Chlorinated polyvinyl chloride (CPVC) is prepared from polyvinyl chloride (PVC). When PVC is made utilizing polyvinyl alcohol, the low molecular weight CPVC compound so prepared is colored. A low molecular weight CPVC compound prepared from PVC that was made in the presence of a cellulose ether instead of polyvinyl alcohol resulted in a very low color compound having a DE of 0 by definition. However, a CPVC compound prepared from PVC made in the presence of polyvinyl alcohol resulted in a relatively high color (DE 18.51). During the polymerization of vinyl chloride, polyvinyl alcohol is replaced with the hydroxypropylmethyl cellulose ether having a methoxyl substitution of 15 - 35 percent and a hydroxypropoxyl substitution of from 4 - 35 percent.
氯化聚
氯乙烯(CP
VC)由聚
氯乙烯(P
VC)制备而成。利用聚
乙烯醇制备 P
VC 时,所制备的低分子量 CP
VC 化合物是有色的。由聚
氯乙烯制备的低分子量 CP
VC 化合物在有
纤维素醚而不是聚
乙烯醇的情况下生成,其色度很低,DE 值为 0。然而,用聚
乙烯醇制成的聚
氯乙烯制备的 CP
VC 化合物的色度相对较高(DE 值为 18.51)。在
氯乙烯聚合过程中,聚
乙烯醇被羟丙基
甲基纤维素醚取代,羟丙基
甲基纤维素醚的甲氧基取代度为 15%-35%,羟丙氧基取代度为 4%-35%。