DGEBF/DDS体系固化动力学机理的研究

以4,4′-二氨基二苯砜(DDS)胺类固化剂固化9,9-二4-(2,3环氧丙氧基)苯基]芴(DGEBF),采用非等温DSC法推导了固化反应参数和固化机理,并用原位红外和移动窗口二维相关红外分析对固化机理和固化模式进行了验证。结果表明:DGEBF/DDS体系固化反应的表观活化能为64.08 kJ/mol,扩散因子为4.05×104s-1,反应级数为1.55;固化工艺为150℃/1.5 h+190℃/2 h+220℃/1.5 h;固化模式为枝状成核的自催化反应;固化机理为伯胺先与环氧基反应生成仲胺,肿胺继续与环氧基反应生成叔胺,2个反应同时进行,以及在高温下的羟基与环氧基的自催化反应,交联的固化网络逐渐形成。

Study of curing kinetics mechanism of DGEBF/DDS

The curing kinetics mechanism and reaction parameters of 9,9′bis4-(2,3-epoxyproxy)phenyl]fluorene using 4,4′-diaminodiphenyl sulfone(DDS) as curing agent were investigated with a non-isothermal differential scanning calorimeter(DSC).The curing reaction mechanism and model were studied by in-situ infrared spectroscopy combined with moving-window two-dimensional(MW2D) correlation spectroscopy.The results showed that the apparent activation energy,diffusion factor and reaction order of curing reaction were 64.08 kJ/mol,3.80×104 s-1 and 1.55 respectivly.The curing process was determinated as being 150 ℃/1.5 h+190 ℃/2 h+220 ℃/1.5 h.The curing mode was auto-catalyze reaction forming branch-like reaction center.The curing mechanism was an epoxy group reacted with a primary amine containing a hydroxyl group and a secondary amine,then a secondary amine reacted with another epoxy group and formed a tertiary amine and a hydroxyl group.The two reactions were independent and a hydroxyl group reacted with an epoxy group to form a hydroxyl group at high temperature,then the curing crossing networks formed gradually.