Polyphenylene sulfide alloying and carbon fiber reinforcing together promote polycarbonate towards superior flame retardant composite with good mechanics

Advanced composite technology is the motive force to develop of high-performance composite materials, which includes the superior flame retardant composite materials with superior physical and mechanical properties. This work reports the flame retardant behavior and mechanism of short-cut carbon fiber (SCF) and polyphenylene sulfide (PPS) in polycarbonate (PC) matrix, so as to their influence on material mechanics. Individually adding SCF already presented visible effectiveness on suppressing PC combustibility. 6SCF/PC achieved a limited oxygen index (LOI) of 30.0 %, and passed UL94 V-0 rating at 3.2 mm thickness. But when the thickness of specimen reduced to 1.6 mm thickness, 6SCF/PC only passed UL94 V-2 rating. The failure of SCF in shortening self-extinguishing time and anti-dripping was overcome by extra introducing PPS to work together with SCF. 20PPS/6SCF/PC passed UL94 V-1 rating at 1.6 thickness, and achieved a LOI of 33.0 %. Meanwhile, the flame retardant mechanism of SCF and PPS in suppressing PC combustibility was investigated from the charring behavior, the thermal decomposition process and volatile release, and the pyrolytic products of relevant composites. Besides, the additive effect of SCF and PPS in improving the char residue retention and flexural stiffness of composites was also confirmed. Polyphenylene sulfide alloying and carbon fiber reinforcing together promote polycarbonate towards superior flame retardant composite with good mechanics.