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为使PLA薄膜的结晶速度进一步加快,提高PLA薄膜的结晶度,提高薄膜的耐热性和力学强度,研究了成核剂对应力诱导PLA薄膜结晶的影响.利用XRD、DSC、FTIR等表征手段,对PLA薄膜拉伸前后的结晶状态进行了表征.研究表明,简单的引入成核剂,并不能实现成核剂和应力诱导促进PLA结晶的协同作用.相反,成核剂的引入会在很大程度上阻碍应力诱导结晶.即使成核剂在与拉伸温度相同的等温冷结晶过程中能够显著的提高PLA结晶速率,但在应力诱导结晶过程中,成核剂的引入使得拉伸后薄膜结晶度较纯PLA体系拉伸后薄膜明显更低.在相对较低的拉伸温度进行实验,成核剂同样起到阻碍应力诱导结晶进行的作用.同时,实验发现相对较低的拉伸温度,更有利于应力诱导结晶的进行,薄膜在较低温度拉伸后结晶度更高且更稳定.
In order to further accelerate the crystallization of PLA film, improve the crystallinity of PLA film and improve the heat resistance and mechanical strength of PLA film, the effect of nucleating agent on the crystallization of PLA film was studied by XRD, DSC and FTIR , The crystallization state of PLA film before and after stretching was characterized.The results show that the introduction of a simple nucleating agent can not achieve nucleating agent and stress-induced synergistic effect of PLA crystallization.In contrast, the introduction of nucleating agent will be very To a great extent impede the stress-induced crystallization.If the nucleating agent can significantly increase the crystallization rate of PLA during the isothermal cold crystallization with the same stretching temperature, the introduction of the nucleating agent during the stress-induced crystallization makes the stretched film The crystallinity is significantly lower than that of the pure PLA system.The nucleating agent also acts as a barrier to stress-induced crystallization at a relatively low stretching temperature.At the same time, it was found that the relatively low stretching temperature , More conducive to the stress-induced crystallization, the film after stretching at a lower temperature higher crystallinity and more stable.