Dynamic viscoelastic properties of wood and acetylated wood in nonequilibrium states swollen by water or organic liquids

Abstract

Abstract To discuss the factors that greatly affect the stabilization and destabilization of the conformation of lignin caused by changes in temperature and/or swelling, the temperature dependence of the loss tangent (tanδ) of the sample given the different cooling rates and the changes in the storage elastic modulus (E′) and the loss elastic modulus (Eʺ) over time during the swelling process were measured using the untreated or the acetylated wood samples swollen by water or organic liquids. The difference in the glass transition temperature of lignin mainly affects the degree of the destabilization of the conformation of lignin caused by quenching in the untreated and acetylated wood samples. The changes in E′ and Eʺ during swelling process were significantly different between the liquids in the untreated wood sample. The differences of E′ and Eʺ in the different liquids were considered to be caused by the balance of the stabilization depending on the swelling amount and passage of time and the destabilization due to the rapid swelling.

Keywords

• Organic liquid
• Swelling rate
• Destabilization
• Conformation of lignin
• Quenching