为制备耐水性能优良且绿色环保的木质复合材料,以高密度聚乙烯塑料( HDPE)为主要黏接剂制备定向木塑复合刨花板,研究HDPE含量(0%~16%)和分布对定向木塑复合刨花板物理力学性能的影响。研究结果表明:定向木塑复合刨花板的弹性模量、静曲强度和内结合强度随HDPE含量的增大而增大,当HDPE含量达到12%时,上述性能在试验范围内达到最大值;塑料含量继续增加则力学性能均有降低的趋势。 HDPE添加量越多,定向木塑复合刨花板的吸水厚度膨胀率越小,且均低于8%。 HDPE在板坯中均匀分布时静曲强度最高,当HDPE仅分布在上下表面时内结合强度最大,且吸水厚度膨胀率较低。
In order to fabricate environmental?friendly wood?based composites with better water resistance, high?density polyethylene ( HDPE) was used as the main adhesive and polydiphenylmethane diisocyanate ( MDI) was used as a cou?pling agent to make oriented strand plastic board ( OSPB) by hot?pressing technology. The effects of HDPE content ( 0%, 4%, 8%, 12% and 16%) and its distribution ( uniform distribution, only in surface layers, only in core layer) in mat on physical and mechanical properties of OSPB were investigated. The results showed that the modulus of rupture ( MOR) , modulus of elasticity ( MOE) and internal bond strength ( IB) increased with the increase of HDPE content, and these values reached the maximum when HDPE content was 12%. When the HDPE content was more than 12%, the mechanical properties of OSPB decreased. Compared with the oriented strand board without HDPE, MOR, MOE and IB of OSPB with 12% HDPE increased by 18.3%, 11.9% and 50.8%, respectively, indicating that the addition of HDPE had the most significant influence on IB. The thickness swelling of OSPB decreased with the increase of HDPE content. However, the thickness swellings of all samples were below 8%, which makes OSPB have the potential application in humid environments. The HDPE distribution in the mat had slight influence on MOE but had great effects on IB and thickness swelling. Maximum of MOR was obtained when HDPE was homogeneously distributed in the mat. Maximum of IB and the lowest thickness swelling properties of OSPB were obtained when HDPE was only placed on the top and bot?tom layers of mat. Regarding the effect of the fiber direction on mechanical properties of OSPB, the perpendicular direc?tion had similar trends, and the maximum of MOR, MOE and IB were 74?0 MPa, 8?4 GPa and 0?98 MPa, respective?ly. Compared with the traditional oriented strand board and other wood?based composites, OSPB had better mechanical and physical properties, which will make OSPB potentially applied to building, furniture, indoor and outdoor decoration.