纳米SiO2改性超高分子量聚乙烯纤维的制备及其结构性能研究

采用萃取阶段加入纳米粒子的方式,制得纳米SiO2改性的超高分子量聚乙烯(UHMWPE)纤维.借助于扫描电镜、声速法、WAXD、DSC、TMA和强力测试等手段,研究了纳米SiO2对UHMWPE纤维结构和性能的影响.结果表明,纳米SiO2粒子在UHMWPE纤维中可达到均匀分散,分散尺寸约为50～100nm;改性后纤维取向度、结晶度基本不变,纤维横向晶粒尺寸大大降低,纤维力学强度稍有增加,力学模量大大增加(由1359.2cNdtex增加到1505.9cNdtex),同时,纤维热性能和热力学性能也得到大大改善.

PREPARATION AND STUDIES ON THE STRUCTURE AND PROPERTIES OF ULTRAHIGH MOLECULAR WEIGHT POLYETHYLENE/NANO-SiO2 COMPOSITE FIBERS

UHMWPE/nano-SiO2 composite fibers were prepared by the method of adding nano-SiO2 in extracting stage, and the influence of nano-SiO2 on the structure and properties of UHMWPE fibers were determined by SEM, sonic orientation, WAXD, DSC, TMA and mechanical measurements. The results showed that nano-SiO2 particles diffused into UHMWPE gel fibers during the extracting stage, and they could be dispersed in nano-size in UHMWPE fibers. Compared to virgin UHMWPE fibers, the orientation and crystallinity of UHMWPE/nano-SiO2 composite fibers remained unchanged, while the crystal size decreased greatly. After incorporating nano-SiO2, UHMWPE fibers became both stiffer and tougher than the virgin ones, especially the fiber modulus, which was increased greatly from 1359.24 cN/dtex to 1505.90 cN/dtex. Meanwhile, nano-composite UHMWPE fibers displayed a better thermal and thermomechanical stability.