水性复合改性剂改性重质碳酸钙及其PP复合材料

Waterborne Composite Surface Modifier and Its Application in PP/Ground Calcium Carbonate Composites

为了更好地改善重质碳酸钙粉体的分散性、流动性以及提高其与树脂材料的融合性,将聚乙二醇-300(PEG-300)、十二烷基硫酸钠(SDS)和硬脂酸钠进行复合配比,制成水性复合改性剂。对重质碳酸钙进行干法表面改性,并对改性前后粉体的吸油值、沉降体积以及表面形貌进行测试和表征。将改性后的重质碳酸钙以质量分数25%,30%,35%和40%添加到聚丙烯(PP)材料中,制成PP/重质碳酸钙复合材料,测试其力学性能、热稳定性和断面微观形貌。研究结果表明,PEG-300,SDS和硬脂酸钠的质量比为6∶2∶2时,表面改性效果最佳,重质碳酸钙粉体的吸油值从32.7 mL/100 g降至15.5 mL/100 g,沉降体积从4.1 mL/g降至1.0 mL/g。水性复合改性重质碳酸钙粒径小、分散性更高,复合材料的结晶性能更好。水性复合改性剂的活化性能及其复合材料的力学性能均优于对照品硬脂酸;随着重质碳酸钙粉体含量的增加,PP/重质碳酸钙复合材料的力学性能先增大后减小,质量分数为30%时力学性能最佳。弯曲强度达到45.75MPa,拉伸强度达到32.58MPa。

In order to better improve the dispersion,fluidity and fusion of ground calcium carbonate powder and improve its fusion with resin materials.Polyethylene glycol-300(PEG-300),sodium dodecyl sulfate(SDS)and sodium stearate were compound‐ed to prepare a water-based composite modifier.The surface of ground calcium carbonate was modified by dry method,and its oil absorption value and sedimentation volume were investigated.The ground calcium carbonate before and after modification was added to the polypropylene(PP)material with a filling amount of 25%,30%,35%and 40%to make a PP/calcium carbonate composite material,and its mechanical properties,thermal stability and cross-section microstructure were tested.The results show that when the mass ratio of PEG-300,sodium dodecyl sulfate and sodium stearate is 6∶2∶2,the surface modification effect is the best.The oil absorption value of ground calcium carbonate powder is reduced from 32.7 mL/100 g to 15.5 mL/100 g,and the sedi‐mentation volume is reduced from 4.1 mL/g to 1.0 mL/g.Water-based composite modified ground calcium carbonate has smaller particle size and higher dispersibility,which improves the crystallization performance of composite materials.The activation perfor‐mance of water-based composite modifier and the mechanical properties of its composites are better than those of stearic acid.With the increase of ground calcium carbonate powder filling,the mechanical properties of polypropylene/ground calcium carbonate composites first increase and then decrease,and the mechanical properties are the best when the filling amount is 30%,The bending strength and tensile strength of the composite reach 45.75 MPa and 32.58 MPa,respectively.