Cross-linked polypropylene composite material and preparation method thereof

Abstract

The invention discloses a cross-linked polypropylene composite material. The cross-linked polypropylene composite material is prepared by mixing polypropylene, an initiator, a cross-linking agent, a self-cross-linking promoter, a catalyst, a primary antioxidant, an auxiliary antioxidant and other processing aids according to a certain proportion. A preparation method of the cross-linked polypropylene composite material comprises the following steps of: weighing other components except the self-cross-linking promoter and the cross-linking catalyst according to the proportion first, fully mixing in a mixing kettle, and then adding into a twin-screw extruder from a feeding port; and adding the self-cross-linking promoter and the cross-linking catalyst into the twin-screw extruder from a side port of a screw, and then extruding and pelleting to obtain the cross-linked polypropylene composite material, wherein the adding of the self-cross-linking promoter from the side port of the screw is delayed, so that silane is grafted on polypropylene first and then reacts with the self-cross-linking promoter to form preliminary cross-linked polypropylene. The invention has the advantages of overcoming a warm water or steam cross-linking process in the conventional silane cross-linked polypropylene, realizing one-step continuous production, meeting the requirement of injection molding, and solving the problem that the subsequent processing cannot be performed by a radiation cross-linking method, along with excellent mechanical property.

Description

technical field [0001] The invention relates to a cross-linked polypropylene composite material. The invention also relates to a preparation method and application of the cross-linked polypropylene composite material. Background technique [0002] After polyolefin is crosslinked, its scope of use can be expanded. Through crosslinking, its tensile strength, impact strength, heat resistance and chemical resistance are all improved. At the same time, its creep resistance, wear resistance, environmental stress resistance, Cracking performance and bonding performance can also be improved; the traditional crosslinking methods of polyolefin mainly include radiation crosslinking, and chemical crosslinking includes peroxide crosslinking and silane crosslinking. These three types of methods are all applicable to polyethylene, but it is much more difficult for polypropylene crosslinking. The main reason is that there is a tertiary carbon structure in polypropylene molecules, which mak...

AI Technical Summary

Problems solved by technology

This post-crosslinking method avoids the contradiction between crosslinking and processing and molding properties in Chinese patents 00123620.2 and 96104681.3, but there are too many steps and the production process is complicated

[0006] To sum up, traditional irradiation crosslinking has the problems of high investment and difficult control of crosslinking and degradation reactions, while traditional silane crosslinking must be soaked in warm water or steam to complete crosslinking after extrusion modification. The crosslinking speed is very slow, and the thickness of the product also directly affects the crosslinking problem