Study On Biomass Material Reinforced Epoxy And Its Curing Kinetics

With the rapid development and progress of society in recent decades,great convenience has been brought to people's lives,while resources are constantly exhausted,the environment is deteriorating constantly while people's awareness of environmental protection has gradually increased.Green technologies,energy-saving,environmental protection have become a hot issue in the modern world of chemical research.Biomass materials because of its advantages of low cost,degradable,pollution-free and so on,have been widely studied by researchers.Epoxy based plastics is widely used in engineering applications and daily life house hold items,but its brittleness and poor toughness limit the ues for high performance applications.In this study,biomass materials,Catechu(AC)and walnut shell powder(WSP)were used to reinforc the system containing epoxy resin(E51),and 4,4-diaminodiphenylmethane(DDM)curing agent.The biomass material and resin matrix were mixed evenly by mechanical stirring and ultrasonic treatment.Then stoichiometric amount of DDM was added and mixed evenly and cured to prepare biomass toughened epoxy resin material.DSC non-isothermal method was used to study the curing kinetics of AC and WSP at different additions.Extrapolation method was used to determine the curing process of each system,Kissinger method was used to calculate the activation energy of each system,Málek method was used to calculate the kinetic equation,and FWO method was used to study the change of activation energy at different conversion rates.The results showed that the kinetics of reaction of epoxy resin was not developed before and after adding biomass.The activation energy of each system lies in between 48-53 kJ/mol.SB(m,n)model can better simulate the non-isothermal curing reaction of each system.Extrapolation method and experimental procedure confirm that the curing process is 80?2h and 135?3h.FT-IR,TGA,DSC,DMA,universal material testing machine and drop hammer impact testing machine were used to test the matrix structure,thermodynamic properties,mechanical properties and toughness of various groups of biomass toughened epoxy resin materials.The results show that:(1)The toughness of the material is obviously improved after adding AC.When AC content is 1wt%,the toughness and impact resistance of the material are 94.20%and 52.8%higher than that of pure epoxy resin respectively.The tensile and bending strength are also slightly increased.Thermal degradation behavior of the material is not changed while thermal stability is improved after adding AC,and the glass transition temperature(T_g)is slightly reduced.(2)After adding WSP,the rigidity of the material is obviously improved.When WSP content is 20wt%,the storage modulus of the material is 44.45%higher than that of pure epoxy resin,and the modulus of tension and bending is also increased.After adding WSP,the thermal stability and thermal degradation behavior of the material are basically unchanged,and Tg remains basically unchanged.FT-IR results showed that hydrogen bonds were formed between AC,WSP and resin matrix.