Viscous polystyrene solns - removed of volatiles

摘要

Volatile materials are sepd. from viscous solns. of styrene polymers and volatile aromatic solvents obtd. by the polymerisation of styrene in soln. by injecting into the soln. of styrene polymer a proportion of water, between 0.50 and 2.75% pref. approx. 1.5% (in proportion to the wt. of styrene polymer) in a zone for eliminating volatiles, held at a pressure below that of the injection zone and at a temp. above the b.pt. of the viscous polymer soln. at the lower press. in order to volatileise the volatile solvents and the water; the volatiles are removed from the zone, to leave a styrene polymer free from volatiles, which is then removed from the chamber. The polymer soln. foams in the volatile elimination zone, and is pref. submitted to a mechanical shearing before discharge. The volatiles may be recovered.