SWELLING OF POLY(METHYL METHACRYLATE) THIN-FILMS IN LOW-MOLECULAR-WEIGHT ALCOHOLS
SWELLING OF POLY(METHYL METHACRYLATE) THIN-FILMS IN LOW-MOLECULAR-WEIGHT ALCOHOLS
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DOI：
10.1002/app.1990.070390404
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发表时间：
1990-02-20
影响因子：
3
通讯作者：
BELL, AT
中科院分区：
文献类型：
--
作者：
PAPANU, JS;HESS, DW;BELL, AT
采用原位椭偏仪研究了溶剂尺寸、温度和聚合物分子量对聚甲基丙烯酸甲酯（PMMA）薄膜在低分子醇中溶胀的影响。表观活化能表明非Fickian扩散，尽管光学数据显示甲醇中溶胀的显著Fickian特征和乙醇中的中度Fickian特征。渗透率强烈依赖于甲醇、乙醇和异丙醇的溶剂摩尔体积，但1-丁醇和2-戊醇的渗透率与异丙醇相似。这些较长分子的有效横截面与异丙醇相似，这显然解释了相似的渗透率。用单分散PMMA（Mn= 6.4-40.0 × 104 g/mol）研究了聚合物分子量（MW）对甲醇渗透速率（21-27°C）的影响。在中等MW下观察到最小值。异丙醇溶胀速率（45-52°C）对MW不敏感。溶胀数据也被用来确定参数的传输模型，描述了薄的聚合物膜的溶胀。
The effects of solvent size, temperature, and polymer molecular weight on the swelling of poly(methyl methacrylate) (PMMA) thin films in low molecular weight alcohols were investigated using anin situellipsometer. Apparent activation energies were indicative of non‐Fickian diffusion, although optical data showed substantial Fickian character for swelling in methanol and moderate Fickian character in ethanol. Penetration rates were strongly dependent on the solvent molar volume for methanol, ethanol, and isopropanol, but 1‐butanol and 2‐pentanol had rates similar to isopropanol. The effective cross sections of these longer molecules are similar to isopropanol, and this apparently explains the similar penetration rates. The effect of polymer molecular weight (MW) on methanol penetration rates (21–27°C) was investigated with monodisperse PMMA (Mn= 6.4–40.0 × 104g/mol). A minimum at intermediate MW was observed. Isopropanol swelling rates (45–52°C) were insensitive to MW. The swelling data were also used to determine parameters for transport models that describe the swelling of thin polymer films.