Synthesis And Properties Of Epoxy Resins Based On Fluorene Structure

Epoxy molding compounds are playing an important role in micro-electronicspackage technology, owing to their high reliability, cheap-cost, easy-processing propertiesand so on. But traditional epoxy molding compounds are facing great challenges for bothof the voice from ever-rising environmental protection and the needs of improvingproperties of electronic encapsulating materials for integrated circuit industry. Therefore,it's necessarily to research and development of the new high performance epoxy moldingcompounds.Considering the potential use of epoxy resins, diglycidyl ether of9,9-bis(4-hydroxyphenyl) fluorene (DGEBF) was synthesized and the structure ofDGEBF was confirmed by means of Fourier transform infrared spectrometer (FT-IR)nuclear magnetic resonance (~1H-NMR) and mass spectrometry (MS). The DGEBF anddiglycidyl ether of bisphenol A (DGEBA) were cured with 4,4-(9-fluorenylidene)--dianiline(FDA) and 4,4-diaminodiphenyl methane (DDM), respectively. The curingkinetics of these four systems (DGEBF—DDM,DGEBF—FDA,DGEBA—DDM,DGEBA—FDA) were studied by non-isothermal differential scanning calorimetry (DSC)method and simulated by the method of Kissinger and Ozawa. With the enhancement offluorene content, the activation energy E were increased, the reaction rate constant k weredecreased, but the the order of reaction n were unchanged, and the infuence was muchmore evidence when fluorene structure were in curing agents. In order to ensure the betterproperties of the resins, the optimal curing condition of these four systems wereconfirmed. The thermogravimetric analysis (TGA) and high-resolution pyrolysis gaschromatography-mass spectrometry (HR PyGC-MS) were used to measure the thermalproperties of the cued resins. The values of degradation activation energy E_d and the charyield of bisphenol fluorene epoxy resins were higher than that of bisphenol A epoxy resins, and the degradation mechanism were similar. Dynamic mechanical analysis (DMA)was used to investigate T_g values of the cured resins. The T_g values of these resins wereincreased with the increasing of the fluorene content, and the enhancement was muchmore evidence when fluorene structure were in epoxy resins. Therefore, the introductionof a fluorene structure into the epoxy skeleton is an effective way to increase the thermalstability, heat-resistance and flame retardant properties of resins.