Epoxy Resin/SBA-15/Glycidyl Methacrylate Composite Materials And Self-healing Properties

With the wide application of polymer materials in the fields of transportation and construction,an increasing amount of researchers focus on how to prolong the life of materials and reduce safety risks.Mesoporous materials have attractedmore interests,owing to their unique structures and excellent performances,such as uniform controllable pore channels,high specific surface area and continuously adjustable pore size,and interworking channels,similar to human microvascular tubes,thus are applied to a quite extensive fields,such as adsorption,release,micro-reactor,composite materials,and so on.But few researches reported the mesoporous SBA-15 can be used as the carrier of encapsulating healing agent for self-healing materials..In this paper,the modified or unmodified mesoporous SBA-15/epoxy resin composites with self-healing agent were prepared.A series of measures were carried out to characterize the composites.The research contents and results are as follows:?1?Mesoporous material SBA-15 was modified with different silane coupling reagents firstly,then the adsorption and release properties of the mesoporous material on adsorbates methyl methacrylate?MMA?,styrene?St?and glycidyl methacrylate?GMA?were studied at room temperature.The results showed that the saturated adsorption capacity of SBA-15decreased obviously after the surface modification by the coupling agent;However,the adsorption and release rate was very quick at first and then became slow with a balance in the end.The kinetic studies indicated that the adsorption of the mesoporous SBA-15 was in consistent with a Pseudo-second-order kinetic equation,but the release behavior could be described by a First-order kinetic equation.The experimental result of the maximum release amount was in good agreement with theoretical value.?2?The partially crosslinked polyglycidyl methacrylate?PGMA?was synthesized with the redox system of benzoyl peroxide?BPO?and ferrocene?Fc?by bulk polymerization at room temperature.The effects of oxidant and reductant level and reaction temperature on the structure and performance of PGMA were investigated by FT-IR,TGA,DSC and degree of cross linking test system.The results showed that polymerization rate increased and gel and curing time decreased obviously with the increasement of the amount of oxidant.When the amount of oxidant exceeded 5‰of monomer,the polymerization was imploded.The reaction rate increased first and then decreased with the increasing amount of reducing agent,which showed that excessive reducing agent could slow down polymerization or prevent polymerization.With the increasement of polymerization temperature,the gel time of polymerization decreased gradually and the curing temperature decreased first and then increased,until it could not be polymerized.When the mole ratio of GMA:BPO:Fc was 1000:2.5:1,the polymerization system started to gel after 4.5 min,then the polymerization was completely gelled within 25min and the polymer was completely cured after 63 min.?3?A fluorescence probe Amino pyrene was prepared by nitration and aminolation of pyrene,when active oxygen groups in GMA reacted with amino groups in NH₂-Py to generate fluorescent molecules?Py-GMA?with C=C bond.The effects of functional group and solution polarity on the fluorescence molecular light effect were studied and the effect of the fluorescence molecule Py-GMA on GMA polymerization was discussed.The structure and properties were characterized by nuclear magnetic resonance spectroscopy?NMR?,Fourier Transform Infrared Spectrometer?FTIR?and ultraviolet?UV?and fluorescence spectra.The results indicated that the fluorescent label Py-GMA and the fluorescent molecule Py-GMA with a red shift obviously compared with Py,and the fine structure disappeared.The fluorescence color changed from light blue to dark blue,and the light intensity increased significantly.The polarity of the functional group and the solution had great influence on its light intensity and maximum emission wavelength.With the increase of the amount of fluorescent labeling Py-GMA,the gel time and curing time gradually became longer and the chroma gradually deepened.However,with the addition of Py-GMA in excess,the steric hindrance effect greatly actioned,leading to a decrease in the polymerization.?4?The self-healing composite material was prepared by mixing epoxy resin matrix with mesoporous material SBA-15 adsorbed GMA.The effects of the amount of mesoporous materials and the modification of the coupling agent on the mechanical properties,thermal stability and self-healing efficiency of the composites such as tensile,bending,and dynamic mechanical properties were investigated,then the healing mechanism of self-healing materials was also discussed.The results showed that,with theincreasing amount of mesoporous materials,the tensile and bending properties of composites,storage modulus,glass transition temperature and self-healing efficiency increased first and then decreased;The SBA-15modified with coupling agent could improve the distribution of mesoporous materials in the matrix,enhance the compatibility,increase the tensile and bending strength slightly,reduce the Tg slightly and reduce the healing efficiency.The fluorescently labeled healing agent in the mesoporous material was released to the fracture surface,and reacted with catalyst to repair cracks.