以香兰素(VAN)改性4,4-二氨基二苯甲烷(DDM),经脱水缩合反应,合成香兰素希夫碱固化剂(VDM)。在催化剂2-乙基-4-甲基咪唑(EMI)作用下,采用VDM固化双酚A型环氧树脂(E44)。交联后的环氧树脂(E44-VDM)表现出优异的拉伸强度(60MPa)、拉伸断裂率(8.2%)和玻璃化转变温度(109℃)。在高温下,基于亚胺键的交换反应,E44-VDM表现出再加工性、快速的应力松弛和形变恢复行为,根据阿伦尼乌斯(Arrhenius)定律,计算出亚胺键交换活化能为65.15kJ/mol。将E44-VDM分别浸没在酸碱溶液中,经过72h处理后,并未溶解或溶胀,仍能保持结构完整性,显示出优异的耐酸碱性。尽管经再加工的E44-VDM力学性能不可避免地低于原始试样,但VDM可应用于多种环氧树脂体系中,可为缓解环境污染和资源消耗提供解决方案。
4,4-diamino-diphenyl methane (DDM) was modified by vanillin (VAN),and the vanillin Schiff base curing agent (VDM) was synthesized by dehydration condensation reaction.The bisphenol A epoxy resin (E44) was cured by VDM in the presence of 2-ethyl-4-methylimidazole (EMI) catalyst.The crosslinked epoxy resin (E44-VDM) showed excellent tensile strength (60MPa),tensile fracture rate (8.2%),and glass transition temperature (109℃).At high temperature,based on the exchange reaction of imine bonds,E44-VDM exhibited reprocessability,rapid stress relaxation and deformation recovery behavior.The activation energy of imine bond exchange was calculated to be 65.15kJ/mol by Arrhenius' law.E44-VDM was immersed in acid and alkali solutions for 72 h respectively,it was not dissolved or swollen,and still remained in structural integrity,demonstrating excellent acid and alkali resistance.The mechanical properties of the reprocessed E44-VDM were inevitably weaker than the original samples,however,VDM could be applied in a variety of epoxy resin systems,providing a solution to mitigate environmental pollution and resource consumption.
[1] Wang Y,Jin B,Ye D,et al.Fully recyclable carbon fiber reinforced vanillin-based epoxy vitrimers[J].Eur Polym J,2022,162:110927.
[2] Jin F L,Li X,Park S J.Synthesis and application of epoxy resins:a review[J].J Ind Eng Chem,2015,29:1-11.
[3] Khan A H,López Maldonado E A,Khan N A,et al.Current solid waste management strategies and energy recovery in developing countries-state of art review[J].Chemosphere,2022,291(Pt 3):133088.
[4] Singh N,Hui D,Singh R,et al.Recycling of plastic solid waste:a state of art review and future applications[J].Compos Part B Eng,2017,115:409-422.
[5] Jin H,Mangun C L,Stradley D S,et al.Self-healing thermoset using encapsulated epoxy-amine healing chemistry[J].Polym,2012,53(2):581-587.
[6] Liao L,Zhang W,Xin Y,et al.Preparation and characterization of microcapsule containing epoxy resin and its self-healing performance of anticorrosion covering material[J].Chin Sci Bull,2011,56(4-5):439-443.
[7] Yu Q,Peng X,Wang Y,et al.Vanillin-based degradable epoxy vitrimers:reprocessability and mechanical properties study[J].Eur Polym J,2019,117:55-63.
[8] Urdl K,Weiss S,Christöfl P,et al.Diels-alder modified self-healing melamine resin[J].Eur Polym J,2020,127:109601.
[9] Zhao W,An L,Wang S.Recyclable high-performance epoxy-anhydride resins with Dmp-30 as the catalyst of transesterification reactions[J].Polym,2021,13(2):296.
[10] Liu Y Y,He J,Li Y D,et al.Biobased,reprocessable and weldable epoxy vitrimers from epoxidized soybean oil[J].Ind Crops Prod,2020,153:109601.
