摘要
液晶聚合物对小分子如水汽、氧等具有超级阻隔特性,因而其作为封装材料的使用日益受到人们的重视。本文概述了液晶聚合物结构对聚合物阻隔性能的影响,总结了小分子在液晶聚合物中的两种主要传输模型。目前广泛认同的模式是小分子在液晶相中不能渗透,聚合物中无定形区域或液晶相边界区的存在是液晶聚合物能够发生渗透的主要原因。接着总结了液晶聚合物的自由体积、液晶相态及分布对小分子在液晶聚合物中渗透行为的影响。小分子在液晶聚合物中的传输符合溶解-扩散机理。文章还对高阻隔性的测试新方法以及近年来液晶聚合物作为阻隔封装材料的应用情况作了介绍。最后分析了液晶聚合物作为阻隔材料使用存在的问题及超级阻隔液晶聚合物封装材料的发展趋势。
Because of their high barrier prosperity that prevents the permeation of small molecular, liquid crystalline polymers have attracted considerable attention for its applications as barrier layers and separation membranes et al. This paper first introduces the structural characteristics and physical properties of liquid crystalline polymers, and then two pass models of small molecular permeation through liquid crystalline polymer membrane are described. It is now generally agreed that the liquid crystal as being impermeable like a 3-dimensional crystal. Small molecules can permeate only in defect regions in the polymer or the phase boundaries among liquid crystalline domains. The relationship between the mesogenic state of polymer liquid crystalline phase and the small molecular permeation properties is also summarized. Liquid crystalline phase content and free volume ratio of a polymer, the orientation and distribution of the mesogens phase, can affect the permeability of small molecules pass through the polymer membrane, which accords with the well-known sorption-diffusion model for molecular transportation. New characterization method for measuring very low permeability of small molecular transportation in super barrier materials and the new applications of super barrier liquid crystalline polymer are reviewed. Problems of the application of liquid crystalline polymers as packaging materials and our perspectives of the future development of liquid crystalline polymers are also given at the end of the paper.
出处
《高分子通报》
CAS
CSCD
北大核心
2011年第3期45-51,共7页
Polymer Bulletin
基金
国家自然科学基金(20774076)
西南科技大学创新基金(CX10-005)
关键词
液晶聚合物
阻隔
渗透
封装材料
Liquid crystalline polymer
Barrier
Permeation
Packaging Materials
