The Preparation And Research Of Halogen-free Flame Retardant Epoxy Resins

In this paper, two kinds of halogen-free flame retardant epoxy resin composites wereprepared by using the self-made flame retardant curing agent (MFP) and silicon-containingepoxy resins (EPSi2-1, EPSi3-2). On the basis of the influences of intumescent flameretardant (IFR), silicon dioxide (SiO2) and organophilic montmorillonite (OMMT) werediscussed to cured EP/MFP, and the influences of IFR and OMMT were discussed tosilicon-containing epoxy resins too.The flame retardant curing agent2,4,6-tri (phenol-methylene-amide) triazine(MFP) wassynthesized by melamine, formaldehyde and phenol, and the structrue of MFP wascharacterized by infrared spectroscopy(IR). And adding40%MFP was used to cure Eepoxyresins. The results showed that the limited oxygen index (LOI value) of cured EP/MFPincreased4.1%compared with using ordinary curing agent to cure epoxy resin. On the basisof EP/MFP/IFR composites was prepared by adding IFR into EP/MFP. When the content ofthe IFR was20%, the verticle flaming test of EP/MFP/IFR composites reached FV-0grade,LOI value reached27.3%, and the impact strength increased from0.5KJ/m2to1.22KJ/m2. Inorder to further improve the flame retardant properties of EP/MFP/IFR composites,EP/MFP/IFR/SiO2, EP/MFP/IFR/OMMT composites were prepared, and researched thesynergic flame-retardant effects of SiO2and OMMT. The LOI value of EP/MFP/IFR/OMMTcomposites increased2.3%and the impact strength increased0.16KJ/m2when added2phrOMMT.Two kinds of silicon-containing epoxy resins (EPSi2-1and EPSi3-2) were prepared byepoxy resins and diphenylsilanediol (DPSD), when the molar ratios of EP and DPSD were2:1and3:2. The structures of EPSi2-1and EPSi3-2were characterized by IR. The result showedthat EPSi2-1and EPSi3-2both appeared the vibration of Si-O-C-shrinkage and deformationvibration peaks in1037cm-1and1127cm-1. It meaned that silicon element has beensuccessfully introduced to the structure of epoxy resins. The LOI value of cured EPSi3-2was23.6%compared with current epoxy resin had a2.9%increase, and the impact strength had a 0.45KJ/m2increase. Adding IFR, IFR/OMMT in curing EPSi3-2system, the flame retardantproperties and the impact of impact energy were discussed. When the content of IFR was20%, the verticle flaming test of EPSi3-2/IFR composites reached FV-0grade and the LOIvalue reached27.0%. The LOI value of EP/MFP/IFR/OMMT composites increased1.4%andthe impact strength increased0.13KJ/m2when added2phr OMMT. It showed that OMMThad a good synergic effect with IFR.