Castor oil based polyurethane adhesive content on OSSB produced with soybean straw

Abstract Oriented Structural Straw Board (OSSB) panels are composites made from straw originally from agricultural residues and non-formaldehyde based adhesive, whose main application is for construction as a closing and ceiling material. The objective of this study was to evaluate the effect of the polyurethane adhesive content on physical and mechanical properties of OSSB produced with locally available SbS (soybean straw). Four castor oil based polyurethane ratios (6%, 9%, 12% and 15%, by mass of the SbS) were tested. OSSB was evaluated according to European standards for wood-based composites; also, a physical and chemical characterization of the SbS was performed. SbS has an irregular shape, which reduced the OSSB mechanical performance due to the low densification of the composite and the development of transversal cracks on the SbS after the OSSB manufacturing process. The static bending and thickness swelling performance of SbS OSSB was not improved by the increase of polyurethane adhesive content. SbS low ash content and neutral pH extractives indicates that probably its chemical properties should not affect the setting of the adhesive.

定向结构秸秆板（Abstract Oriented Structural Straw Board，OSSB）是以农业废弃物秸秆为原料、搭配无醛胶粘剂制备而成的复合材料，主要用作建筑领域的围护与吊顶材料。本研究旨在探究聚氨酯胶粘剂掺量对采用当地取材的大豆秸秆（soybean straw，SbS）制备的OSSB物理与力学性能的影响。试验设置了4种以蓖麻油为基底的聚氨酯胶粘剂掺量，按SbS质量计分别为6%、9%、12%和15%。本研究依据欧洲人造板相关标准对OSSB进行性能测试，并对SbS开展了物理与化学表征。SbS形貌不规则，加之OSSB制备过程中复合材料致密化程度偏低，且SbS在制备后内部产生横向裂纹，最终导致OSSB的力学性能下降。提高聚氨酯胶粘剂掺量并未改善SbS基OSSB的静曲强度与厚度膨胀性能。SbS的灰分含量较低，且其萃取物呈中性pH，表明其化学性质大概率不会影响胶粘剂的固化过程。