Simultaneously improving the toughness and stiffness of wood flour/polypropylene composites using elastomer A669/talcum blends

It is important for wood plastic composites to possess satisfactory toughness and stiffness in practical applications, such as construction formworks. In this study, an elastomer-grafted polyolefin (A669) was introduced to improve the toughness of wood flour/polypropylene (WF/PP) composites, with talcum powder used as the reinforced phase to maintain the flexural strength and stiffness of the WF/PP composites. The impact strength and bending properties of the composites were tested. Differential scanning calorimetry, dynamic mechanical analysis, and scanning electron microscopy were used to analyze this composite system. Test results show that the combination of A669 and talcum powder can provide the WF/PP composites with both good toughness and flexural properties. The optimum additions of A669 and talcum powder were 6% and 9%, respectively. Talcum powder plays an important role in the heterogeneous nucleation, which is helpful for increasing crystallinity and improving flexural properties. However, this function could be offset by the addition of A669. The WF/PP composites with elastomer A669 and talcum powder present more viscosity characteristics and rougher fracture surfaces. In addition, the WF/PP composites containing elastomer A669 and talcum powder have better processability. POLYM. COMPOS., 40:1335-1341, 2019. (c) 2018 Society of Plastics Engineers