聚氨酯偶联麦秸/回收LDPE复合材料的物理及力学性能

以正交分析法研究了自合成的端异氰酸酯聚氨酯(PU)偶联制造麦秸和回收低密度聚乙烯(LDPE)复合材料工艺因子对材料物理及力学性能的影响。研究表明,偶联剂的种类、用量及材料密度是影响材料内结合强度(IB)、2 h沸水后内结合强度(2hWIB)、静曲强度(MOR)和弹性模量(MOE)非常显著的因子;PU游离异氰酸酯基含量愈高、分子量愈大,偶联效果愈好;复合材料的IB、2hWIB、MOR和MOE,均随PU用量及材料密度的增加而递增。180℃,热压时间为1.1 min/mm~1.4 min/mm材料性能最好。以2.0%的PU偶联的麦秸与回收LDPE复合材料,24h吸水厚度膨胀率(24hTS%)及其它各项力学性能指标均超过GB/T4897.7-2003规定的在潮湿状态下使用的增强结构用板要求。

Physical and Mechanical Properties of Wheat Straw/Recycled LDPE Composites with Polyurethane Coupling Agents

The composites were prepared using wheat straw and recycled low density polyrethene(LDPE) as main materials,isocyanate end group polyurethane(PU) synthesized as coupling agents.Orthogonal study results show that coupling agent types and ratios and composite densities are very significant affecting factors on internal bonding strength(IB),boiling water for 2 hour later IB(2hWIB),modulus of rupture(MOR),modulus of elasticity(MOE).Coupling capability increases with increasing free isocyanate group percentage and molecular weight of coupling agents and composite densities.1.1 min/mm~1.4 min/mm is optimizing hot pressing time.With 2.0% PU added,the mechanical properties and thickness expansion ratio of water adsorbing for 24 hour(24hTS%)of the composite exceed the standard GB/T4897.6-2003 for heavy-duty load-bearing boards for use in humid conditions.