拉伸工艺对PVDF薄膜形貌与结构的影响

聚偏二氟乙烯(PVDF)薄膜中,β相的相对含量对其压电、铁电性能起决定性作用。利用单轴拉伸工艺制备了高β相的相对含量的PVDF薄膜,运用XRD、SEM和FT-IR等测试手段,分析了拉伸过程中PVDF薄膜形貌与结构的变化,重点讨论了不同拉伸比R对薄膜微观结构及β相的相对含量的影响。结果表明:PVDF薄膜中的α晶相受均匀外力作用转变成β晶相,在80℃下拉伸5倍时,薄膜中β相的相对含量可高达77%。

Effects of stretching technology on morphology and structure of PVDF films

In polyvinylidene fluoride (PVDF) films, the relative content of β phase had a crucial import on their piezoelectric and ferroelectric properties. PVDF films with high β phase relative content were prepared by uniaxial stretching. SEM, XRD and FT-IR were used to analyse the changes of the morphology and structure in PVDF films during the stretching process. And then effects of different stretching ratio R were discussed on the microstructure of films and the relative content of the β phase. As indicated by results, α phase in PVDF films is converted to β phase under constant external force, at 80 ℃, the relative content of β phase in films can be up to 77 % when the films are stretched 5 times.