Transformation of a Kurome natural lacquer film from glassy to rubbery polymer by the presence of moisture

• Published in: Progress in organic coatings Vol. 104; pp. 43 - 49
• Main Authors: Sato, Shuichi, Ido, Ryohei, Ose, Takamasa, Takahashi, Yoichi, Kanehashi, Shinji, Ishimura, Takahisa, Honda, Takayuki, Miyakoshi, Tetsuo, Nagai, Kazukiyo
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-03-2017; Elsevier BV
• Subjects: Carbon dioxide; Dissolved gas; Emulsion polymerization; Gas permeability; Gas permeation; Kurome natural lacquer film; Moisture; Natural gas; Oxygen; Permeability; Polymer films; Polymers; Temperature dependence; Water vapor; Water vapor permeability; Temperature dependence; Gas permeability; Kurome natural lacquer film; Dissolved gas; Water vapor permeability
• ISSN: 0300-9440; 1873-331X
• DOI: 10.1016/j.porgcoat.2016.12.003

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•Gas permeability through a Kurome natural lacquer film was investigated.•Gas permeation behavior in a dry state is indicative of glassy polymers.•Gas permeation behavior in a wet state is indicative of rubbery polymers.•Lacquer films can adapt to different environments in the presence of moisture.
The permeabilities of gaseous and dissolved (in water) oxygen and carbon dioxide through a Kurome natural lacquer film, as well as the water vapor permeability, were systematically investigated. The Kurome lacquer films contained water in their oil emulsion structure, and the films had phase-separated structures with hydrophobic glassy (i.e., urushiol) and hydrophilic rubbery (i.e., polysaccharide) polymer components. The Kurome lacquer films exhibited a relatively higher permeability for water vapor than for oxygen and carbon dioxide, indicating that the presence of hydrophilic components influenced the water vapor permeability. The gas permeation behavior of the Kurome lacquer films revealed that they behave like glassy and rubbery polymers in the dry and wet states, respectively. Thus, Kurome lacquer films are polymer materials that adapt to different environments in the presence of moisture.