| 摘要 |
Vinyl chloride (co)polymers prepd. by bulk polymn. are vented from residual monomers by bringing the pressure on the monomer compsn., which is to be eliminated from the polymzn., to an absolute pressure less than 0.16 bar; maintaining the agitated polymer at at least 70 c and lower than the degradation temp. of the (co)polymer; keeping those conditions of temp. and pressure until the venting is stopped; and then contacting the polymer with water after the residual monomer content of the (co)polymer has dropped to below 2000 mg/kg. The novel feature is that an anionic surfactant is added to the water, giving (co)polymers with improved sieving properties.
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