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Unusual Thermal Properties of Certain Poly(3,5-disubstituted styrene)s
Macromolecules ( IF 5.1 ) Pub Date : 2020-06-25 , DOI: 10.1021/acs.macromol.0c00163
Jai Hyun Koh , Qingjun Zhu , Yusuke Asano , Michael J. Maher 1 , Heonjoo Ha 1 , Sung-Soo Kim 1 , Henry L. Cater , Emmanuel U. Mapesa 2 , Joshua R. Sangoro 2 , Christopher J. Ellison 1 , Nathaniel A. Lynd , C. Grant Willson
Affiliation  

During the course of studying silicon-containing diblock copolymers, it was discovered that poly(3,5-di(trimethylsilyl)styrene)-block-poly(3,4-methylenedioxystyrene) (PDTMSS-b-PMDOS) showed very unusual thermal properties. The material can be recovered as a free-flowing powder despite heating above 250 °C. To better understand this behavior, homopolymers of the 3,5-disubstituted styrenes, poly(3,5-di(trimethylsilyl)styrene) (PDTMSS) and poly(3,5-di-tert-butylstyrene) (PDtBS), were prepared. These polymers are soluble in common organic solvents and formed clear, glassy thin films upon spin coating. These homopolymers were studied by differential scanning calorimetry (DSC), broadband dielectric spectroscopy (BDS), dynamic mechanical analysis (DMA), and temperature-programmed ellipsometry. These experiments document the lack of a conventional glass transition in these materials below their decomposition temperature. A series of statistical copolymers of PDTMSS and PDtBS with styrene was synthesized and studied by DSC in an attempt to establish the Tg of the homopolymers by model-based extrapolation.

中文翻译:

某些聚(3,5-二取代苯乙烯)的异常热学性质

在研究含硅二嵌段共聚物的过程中,人们发现,聚(3,5-二(三甲硅烷基)苯乙烯) -嵌段-聚(3,4- methylenedioxystyrene)(PDTMSS- b -PMDOS)显示非常不寻常的热性能。尽管加热到250°C以上,该材料仍可以以自由流动的粉末形式回收。为了更好地理解这种行为,可以使用3,5-二取代苯乙烯,聚(3,5-二(三甲基甲硅烷基)苯乙烯)(PDTMSS)和聚(3,5-二叔丁基)的均聚物制备了丁基丁基苯乙烯(PDtBS)。这些聚合物可溶于常见的有机溶剂,并在旋涂后形成透明的玻璃状薄膜。这些均聚物通过差示扫描量热法(DSC),宽带介电谱(BDS),动态力学分析(DMA)和程序升温椭圆光度法进行了研究。这些实验证明了这些材料在低于其分解温度时缺乏常规的玻璃化转变。通过DSC合成和研究了一系列PDTMSS和PDtBS与苯乙烯的统计共聚物,以试图通过基于模型的外推法确定均聚物的T g
更新日期:2020-07-14
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