Moisture-induced crossover in the thermodynamic and mechanical response of hydrophilic biopolymer

Autor: Benoit Coasne, Chi Zhang, Dominique Derome, Robert A. Guyer, Jan Carmeliet
Přispěvatelé: CNRS and Université Grenoble Alpes, 38041 Grenoble, France
Rok vydání: 2019
Předmět:
Zdroj: Cellulose, 27 (1)
Cellulose
Cellulose, Springer Verlag, 2020, 27 (1), pp.89-99. ⟨10.1007/s10570-019-02808-z⟩
Cellulose (London, England)
ISSN: 1572-882X
0969-0239
Popis: The use of natural sustainable resources such as wood in green industrial processes is currently limited by our poor understanding of the impact of moisture on their thermodynamic and mechanical behaviors. Here, a molecular dynamics approach is used to investigate the physical response of a typical hydrophilic biopolymer in softwood hemicellulose—xylan—when subjected to moisture adsorption. A unique moisture-induced crossover is found in the thermodynamic and mechanical properties of this prototypical biopolymer with many quantities such as the heat of adsorption, heat capacity, thermal expansion and elastic moduli exhibiting a marked evolution change for a moisture content about 30 wt%. By investigating the microscopic structure of the confined water molecules and the polymer–water interfacial area, the molecular mechanism responsible for this crossover is shown to correspond to the formation of a double-layer adsorbed film along the amorphous polymeric chains. In addition to this moisture-induced crossover, many properties of the hydrated biopolymer are found to obey simple material models.
Cellulose, 27 (1)
ISSN:1572-882X
ISSN:0969-0239
Databáze: OpenAIRE
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