1 PVC copolymer
If the composition of PVC (vinyl chloride) and other monomers copolymer contains polar or large group composition, the thermal deformation temperature of the copolymer increases accordingly, and the heat resistance is better than PVC, so the heat-resistant product is prepared. The softening temperature of PVC is 78 DEG C, while the softening temperature of copolymer of vinyl chloride, vinylidene chloride, vinyl chloride, methyl methacrylate, vinyl chloride and acrylonitrile is 100~130, 85 and 140~150 DEG C, respectively.
2, PVC chloride
Chlorinated polyvinyl chloride is prepared by chlorination of PVC resin with a chlorine content of 62%~68%. Chlorinated polyvinyl chloride can be used continuously at 100 DEG C (higher than PVC, 20~35 DEG C), and the maximum service temperature is up to 100~ 105 DEG C. The chemical stability, flammability and cold resistance are better than PVC. But chlorinated equipment needs strict corrosion protection. The resin is not easy to be processed and has a bad impact toughness, which restricts its application and development.
3, PVC crosslinking
Crosslinked PVC can be obtained by radiation crosslinking and chemical cross-linking. Compared with ordinary PVC products, crosslinked PVC products have higher mechanical strength, good dimensional stability, good heat resistance, wear resistance and chemical resistance. Radiation crosslinked wires can be used continuously at 100~110 degrees centigrade.
4, PVC and other polymer blends
PVC blends with other polymers in a certain proportion, and the properties of the blends (fully compatible) are better than those of PVC. Because the miscibility of the two polymers after mixing, can reach the molecular level of mutual melting, forming a single-phase structure, so that the properties of the blends are supplemented and enhanced, such as PVC/PS, PVC/PE, PVC/CPVC and so on.
5. Heat resistance modifier
Heat resistant modifier is a kind of polymer which has high heat resistance for the development of PVC heat resistance.
Polyglutarylamine: the reaction of methyl methacrylate and CH3NH4.
SMA (styrene maleic anhydride copolymer) is a better PVC heat resistant modifier introduced by American manufacturers.
Ht-510 (day) is an acrylic series amine-based copolymer.
S700N is a copolymer of alpha-methylstyrene-acrylonitrile.
ABS type heat resistant modifier: A15, A50B, A10 (Japanese zhong yuan).
MBS type heat resistant modifier: mitsubishi H602, 605, 632.
Also, ELIX200, 300;
GE Blendex 702, 703, 586, 975, etc.
Add inorganic filler to PVC
After adding a certain amount of filler, it can improve the heat resistance of PVC.
The commonly used fillings include: heavy calcium carbonate, light calcium carbonate, precipitation calcium carbonate, calcined pottery, barium sulfate, red mud, titanium self-powder, etc.
Add fiberglass to PVC
Adding 20% ~ 30% glass fiber, PVC in without (or less) under the condition of plasticizer, its heat resistance can be increased to more than 100 ℃.
In particular, the thermal deformation temperature of PVC with long fiber reinforced is more obvious.