A novel waterborne g-CPP sizing agent for the interfacial enhancement of SCF/PP composites

To enhance the interfacial adhesion of short carbon fiber (SCF) reinforced polypropylene (PP) composites, a new modified chlorinated polypropylene resin (g-CPP) was synthesized and utilized to manufacture the sizing agent for SCF. The findings of thermogravimetric analysis and differential scanning calorimetry showed that g-CPP had high thermal characteristics, with its glass transition temperature (Tg) raised by 11°C.The g-CPP sizing agent that has been developed has increased storage stability (particle size was 109.8 nm). The contact angle of SCF was reduced from 81.52° to 60.04° after sizing, and the surface free energy was raised from 29.31 mN/m soared to 47.13 mN/m. The SCF/PP composites with 1 wt% sizing agent demonstrated the best interfacial adhesion, with improvements in flexural and tensile strengths of 54% and 39%, respectively. The interfacial reinforcement mechanism of sizing agent to improve interfacial adhesion was investigated. This work proposes an attractive way for the future preparation of high-performance SCF/PP composites.