聚丙烯/木粉复合材料的制备及其力学性能的研究

Study on Mechanical Properties of Polypropylene/Wood Flour Composites and Its Preparation

以聚丙烯为基体,木粉为填料,采用机械共混、二次挤出共混和注塑成型方法制备不同木粉含量的PP/木粉复合材料,并且测定了PP/木粉复合材料的力学性能。实验结果表明:随着木粉用量的增加,复合材料拉伸强度逐渐增大;木粉用量为60%时,复合材料拉伸强度达到最大值36.04 MPa;木粉用量为80%时,复合材料拉伸强度降低到34.60 MPa。木粉的含量由20%增加到80%,复合材料弹性模量由579.12 MPa增加到869.80MPa,断裂伸长率从18.92%降低到7.39%,冲击强度由9.33 kJ/m2降低到7.76 kJ/m2。这是因为PP/木粉复合材料体系中随着木粉含量的增加,木粉起到了应力集中的作用,使材料变脆,冲击强度降低。

Polypropylene/wood flour composites materials with different wood flour content were prepared by mechanical blending, secondary-extruded blending and injection molding, and the mechanical properties of PP/wood flour composites were tested. The results show that： the tensile strength of PP/wood flour composites increases with the increase of content of wood flour, and reaches to 36.04 MPa when the content of wood flour is 60%; and the tensile strength decreases to 34.60 MPa when the content of wood flour is 80%. With the increasing of wood flour content from 20% to 80%, the modulus of elasticity of PP/wood flour composites increases from 579.12 MPa to 869.80 MPa, the elongation at break and impact strength decrease from 18.92% to 7.39%, and from 9.33 k J/m2 to 7.76 k J/m2 respectively. The reason is that with increasing of wood flour content, wood flour plays the role of stress concentration, which leads to the elongation at break and impact strength decrease.