预测相融共混膜氧气透过率的分形渝渗模型

目的 预测相融体系共混膜氧气透过率,为高阻氧共混膜的生产和设计提供理论依据.方法 应用分形与渝渗理论提出一种氧气透过率预测模型,该模型能够在高阻氧材料体积分数条件下更准确地估算相融体系共混膜的氧气透过率.以聚酯/聚萘二甲酸乙二醇酯(PET/PEN)共混膜为例,通过扫描电镜分析共混膜微观形貌,确定PET/PEN共混膜中氧气渗透维数,并根据渗透维数结合文中提出的预测模型计算PET/PEN共混膜氧气透过率,最后通过实验数据验证该模型的有效性.结果 氧气在PET/PEN混合膜中的渗透可以简化为二维渗透.在低PEN体积分数条件下,现有模型和文中提出的预测模型均与实验结果高度吻合.该模型在高PEN体积分数条件下展现出了现有其他模型所没有的曲线趋势,能够更准确地描述高阻氧材料在共混膜体系中对氧气的阻隔作用.结论 文中提出的预测模型能够用于预测相融体系共混膜的氧气透过率.

Fractal and Percolation Model for Predicting the Oxygen Permeability of Miscibility Blended Film

The work aims to predict the oxygen permeability of miscibility blended film, and provide a theoretical support for the manufacture and design of high oxygen barrier blended film. In this research,a prediction model of oxygen permeability was proposed according to the application of fractal theory and percolation theory. This model can predict oxygen permeability of miscibility blended films more accurately at a high content (mass fraction) of oxygen barrier polymer. A scanning electron microscopy (SEM) was used to analyze the micro-structure of PET/PEN blended films, determine the dimension of oxygen permeability in PET/PEN blended films. Then the oxygen permeability of PET/PEN blended film was calculated according to the permeability dimension combined with the prediction model proposed in this work. Finally, the validity of the model was verified by experimental data. The results indicated that the oxygen permeation in PET/PEN blended films can be simplified into a 2-D percolation. Both the existing model and the proposed model had a good agreement with the experimental data at low PEN content (volume fraction). However, the proposed model showed a unique curve trend which had a more accurate prediction to experimental data at the high PEN content (volume fraction) in blended films and can describe the barrier effect of high oxygen barrier polymer on oxygen in the blended film system more accurately. The proposed model can be used to predict the oxygen permeability of miscibility blended film.