【作者】 王伟；

【导师】 谢海安；

【作者基本信息】 武汉理工大学 ， 材料学， 2008， 硕士

【摘要】 环氧树脂(EP)是工业中重要的热固性树脂之一。由于其优秀的附着性、高强度以及抗化学腐蚀性,被广泛的应用于黏结剂、涂料、封装材料等领域。然而,由于环氧树脂的固化密度高所引起的脆性大和抗冲击性差的缺点阻碍了其进一步的应用。本文研究的主要目的是将聚氨酯预聚体加入到环氧树脂体系中,形成环氧树脂/聚氨酯互穿网络聚合体(EP/PU IPNs),得到EP/PU复合材料。通过力学测试,DSC,TGA,SEM等方法研究改性材料的机械性能、热性能以及微观结构,并通过非等温DSC法研究了改性材料的固化动力学。实验考察了反应时间和反应温度对聚氨酯预聚物的影响,得到了制备聚氨酯预聚物的适宜温度为70℃,反应时间为70～90min。对聚氨酯预聚物的红外分析表明,各官能团基本反应完全,得到了预期的产物,并讨论了水对预聚物的影响因素。力学测试表明,用聚氨酯改性后的环氧树脂的韧性得到了很大程度的提高,同时其力学性能也有较大的提高。对端异氰酸酯基聚氨酯改性环氧树脂而言,15%的聚氨酯与环氧树脂能够很好的形成互穿网络结构,使得互穿材料的拉伸性能比纯环氧树脂的提高了48.1%,冲击强度提高了14.9%;对端羟基聚氨酯改性环氧树脂而言,12%的聚氨酯与环氧树脂能够很好的形成互穿网络结构,使得互穿材料的拉伸性能比纯环氧树脂的提高了23.7%,冲击强度提高了78.9%。TG-DSC研究表明,聚氨酯改性环氧树脂的热稳定性较纯环氧树脂有较大的提高。这是因为聚氨酯和环氧树脂形成了两相互穿网络结构,使其热稳定性大幅增强。采用非等温DSC法对改性环氧树脂的固化动力学研究表明,填加了PU的改性EP的表观活化能降低,固化反应的活性提高。更多还原

【Abstract】 Epoxy resins(EP)are the most important class of thermosetting matrices used in engineering because of their outstanding adhesion to most surfaces,high mechanical strength,and chemical resistance.They have been used as adhesives,coatings and resin matrices for advanced composites. However,their brittle behavior with low elongation and impact strength restrict the utility for high performance applications.The major concern of this paper is to study the preparation of the EP/PU IPNs on improving mechanical and thermal properties of pure EP were investigated by mechanical test,SEM,TEM,DSC,TGA.And EP/PU IPNs’ curing dynamics is researched by using Non-uniform temperature DSC methard.Reaction time and reaction temperature of the PU prepolymer are researched,and obtained the preparation matters concerned temperature for 70℃,the reaction time is 70～90min.Indicated to the polyurethane prepolymer’s infrared analysis that the various functional groups are complete reacted,obtained the anticipated product,and discussed the water’s influence to the prepolymer.Mechanics test indicated that the mechanical properties of the epoxy resin with polyurethane modificated was strengthened while its toughness improved highly.For the epoxy resin with wt15%-NCO terminated polyurethane modificated,the tensile strength of EP/PU IPNs could increase by 48.1%,the impact strength could increase by 14.9%,which compared with pure epoxy resin.For the epoxy resin with 12%-OH terminated polyurethane modificated,the tensile strength of EP/PU IPNs could increase by23.7%,the impact strength could increase by 78.9%.TG-DSC showed the thermostability of hybrid materials were greatly improved,because the IPNs were formed mutually by polyurethane and epoxy resin,which improved its thermostabilit’y in a wide range.Non-uniform temperature DSC test indicated that,compared with pure epoxy resin,the apparent activation e.nergy of the modified epoxy resin with polyurethane decreased and its activity of curing reaction increased.更多还原