碳纳米管与二硫化钼填充PTFE蠕变性能  

Creep Properties of PTFE Filled with CNTS and MoS_2

作　　者：李朋辉 侯根良 毕松 李浩 林阳阳 应承展 Li Penghui;Hou Genliang;Bi Song;Li Hao;Lin Yangyang;Ying Chengzhan(The Rocket Force University of Engineering,Xi’an 710025,China)

机构地区：[1]火箭军工程大学,西安710025

出　　处：《工程塑料应用》2018年第10期98-102,116,共6页Engineering Plastics Application

摘　　要：为提高聚四氟乙烯(PTFE)在高载荷下的抗蠕变性,强酸氧化处理碳纳米管(CNTs),干燥过筛MoS_2,模压成型烧结制备PTFE/CNTs,PTFE/MoS_2,PTFE/CNTs/MoS_2复合材料,长期压缩研究复合材料的蠕变性能。结果表明:所有材料均在试验初期应变量线性增加,应变增加速率为1.74%/min,PTFE基复合材料受载初期应变量线性增加与PTFE分子链键角振动有关,与填充物类型和填充量无关。载荷作用30min后,随着时间延续,应变量又呈现出类似于线性的增加,增速稳定、增幅极小,这一阶段伴随黏性流动。材料屈服导致应变量增速出现急剧减缓,CNTs,MoS_2在屈服阶段作用机制分别为纤维捆束PTFE分子链和物理交联限制PTFE链段运动。同一填充量的材料在进入应变量小幅增加阶段后,恒定载荷大的材料,其应变量也大。随着CNTs或者MoS_2填充量增大,试样在同一恒定载荷作用阶段的应变量是逐步减小的。在降低材料应变量方面,20%MoS_2填充优于7%CNTs填充,5%CNTs/20%MoS_2填充效果好于20%MoS_2填充,物理交联较纤维捆束更能提高PTFE材料的抗蠕变性。PTFE屈服应力为7.937MPa,波动性δ2为0.09。The creep properties of polytetrafluoroethylene(PTFE)composites filled with carbon nanotube(CNTs)and molybdenum disulfide(MoS2)were investigated by means of long term compressive creep.The results show that all materials present linear increase in strain in early test,growth rate of strain is 1.74%/min,the changing of strain in the early experiment has nothing to do with the CNTs and MoS2 exited or not,the changing of strain is bond angles which belong to PTFE molecular chain vibrating at the equilibrium position.Yield slows down growth rate of strain sharp,the action mechanisms of CNTs and MoS2 are binding molecular chains of PTFE and limiting segment motion by physical crosslinking respectively at this stage.The strain is increasing with permanent load increasing at small amplitude increasing phase of the strain.With increasing mass fraction and strain capacity decreasing gradually,the most prominent filling type is samples with a mass fraction of 5%CNTs and 20%MoS2 in reducing materials strain,samples with a mass fraction of 20%MoS2 is better than samples with a mass fraction of 7%CNTs,physical crosslinking is more effective than the fiber binding in improving creep resistance.The yield stress of PTFE is 7.937 MPa,volatilityδ2 is 0.09.

关 键 词：聚四氟乙烯 碳纳米管 二硫化钼 蠕变 屈服强度 

分 类 号：TQ325.4[化学工程—合成树脂塑料工业]