Thermopressed binderless fiberboards from wheat straw by adding black liquor
For the shortage of timber resources and the sake of the formaldehyde emissions, people desire to use non-adhesive bonding technology. This paper studies the chemical composites of black liquor, at different contents ranging from 20 to 40 wt%, into fiberboards made from wheat straw pulp. Adding a little black liquor has positive effect on qualities of boards, contributing to presence of proteins and lignin in black liquor, but adding too much liquor would decrease properties of them for the ash content. The FT-IR measurements indicated that there are more low-molecular substance and hydrogen bonds producing after fining and thermopressing processes. The thermo analysis were conducted to better understand these results. The physical and mechanical properties of the resulting fiberboard were evaluated. The results showed that binderless fiberboards by adding 30 wt% have good mechanical and water resistance properties which can partly satisfy the requirements of the relevant standards specifications.