Preparation And Properties Of Organic Functionalized Aluminum Hydroxide And Its Intrinsic Flame Retardant Epoxy Resin

Epoxy resin（EP）is one of the important thermosetting polymer materials.Due to its excellent creep resistance,strength,high bonding strength and low curing shrinkage,as well as heat and wear resistance,oil resistance and corrosion resistance,it is widely used in many fields,such as construction,machinery,petrochemical,printing circuit,electronic components and so on.However,EP is extremely flammable,and in the combustion process it will release a lot of smoke and some toxic gases.Therefore,it is necessary to develop green flame retardant to reduce its combustion performance.In this paper,a curing agent with flame retardant properties was designed and prepared.On this basis,intrinsic flame retardant epoxy resin was prepared through curing cross-linking reaction.The main work content is as follows:1.Modified aluminum hydroxide with ethylene diamine tetramethylene phosphonic acid（EDTMPA）and melamine（MEL）to obtain a new functional inorganic curing agent（EA-MEL）,and prepared intrinsic flame-retardant epoxy resin composite material using EA-MEL.Through Fourier transform infrared spectroscopy（FTIR）,X-ray photoelectron spectroscopy（XPS）and scanning electron microscope（SEM）,the composition and surface structure of EA-MEL and its intrinsic flame-retardant epoxy resin composite materials were observed and analyzed.The flame retardant properties of the prepared intrinsic epoxy resin materials were tested,and the possible fire protection mechanism was explored.The flame retardant test showed that the peak heat release rate（p HRR）and peak carbon monoxide release rate（p COPR）of the intrinsic flame-retardant epoxy resin material containing 20 wt%EA-MEL were 849.28 k W/m²and 0.019 g/s,respectively.47.8%and 68.8%lower than pure EP,respectively.2.Phosphoric acid and aluminum hydroxide are reacted to synthesize intermediate aluminum phosphate（PAA）,and then reacted with triazine compound melamine to synthesize a new multifunctional inorganic curing agent（PAAM）;PAAM and epoxy monomers are polycondensed to further prepare intrinsic flame-retardant EP materials.The basic structure and morphology of PAAM were characterized by FTIR,XPS and SEM;the flame-retardant and fire-resistant safety properties of the prepared epoxy resin composite were tested,and the flame-retardant mechanism was studied.The combustion test showed that the p HRR,p COPR and peak carbon dioxide release rate（p CO₂PR）of 20 wt%PAAM intrinsic EP materials were reduced by 60.2%,73.6%and65.6%,respectively,compared with pure EP.3.An aluminum-based inorganic multifunctional curing agent（APEAM）was synthesized with phosphoric acid,aluminum hydroxide,pentaerythritol and melamine;the intrinsic flame-retardant epoxy resin was prepared by cross-linking it with epoxy monomer.The chemical composition and microscopic morphology of APEAM were analyzed by FTIR,XPS and SEM observations;the influence of APEAM on the flame retardant and mechanical properties of EP materials was investigated.The cone calorimetry test showed that the p HRR and p COPR of the 12 wt%APEAM intrinsic flame-retardant epoxy resin were reduced by 68.2%and 53.6%,respectively,and the mechanical performance test showed that the bending strength was increased by 63.3%.