ガラス状態とガラス転移―その解明と応用への新展開　ＩＩ　カルボキシメチルセルロース‐不凍水系のガラス転移近傍の熱容量

DOI

書誌事項

タイトル別名
  • Glassy State and Glass Transition-Its Elucidation and New Applications. II. Heat Capacities of Carboxymethylcellulose-Nonfreezing Water Systems at around Glass Transition Temperature.

抄録

Heat capacities (Cp) of carboxymethylcellulose (CMC) and CMC-water systems were measured by differential scanning calorimetry (DSC). Molecular weight (Mw) of CMC ranged from 1.7×104 to 3.8×105, and degree of substitution (DS) ranged from 0.6 to 1.7. Cp's of CMC in the dry state were 1.2 to 1.5 J/g·°C in the glassy region, regardless of Mw and DS. Glass transition temperature (Tg) of CMC in the dry state was maintained at around 135°C, regardless of Mw (DS=1.4), and Tg slightly increased with increasing DS. Tg of CMC decreased from ca. 135°C to -85°C on addition of 0.2 to 0.5 (g/g) of water (water content, Wc= mass of water/mass of dry sample). Water molecules in the above systems are categorized into nonfreezing water which is calculated by subtraction of the mass of freezing water from the total mass of water. It was found that Cp's at the glassy state markedly decreased in the presence of nonfreezing water. The minimum Cp value (ca. 0.5-1.4 J/g·°C) was found at around Wc = 0.3. The above facts suggest that CMC molecules take more stable states in the presence of nonfreezing water.

収録刊行物

  • 高分子論文集

    高分子論文集 53 (12), 860-865, 1996

    公益社団法人 高分子学会

キーワード

詳細情報 詳細情報について

  • CRID
    1390001206521601024
  • NII論文ID
    130004035152
  • DOI
    10.1295/koron.53.860
  • ISSN
    18815685
    03862186
  • 本文言語コード
    ja
  • データソース種別
    • JaLC
    • Crossref
    • CiNii Articles
  • 抄録ライセンスフラグ
    使用不可

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