微层聚氯乙烯/纳米二氧化硅复合材料的结构与性能

Structure and Properties of Micro Layer PVC/Nano-SiO2 Composites

利用微纳层叠挤出技术在挤出聚合物熔体过程产生的持续剪切作用,制备出PVC/nano-SiO2复合材料片材,并通过转矩流变仪、扫描电子显微镜、真空干燥箱、万能试验机等对片材的结构与性能进行了分析和表征。结果表明：（1）随着nano-SiO2用量的增加,最大扭矩和最小扭矩不断增大,但平衡扭矩维持在同一水平,而塑化时间先减小后增大,熔融因数先增大后减小,且在nano-SiO2含量为3%时取得最大值,加工性能最佳。（2）试样的加热损失率随着nano-SiO2用量增加先增大后减小,用量为3%时加热损失率最小。当nano-SiO2用量为3%,同1层试样比较,9层试样的加热损失率降低34.5%;81层降低36.3%;729层降低41.7%。（3）随着nano-SiO2用量的增加,PVC/nano-SiO2复合材料的纵向拉伸强度逐渐增大,nano-SiO2用量为3%时达到最大,当其用量超过3%后,材料的拉伸强度呈逐渐降低的趋势;nano-SiO2用量为3%时,与1层试样比较,9层试样的纵向拉伸强度提升了3.6%;81层试样提升了17.6%;729层试样提升了25.5%。（4）nano-SiO2用量为3%时,伴随微纳层数增加,纵向屈服强度增大,界面作用不断增强;加入6节微纳层叠器（微纳层数为729）时,nano-SiO2用量为3%时的界面作用最强。

PVC/nano-SiO2 microlayered composite sheets were prepared via micro-nano laminated technology, which produced continuous shear force in the extrusion processing of polymers. The structure and properties of the sheets were analyzed and characterized by torque rheometer, scanning electron microscope, vacuum drying box and universal testing machine. The results were as followings：（1） With the increase of nano-SiO2, the minimum and maximum torque increased, but the balance torque was maintained at the same level, while the plasticizing time decreased first and then increased, fusion factor increased first and then decreased with the maximum value in the sample with 3% nano-SiO2.（2） The heating loss rate increased first and then decreased with the increase of nano-SiO2 and reached the least values in the sample with 3% nano-SiO2. When containing 3% nano-SiO2, compared with the 1 layer samples, the heating loss rate of 9 layers samples, 81 layers and 729 layers samples decreased by 34.5%, 36.3% and 41.7%.（3） With the increase of nano-SiO2, the longitudinal tensile strength of PVC/nano-SiO2 composite sheets increased gradually and reached the maximum in the sample with 3% nano-SiO2, when the content exceeded 3%, the tensile strength was gradually decreased; with 3% nano-SiO2, compared with the 1 layer samples, the longitudinal tensile strength of 9 layers samples,81 layers and 729 layers samples increased by 3.6%, 17.6% and 25.5%.（4） When nano-SiO2 was added to 3%, the longitudinal yield strength and interface function increased with the the number of layers increasing; when adding 6 laminating devices（the number of layers was 729）, the interfacial action was strongest with 3% nano-SiO2.