Preparation And Properties Of Continuous Carbon Fiber Reinforced Thermoplastic Composites

Continuous fiber reinforced thermoplastic composites have attracted more and more attention due to their high toughness,short molding cycle and reproducible processing.However,due to the high viscosity of the thermoplastic matrix,the difficulty of infiltrating the fibers by the matrix is raised,and the performance is not well exhibited.Only by improving the impregnation degree of the matrix to the fiber,can be the synergy of the carbon fiber and thermoplastic matrix be fully utilized,and the application of the continuous fiber reinforced thermoplastic composite material is more extensive.In order to overcome the shortcomings of the viscosity of the thermoplastic melt and the difficulty of uniformly impregnating the carbon fiber,this paper uses the laboratory-made fiber-optic device to broaden the carbon fiber tow and then prepare the continuous carbon fiber(CCF)reinforced thermoplastic by electrostatic powder coating.The prepreg tape is obtained by laminating hot melt on the prepared prepreg tape to obtain a CCF reinforced thermoplastic composite material.Built on different matrix materials,unidirectional continuous carbon fiber reinforced nylon 6(CCF/PA6)composites and unidirectional continuous carbon fiber reinforced polyetheretherketone(CCF/PEEK)composites were prepared.The effects of the preparation process on the tensile properties of unidirectional prepreg tapes were investigated.When the PA6 matrix powder has a mass fraction of 25%,a hot pressing temperature of 250 C,and a hot pressing pressure of 1.5 MPa,it has the best performance,and the maximum tensile strength is 1364 MPa.When the PEEK mass fraction is 30%,the hot pressing pressure is 2 MPa,and the hot pressing temperature is 380 C.CF/PEEK has the best tensile properties,the strength is 1125.73 MPa,and its tensile properties are lower than CF/PA6.Further SEM It shows that the thermoplastic matrix impregnates the carbon fiber to a good extent,but because the particle size of the PEEK powder is more important than that of the PA6 powder,the prepreg effect is less than ideal.The unidirectional CCF reinforced thermoplastic composite laminate was prepared by laminating and hot pressing the prepreg tape,and the optimum molding pressure and molding temperature during the molding process of the composite were explored.Finally,the CCF/thermoplastic composite with excellent mechanical properties was successfully prepared..The CCF/PA6 unidirectional plate prepared at a molding temperature of 250 ° C,a molding pressure of 3.5 MPa,and a dwell time of 20 min has the best performance,and the maximum tensile strength is(1.40 ± 0.032)GPa;the maximum bending strength and flexural modulus are(1.37 ± 0.04)GPa and(122.69 ± 7.98)GPa.The CCF/PEEK unidirectional plate prepared at a molding temperature of 380 ° C,a molding pressure of 4.7 MPa and a dwell time of 20 min has the best performance,and the maximum tensile strength is(1.71±0.04)GPa;the maximum bending strength and flexural modulus are(1.82 ± 0.018)GPa and(124.75 ± 2.57)GPa.Scanning electron microscopy showed that there were no obvious pores and bubbles inside the composite,and the matrix and carbon fiber was well impregnated.