High-content fiber-reinforced polyoxymethylene composite material and its preparation method

Abstract

The invention discloses a high-content fiber-reinforced polyoxymethylene composite material and a preparation method thereof. The composite material comprises, by mass, 43.5-76.7wt% of acetal resin, 20.0-50.0wt% of reinforcement fibers after surface treatment, 3-5wt% of novolac, 0.2-0.5wt% of an antioxidant and 0.1-1.0wt% of a formaldehyde absorbent. The novolac is added into the composite material, the motion of polyoxymethylene molecular chains is interfered after mixing of the novolac with polyoxymethylene, the dimension of polyoxymethylene spherocrystals is obviously reduced, the degree of crystallinity is reduced, mobility and dispersity of fibers in resin are promoted, the mechanical property of the prepared high-content fiber-reinforced polyoxymethylene composite material is greatly improved; the used reinforcement fibers are subjected to surface treatment through a coupling agent and the surface modification effect is improved; and the mechanical property of the polyoxymethylene can be improved by using a novel reinforcing material of basalt fibers for reinforcing the polyoxymethylene.

Description

technical field [0001] The invention relates to a polyoxymethylene composite material and a preparation method thereof, in particular to a high-content fiber-reinforced polyoxymethylene composite material and a preparation method thereof. Background technique [0002] POM (Polyoxymethylene), referred to as POM, is the main chain of the molecule containing -CH 2 O-link thermoplastic resin. Polyoxymethylene was produced in the 1960s and is one of the world's top five engineering plastics. Its output ranks third after nylon and polycarbonate. The polyoxymethylene molecular chain is alternately arranged by C-O and twisted into a helical shape. The regular molecular chain structure makes the crystallization speed of polyoxymethylene fast during melting processing, with high crystallinity (about 60-80%), and high tensile strength and bending strength. , The specific strength and specific rigidity are close to metal, so it is called metal plastic, which can replace metal, especia...

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Problems solved by technology

Chinese patent application CN 102161812 A utilizes processed chopped carbon fibers to reinforce polyoxymethylene, and also improves the wear resistance of polyoxymethylene composite materials, but the use of carbon fibers alone increases the production cost of polyoxymethylene, and due to the low density of carbon fibers, continuous During the processing of fiber-reinforced polyoxymethylene resin, it is more difficult to increase the content of carbon fiber. Generally, the content of carbon fiber in traditional carbon fiber-reinforced polyoxymethylene composite materials can only be increased to 20%, and the distribution of carbon fibers is uneven, forming agglomerations. At the same time, because The high crystallinity of polyoxymethylene greatly reduces the notched impact strength of carbon fiber reinforced polyoxymethylene composites

[0006] Continuous fiber-reinforced polyoxymethylene composites are now industrialized products. However, due to the simple and regular molecular chain structure of polyoxymethylene, the crystallization speed is fast and the crystallinity is high. In fiber-reinforced polyoxymethylene composite materials, due to the non-phase In a compatible system, macroscopic phase separation occurs in the blend, and polyoxymethylene molecular chains can freely enter the crystal lattice to form spherulites without hindrance. Incompatibility, the fibers can only be dispersed in the amorphous area, and cannot be evenly distributed in the material, resulting in a decline in the performance of high-content fiber-reinforced polyoxymethylene composites, and the accumulation of fibers increases the processing difficulty or even cannot be processed. , it is difficult to prepare high-content fiber-reinforced polyoxymethylene composites

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