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Chemical Research in Chinese Universities ›› 2000, Vol. 16 ›› Issue (4): 363-368.

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Studies on the Condensed Structure of Vacuum Cast Atactic Polystyrene Films

WANG You1, HE Chu-ning1, SHEN Jing-shu1, WU Li-heng2, SONG Qing2   

  1. 1. Polymer Physics Laboratory, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China;
    2. China Textile Academy, Beijing 100025, China
  • Received:2000-01-17 Online:2000-12-24 Published:2011-09-09
  • Supported by:

    Supported by the National Key Fundamental Research——"Macromolecular Condensed State" the State Scienceand Technology Commission of China.

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Abstract: The condensed structure of atactic-polystyrene (a - PS ) films cast from the solutions of differ- ent concentrations in dichloromethane under vacuum and atmospheric conditions was studied by differential scanning calorimetry(DSC).It was found that only under vacuum evaporating conditions did the endothermic peak in the DSCcurves of a-PSfilms depend on the concentration of the a-PSsolution.For the samples cast from the solution of concentration below 0.010 g/mL, no endothermal peak was observed, but for those cast from the solution of concentration above 0.020 g/mL, obvious endothermal peaks appeared.The onset of the endothermal peak is correlated with the critical overlapping concentration c* (0.010-0.020 g/mL), which is in agreement with the theoretically calculated one (C*cal=0.014 g/mL).

Key words: Differential scanning calorimeter(DSC), Critical overlapping concentration, Atactic polystyrene film