Aromatic thermoset materials have shown great potential applications in various fields owing to their excellent mechanical strengths. However, their poor ductility is still hinders their large-scale applications. In this study, a new class of aromatic thermosets consisting of two types of crosslinks was successfully developed by incorporating the special group imidazole into a type of crosslinked thermoset. One crosslink is constituted of reversible multiple noncovalent interactions containing “face-face” π–π stacking, “point-point” hydrogen bonds, and ion-pair electrostatic interactions, whereas the other is composed of permanent covalent bonds. Most importantly, the synergetic interplay among these reversible multiple noncovalent interactions enables them to evade the restrictions from the aromatic polymer skeletons to proceed with their dynamic dissociating-rebuilding processes, which can timely and effectively dissipate the internal stress. Finally, owing to the coefficient of these two types of crosslinks, a significantly enhanced ductility was successfully obtained on these aromatic thermosets and their tensile strengths were also improved. Such thermosets having simultaneously enhanced strengths and ductility are predicted to be eventually used in a wide range of applications.
HaradaMYokoyamaYOchiM. Synthesis of multifunctional liquid crystalline epoxy resin embedded cyclic-siloxane chain with Tg-less behavior and enhanced toughness. High Perform Polym2021; 33: 1–9.
2.
ChangGYangLYangJ, et al.High-performance pH-switchable supramolecular thermosets via cation-π interactions. Adv Mater2018; 30: 1704234.
3.
LianRLeiXChenY, et al.Hyperbranched-polysiloxane-based hyperbranched polyimide films with low dielectric permittivity and high mechanical and thermal properties. J Appl Polym Sci2019; 136: 47771–47778.
4.
JayanJSSarithaADeerajBDS, et al.Graphene oxide as a prospective graft in polyethylene glycol for enhancing the toughness of epoxy nanocomposites. Polym Eng Sci2020; 60: 773–781.
5.
XuYMLeNLZuoJ, et al.Aromatic polyimide and crosslinked thermally rearranged poly(benzoxazole-co-imide) membranes for isopropanol dehydration via pervaporation. J Membr Sci2016; 499: 317–325.
6.
RenXPengSZhangW, et al.Preparation of adipic acid-polyoxypropylene diamine copolymer and its application for toughening epoxy resins. Compos Part B-Eng2017; 119: 32–40.
7.
RenHYHeZLLiDL, et al.Synergistic enhanced yield strength, tensile ductility and impact toughness of polydicyclopentadiene nanocomposites by introducing low loadings of di-functionalized silica. Polym Test2019; 79: 106052.
8.
ZhangJMiXChenS, et al.A bio-based hyperbranched flame retardant for epoxy resins. Chem Eng J2020; 381: 122719.
9.
ChenSZhangJZhouJ, et al.Dramatic toughness enhancement of benzoxazine/epoxy thermosets with a novel hyperbranched polymeric ionic liquid. Chem Eng J2018; 334: 1371–1382.
10.
WernekeSWSwannCFarquharsonLA, et al.The role of metals in molluscan adhesive gels. J Exp Biol2007; 210: 2137–2145.
11.
Holten-AndersenNMatesTEToprakMS, et al.Metals and the integrity of a biological coating: the cuticle of mussel byssus. Langmuir2009; 25: 3323–3326.
12.
LiXQiuHGaoP, et al.Synergetic coordination and catecholamine chemistry for catalytic generation of nitric oxide on vascular stents. NPG Asia Mater2018; 10: 482–496.
13.
FilippidiECristianiTREisenbachCD, et al.Toughening elastomers using mussel-inspired iron-catechol complexes. Science2017; 358: 502–505.
14.
WuJCaiL-HWeitzDA. Tough self-healing elastomers by molecular enforced integration of covalent and reversible networks. Adv Mater2017; 29: 1702616.
CaoKLiuG. Low-molecular-weight, high-mechanical-strength, and solution-processable telechelic poly(ether imide) end-capped with ureidopyrimidinone. Macromolecules2017; 50: 2016–2023.
17.
GuanXMaYYangL, et al.Unprecedented toughening high-performance polyhexahydrotriazines constructed by incorporating point-face cation-π interactions in covalently crosslinked networks and the visual detection of tensile strength. Chem Commun2019; 56: 1054–1057.
18.
DuMYangLLiaoC, et al.Recyclable and dual cross-linked high-performance polymer with an amplified strength-toughness combination. Macromol Rapid Commun2020; 41: 1900606.
19.
WangCZhangSZhangL, et al.Evading the strength-ductility trade-off dilemma of rigid thermosets by incorporating triple cross-links of varying strengths. Polym Chem2020; 11: 6281–6287.
20.
XuY-JWangJTanY, et al.A novel and feasible approach for one-pack flame-retardant epoxy resin with long pot life and fast curing. Chem Eng J2018; 337: 30–39.
