Glass fiber reinforced polypropylene composite material and preparation method thereof

Abstract

The invention relates to a glass fiber reinforced polypropylene composite material and a preparation method thereof. The composite material comprises the following raw materials in parts by weight: 50-80 parts of polypropylene, 10-50 parts of short glass fiber reinforcement, 5-10 parts of interface compatilizer and 0.5-3 parts of micro-structure adjustment auxiliary. In the invention, the glass fiber reinforcing systems different in structure and diameter are matched to form an organic-inorganic two-phase reinforcing system with uniform distribution and good interface bonding under the auxiliary effect of efficient interface compatibilization and quick crystallization nucleation; the warping deformation of the obtained polypropylene composite material is reduced by 30-60% compared with a traditional material; particularly, the behaviors of the low-content glass fiber reinforcing system are more outstanding; the rigid indexes of the material such as bending strength and bending modulus are improved by 30%; and meanwhile, the material shrinkage is lower, and the dimensional stability is excellent in high- and low-temperature environments.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, and in particular relates to a glass fiber reinforced polypropylene composite material with low warpage, high dimensional stability and high rigidity and a preparation method thereof. Background technique [0002] Polypropylene PP is a widely used general-purpose plastic. It has excellent comprehensive performance, molding processability, and relatively low price. Adding glass fiber GF can not only effectively make up for the performance defects of polypropylene, but also further reduce material costs. It is currently One of the focuses of the modification of polypropylene materials for automobiles. [0003] With the increasing demand for lightweight and environmental protection of automobiles, the cost-effective glass fiber reinforced thermoplastic composite material is an ideal solution. It has the characteristics of simple processing, easy injection molding, and uniform fiber distrib...

AI Technical Summary

Problems solved by technology

Taking the front-end frame as an example, small passenger cars with relatively low performance requirements and higher output have gradually adopted glass fiber reinforced thermoplastic pellets that can be injection molded. An outstanding example is the long glass fiber reinforced material LFT, but due to the The fiber content is long, which requires high requirements on the gate, flow channel and structural design of the mold during part molding, and the processing output is low and the cost is high, which is not conducive to large-scale promotion in automobiles, and these are short glass fiber reinforced materials The advantage of SFT

[0004] However, the defects of short glass fiber reinforced polypropylene composites are also very prominent. The most obvious is that the distribution length of the reinforcing fibers contained in the particles is too short (05-0.8mm), which is much lower than that of long glass fiber reinforced polypropylene. Therefore, not only is the fiber reinforcement effect and material mechanical properties significantly lower, but the overall support effect on injection molded parts is also very limited, and the products are easy to warp and deform, especially when used for some low thickness ( ≤2mm) large flat parts such as bottom guard, engine compartment cover, trunk cover, etc. are particularly prominent

Therefore, traditional solutions such as shallow sink marks and low warpage glass fiber reinforced polypropylene materials described in CN201210281373 use isotropic mineral fillers to partially replace one-dimensionally oriented glass fiber reinforcements, although it can improve its The degree of deformation of the material, but the use of mineral powder with a relatively effective reinforcement effect reduces the rigidity and strength of the material to a certain extent; CN201310465800 also uses a similar solution, although the reinforcement effect of glass fiber powder is better than that of mineral systems, but The loss of length keeps the overall mechanical properties of the material at a relatively low level; existing cases have shown that the introduction of an isotropic powder system can improve the orientation of fiber reinforced materials to a certain extent, but partially reduce the mechanical properties of the material. Performance is at the expense of performance, and its modification focuses solely on fiber reinforced systems, while ignoring the overall effect of fiber reinforced composites, especially the effect of matrix modification. Therefore, this cannot really respond to the current automobile "substituting plastic for steel" The lightweight trend of the core demand for high-performance glass fiber reinforced polypropylene products used

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