Hemicellulose-rich transparent wood: Microstructure and macroscopic properties.

Hemicellulose plays a vital role in nature wood matrix. Here, we first demonstrate the significance of hemicellulose for improving the microstructure and macroscopic properties of transparent wood (i.e. wood/polymer composite), an emerging structural material. A delignified basswood templet with high hemicellulose content (~23 wt%) and well-preserved cellulose supramolecular structure was prepared via a peracetic acid-based process. This hemicellulose-rich delignified wood templet possesses nearly intact cell wall structure and sufficient space in the lumen and middle lamella for petroleum-based polymer space-filling. Consequently, the resultant hemicellulose-rich wood/PMMA composite exhibits high optical transmittance (~85 %), medium haze (~72 %), acceptable optical stability as well as excellent mechanical strength (tensile strength of 165.3 MPa and toughness of 1.65 MJ/m), benefitting from the absence of microstructural defects and heterogeneity in the matrix. It is anticipated that our study would provide new insights into the fabrication of advanced transparent wood material from the point-of-view of wood chemical composition.