| Epoxy Resin（EPR）is an important thermosetting with excellent resistance toochemical corrosion and mechanical properties such as high mechanical strength,lowshrinkage, electrical insulation properties, strong adhesion and so on.It is Widely usedin paints, adhesives, casting parts (mainly the electrical field), molding materials,composite materials. General the Epoxy Resin is highly flammable, therefore we needthe flame retardant epoxy resins in many fields, so we must modify Epoxy Resin withflame retardant.According to the importance of protecting environment and thedevelopment of halogen-free flame retardant, it is very necessary to develop highlyefficiency flame retardant. Only the cured epoxy resin can be used as useful materialwith excellent properties. The use of the latent curing agent of epoxy resin caneffectively simplify the using processing reduce the cost and improve the productquality. So the development of the latent curing agent with propriety offlame-retardant has well prospects.9,10-dihydro-9-oxa-10-phosphahenanthrene-10oxide(DOPO) and its derivativeshave high thermal stability, were used as reactive flame retardants for many polymers.In this thesis, DOPO derivatives (ODOPM) was synthesized, and was introduced toamine curing agent of boron. This curing agent is synthesized and use in epoxy resinand performs excellent flame retardant and latency properties. This thesissystematically studied the relationship between the amount of ODOPM-BN andproperties of the flame-retardant EPR, such as retardancy, thermal stability and curingreaction; deeply analysed that how the structures of derivatives affected retardancy,thermal stability and curing reaction; made use of Scanning Electron Microscopy(SEM), Fourier Transform Infrared Spectroscopy(FTIR) and Thermal GravimetricAnalysis(TGA) to explore flame retardant mechnism.DOPO derivatives ODOPM which conclude hydroxyl was synthesised by DOPOand formaldehyde.And ODOPM reacted with tributyl borate andN,N-Dimethylethanolamine to get ODOPM-BN which was flame retardantlatent curing agent. Fourier transform infrared spectroscopy (FT-IR) and nuclearmagnetic resonance spectroscopy (NMR) proved that ODOPM involved in theTransesterification.ODOPM-BN and epoxy resin E-51were blend by a certain percentage, and cured in high temperature to prepare flame-retardant epoxy PBN-EPR.When the amount ofODOPM-BN increased, the limited oxygen index (LOI) of PBN-EPR series increased.When the amount of ODOPM-BN was16.7%（ODOPM-BN:E51=20:100）, it couldachieve UL-94V-0level and LOI was35.4%.Using TGA to study that how amount and structure of ODOPM-BN affected thethermal stability of PBN-EPR series. Comparing PBN-EPR with N-EPR cared bydimethylamino-ethanol and BN-EPR cured by boron urethane type curing agent. Theresults show that: PBN-EPR system, the thermal stability and N-EPR rather, BN-EPRsystem, the best thermal stability. With the increased use of ODOPM-BN, PBN-EPRsystem, the initial decomposition temperature decreased; N-PBN char yield (800℃,N2) is only5.7%, while the PBN-EPR3is as high as17.6%, and its flame retardantproperties variation of the same.FTIR and SEM test results for residue carbon layer showed that the Pconcentration in surface was greatly increased and it had a compact structure,indicating that the condensed phase flame retardant mechanism was the main.Using differential scanning calorimetry(DSC) to study the cure curves ofEPR-PBN series, found that the system’s maximum exothermic peak at204℃，at140℃constant temperature no exothermic peak showed in30min，at170℃appear a significant exothermic peak, showed that the curing agent curing had lowactivity at140℃, there is some latent, at170℃showed a good curing ability;PBN-EPR epoxy premixed material was put into60℃water bath，and tested itsstorage life and viscosity increase in48h。The results show that：the storage life ofPBN-EPR,which had contain16.7wt%ODOPM-BN,was7d; the viscosity increase in48h was257%. |
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