Molding Process And Research Of Carbon Fiber Fabric Reinforced Thermoplastic Composite

Thermoplastic composite materials is a kind of promising hot composite materialand it offer unique performance advantages. As a general plastics, Polypropylene (PP)have comprehensive performance, can be used as automobile composite matrix inlarge amounts. As a special engineering plastics, Polyphenylene sulfide has excellentmechanical properties, molding performance and other properties, can be used ascomposite matrix for aviation in large amounts. This paper aims at using the filmstacking technique to prepare carbon fiber fabric reinforced Polypropylene(CFF/PP)and Polyphenylene sulfide (CFF/PPS) laminates. A series of composite laminates(CFF/PPS or CFF/PP) were prepared by compression-molding processing. Thecharacterizations on the properties of those laminates were conducted by DSC, SEM,and DMAtest.In this study, the effect of maleic anhydride grafted polypropylene (MAPP)coupling agents addition into PP matrix on the mechanical properties of compositeand the interfacial adhesion between CFF and PP matrix were investigated. WhenMAPP/PP was10%,the composite’s tensile strength and impact strength achievedoptimum performance,and the improvement were not so much. When MAPP/PP was15%, the composite’s flexural strength and interlaminar shearing strength achievedoptimum performance, and it’s a great improvement.The modification of PP by MAPP, can improve the performance of CFF/PPcomposites, but the excess of MAPP has a negative effect on the performance. Basedon the enlightenment of prepreg about thermosetting resin. MAPP can be dissolved bysome hot organic solvent and will be separated out from the solution in small particlesform when temperature reduces, so this characteristic of MAPP could be used in preparation of prepreg of thermoplastic (CFF/M-x). Then using CFF/M-x to prepare aseries of laminates by film stacking technique. The properties of those laminates wereanalyzed, compared the modification of PP, it’s tensile strength, bending strength,impact strength and interlayer shear strength were obviously improved, especially thetensile strength increased2times.Also the relationship between the deformation of woven carbon fabric,theinterface strength and mechanical properties of composites was studied in this paper.Use PP and M-PP-10to achieve two different interface bonding strength, and throughchange the regularity of the carbon fiber fabric in the composites artificially, we gottwo kinds of composite with different interfacial bonding and similar fabricdeformation. It was found that the deformation of CFF was badly impact compositestrength especially in a condition of good interface bonding strength.In view of the CFF/PPS aviation composite.CFF/PPS’s non-isothermalcrystallization kinetics and induced crystallization behavior were mainly studied inthis paper. The results shows that the cooling rate have obvious effect on thecrystallization of PPS. Between the rate of10k/min and70k/min,with the speeding upof the cooling rate CFF/PPS’s starting crystallization temperature and crystallizationpeak temperature were moving to low temperature direction. Also grain size andcrystallinity were decreased, and it’s toughness and mechanical properties wereimproved. The results showed that The best cooling rate can improve the flexuralmodulus and impact strength by about23.8and15.1%respectively.A trans-crystallization layer around CF could be observed by polarizing opticalmicroscopy (POM), which proved the nucleation effect of carbon fiber surface on thecrystallization of PPS. During the crystallization of CFF/PPS, trans-crystallizationlayer was developed around CF under an extra load pressure. When CF was coated bySKE1also can induced trans-crystallization layer around fibers. trans-crystallizationchanged the interface structure of complex system, increase the interfacialcompatibility and the stress transfer between fibers and matrix, finally significantlyimprove the mechanical properties of the composite material.