聚醋酸乙烯酯/二氧化硅复合乳液的制备及其对水泥的改性

Preparation of Poly(vinyl acetate)/Silicon Dioxide Emulsion and Modification to Cements

采用乳液聚合制备了聚醋酸乙烯酯/二氧化硅复合乳液,并将其加入水泥浆中制备了水泥基聚合物复合材料。用扫描电镜、激光粒度仪、旋转流变仪、力学试验机等测试及表征了复合乳液的表观形貌、粒径分布、流变行为以及复合水泥石的力学性能。结果表明,二氧化硅的加入可以改变乳胶粒子的尺寸;复合乳液的加入,在一定程度上提高了水泥石的力学性能。其中,当聚醋酸乙烯酯/20%二氧化硅复合乳液在水泥石中的添加量为5%时,弯曲强度达到最大值10.6 MPa;当添加量为7%时,压缩强度可从12.5 MPa提高到33.06 MPa。

Poly（ vinyl acetate）（ PVAc）/silicon dioxide emulsion prepared by emulsion polymerization was added into cements. The morphology, particle size, rheological and mechanical properties were investigated by laser particle analyzer, rotational rheometer, scanning electron microscope etc. The results show that the size of emulsion particles can be reduced by the addition of silicon dioxide, and the mechanical properties of cements containing PVAc/SiO2 emulsion are improved to some extent. When the loading of PVAc/SiO2（20% ） emulsion is 5%, the flexural strength reaches the maximum of 10. 6 MPa. When the loading of PVAc/SiO2 （20%） emulsion is 7%, the compression strength increases from 12. 5 MPa to 33.06 MPa.