Development of hybrid composites reinforced with biocarbon/carbon fiber system. The comparative study for PC, ABS and PC/ABS based materials

A PC/ABS blend was used to prepare hybrid composites reinforced with the use of a biocarbon/carbon fiber (BC/CF) system. The purpose of using blends of this type was to reduce the degradation of PC during the blending processes, which turned out to be effective already at 40% ABS in the blend structure. TGA analysis and rheological measurements confirmed that the addition of ABS in the matrix structure allowed reduction of PC hydrolytic degradation. The decrease in DTG peak value for the PC/20BC composite is even 50 °C, whereas for the ABS/20BC sample the peak values were the same as reference pure ABS. Izod tests showed that the impact resistance for ABS/BC composites was more than twice as high as PC/BC materials, 37 J/m to 13 J/m respectively. For PC/ABS composites, the addition of ABS in the structure also served to improve impact resistance. The main purpose of the hybridized reinforcement application was the reduction of thermal expansion in the material and homogenization of the fibrous CF structures. For reference PC/20CF samples the difference in CLTE values is over 1000%, while for PC/20(BC-CF) hybrid composites it is reduced below 300%. Detailed analysis of the expansion characteristics, carried out by TMA methodology, showed significant improvement in the isotropy of hybrid materials, which was also confirmed by structural observations. The improvement of process stability as well as excellent thermomechanical parameters indicates that biocarbon can be an excellent additive for standard fibrous reinforcement, limiting the phenomenon of structure anisotropy.