关键词: 聚苯硫醚, 玻璃纤维, 热压工艺优化, 正交试验, 破坏机理

Abstract: In recent years, glass fiber/polyphenylene sulfide (PPS) composites have received widespread attention due to their superior mechanical strength and dimensional stability. Glass fiber fabrics exhibit exceptional strength, particularly in the tensile direction, along with excellent electrical insulation properties, and they maintain their strength and stability even in high-temperature environments. PPS films are hard and brittle, with a high degree of crystallinity, excellent creep and fatigue resistance, and electrical insulation properties. Combining these two materials can achieve overall lightweighting of the composite material. Common preparation processes include melt blending and hot-pressing molding. Melt blending for the preparation of PPS composites allows for continuous production; however, it is not suitable for manufacturing large flat composite panels. Hot-pressing molding is a promising alternative method that can broaden the application scope of PPS-based composites. Therefore, in this study, glass fiber fabrics and PPS films were laminated and hot pressed to prepare glass fiber/PPS hot-pressed composites. For the experimental design, a three-factor, three-level orthogonal experiment was conducted, with hot-pressing times ranging from 10 to 30 minutes, temperatures from 310 to 330 degrees Celsius, and pressures from 1 to 3 MPa. Mechanical property tests were conducted on the composites prepared through the orthogonal experiment to investigate the effects of hot-pressing time, temperature, and pressure on the mechanical properties of the composites. Subsequently, range analysis and variance analysis were conducted on the results of the orthogonal experiment to determine the optimal hot-pressing process. The conclusions drawn were that time exerted a significant influence on the tensile strength of the composites, while temperature had a significant impact on the flexural strength of the composites. The optimal tensile properties of the composites, with a tensile strength of 125.6 MPa, were achieved at the process parameters of 320℃, 2 MPa, and 20 minutes. For optimal flexural performance, with a flexural strength of 219.3 MPa, the process parameters were 330℃, 1 MPa, and 10 minutes. To further validate the effect of the optimal process on the composite mechanical properties, two additional sets of composites were prepared under the optimal process conditions and then tested for mechanical properties. By investigating the failure mechanisms of the composites, it was discovered that the tensile failure modes of glass fiber/polyphenylene sulfide composites include fiber pullout, matrix brittle fracture, matrix shear failure, and fiber bundle fracture. After optimization, there was minimal fiber pullout during tensile failure, reduced shear failure, and neat fracture of fiber bundles, resulting in a 32.4% increase in tensile strength of the composites. The flexural failure modes include compressive failure on the upper surface, tensile failure on the lower surface, and interlayer delamination. After optimization, the fibers and resin layers of the composites were tightly bonded, and the degree of resin infiltration into the fiber layers was effectively enhanced, leading to a 33.9% increase in flexural strength. This paper identifies the optimized process conditions for tensile and flexural strength of glass fiber/polyphenylene sulfide composites through orthogonal experiments, and further explores the failure mechanisms of the composites. It provides theoretical and experimental references for the performance improvement and development of polyphenylene sulfide/glass fiber composites.

Key words: polyphenylene sulfide, glass fiber, hot-pressing process optimization, orthogonal experiment, failure mechanism