原位固相接枝改性碳酸钙/聚丙烯复合材料的制备

用马来酸酐（MAH）在碳酸钙（CaCO3）表面引入双键，通过原位固相接枝法将聚丙烯蜡（PPW）化学键合在CaCO3表面，制得3种接枝率的CaCO3-MAH-PPW。 将这3种改性CaCO3填充聚丙烯（PP）制备复合材料，研究了PP/CaCO3界面作用对复合材料强度的影响。 结果表明，CaCO3表面经PPW接枝改性后在PP中的分散性提高，与PP相容性变好；随着改性CaCO3表面PPW接枝率的提高，CaCO3与PP之间界面作用逐渐增强。 当PPW接枝率为4.48 mg PPW/g CaCO3时，CaCO3与PP之间的界面作用最强，复合材料拉伸强度下降最小，杨氏模量提升最大，当m(PP)∶m(CaCO3)=100∶50时，杨氏模量达0.86 GPa，是纯PP的1.63倍；而PPW化学接枝率为2.49 mg PPW/g CaCO3时，CaCO3与PP之间的界面作用适中，复合材料缺口冲击强度提升最大，且当m(PP)∶m(CaCO3)=100∶10时，缺口冲击强度达3.91 kJ/m2，是纯PP的1.35倍。

Preparation of Polypropylene Composites Filled with Surface-modified Calcium Carbonate by in-situ Solid Phase Grafting

The surface of calcium carbonate(CaCO3) was firstly pretreated with maleic anhydride(MAH) to introduce active double bond groups, then grafted chemically by polypropylene wax(PPW) via in-situ solid phase grafting to increase its compatibility with polypropylene. Three kinds of modified CaCO3 with different chemical grafting ratio of PPW were prepared by changing experimental conditions, and their PP-based composites were produced. The effects of interfacial interaction between CaCO3-MAH-PPW and PP matrix on the strength of PP-based composite filled with modified CaCO3 were studied. The results show that the dispersibility of CaCO3-MAH-PPW in PP is improved, suggesting an improved compatibility between them. With the improvement of grafting ratio of PPW on the surface of CaCO3, the interfacial interaction between CaCO3 and PP increases gradually. When the grafting ratio of PPW is 4.48 mg PPW/g CaCO3, the interfacial interaction between CaCO3 and PP is strongest and the decrease of tensile strength of composites is the least, the young′s modulus increases most at the same time. When m(PP)∶m(CaCO3)=100∶50, the young′s modulus reaches 0.86 GPa, which is the 1.63 times of PP′s. When the grafting ratio of PPW is 2.49 mg PPW/g CaCO3, the interfacial interaction between CaCO3 and PP is suitable and the notch impact strength of composites improves the most. And when m(PP)∶m(CaCO3)=100∶10, its notch impact strength is 3.91 kJ/m2, which is the 1.35 times of PP′s.