Preparationand Performance Research Of Uhmwpe Fiber/Natural Rubber Composites

As is known, the melt point of UHMWPE fiber is about130℃,while thetemperature of rubber vulcanization is above150℃.In this thesis, based on the curingtechnology of NR at lower temperature and its reaction mechanism, the UHMWPEfiber/NR composite is fabricated with the surface of UHMWPE fibers modifed bychemical agents. Furthermore, the influence of chemical agents, fiber length and theprocessing conditions on the properties of UHMWPE fiber/NR composites is alsoinvestigated.The results show that rubber compounds could not be cured properly usingtraditional methods at lower temperature with quasi-or medium-speed accelerator suchas MBT, CZ and DPG. In this research, the properties of rubber compounds could beimproved during the lower temperature curing with the dithiocarbamate accelerator,for example, ZBEC and ZDMC. Besides, the curing rate could be accelerated withseveral kinds of accelerators. For example, the vulcanization characteristics wereimproved while its aging properties were slightly reduced with thiazole acceleratorssuch as MBT, DM and CZ. However, the vulcanization characteristics could beimproved largely when using the guanidine accelerators such as DPG, and the agingperformance could be greatly improved.Based on the testing methods such as nuclear magnetic resonance crosslinkingdensity experiments (NMR-CDS), chemical detection method, the in suit fouriertransform infrared spectrometry (FTIR) and so on, we found that a more perfectnetwork structure could be generated when adding MBT or DPG into the compounds,while the poor thermal oxidation was due to many multi-sulfur bonds and disulfur bonds during the vulcanization process. Moreover, the aging performances were betterbecause of numerous sulfur bonds and carbon-carbon bonds when adding MBT orDPG into the compounds,Different processing methods of UHMWPE fiber have been studied. The resultshowed that every method could make an effect on the fiber surface. The contact anglebetween the fiber and ethylene glycol would be reduced and adhesive property couldbe improved. The effect of BPO was the most effective and this method avoided thedamage of the fiber. Then, the effect of chromic acid and potassium permanganate wasrelatively less efficient. Ultra-high molecular weight polyethylene fiber/natural rubbercomposites with good properties could be obtained with the treatment of chromic acidfor3minutes or BPO for20minutes.In this article, fiber frictioning was used, the great dispersion and physical,mechanical properties was achieved. When the content of fiber was2phr, orientationdegree of the fiber was the maximum, that is, anisotropism was the best. But theproperties between longitudinal and latitudinal direction were very different. Moreover,when the treatment of chromic acid for3minutes or BPO for20minutes was available,physical and mechanical properties was significantly improved and strong adhesiveinteraction between the fiber and the rubber could be obtained.