用傅立叶变换红外光谱仪(FT-IR),在应力(σ)作用下,测定聚丙烯膜的碳-碳分子链红外吸收频率的位移。吸收峰的形状和位移与应力有关,其位移与应力成正比Δv=ασ,α为比例常数。所得α_(1167)=0.0575、α_(975)=0.0361、α_(841)=0.0383:与国外参考文献所测值相近,本文提出可用测定α的方法来分析薄膜受力的历史,为改进设计和工艺提供依据。 Fourier transform infrared spectroscopy (FT-IR) was used to measure the displacement of the infrared absorption frequency of the carbon-carbon molecular chain of the polypropylene film under stress (σ). Absorption peak shape and displacement and stress, the displacement and stress is proportional to Δv = ασ, α is the proportionality constant. The obtained values ​​of α_ (1167) = 0.0575, α_ (975) = 0.0361, α_ (841) = 0.0383 are similar to those measured by foreign references. This paper presents the method of measuring α by analyzing the history of film stress. In order to improve the design and Process to provide the basis.