The effect of cross-linking on gas permeability in cross-linked poly(ethylene glycol diacrylate)
The effect of cross-linking on gas permeability in cross-linked poly(ethylene glycol diacrylate)
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DOI：
10.1021/ma0510136
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发表时间：
2005-10-04
期刊：
影响因子：
5.5
通讯作者：
Kalika, DS
中科院分区：
文献类型：
--
作者：
Lin, HQ;Kai, T;Kalika, DS
在不同量的水或单功能聚乙二醇甲基丙烯酸酯（PEGMEA）存在下，光聚合聚乙二醇二丙烯酸酯（PEGDA），以改变交联密度，制备了一系列交联聚合物XLPEGDA。所有的聚合物本质上具有相同的化学成分，但从水膨胀实验、Flory-Rehner模型和改进的Flory-Rehner理论模型以及动态力学测试中可以估计出交联密度的系统性变化。交联密度随预聚体溶液中水或PEGMEA含量的增加而降低。有趣的是，由PEGDA和水制备的一系列材料的气体溶解度、扩散率和渗透率基本上与交联密度无关。当水改变交联密度时，聚合物密度、自由体积分数、玻璃化转变温度和聚合物间距也保持不变。基于这一结果，似乎交联密度不一定会影响气体扩散和渗透、聚合物玻璃化转变温度或网状聚合物中的自由体积分数，并且应非常小心地将这些性质的变化仅仅归因于交联密度的变化，正如在文献中常见的那样。
A series of cross-linked polymers, XLPEGDA, was prepared by photopolymerizing poly(ethylene glycol) diacrylate (PEGDA) in the presence of varying amounts of water or monofunctional poly(ethylene glycol) methyl ether acrylate (PEGMEA) to vary cross-link density. All of the polymers had essentially the same chemical composition but displayed a systematic variation in cross-link density as estimated from water swelling experiments, models such as the Flory-Rehner and modified Flory-Rehner theories, and dynamic mechanical testing. Cross-link density decreased with increasing water or PEGMEA content in the prepolymer solutions. Interestingly, gas solubility, diffusivity, and permeability were essentially independent of cross-link density for the series of materials prepared from PEGDA and water. The polymer density, fractional free volume, glass transition temperature, and polymer d spacing were also constant when water was used to vary cross-link density. On the basis of this result, it appears that cross-link density does not necessarily affect gas diffusion and permeation, the polymer glass transition temperature, or the fractional free volume in network polymers, and ascribing changes in these properties to changes in cross-link density alone, as is seen commonly in the literature, should be done with great care.