PVC impact modifiers sometimes also function as plastic […]
PVC impact modifiers sometimes also function as plasticizers, so they can also be regarded as plasticizers. The impact modifiers for PVC resins are as follows:
At present, CPE is the dominant impact modifier in China, especially in the production of PVC pipes and profiles, most of which use CPE. The amount added is generally 5-15 parts. CPE can be used in combination with other toughening agents, such as rubber, EVA, etc., but the rubber additives are not resistant to aging.
CPE impact modifier selection
Domestic CPE models are generally identified by 135A, 140B, 239C, etc., where the first digits 1 and 2 represent the residual crystallinity (TAC value), 1 represents a TAC value of 0-10%, and 2 represents a TAC value of >10. %, the second and third digits indicate the chlorine content, such as 35 means the chlorine content is 35%, and the last digit is the letter ABC, which is used to indicate the molecular weight of the raw material PE, A is the largest and C is the smallest.
The influence of molecular weight: CPE A type material has the largest molecular weight and large melt viscosity. Its viscosity is the best match with PVC. It has the best dispersion effect in PVC and can form an ideal network-like dispersion form. Therefore, C-type A material is generally selected. Made of PVC modifier.