一种潜伏性咪唑类中温固化剂的制备和性能研究

Preparation and Properties of a Latent Imidazole Medium Temperature Curing Agent

本课题组用溶液法制备咪唑类过度金属离子络合体系,分别采用六水合氯化钴(CoCl_(2)·6H_(2)O)、六水合氯化镍(NiCl_(2)·6H_(2)O)、六水合三氯化铁(FeCl_(3)·6H_(2)O)、二水合氯化铜(CuCl_(2)·2H_(2)O)为原料,以甲醇为溶剂,对2-乙基-4-甲基咪唑(EMI)进行改性。EMI/水合金属盐按化学摩尔比4:1进行反应,得到具有一定潜伏性的环氧树脂固化剂。通过凝胶时间、DSC测试和力学性能测试,研究了各类过渡金属盐改性咪唑类固化剂固化环氧树脂的反应活性。研究表明,EMI上叔氮原子上的弧对电子与具有空轨道的金属离子形成配位体,阻碍了室温时叔胺的催化作用,使之具有较好的潜伏性。而且,随着过渡金属原子的原子半径的减小,形成的配位体越紧密,潜伏性也就越好,但力学性能却受到相应的影响。

The imidazoles complex system was prepared by solution method.Cobalt hexahydrate(CoCl_(2)·6H_(2)O),nickel hexahydrate(NiCl_(2)·6H_(2)O),iron hexahydrate(FeCl_(3)·6H_(2)O)and copper dihydrate(CuCl_(2)·2H_(2)O)were used as raw materials,and methanol was used as solvent to modify 2-ethyl-4-methylimidazole(EMI).EMI/hydrated metal salts were reacted by chemical molar ratio 4:1 to obtain epoxy resin curing agent with certain potential.The reaction activity of imidazoles modified by transition metal salts was studied by gel time,DSC test and mechanical property test.It is shown that the arc on the supertertiary nitrogen atom of EMI forms a ligand for electrons and metal ions with vacant orbitals,which hinders the catalytic action of tertiary amine at room temperature and makes it have a good latent property.Moreover,as the atomic radius of the transition metal atom decreases,the closer the ligand is formed,the better the latent property is,but the mechanical properties are affected accordingly.