Influence of matrix molecular weight and processing conditions on the interfacial adhesion in bisphenol-A polycarbonate/carbon fiber composites

Abstract

The adhesion of bisphenol-A polycarbonate, an amorphous thermoplastic, to carbon fiber was studied by varying both the intrinsic and the extrinsic properties such as the molecular weight, processing conditions, and test temperature. It was seen that processing methods and conditions had a significant effect on adhesion as measured by the interfacial shear strength. Commercial grade Lexan 141 solvent deposited onto carbon fibers showed poor adhesion when processed below the glass transition temperature and reached a limiting value at a higher temperature. Melt consolidated pure polycarbonate specimens showed increases in adhesion both with increasing processing temperature and with time. Pure polycarbonate having a molecular weight above the critical molecular weight exhibited a higher adhesion at different processing conditions, while for polycarbonate below the critical molecular weight adhesion was poor and unaffected by the processing temperature. Increases in temperature lowered the adhesion as a result of the dependence of adhesion on the matrix modulus, which decreases with increasing temperature.

Effect of surface oxygen content and roughness on interfacial adhesion in carbon fiber–polycarbonate composites

“…The carbon ber reinforced thermoplastic polycarbonate composites were fabricated from the amorphous resin and the carbon bers by compression molding. The choice of the molecular weight of the polycarbonate resin and the time and temperatures for the consolidation were decided based upon the previous work done with this ber-matrix system in our laboratory [30]. In that study, it was shown that the higher molecular weight of the polymer matrix resulted in higher interfacial adhesion than compounded grades with a high degree of polydispersit y or additives and stabilizers.…”

Study on long fiber–reinforced thermoplastic composites prepared by in situ solid‐state polycondensation

“…Drzal and coworkers4 reported a similar experimental result in which an improvement in the interfacial adhesion was achieved with increasing molecular weight of the BPA–PC. They explained it as that the improvement in the level of adhesion with higher molecular weight was attributed to the formation of a beneficial interphase in which the PC experienced stronger adsorption.…”

“…All of these processes adapt the high molecular weight resin to impregnate reinforcing fibers, for which the most serious problem exists as to how the wetting between the matrix resin and the reinforcing fiber may be improved. Several investigations have been carried out to address this issue 2–4. Blends of poly(ethylene terephthalate) (PET) and epoxy have been used as matrix materials for continuous‐fiber–reinforced composites 5.…”

Dielectric investigation of interphase formation in composite materials. I. Ionic conductivity and permittivity exploration

“…Interface and interphase formations were studied during processing, under given temperature and pressure conditions. Some previous observations have shown the influence of matrix properties and processing conditions on the interfacial adhesion of carbon-fiber composites 16 and glass-fiber composites. 17 In the same vein, we mentioned in a previous work 18 the effects of the process conditions on interfacial shear stress (IFSS), as measured by the microdroplet pullout test.…”