof. Further comonomers such as vinyl acetate, styrene or methyl acrylate may also be present. The copolymer produced contains at least 80% acrylonitrile and preferably 0,5 to 5% methallyl sulphonate. In the examples the polymerization is carried out in 50% aqueous sodium thiocyanate solution using azo-bis-isobutyronitrile as catalyst and in the presence of thiourea dioxide and may be carried out at pH5. In a comparison example sodium allyl sulphonate is copolymerized with acrylonitrile.