Effect of nano-OMMTs on mode I and mode II fracture toughness of continuous glass fibre reinforced polypropylene composites

Abstract

Abstract The influence of nano-organic montmorillonites (nano-OMMTs) on mode I and mode II interlaminar fracture toughness of continuous glass fibre reinforced ammonium polyphosphate polypropylene (CGF/PP/APP) composites was experimentally studied in this paper. Nano-OMMTs modified CGF/PP/APP unidirectional prepreg composites were fabricated by hot-melt impregnation process. To investigate the effect of nano-OMMTs on the interlaminar fracture toughness of composites, double cantilever beam (DCB) test and end-notched flexure (ENF) test were conducted to obtain the mode I initiation interlaminar fracture toughness (GIC init.), mode I propagation interlaminar fracture toughness (GIC prop.), and mode II initiation interlaminar fracture toughness (GII C init.) of samples, respectively. Through comparison against to the neat CGF/PP/APP composites, with the addition of 6.5\u202fwt% nano-OMMTs into PP matrix, the GIC init., GIC prop., and GII C init. of composites can be enhanced from 0.502\u202fkJ/m2, 0.746\u202fkJ/m2 and 0.623\u202fkJ/m2 to 0.712\u202fkJ/m2, 1.119\u202fkJ/m2, and 1.195\u202fkJ/m2, respectively. Finally, it was found that nano-OMMTs in matrix can act as “pins”, which could absorb energy in the forms of nano-particles pullout and enhance the interlaminar fracture toughness values in DCB and ENF tests.