High-surface glossiness and high-dimensional stability polyamide composite material and preparation method thereof

Abstract

The invention belongs to the technical field of polymeric composite materials, and particularly relates to a high-surface glossiness and high-dimensional stability polyamide composite material and a preparation method thereof. In parts by weight, the polyamide composite material is prepared from the following components: 30 to 90 parts of polyamide; 5 to 15 parts of semi-aromatic polyamide; 0.1 to 1.0 part of coupling agent; 0.1 to 1.0 part of antioxidant; 0 to 1.0 part of heat-resistant agent; 0.1 to 2.0 parts of lubricating agent; 0.1 to 1.0 part of fluidity-improving agent; 20 to 50 parts of glass fibers; and 0 to 10 parts of filler. The polyamide composite material disclosed by the invention has high glossiness, high fluidity, chemical resistance and good mechanical properties; moreover, after moisture is absorbed, the decrease of the physical properties of the material is little, the dimensional stability is high, wear and abrasion can be resisted, heat resistance is good, and the processability is good.

Description

technical field [0001] The invention belongs to the technical field of polymer composite materials, and in particular relates to a polyamide composite material with high surface gloss and high dimensional stability and a preparation method thereof. Background technique [0002] Polyamide resin has good mechanical properties, chemical resistance, wear resistance, heat resistance and other excellent properties, and has been widely used in automobiles, aerospace, chemical industry, machinery, electronic appliances, sports equipment and other fields. Due to the linear asymmetric molecular structure of traditional polyamide, the molecular chain is in a winding state, so the crystallinity of the material is relatively low, generally only 25%-45%. Due to the existence of hydrogen, oxygen and nitrogen atoms in the polyamide molecules, hydrogen bonds are easily formed between the molecules, resulting in a strong intermolecular force, which makes the material have high strength and hi...

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Problems solved by technology

[0003] However, because polyamide contains amine groups and carbonyl groups, it is easy to form hydrogen bonds with water molecules, so the various materials obtained are easy to absorb water when used, resulting in a plasticizing effect, resulting in volume expansion of the material, a decrease in modulus, and instability in the size of the material.

The poor creep resistance of the material reduces the mechanical properties and poor dimensional stability, which limits the application of the material to a large extent, especially in fields with high mechanical properties and dimensional stability requirements in high-temperature and high-humidity environments. application

At the same time, the surface gloss of glass fiber reinforced polyamide materials is low, and most of them can only be used as structural parts at present. When they are used as exterior parts, they need to be sprayed, which is costly and pollutes the environment to a certain extent.

At present, the floating fibers on the surface of glass fiber reinforced polyamide materials are serious, mainly through the following methods: a. Add a large amount of surface lubricant; b. Add fluidity improver; c. Replace part of mineral fiber or glass beads Glass fiber, in order to improve the surface gloss of PA66, Chinese patent CN104672898A uses glass microspheres to replace part of glass fiber to improve the dimensional stability of the material. Glass microspheres can improve the dimensional stability of the material, but the mechanical properties and heat resistance of the material are not There is a greater impact, and at the same time, the late material has poor dimensional stability due to moisture absorption

CN201210340033.1 Adding the fluidity improver oxalic acid can effectively improve the fluidity of the material, but as a reactive additive, oxalic acid is likely to remain and continue to react in the later stage, resulting in poor flexibility of the material and the problem of later precipitation

There are few studies on the dimensional stability of polyamide caused by moisture absorption in the later stage

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