Reduction of monomer level in acrylonitrile polymers - by exposure to ionising radiation at defined low dosage

摘要

Acrylonitrile polymers, partic. including acrylonitrile/styrene copolymers, are exposed to ionising radiation at a dosage level of 0.05-2 megarads. Such polymers can be in the form of shaped articles. Irradiation can be followed by an HCN degassing treatment. The ionisation radiation can be provided by an electron beam. Other suitable copolymers are those of acrylonitrile with butadiene, methyl acrylate and other acrylates. If desired, the treatment can be applied first to the material in ground or pelletised form, then to the article produced from it. The material can also be treated in soln. or in suspension e.g. in a polymerisation medium. Carcinogenic acrylonitrile monomer can be removed while causing only a low level of HCN generation, which itself is removed in the process by degassing.