21.
ZhaoXHuangZSongP, et al.Curing kinetics and mechanical properties of fast curing epoxy resins with isophorone diamine and N-(3-aminopropyl)-imidazole. J Appl Polym Sci2019; 136: 47950.
22.
YuGMuMLiJ, et al.Imidazolium-based ionic liquids introduced into π-electron donors: highly efficient toluene capture. ACS Sustain Chem Eng2020; 8: 9058–9069.
23.
GutelTSantiniCCPáduaAAH, et al.Interaction between the π-system of toluene and the imidazolium ring of ionic liquids: a combined NMR and molecular simulation study. J Phys Chem B2009; 113: 170–177.
24.
LeeHMYounISSalehM, et al.Interactions of CO2 with various functional molecules. Phys Chem Chem Phys2015; 17: 10925–10933.
25.
MaJCDoughertyDA. The cation-π interaction. Chem Rev1997; 97: 1303–1324.
26.
WangYZhangLYangL, et al.Recyclable indole-based polymer for trinitrotoluene adsorption via the synergistic effect of dipole-π and donor-acceptor interactions. Polym Chem2019; 10: 4632–4636.
27.
QuiñoneroDFronteraAGarauC, et al.Interplay between cation-π, anion-π and π-π interactions. Chem Phys Chem2006; 7: 2487–2491.
28.
BaiYZhangB-GXuJ, et al.Conformational switching fluorescent chemosensor for chloride anion. New J Chem2005; 29: 777–779.
29.
YoonJKimSKSinghNJ, et al.Imidazolium receptors for the recognition of anions. Chem Soc Rev2006; 35: 355–360.
30.
KellyTRKimMH. Relative binding affinity of carboxylate and its isosteres: nitro, phosphate, phosphonate, sulfonate, and δ-lactone. J Am Chem Soc1994; 116: 7072–7080.
31.
IshidaHAllenDJ. Mechanical characterization of copolymers based on benzoxazine and epoxy. Polymer1996; 37: 4487–4495.
32.
IshidaMOshimaJYoshinagaK, et al.Structural analysis of core-shell type polymer particles composed of poly(butyl acrylate) and poly(methyl methacrylate) by high-resolution solid-state 13C n.m.r. spectroscopy. Polymer1999; 40: 3323–3329.
33.
YuCWongKM-CChanKH-Y, et al.Polymer-induced self-assembly of alkynylplatinum(II) terpyridyl complexes by metal…metal/π…π interactions. Angew Chem Int Ed2005; 117: 801–804.
34.
MizukamiSHoujouHSugayaK, et al.Fluorescence color modulation by intramolecular and intermolecular π-π interactions in a helical zinc(II) complex. Chem Mater2005; 17: 50–56.
35.
ZhangXFengYTangS, et al.Preparation of a graphene oxide-phthalocyanine hybrid through strong π-π interactions. Carbon2010; 48: 211–216.
36.
HoHALeclercM. New colorimetric and fluorometric chemosensor based on a cationic polythiophene derivative for iodide-specific detection. J Am Chem Soc2003; 125: 4412–4413.
37.
UzunOSanyalANakadeH, et al.Recognition-induced transformation of microspheres into vesicles: morphology and size control. J Am Chem Soc2004; 126: 14773–14777.
38.
ChengCCLiangMCLiaoZS, et al.Self-assembled supramolecular nanogels as a safe and effective drug delivery vector for cancer therapy. Macromol Biosci2017; 17: 1600370.
39.
SkrovanekDJPainterPCColemanMM. Hydrogen bonding in polymers. 2. Infrared temperature studies of nylon 11. Macromolecules1986; 19: 699–705.
40.
DomunNHadaviniaHZhangT, et al.Improving the fracture toughness and the strength of epoxy using nanomaterials—a review of the current status. Nanoscale2015; 7: 10294–10329.
41.
CaiMChenMYuY, et al.Synthesis and properties of novel poly(aryl ether ketone)s containing both 2,6-naphthylene moieties and amide linkages in the main chains. Polym Adv Technol2013; 24: 466–472.
42.
TaoGXiaZ. Mean stress/strain effect on fatigue behavior of an epoxy resin. Int J Fatigue2007; 29: 2180–2190.
43.
YangGFuS-YYangJ-P. Preparation and mechanical properties of modified epoxy resins with flexible diamines. Polymer2007; 48: 302–310.
44.
XiaoLHuangJWangY, et al.Tung oil-based modifier toughening epoxy resin by sacrificial bonds. ACS Sustain Chem Eng2019; 7: 17344–17353.
45.
LaiJ-CJiaX-YWangD-P, et al.Thermodynamically stable whilst kinetically labile coordination bonds lead to strong and tough self-healing polymers. Nat Commun2019; 10: 1164.
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
