PVDF热收缩套管耐弯折性能研究

Research on Flexural Endurance of PVDF Heat Shrinkable Tube

通过熔融共混、辐照交联、扩张定型制备了4种不同共混比例聚偏氟乙烯(PVDF)热收缩套管及一种PVDF/氟橡胶(FKM)热收缩套管,研究了5种热收缩套管耐弯折性能的变化规律。结果表明:PVDF热收缩套管的耐弯折性能与基材的断裂伸长率呈正相关。加入一定质量FKM可以有效提高PVDF热收缩套管的断裂伸长率,进而提高其耐弯折性能。降低辐照剂量能够提高PVDF/FKM热收缩套管的耐弯折性能。整个失效过程中,热收缩套管同时受到屈挠应力及摩擦阻力作用,其中,屈挠应力占主导因素。

Four polyvinylidene fluoride(PVDF) heat shrinkable tubes with different blending ratios and one PVDF/fluororubber(FKM) heat shrinkable tube were prepared by melt blending, irradiation crosslinking, and expansion molding. The flexural endurance of the five types of heat shrinkable tubes were studied. The results show that the flexural endurance of PVDF heat shrinkable tube is positively correlated with the elongation at break of the substrate. The addition of a certain amount of FKM can effectively improve the elongation at break of PVDF heat shrinkable tube, and then improve its flexural endurance. The flexural endurance of PVDF/FKM heat shrinkable tube can be improved by reducing the irradiation dose. In the whole failure process, the heat shrinkable tube is simultaneously subjected to flexural stress and frictional resistance, among which flexural stress is the dominant factor.