| Epoxy resin is one of the three major thermosetting resins.Because of its excellent adhesion,corrosion resistance,and electrical insulation,has been widely used in the fields of electronics,construction,automobiles,and aerospace.At present,the bisphenol A epoxy resin(DGEBA)accounts for 90%of total global epoxy resin consumption,but bisphenol A epoxy resin was completely dependent on petroleum resources.And DGEBA will release bisphenol A(BPA)during use,and BPA has a certain degree of toxicity to the human body.the of raw materialsTherefore,the bio-based epoxy resin matrix be synthesized based on bio-based.And used the bio-based epoxy resin matrix to replace BPA to prepared the bio-based epoxy resin was very important for the scientific research and environmental protection.A large of numbers bio-based epoxy resins have poor mechanical properties and thermal stability due to the influence of materials and molecular structure.It can be seen that the development of high-impact bio-based epoxy resins with thermal stability were of great significance.In this paper,naringenin with a thick aromatic structure was used to synthesized naringenin epoxy resin matrix(NER).Five nano-modifiers with different molecular structures were prepared,and halloysite nanotubes(HNTs)were separated and purified.Naringenin epoxy resin matrix was used to prepare epoxy resin and modified with nano-modifiers with different molecular structures.The main content and results are as follows:(1)Functionalized caged silsesquioxane(ED-POSS)was prepared with epoxy silicon cage(E-POSS)and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO).Halloysite nanotubes(HNTs)were obtained by the stepwise sedimentation method.ED-POSS and HNTs were used separately and compounded to modify the naringenin epoxy resin,and compared with bisphenol A epoxy resin.The results showed as follows.The comprehensive performance of naringenin epoxy resin is better than that of bisphenol A epoxy resin,and it can be one of the epoxy resin products that can replace bisphenol A.ED-POSS can improve the thermal stability of naringenin epoxy resin while improving the impact strength.When the addition amount of ED-POSS was 15 wt.%,the impact strength and initial thermal degradation temperature of the naringenin epoxy/ED-POSS composite were the largest,which were 6.90 k J/m~2 and 306.9?,respectively.The impact strength and initial thermal degradation temperature of the naringenin epoxy/ED-POSS composite compared with the naringenin epoxy resin(NEP)increased by 91.6%and 15.6?respectively.Low addition of halloysite nanotubes can significantly improve the impact strength of naringenin epoxy/HNTs composites.When the addition amount of halloysite nanotubes was 0.8 wt.%,the impact strength of the naringenin epoxy/HNTs composite was 5.50 k J/m~2,which was 52.7% higher than that of NEP.ED-POSS and HNTs were used together for the modification of naringenin epoxy resin,which were better toughening effect than each alone,which can further improve the mechanical properties and thermal stability of composite materials.Fixed ED-POSS addition amount was 15 wt.%,when the halloysite nanotube addition amount was 1 wt.%,the impact strength of the composite was the largest,8.2 k J/m~2.Which compared with the epoxy nanocomposite obtained by adding 15 wt.%of ED-POSS modifier to the naringenin epoxy matrix,its impact strength increased by28.1%.(2)The aminated graphene(E-GO)was prepared by reacting ethylenediamine with graphene oxide(GO).ED-POSS grafted aminated graphene(ED-POSS-E-GO)was obtained by grafting ED-POSS onto E-GO.E-GO and ED-POSS-E-GO were used to modify the naringenin epoxy resin.The results showed as follows.A small amount of E-GO can significantly improve the impact strength of naringenin epoxy resin.When the amount of E-GO added was 0.6 wt.%,the impact strength,Tg and the initial thermal degradation temperature of naringenin epoxy/E-GO composite are the largest,which were increased by 57.1%,20?,6.3?,respectively,compared with NEP.When the addition amount of ED-POSS-E-GO was 0.6 wt.%,the impact strength of naringenin epoxy/ED-POSS-E-GO composite was the largest.Which compared with NEP,its impact strength was increased by 72.2%ED-POSS-E-GO had a better toughening effect on naringenin epoxy resin than E-GO.(3)The metal organic framework compound(Ui O-66)and the organometallic framework compounds containing pendant amino groups(Ui O-66-NH2)(Ui O-66-NH2)were respectively prepared.Modification of naringenin epoxy resin with Ui O-66 and Ui O-66-NH2 respectively.The results showed as follows.After Ui O-66 without reactive functional groups was added to the naringenin epoxy matrix,the crosslinking density of the cured were significantly reduced due to its steric effect.Ui O-66 can significantly improve the mechanical properties of naringenin epoxy resin,but its compatibility with NER needs to be further improved.Ui O-66 did not significantly improve the flame retardancy of composite materials.When the Ui O-66content was 4 wt.%,the impact strength of the naringenin epoxy/Ui O-66 composite was 7.60 k J/m~2.Which compared with naringenin epoxy resin(NEP),its impact strength was increased by 85.4%Ui O-66-NH2 can simultaneously improve the toughness and flame retardancy of naringenin epoxy resin.Ui O-66-NH2 improves the flame retardancy of naringenin epoxy resin more significantly than Ui O-66.Ui O-66-NH2 was more compatible with NER.When the Ui O-66-NH2 content was 4wt.%,the impact strength of naringenin epoxy/Ui O-66-NH2 composite was the largest,7.70 k J/m~2,and the ultimate combustion oxygen index was 26.2%,compared to NEP increased by 54.0% and 4.1% respectively. |
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