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Liquid dewetting of ultrathin polystyrene films: Is there a molecular architecture effect?
Journal of Polymer Science ( IF 3.9 ) Pub Date : 2020-12-24 , DOI: 10.1002/pol.20200785
James R. Tata 1 , Astrid K. Torres Arellano 1, 2 , Gregory B. McKenna 1
Affiliation  

We have used a liquid dewetting method to investigate the glass transition temperature Tg of high molecular weight linear, long branched 3‐arm star, and short branched 8‐arm star polystyrene (PS) in the form of ultrathin films. The results of these dewetting experiments are consistent with prior studies of dewetting of linear PS films and show that, independent of molecular architecture, the glass transition temperature Tg reductions with decreasing film thickness, while important below about 20 nm, are weaker than those observed for linear PS supported on a rigid substrate and as well as those observed in freely standing films. The lack of a strong molecular architecture effect on the Tg‐reductions is consistent with the Tg reductions for the dewetting from a liquid substrate reflects changes in segmental dynamics upon confinement rather than chain effects. This contrasts with changes, including increases seen in dewetting from a rigid substrate, for different molecular architectures reported in the literature.

中文翻译:

超薄聚苯乙烯薄膜的液体脱湿:有分子结构效应吗?

我们已经使用液体去湿法研究了以超薄膜形式存在的高分子量线性,长支链3臂星形和短支链8臂星形聚苯乙烯(PS)的玻璃化转变温度T g。这些去湿实验的结果与线性PS膜去湿的先前研究一致,并且表明,与分子结构无关,随着膜厚度的降低,玻璃化转变温度T g的降低(虽然重要的是在约20 nm以下)比观察到的要弱。用于支撑在刚性基材上的线性PS,以及在自由站立的薄膜中观察到的线性PS。缺乏对T g的强分子构架作用-减少与从液体底物上去湿的T g减少一致,这反映了约束条件下链段动力学的变化,而不是链效应。这与文献中报道的不同分子结构的变化形成对比,包括从刚性基材上去湿时看到的变化。
更新日期:2021-02-01
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