[11] Liu Y Y,He J,Li Y D,et al.Biobased epoxy vitrimer from epoxidized soybean oil for reprocessable and recyclable carbon fiber reinforced composite[J].Compos Commun,2020,22:100445.
[12] Li X,Yu R,Zhao T,et al.A self-healing polysiloxane elastomer based on siloxane equilibration synthesized through amino-ene michael addition reaction[J].Eur Polym J,2018,108:399-405.
[13] Shin J H,Yi M B,Lee T H,et al.Rapidly deformable vitrimer epoxy system with supreme stress-relaxation capabilities via coordination of solvate ionic liquids[J].Adv Funct Mater,2022:2207329.
[14] Ma S,Liu X,Fan L,et al.Synthesis and properties of a bio-based epoxy resin with high epoxy value and low viscosity[J].Chem Sus Chem,2014,7(2):555-562.
[15] Zhang T,Tan J,Han X,et al.Novel epoxy-ended hyperbranched polyether derived from xylitol as sustainable tougheners for epoxy resin[J].Polym Test,2021,94:2207329.
[16] Miao J T,Yuan L,Guan Q,et al.Biobased heat resistant epoxy resin with extremely high biomass content from 2,5-furandicarboxylic acid and eugenol[J].ACS Sus Chem Eng,2017,5(8):7003-7011.
[17] Dai P,Liang M,Ma X,et al.Highly efficient,environmentally friendly lignin-based flame retardant used in epoxy resin[J].ACS Omega,2020,5(49):32084-32093.
[18] Ma J,Li G,Hua X,et al.Biodegradable epoxy resin from vanillin with excellent flame-retardant and outstanding mechanical properties[J].Polym Degrad Stab,2022,201:109989.
[19] Nabipour H,Niu H,Wang X,et al.Fully bio-based epoxy resin derived from vanillin with flame retardancy and degradability[J].React Funct Polym,2021,168:109989.
[20] Liu X,Zhang E,Feng Z,et al.Degradable bio-based epoxy vitrimers based on imine chemistry and their application in recyclable carbon fiber composites[J].J Mater Sci,2021,56(28):15733-15751.
[21] Mai V D,Shin S R,Lee D S,et al.Thermal healing,reshaping and ecofriendly recycling of epoxy resin crosslinked with schiff base of vanillin and hexane-1,6-diamine[J].Polym,2019,11(2):293.
[22] Memon H,Liu H,Rashid M A,et al.Vanillin-based epoxy vitrimer with high performance and closed-loop recyclability[J].Macromol,2020,53(2):621-630.
[23] Zhao X L,Liu Y Y,Weng Y,et al.Sustainable epoxy vitrimers from epoxidized soybean oil and vanillin[J].ACS Sus Chem Eng,2020,8(39):15020-15029.
[24] Wu J N,Chen L,Fu T,et al.New application for aromatic schiff base:high efficient flame-retardant and anti-dripping action for polyesters[J].Chem Eng J,2018,336:622-632.
[25] Jian X Y,He Y,Li Y D,et al.Curing of epoxidized soybean oil with crystalline oligomeric poly(butylene succinate) towards high performance and sustainable epoxy resins[J].Chem Eng J,2017,326:875-885.
[26] L V J,J C G,I M B.Uncertainties in the determination of cross-link density by equilibrium swelling experiments in natural rubber[J].Macromol,2008,41(13):4717-4729.
[27] Lee S H,Shin S R,Lee D S.Self-healing of cross-linked pu via dual-dynamic covalent bonds of a schiff base from cystine and vanillin[J].Mater Des,2019,172:107774.
[28] Zhang Y,Dai C,Zhou S,et al.Enabling shape memory and healable effects in a conjugated polymer by incorporating siloxane via dynamic imine bond[J].Chem Commun,2018,54(72):10092-10095.
基金资助
湖北省重点实验室基金(WKDM202105)
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