Solvent-Induced Stresses and Surface Pattern in Glassy Polymer

溶劑在玻璃態高分子所引發的應力和表面波紋

劉奕宏(Yi-Hung Liu)

指導教授 ： 李三保

國立清華大學/工學院/材料科學工程學系/碩士(2010年)

摘要

We studied the solvent-induced stresses and solvent-induced surface pattern in glassy polymers. The solvent transport in glassy polymers is described by Case I, Case II, and anomalous transport. Case I transport is driven by concentration gradient, and Case II transport is due to stress relaxation. Anomalous transport is the mixture of Case I and Case II. Concentration profile for both two-side absorption of anomalous transport and one-side desorption of Case I transport were derived. Two initial conditions for one-side desorption in PMMA were analyzed. The activation energy of diffusion coefficient is found to be lower in one-side desorption than that in two-side absorption. The elastic models of stress distributions and longitudinal displacement arising from the mass transport were built up and were analyzed for PMMA. From the displacement data, the partial molar volume of methanol in PMMA during the transport process was determined.
Surface pattern occurs when a polymer slab is under a large enough compressive stresses. The stresses arising from the mass transport are found to be compressive near the surfaces for two-side resorption in PC. A method combining the solvent-induced stresses and the mechanical instability of a slab under compression is developed to analyze the solvent-induced surface pattern on PC. The calculated pattern wavelengths are at the same order and have the same trend with that of experimental results.

關鍵字

聚甲基丙烯酸甲酯 ； 甲醇質傳 ； 除吸收 ； 聚碳酸酯 ； 表面波紋

並列摘要

無資料

並列關鍵字

PMMA ； methanol transport ； desorption ； polycarbonate ； surface pattern

參考文獻

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