预热处理对超高分子量聚乙烯层积状片晶凝胶膜结构的影响

EFFECT OF ANNEALING ON THE STRUCTURE OF UHMWPE GEL-FILMS WITH SINGLE-VRYSTAL MATS

由准稀溶液速冷制备的超高分子量聚乙烯（ＵＨＭＷＰＥ）凝胶膜，具有片晶（Ｌａｍｅｌｌａ）取向平行于膜面的层积状结构，在１２９—１３４℃的温度范围内拉伸，可获得超高拉伸比（λ＞２００）．通过ＩＲ及Ｘ－ｒａｙ衍射等方法研究发现，拉伸前用不同温度退火处理后，凝胶膜的片晶微结构产生明显变化，在对应于超高拉伸温度范围内，其结晶度增加，微晶的ｃ和ｂ轴方向尺寸变大，而ａ轴方向的尺寸减小，从理论上对这一变化过程作了考察，并讨论了超高拉伸取向性与这些结构变化的关系以及可超拉伸取向性的最佳温度范围．

el-- films of ultrahigh molecular weight polyethylene (UHMWPE) were prepared from tri -- dilute solutions. The films were composed of lamellarcrystals oriented parallel to the film surfaces and could be ultradrawn (λ > 200) at the temperatures ranged from 129℃ to 134℃. When the undrawn films were annealed atthose temperatures, the morphologies in the lamellar crystals had change. WAXDand iR studies shown that the crystallinities incrcand, dimensions in (002) and(020) normals increased while that in (200) fold had slight decreases. The relationship between the orientation of the drawn UHMWPE gel-- films and the structure changes and the optimum drawing temperature had ho disscussed.