Study Of Properties And Foaming Behaviors Of Chopped Carbon Fiber Reinforced PC/PS Composites

Carbon fibers(CF),the current hotspot research in reinforced material,can significantly improve the strength and lightweight of composite material.But the sizing agents affected its applications.CF/PS composites has excellent strength,but the poor toughness restricts its applications.PS/PC alloys has good molding performance and combine the advantages of two polymers,but the compatibility between two polymers is poor.Composite materials can expand the properties of materials,but the microcellular foaming properties of composite materials still face difficulties in molding and applications.In this paper,the carbon fiber surface treatment,the CF/PS and PS/PC composite materials and the foaming behavior of the composite materials are studied.The research has important theoretical and engineering significance.The research contents of this paper is as follows:(1)Two types of surface degumming methods of carbon fiber were studied,atmosphere protection heat treatment and organic immersion degumming.Byinvestigating the weight loss ratio and microstructure,the most effective the degumming method was heat treatment for 1.5 hours at 450?.Carbon fiber was oxidized by liquid-phase oxidation.Through Raman spectra analysis,FTIR measurements and SEM observation,liquid-phase oxidation can etch the grain on the fiber surface and increase the strength of hydroxyl and carbonyl groups,which can improve combination between fiber and plastic matrix.(2)CF/PS composites with mass fractions of 5%-20%were prepared and the properties of the composites were studied.Through the analysis of mechanical properties,melt flow properties,thermal properties,and microscopic morphology,the reinforcement mechanism of carbon fibers was revealed.When the CF content is 20%,the tensile strength of the composite is increased by 98.9%,the flexural strength is increased by 50.4%,the impact strength is increased by 34.69%.When CF content is 15%,the toughening effect and mechanism of domestic toughening agent,K resin and modified PS were studied.The results show that the addition of domestic toughening agent and K resin can increase the impact strength by 10%,and the modified PS improves the impact strength by 17.29%.(3)The mechanical properties and micro-morphology of PS/PC blends with different ratios were studied.For 60/40 PS/PC blends,the compatibilization and its mechanisms of EMA,SMA,MBS,MS were studied.The results showed that the tensile strength and flexural strength of PS/PC blends were not significantly improved when the PC content was less than 50%.After the PC content exceeds 60%,the mechanical properties of the composite material were greatly improved.With the increase of PC content,the impact strength of the blended material decreases first and then increases.When the PS/PC is 30/70,the impact strength of the composite material increases by 68.31%.Four kinds of compatilizer both can improve compatibilization.Proper addition can significantly increase the impact strength of composites.(4)Foaming samples of pure PS,CF/PS,pure PC and PS/PC were prepared by solid-state intermittent foaming.By measuring the foaming ratio,cell density,cell diameter,and cell structure of the sample,the effects of fiber content and foaming process parameters were studied.The results showed that the pure PS and CF/PS can obtain better effect of foam between 110?-140?.The more fiber content,the more difficult the microporous foaming.There are differences in cell diameters of different areas for PC foam sample.The edges of the sample are non-cell areas,the center area is a large cell area,the area between the edge and the center is a transition zone.PS/PC blending ratio of 10/90 and 90/10 can obtain good foam structure.The number of foam cells in PS/PC blending ratio of 30/70 and 70/30 was low,and the foam cells are in series.So,the foaming effect was poor.Through the above research,this paper developed the degumming process of short carbon fiber,and revealed the strengthen mechanism of CF.The toughness of CF/PS composite and compatibilization of PS/PC was improved a lot.The foaming mechanism was revealed by the research of solid-state intermittent microcellular foaming process for pure material and blends.These research provide valuable theories for the application of the studied materials.