表面活性剂对PBS/淀粉复合材料性能的影响

Effects of Surfactants on Properties of PBS/Starch Composites

比较了三种不同表面活性剂三聚甘油酯(TOST)、硬脂酸聚乙二醇酯(PEOST)、乙二醇单甘酯(MOST)对聚丁二酸丁二醇酯(PBS)/淀粉复合材料力学性能的影响,并采用差示扫描量热仪(DSC)、偏光显微镜(POM)和傅里叶变换红外光谱仪(FTIR)进行了表征。结果表明:PEOST的增塑效果好于TOST和MOST,而后两者还起分散剂的作用。TOST、PEOST、MOST分别使PBS/淀粉复合材料的拉伸强度降低15.60%、9.65%、4.81%;PEOST使断裂伸长率明显提高,增加243.73%,而TOST和MOST仅使断裂伸长率提高40.88%和23.85%。TOST和MOST使PBS的结晶温度(Tc)分别提高0.56和4.29℃,而PEOST使PBS的Tc降低1.25℃;但表面活性剂的加入对熔融温度(Tm)的影响不大。POM测试显示:PEOST使复合材料中PBS晶体体现出清晰的环带球晶特征。FTIR分析显示:表面活性剂改性的PBS/淀粉复合材料在3 360和1 617 cm^-1处的红外响应峰略有差异。其中,TOST改性后在1 005 cm^-1处出现较强的醇类C-OH伸缩振动峰。

The effects of three different surfactants, triglyceride(TOST), polyglycol stearate(PEOST) and ethylene glycol monoglyceride(MOST), on the mechanical properties of poly(butylene succinate)(PBS)/starch composites were compared, and characterized by differential scanning calorimeter(DSC), polarizing microscope(POM) and fourier transform infrared spectrometer(FTIR). The results show that the plasticizing effect of PEOST is better than that of TOST and MOST, and the latter two also act as dispersants. TOST, PEOST and MOST can reduce the tensile strength of PBS/starch composites by 15.60%, 9.65% and 4.81% respectively. The elongation at break increases significantly about 243.73% for PBS/starch composites with PEOST, but increases only about 40.88% and 23.85% for TOST and MOST respectively. The crystallization temperature(Tc) of PBS increases about 0.56℃ and 4.29℃ by the addition of TOST and MOST respectively, while decreases about 1.25℃ by PEOST. However, the three surfactants have little effect on the melting temperature(Tm) of PBS. The polarizing microscope shows that PBS crystals in the composite with PEOST exhibit clearer characteristics of banded spherulites than others. FTIR shows that the IR response peaks of PBS/modified starch composites are different at 3 360 cm^-1 and 1 617 cm^-1, in which that of TOST modified have strong C- OH stretching vibration peak at 1 005 cm^-1.