聚氨酯改性环氧树脂结构胶粘剂制备及结构表征

【作者】 丑纪能；

【导师】 邓飞跃； 李芝华；

【作者基本信息】 中南大学 ， 分析化学， 2007， 硕士

【摘要】 本论文以TDE-85环氧树脂与E-51环氧树脂共混组成混合环氧树脂基体，选用聚氨酯(PU)与环氧树脂(EP)形成互穿聚合物网络(IPN)对环氧树脂进行增韧，制备了150℃固化耐高温环氧树脂结构胶粘剂。通过差示扫描量热分析确定PU／EP IPN体系的最佳固化条件，并对PU／EP IPN体系固化反应动力学进行了研究；通过红外光谱对PU／EP IPN体系进行了结构表征，探讨了聚氨酯改性环氧树脂反应机理；通过扫描电子显微镜(SEM)对冲击断口进行分析，研究了PU／EP IPN材料的两相相容性及形貌特征；通过热重分析对PU／EP IPN材料热稳定性进行研究。运用电子万能试验机测定聚氨酯改性环氧树脂结构胶粘剂的室温拉伸剪切强度、160℃高温拉伸剪切强度和室温剥离强度，对组成环氧树脂结构胶粘剂的组分及添加量进行优化。研究结果表明：PU／EP IPN体系活化能为69.18KJ／mol，反应级数为0.901。聚氨酯改性环氧树脂体系中存在三种反应，即聚氨酯预聚体与1，4丁二醇的扩链反应，聚氨酯预聚体与环氧树脂的化学交联反应，环氧树脂与混合芳胺固化剂的固化反应，固化体系反应最终生成交联网状聚合物；随PU／EP增大，PU／EP IPN表面形貌由“海岛结构”向双连续相结构转变；环氧树脂经聚氨酯改性后，力学性能大幅上升，随聚氨酯添加量的增加，PU／EP IPN材料力学性能呈先上升后下降趋势；PU／EP IPN材料在低温区间的热稳定性与PU／EP IPN材料互穿程度有关。在聚氨酯添加量和混合芳胺固化剂添加量分别为环氧树脂质量的30％和33％时，聚氨酯改性环氧树脂胶粘剂综合性能最优。最终制备的聚氨酯改性环氧树脂结构胶粘剂，室温拉伸剪切强度为25.81Mpa，160℃高温拉伸剪切强度为12.85Mpa，剥离强度为51.68N／cm，能够满足耐高温结构胶粘剂使用要求。更多还原

【Abstract】 Epoxy resin structureal adhesive with high temperature resistance cured at 150°C was prepared by polyurethane/epoxy interpenetrate polymer network (IPN) method in this research. Epoxy resin TDE-85 and epoxy resin E-51 was selected as resin matrix.The optimum curing condition was determined by examining the DSC curve of PU/EP IPN system. The characterization of the IPN structure was performed by the IR method. The phase compatibility and pattern features of two phase was analyzed by scanning electron microscopy (SEM). The curing reaction kinetics about this systems was studied and the apparent activated energy was examined. The thermostability of the PU/EP IPN materials was estimated by TG studies. Adhesive mechanical properties of different components and their addition have been evaluated in terms of the shear strength at room temperature and high temperature and peel strength at room temperature by the electronic powerful testing machine.The research results indicate: The kinetics calculation of the PU/EP IPN system is 69.18KJ/mol and the curing reaction order of PU/EP IPN system is 0.901. There are three kinds chemical reaction in the PU/EP IPN system: the chain-extended reaction between 1,4-butanediol and PU prepolymer, the two-phase chemical reaction between epoxy resin and PU prepolymer, the curing reaction between epoxy resin and aromatic amine.The network polymer is formed at end. The morphology of the PU/EP IPN materials from the "sea island" to "double continuous phase" as a function of the ratio of PU/EP rise, The mechanical properties of the PU/EP IPN materials improve obviously toward unmodified materials and increase then decline with the increasing of PU. The thermostability of the PU/EP IPN materials in the low temperature section affect by the structure of the PU/EP IPN.While the mass fraction of PU210 and aromatic amine are 30% and 33% respectively.The integrative properties of the adhesives reach to top, the shear strength is 25.81Mpa at room temperature and 12.85Mpa at 160°C, the peel strength is 51.68N/cm.The adhesives satisfy with the demand of structure adhesives with high temperature resistance.更多还原