This improved of the polymers and copolymers prepared by polymerization in the mass of a monomer composition based on vinyl chloride

摘要

1506981 Degassing polymers RHONE - POULENC INDUSTRIES 26 March 1976 [28 March 1975] 12310/76 Heading B1F [Also in Division C3] The invention relates to a method of degassing polymers and copolymers prepared by bulk polymerisation of a monomeric composition based on vinyl chloride, in which the polymer is kept agitated and brought from polymerisation pressure to a pressure such that the partial pressure of the monomeric composition to be eliminated is below 120mm of Hg and brought to or kept at a temperature of at least 70‹C but below the temperature at which degredation of the polymer or copolymer commences, and the conditions of pressure and temperature together with the agitation, are maintained until the end of the process, and the polymer is put into contact with a quantity of water representing 0.01-0.8% of its weight after the residual monomeric vinyl chloride content of the polymer or copolymer has been reduced below 2000ppm. Nitrogen may be put in'to contact with the polymer during degassing. The degassed polymer may have a residual monomeric vinyl chloride content of less than 50ppm.