造纸黑液干粉用量对PVC/CPE热塑性弹性体性能的影响

Influence of the Loading of Black Liquor Powder from Paper Industry on the Properties of PVC/CPE Thermoplastic Elastomer

以造纸黑液经硫酸中和处理脱水后的黑液干粉为填料,采用熔融共混法制备了聚氯乙烯(PVC)/氯化聚乙烯(CPE)/黑液干粉热塑性弹性体复合材料。利用FTIR和TGA测试了黑液干粉的结构和热性能;利用微控电子万能试验机、TGA研究了黑液干粉含量对弹性体复合材料的力学性能、热降解性能和老化性能的影响。结果表明:黑液干粉中木质素等有机物含量为33%;添加黑液干粉能改善PVC/CPE弹性体复合材料的力学性能,当黑液干粉含量为30phr时,拉伸强度保持不变,断裂伸长率提高了8%,撕裂强度提高了5%;采用硬脂酸处理的黑液干粉,其用量为30phr时,复合材料综合性能较佳,其拉伸强度提高了7%,断裂伸长率提高了12%,撕裂强度提高了18%;黑液干粉含量30phr时,PVC/CPE弹性体复合材料热降解温度提高了5℃;添加黑液干粉的复合材料,在热氧老化后拉伸强度和邵尔A型硬度增加,断裂伸长率稍有下降。

PVC/CPE/black liquor powder thermoplastic elastomers were prepared by melt blending using black liquor powder, which was prepared from black liquor in paper industry after neutralized by sulfuric acid and dried. The structure of black liquor powder was characterized using FTIR while the thermal properties were tested using TGA. The influence of the loading of black liquor powder on the mechanical properties, the thermal degradation properties, and the thermo-oxidative aging of PVC/CPE composites were studied using micro-controlled electronic universal testing machine and TGA. The experimental results indicated that the lignin content in the black liquor powder was about 33%. The mechanical properties of PVC/CPE/black liquor powder composites were improved due to the presence of black liquor powder. It has also been found that there was no change in the tensile strength of PVC/CPE compesites at a black liquor powder loading of 30 phr while the elongation at break and tear strength were increased up to 8% and 5%, respectively compared to the composites without black liquor powder. The stearic acid treated black liquor powder could enhance the comprehensive property of PVC/CPE composites. The tensile strength, elongation at break, and tear strength of PVC/CPE/black liquor powder composite at a loading of 30 phr were increased up to 7%, 12%, and 18% respectively compared to composites without black liquor powder. The TGA results indicated that the thermal degradation temperature of PVC/CPE composites were enhanced. The difference was about 5℃ at a black liquor powder loading of 30 phr. In general, the tensile strength and Shore A hardness of PVC/CPE/black liquor powder composites were increased while the elongation at break was slightly decreased after thermo-oxidative aged.