异氰酸酯对木塑力学性能与疏水性的影响

将木粉表面的羟基分别与异氟尔酮二异氰酸酯(IPDI)、甲苯二异氰酸酯(TDI)反应,再与聚乙烯(PE)通过挤出混合,挤出成型制备出了不同处理效果的木塑复合材料(WPC)。在不同种类和不同浓度的条件下,异氰酸酯改性木粉对木塑复合材料(WPC)的力学性能以及吸水率具有不同的影响。红外光谱(FTIR)和接触角测试表明,异氰酸酯成功接枝到木粉上。采用场发射扫描电子显微镜(FESEM)观察木粉与聚乙烯(PE)的相容性变化,通过微机控制电子万能试验机测试不同处理条件下的木塑复合材料力学性能,并参照GB/T 1462—2005计算了木塑吸水率。结果表明,在质量比为TDI∶木粉=5∶100条件下,木塑的力学性能和疏水效果最佳,拉伸强度达到27.8±0.7 MPa,浸入水中48 h吸水率达到0.45%。

Effect of Isocyanate on Mechanical Properties and Hydrophobicity of WPC

The hydroxyl groups of wood flour on the surface was reacted with 3-Isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate(IPDI),toluene diisocyanate(TDI),and mixed with polyethylene(PE)to prepare wood-plastic composite(WPC)with different conditions.The effects of wood flour modified by isocyanate on the mechanical properties and water absorption rate were also investigated under different kinds and concentrations condition.The Infrared spectroscopy(FTIR)and contact angle proved that isocyanate was successfully grafted onto the wood flour.Field emission scanning electron microscope(FESEM)was observed to deal with the change of compatibility between wood flour and polyethylene(PE),the mechanical properties of WPC under different treatment conditions were obtained by microcomputer controlled electronic universal testing machine,and the water absorption rate of WPC under different treatment conditions was obtained by GB/T 1462—2005.The results showed that the quality ratio at TDI∶wood powder=5∶100,WPC has the best mechanical properties and hydrophobic,the tensile strength reached 27.8±0.7 MPa and water absorption reached 0.45%after 48 hours immersion.