Structural Effects on the Transport of Water in Polyimides
Structural Effects on the Transport of Water in Polyimides
复制标题
结构对聚酰亚胺中水传输的影响
DOI：
10.1021/ma00092a011
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
J. Coburn
中科院分区：
文献类型：
--
作者：
J. V. Alsten;J. Coburn
用红外-衰减全反射（IR-ATR）方法研究了一系列化学结构相似的聚酰亚胺分子的一级和二级结构对水输运的影响。水的扩散率通常随着链骨架刚度的增加而降低（如从机械β转变所确定的），并且扩散的活化能通常随着骨架刚度的增加而增加。对于一个给定的骨干组合物，扩散系数也被证明显着增加的非晶相的密度降低。振动光谱表明，吸收的水分配成双峰分布的网站，大概代表单一和集群的水分子
The influence of molecular primary and secondary structure on the transport of water has been investigated for a series of chemically similar polyimides using an IR ATR method. The diffusivity of water generally decreased with increased chain backbone stiffness (as determined from the mechanical β transition), and the activation energies for diffusion generally increased with backbone stiffness. For a given backbone composition, the diffusivity was also shown to markedly increase as the density of the amorphous phase decreased. The vibrational spectra show that the absorbed water partitions into a bimodal distribution of sites, presumably representing single and clustered water molecules