中文摘要：

用红外分光光度计、X射线粉末衍射仪和光学显微镜对CaSO4晶须A、B和C进行结构表征和形貌观察。结果表明,晶须A、B和C的长径比为5.2、9.1和3.3,经改性的晶须B晶体结构规整,缺陷最少。分别制备了以3种晶须为补强材料的PVC复合体系,讨论了晶须结构对CaSO4晶须/PVC复合体系的力学性能、绝缘电阻和200℃静态热稳定时间的影响。用光学显微镜、扫描电镜和热重分析仪分析了晶须在复合体系中的分散形态和体系的热稳定性。研究发现,长晶须A和B对复合材料的增强增韧和热稳定作用好于短晶须C、CaCO3和气相法白炭黑。经改性的晶须B与PVC树脂有良好的相容性和界面结构,体系的拉伸强度、断裂伸长率和热稳定时间分别达到了23.20MPa、380.85%和95min,可以看出,长径比大,结晶性良好,且经过改性的CaSO4晶须能明显提高复合体系的综合性能。

英文摘要：

Structure of CaSO4 whisker A,B and C were characterized by IR,XRD and the optical microscope.The results showed that the ratios of length to diameter of CaSO4 whisker A,B and C were 5.2,9.1 and 3.3.The modified CaSO4 whisker B had perfect crystal structure and less defects.Three kinds of composites with CaSO4 whisker A,B and C were prepared separately and the mechanical properties,insulation resistances and static thermal stability time at 200℃ of three composites were investigated,and the degradation processes were analyzed by TG at 50-400℃,N2 atmosphere by comparing with CaCO3/PVC.The dispersing states of three whiskers were observed in the composites by means of optical microscope and SEM.The experimental results indicated that the toughening,reinforcing effects and thermal stability of long CaSO4 whiskers A and B /PVC composites were better than those of CaSO4whisker C,CaCO3 /PVC and gas phase method silica aerogel/ PVC.The modified CaSO4 whisker B had the best consistency and interfacial configuration with PVC resin and the tensile strength,elongation at break and thermal stability time of composites reached 23.20MPa,380.85% and 95min.In a word,the excellent comprehensive properties will be obtained as well as the crystallinity when the modified whisker’s ratio of length to diameter is big.