EMULSION POLYMERIZATION OF VINYL CHLORIDE WITH REDOX INITIATOR SYSTEM COMPONENTS AND EMULSIFIER PREPARED BEFORE MONOMER ADDITION

摘要

Vinyl chloride is polymerized or copolymerized by (a) mixing water, an emulsifying agent and a redox catalyst comprising sulphate and sulphite and an activating metal ion, (b) allowing these to interact for 10 minutes to 3 hours and (c) adding monomer and polymerizing narrow range particle size are reproducibly obtained. Emulsifiers are ammonium, sodium or potassium alkyl sulphates. The catalyst may be a mixture of ammonium, sodium or potassium persulphate with a bisulphite, sodium formaldehyde sulphoxylate, sulphur dioxide, a thiosulphite, or diethyl sulphite the activating metal may be a trace-impurity in water. A buffer such as sodium bicarbonate is also added. The mixture is preferably heated to 40-60 C. for 15-45 mins. and the monomer then added. In one example a copolymer with vinyl acetate is produced.