超高分子量聚乙烯纤维复合表面改性及其橡胶基复合材料的力学性能

针对超高分子量聚乙烯(UHMWPE)纤维与基体之间界面结合强度低的问题,采用超声波结合铬酸溶液氧化的复合工艺对UHMWPE纤维进行表面处理,并将处理后的纤维加入到天然橡胶(NR)中制备短切UHMWPE纤维/NR复合材料。结果表明:复合改性工艺可有效增加纤维表面粗糙度及表面含氧官能团含量,最佳改性工艺条件为:按照重铬酸钾、水及浓硫酸的质量比7∶12∶150配置铬酸溶液,将含有一定质量UHMWPE纤维的铬酸溶液放入35℃的超声波清洗仪中氧化5min,其中超声波频率为100kHz。与纯NR样品相比,在UHMWPE纤维与NR的质量比为0~6∶100范围内,随着处理后短纤维含量的增加,复合材料的拉伸强度逐渐减小,最大损失量达到50%;复合材料的硬度不断增大,最大增加量达到96%;复合材料的撕裂强度先增大后减小,在UHMWPE纤维与NR的质量比为5∶100时达到最大值,最大增加量达到49%。

Compound surface modification of ultra-high molecular weight polyethylene fiber and mechanical properties of its rubber matrix composites

Aiming at the problem of low interfacial adhesion strength between ultra-high molecular weight polyethylene (UHMWPE) fiber and matrix, ultrasonic treatment and chromic acid solution oxidation compound process were used to perform surface modifications of UHMWPE fiber, and the modified fiber was added into natural rubber (NR) to prepare short-cut UHMWPE fiber/NR composites. The results show that the compound modification process could effectively increase the roughness and oxygen-containing group contents on surface of fibers, and the optimum modification conditions are: the chromic acid etching solution is prepared by mixing potassium dichromate, distilled water, and sulfuric acid with 7:12:150 mass ratio, and put the chromic acid solution which is filled with a certain quality UHMWPE fiber into ultrasonic cleaning instrument to oxidize for 5 min at 35 ℃, and the ultrasonic frequency is 100 kHz. Then, the as-prepared fibers were added into NR with mass ratio ranging from 0 to 6:100. Compared with the pure NR samples, with the increase of short fiber content, the tensile strength of composites decreases, mostly by 50%, the hardness increases, mostly by 96%, the tear strength first increases then decreases, and reaches mostly by 49% with mass ratio 5:100 between UHMWPE fibers and NR.