Wood Veneer Reinforced with Bacterial Cellulose: Tensile Strength and Dynamic Mechanical Analysis

Abstract

Cellulose from plants is a natural polymer that is very abundant, cheap and easy to process. In addition, there is bacterial cellulose produced from bacterial fermentation of acetic acid with limited production but has high purity, crystallinity, and tensile strength. In this research, the process of wood-veneer delignification was carried out to self-assembly bacterial cellulose into wood cavities on bacterial culture media. Wood veneer reinforced bacteria cellulose was given heat pressure to increase the density and it was expected to form hydrogen bonds between their cellulose molecular chains. This study observed the duration of fermentation in bacterial media culture on the tensile strength of hybrid veneers, microscopic observations, the effect of water on set-recovery, and the characteristics of solid veneers on cyclic loading and temperature using dynamic mechanical analysis (DMA) testing. The microscopic observations prove that Acetobacter xylinum can penetrate the veneer and assemble bacterial cellulose in the cavity. A higher tensile strength ratio of 81.38% was observed in densified veneers with a five-day fermentation period with a modulus of elasticity 156.63% higher than natural veneers. The minimum set-recovery after boiling the hybrid veneer was 29.32%. DMA showed that by reinforcing wood veneer with bacterial cellulose and compacting, it increased cyclic energy storage ability, reduced energy loss, and increased stability under increasing temperatures. Strengthening wood with bacterial cellulose in this method opens new potential for developing more environmentally friendly forest products in the future.

Energy absorption of densified veneer-aramid hybrid composites subjected to ballistic impact

“…This has been estimated because the tensile strength of aramid fiber is around 3000 MPa. It is stronger than the tensile strength of BC-densified veneer, which is about 140–190 MPa [ 21 ]. However, the BC-densified veneer with epoxy-reinforced laminate contributed to the absorption of ballistic energy in the hybrid panel.…”

“…Because bacterial cellulose products can be degraded in the soil for 5–6 weeks, making them environmentally friendly [ 19 ]. We previously reported the ability of cellulose bacteria to penetrate the wood pores and the interaction of cellulose bacteria with fibers to form hydrogen bonds in the veneer [ 20 , 21 ]. This process involved the self-assembly of bacterial cellulose in situ in a culture medium by Acetobacter xylinum in the veneer fibers.…”

Bacteria Cellulose and Resin Stabilization in Densified Veneer

“…Wood delignification is required to remove lignin and hemicellulose. The veneer sample is delignified by boiling it in a 1 M NaOH solution in beaker glass at 90 C for 90 minutes [10,11]. After that, it was washed with water.…”

“…BC is also able to increase the surface bond between polymer adhesives and natural fibers [9]. Previously, we discovered Acetobacter xylinum could enter the veneer cavity and form a pellicle in the culture medium [10].The finished product is a densified hybrid veneer-BC with improved mechanical strength [11]. Elastic deformation occurs during microfiber, recovery to original shape is possible.…”