Abstract: Blocky chlorinated polyolefins are disclosed as compatibilizers of PVC and/or CPVC resins with polyolefin elastomers. The blocky chlorinated polyolefins facilitate the dispersion of the elastomers as a dispersed phase with the proper size for impact modification of the PVC and/or CPVC. The blocky chlorinated polyolefin provides better adhesion between the elastomer and the PVC and/or CPVC providing better physical properties such as impact strength as measured by Notched Izod and variable height impact testing (VHIT) than did the randomly chlorinated polyolefins, often used as processing aids and as impact modifiers in PVC or CPVC. The differences in properties achieved with blocky chlorinated polyolefins versus randomly chlorinated polyolefins are attributed to the individual blocks of the blocky polyolefin being compatible (and/or co-crystalizable) with either the polyolefin elastomer or the PVC/CPVC resulting in better adhesion between phases.

Abstract: A novel chlorinated poly(vinyl chloride) ("CPVC") resin is prepared by a two-step process which uses an organic peroxide catalyst rather than a source of actinic light. The novel two-step "photoless" process yields a CPVC ("two-step CPVC") which, even at 72% Cl, is easily fusible at 170.degree. C. It is now possible to extrude and injection mold parts with exceptional heat distortion properties attributable to the higher Cl content of the resin. The key distinguishing characteristic over a CPVC made in the presence of a distinct liquid chlorine phase, which CPVC is the most closely comparable CPVC, is when lines are drawn connecting points for measured T.sub.g s as a function of Cl content, for each type of CPVC. The slope of a line for two-step CPVC is about 15% less than the slope of a line for CPVC produced by a process in which excess chlorine is present as a distinct liquid phase.

Abstract: A two-step process for the post-chlorination of PVC homopolymer and other predominantly vinyl chloride-containing polymers is disclosed, which process produces chlorinated PVC ("CPVC") containing at least 70% by weight Cl, in a fast, but controllable, aqueous, two-step process catalyzed using an organic peroxide catalyst instead of actinic radiation. Less than 10% excess Cl remains after the second stage, even when 75 wt% Cl CPVC is made. In the first step, an aqueous slurry of PVC is chlorinated in the absence of liquid chlorine and free oxygen, preferably at a starting temperature in the range from about 30.degree. C. to 75.degree. C., in the presence of at least an essentially stoichiometric amount of chlorine required to make the desired Cl content in the end product, and, a catalytic amount of the peroxy catalyst, at least sufficient to produce `first step CPVC` having an intermediate Cl level of chemically bound Cl in the range from 67% to 72% by weight. The temperature is maintained below the T.sub.

Abstract: A chlorinated copolymer made from vinyl chloride monomers and vinyl containing comonomers such as vinyl acetate has good low (e.g., about 120.degree. C.) and high (e.g., about 170.degree. C.) temperature stability as measured by hydrogen chloride elimination. The copolymer is made by suspension polymerizing vinyl chloride monomers (from about 70 to about 95 percent by weight) and vinyl containing comonomers (from about 5 to about 30 percent by weight) and subsequently chlorinating the copolymer to add chloride sites to the vinyl chloride units as well as to the comonomer units such as vinyl acetate. After chlorination, the copolymer is subjected to a heat treatment chlorination process whereby the stability of the copolymer is dramatically improved. The heat treatment chlorination process comprises heating the copolymer to temperatures generally in excess of 100.degree. C. to degrade the resin whereby hydrogen chloride is liberated and then chlorinating the resin by adding pressurized chlorine thereto.

Abstract: Ethylene and propylene copolymers and terpolymers are modified by addition of up to about 20% of crystalline polypropylene in order to reduce plastic flow which said copolymers and terpolymers undergo during storage but without significantly altering original physical properties thereof.