超高分子量聚乙烯纤维的热力学稳定性能

针对超高分子量聚乙烯(UHMWPE)纤维熔点低、易蠕变等不足,以油田井下作业环境为测试条件,研究了UHMWPE纤维在干热和湿热状态下的力学稳定性能,借助差示扫描量热仪、热重分析仪、扫描电子显微镜、X射线衍射仪和电子能谱分析仪,表征并分析了UHMWPE纤维的热学性能和微观结构。结果表明:UHMWPE纤维表面在热和处理液的刻蚀作用下产生明显的沟槽;在相同的温度下处理,湿热状态下纤维的力学性能损失比干态下小,尤其在70 ℃下湿热连续处理30 d,纤维强力下降率基本控制在6%以内;对纤维进行干热处理,当温度接近纤维熔点时,随着温度的升高,纤维强力下降明显,140 ℃下干热处理1 h,强力最大下降率达19.87%。

Thermal mechanical stability of ultrahigh molecular weight polyethylene fiber

Aiming at low melting point and easy creeping of ultrahigh molecular weight polyethy-lene (UHMWPE) fiber, the mechanical properties of UHMWPE at dry and wet heating was investigated, simulating the oilfield underground operation as the measurement conditions. The differential scanning calorimeter, thermal gravity, scanning electron microscopy, X-ray diffraction analyzer and energy dispersive spectrometer were used to characterize and analyze the heating property and microscopic images. The results show that with the etching by heat and treatment solution, obvious groove appears on the surface of the UHMWPE fibers. When treated with the same temperature, the loss in mechanical property is lower at wet heating than that at dry heating, especially when the fibers are wet heated at 70 ℃ for 30 d, the decrease of fibers strength could be controlled within 6%. However, with the increase of treatment temperature at a dry environment, the fibers strength decreases significantly, and particularly when the fibers are dry heated at 140 ℃ for 1 h, the maximum strength loss reaches 19.87%.