Wear and mechanical properties of reactive thermotropic liquid crystalline polymer/unsaturated polyester/glass fiber hybrid composites

Abstract

To improve the performance of unsaturated polyester (UP) under cold-heat alternate temperature, selfsynthesized reactive thermotropic liquid crystalline polymer (TLCP)-methacryloyl copolymer (LCMC), UP, and glass fiber (GF) hybrid composites was prepared by molding technology. The apparent activation energy and crystal behavior analysis of LCMC/UP blends were investigated by Differential scanning calorimetry and X-ray diffraction (XRD), respectively, the results showed that the addition of LCMC can reduce apparent activation energy and accelerate the curing reaction of UP, the XRD analysis indicated that the crystal phase of LCMC still exist in the blends after blending with UP. The effect of LCMC content on the properties of LCMC/UP/GF hybrid composites such as impact strength, bending strength, and ring-on-block wear were also investigated through static mechanical tests and wear tests. The mechanical properties of hybrid composites increased significantly because of the addition of LCMC. The wear tests showed that LCMC can improve the wear resistance of the UP/GF/LCMC hybrid composites even though the content of LCMC was at a relatively low level (5-7.5 wt %). This makes it possible to develop novel kind of UP-based materials with good wear resistance for various applications. The Worn surface was observed by scanning electron microscopy (SEM) and the mechanism for the improvement is discussed in this paper.

Mechanical Properties and Morphology Studies of Thermosets from a Liquid‐Crystalline Epoxy Resin with Biphenol and Aromatic Ester Groups

“…The maximum impact strength of M1 /DGEBA was 2.77 kJ · m −2 , which was 35% higher than that of pure DGEBA. Since impact strength reflected the energy consumed before fracture, the results in Figure 4 demonstrated that DGEBA could obviously induce impacting crack deformation of the surrounding matrix networks to a certain extent after the introduction of M1 and M2 35. Moreover, the impact strength of the composites decreased after certain content of M1 and M2 because the compatibility of the components became worse and the interaction among them became weaker in the curing networks.…”

Rheological, Dynamic Mechanical and Thermal Properties of Thermotropic Liquid Crystalline Polymer/Unsaturated Polyester/Glass Fiber Hybrid Composites

“…The decrease of E of composite containing 10% LCMC attributes to the worse compatibility between LCMC and matrix. 11 It is apparent that the changes in the E values show significant fall at temperatures between 50 and 150 C. The detailed values of storage modulus at temperatures of −100, 0, and 100 C were listed in Table I. It can be seen that the E values of hybrid composites containing LCMC are higher than that of hybrid composites without LCMC under the three temperature points.…”

Friction and wear behavior of glass fabric/phenolic resin composites with surface‐modified glass fabric

“…Among fabric composites, GF is widely employed and costs very little in comparison with other advanced fabrics such as carbon fabric and Kevlar fabric. Moreover, glass fiber/fabric, exhibiting high tensile strength and tensile modulus as well as good thermal conductivity, has been widely used to promote the wear resistance and mechanical properties of various polymer–matrix composites 13–15. For example, glass fiber has been attracting much attention in the modification and reinforcement of polytetrafluoroethylene because of its good thermal stability and relatively low cost 14, 15…”

“…In addition, the physical–chemical interactions between the fiber and resin at the fiber–resin interface play an important role in the mechanical and tribological properties of fabric composites. There are some defects in glass fiber, such as poor compatibility with adhesive resins and a large friction coefficient 14–16. Many surface modification methods for glass fiber, such as the use of coupling agents and plasma treatment, can improve interfacial adhesion between the glass fiber and polymer matrix.…”

“…Many surface modification methods for glass fiber, such as the use of coupling agents and plasma treatment, can improve interfacial adhesion between the glass fiber and polymer matrix. The improved interfacial adhesion can enhance the mechanical or tribological properties of surface‐modified glass‐fiber‐reinforced polymer–matrix composites 14, 15, 17–20. Therefore, we treated GF with plasma bombardment and β‐aminoethyltrimethoxylsilane (OB551) to endow a GF/phenolic composite with good tribological properties.…”