Properties Of Rice Straw Particleboard Based On The Adhesive Of Soy Protein Isolate Modificaotion

Energy conservation, resources substitution, environment protection and economic sustainable development have been the main concepts of modern society. Most of the adhesives used for a considerable extent such as furniture, indoor decoration, packaging, construction, dining, etc. are based on petroleum products, which prove to be non-renewable and also pollute the environment. Petroleum alternatives made from renewable resources have been a new research area for scientists all over the world. The goal of this study was two fold. The first was to modify the soy protein isolate (SPI) and obtain environmental friendly adhesive. The second was to make rice straw particleboard bonded with SPI adhesive and provide scientific basis and reasonable technology for the parameter optimization and product evaluation of straw particleboard. This research would make great contribution to promote the utilization of renewable resources and agriculture products, and protect the ecologic environment and forest resources. The main research contents and results were as follows:1. Modification of soy protein isolate (SPI)SPIwas modified by chemical method. The adhesive properties of modified SPI were investigated. The effect of different concentrations of SPI and modifying reagent, modifying temperature, modifying time, on the extent of modification was also evaluated. The result showed that SPI adhesive had the highest adhesive strength (5.58MPa) with the modification of 0.2% NaOH solution at 40℃. It's also proved that 3mol/l urea solution could also result in an excellent adhesive property (3.46MPa) at normal temperature.2. Evaluation of particleboard made from rice straw bonded with NaOH modified SPI adhesiveThe effects of mold pressing temperature, mold pressing pressure, mold pressing time, initial moisture content of NaOH modified SPI adhesive coated rice straw, etc. on the mechanical properties of strawboard were investigated. The strawboard bonded with NaOH modified SPI adhesive showed the best properties with the temperature of 140℃, pressure of 8MPa, time of 10 min, and initial moisture content of 30%. The properties are as the following: tensile strength 2.70MPa, modulus of rupture 8.42MPa, modulus of elasticity 456.33MPa, and with the water absorption of 102.34%. 3. Evaluation of particleboard made from rice straw bonded with urea modified SPI adhesiveThe effects of mold pressing temperature, mold pressing pressure, mold pressing time, initial moisture content of urea modified SPI adhesive coated rice straw, etc. on the mechanical properties of strawboard were investigated. The strawboard bonded with urea modified SPI adhesive showed the best properties with the temperature of 150℃, pressure of 8MPa, time of 20 min, and initial moisture content of 30%. The properties are as the following: tensile strength 1.92MPa, modulus of rupture 12.9MPa, modulus of elasticity 581.16MPa, and with the water absorption of 112.09%.