马来酸酐偶联剂对麦秸/废旧聚丙烯复合材料性能的影响

The effect of coupling agent on propertiesof wheat straw/PP composite

以麦秸和废旧聚丙烯为原料,以马来酸酐作为偶联剂,异氰酸酯(MDI)作为胶黏剂,采用热压工艺压制麦秸/废旧聚丙烯复合材料,通过正交实验研究了偶联剂对该复合材料力学性能的影响。结果表明:单独施用马来酸酐偶联剂,内结合强度极低,静曲强度较低,吸水厚度膨胀率较高,板材性能差;与施用马来酸酐偶联剂相比较,单独施用MDI胶黏剂,内结合强度提高,吸水厚度膨胀率值降低,材料的综合性能好于施用马来酸酐偶联剂的情况,但还不能完全达到刨花板国家标准(GB/T4897.1-4897.7-2003)要求;同时施用马来酸酐偶联剂和MDI胶黏剂时,除密度对内结合强度影响较大外,聚丙烯含量对内结合强度、马来酸酐用量对内结合强度、施胶量对静曲强度和吸水厚度膨胀率均有显著影响,其中马来酸酐用量对内结合强度的影响最为显著。但过多的马来酸酐不但起不到促进作用,反而影响了胶黏剂的胶结性能。

In order to reuse the waste from cities and countryside, the wheat straw and recycled Polypropylene （PP） were used to manufacture composite material as a nice attempt. In the test, maleic anhydride was used to be coupling agent and diphenyl methane diisocyanate （MDI） was used as material, Wheat straw/PP composite was manufactured with hot press process through orthogonal experiments to study the effect of coupling agent on mechanical properties of the composite. The results showed that： a. When maleic anhydride, the coupling agent, is only used in the material manufacturing, the key properties of the final product, such as internal bonding strength, bending strength, and thickness swelling, are poor. b. When MDI adhesive is only used in the material manufacturing, the main properties of the final product are improved comparing to the case that maleic anhydride is only used as coupling agent, but the final product is still not tallying with Chinese National Particle Board Standard （GB/T4897.1-4897.7-2003）. c. When both of maleic anhydride coupling agent and MDI adhesive were used simultaneously, the properties of wheat straw/pp composite are changed into a better level. The composite density, PP content, and maleic anhydride coupling agent content significantly affected the internal bonding strength of composite. Adhesive applying content significantly affected the bending strength, the thickness swelling and the internal bonding strength of the final product. Further, the content of maleic anhydride coupling agent high significantly affected the internal bonding strength. In hot pressing, maleic anhydride coupling agent has made the cross-linked bridge between straws and PP, and also has been helpful for the improving of the final product. However, over applying of maleic anhydride coupling agent Could adversely affect the function of adhesive and would not enhance the properties of the composite material.