The inherent brittleness of epoxy (EP) has long imposed limitations on its utilization within advanced field. This study synthesized a novel high-performance soluble polymer with a tetramethyl biphenyl structure (named tetramethyl biphenyl poly arylene ether ketone, S-TBPAEK) as a toughening agent for preparing EP composites. The aromatic structure in S-TBPAEK enhanced the heat resistance of composites, while its unique tetramethyl structure promoted excellent compatibility with EP. Additionally, it was observed that when S-TBPAEK content reached 12.5 phr, the impact strength of composite was significantly increased by 170 %. Additionally, the mechanical properties of the composite, such as flexural strength and tensile strength, have been enhanced by approximately 43.7 % and 55.8 % respectively. Finally, the fracture surfaces of the composites were analyzed using SEM to investigate the fracture mechanism. The results revealed that the fracture behavior of impact, flexural and tensile specimens transitioned from brittle to ductile fracture. The phenomenon suggested that the S-TBPAEK/EP composite absorbed more energy during fracturing process, thereby enhancing its toughness. In summary, S-TBPAEK shows great promise as a toughening agent for epoxy composites, offering new insights into the field of epoxy toughening.
LiNLiuTShiX, et al.Ultra-tough and sustainable epoxy adhesive enabled by microphase separation and dynamic chemical structure. Eur Polym J2026; 245: 114538. https://doi.org/10.1016/j.eurpolymj.2026.114538
2.
XieHBaoFZhangH, et al.Ultratough, robustness, and reprocessable thermoset epoxy resins synergistically enhanced by hierarchical coordination interactions and dynamic covalent networks. Adv Funct Mater2024; 34(48): 2408411. https://doi.org/10.1002/adfm.202408411
LiuXWuHXuW, et al.Ultrastrong and high‐tough thermoset epoxy resins from hyperbranched topological structure and subnanoscaled free volume. Adv Mater2024; 36(9): 2308434. https://doi.org/10.1002/adma.202308434
5.
ShundoAAokiMWangP, et al.Effect of a heterogeneous network on the fracture behavior of epoxy resins. Macromolecules2023; 56(11): 3884–3890. https://doi.org/10.1021/acs.macromol.3c00341
6.
YangCXiaXWeiG, et al.Tetrafunctional bio-based epoxy resin derived from divanillin with excellent heat resistance, mechanical and flame-retardant properties. Chem Eng J2025; 512: 162333. https://doi.org/10.1016/j.cej.2025.162333
7.
ZhangZWangYMuZ, et al.High-toughness epoxy-based composites with a bioinspired three-dimensional interconnected skeleton for photothermal conversion applications. Nano Lett2025; 25(4): 1287–1295. https://doi.org/10.1021/acs.nanolett.4c04324
8.
YangKLongYLuoJ, et al.Bridging solvent-free polyamic acid and epoxy resin by Si-O-C hyperbranched polymer for enhanced compatibility, toughness and self-lubrication performance. Chem Eng J2024; 481: 148662. https://doi.org/10.1016/j.cej.2024.148662
9.
LiangNLiuXHuJ, et al.Influence of topological structure on mechanical property of recyclable bio-based hyperbranched epoxy/carbon fiber fabric composites. Chem Eng J2023; 471: 144329. https://doi.org/10.1016/j.cej.2023.144329
10.
TangQLiHYinS, et al.Synergistic strengthening and toughening of epoxy composites via Li+ ‐π interaction induced microsphere rolling mechanism: rotational stability and wide-range effect. Adv Funct Mater2026; 36(13): e09971. https://doi.org/10.1002/adfm.202509971
11.
FarzanehfarNTaheriARafiemanzelatF, et al.High-performance epoxy nanocomposite adhesives with enhanced mechanical, thermal and adhesion properties based on new nanoscale ionic materials. Chem Eng J2023; 471: 144428. https://doi.org/10.1016/j.cej.2023.144428
12.
DingPPanXZhouX, et al.Grafting-engineered biomass-based quasi-solid composite electrolyte with suppressed filler aggregation and enhanced interfacial compatibility for high-performance solid-state lithium metal batteries. Chem Eng J2026; 530: 173400. https://doi.org/10.1016/j.cej.2026.173400
13.
HickeyRJ. Controlling polymer material structure during reaction-induced phase transitions. Acc Mater Res2023; 4(9): 798–808. https://doi.org/10.1021/accountsmr.3c00071
14.
SinghAKSinghA. Phase separation kinetics of block copolymer melts confined under moving parallel walls: a DPD study. Comput Mater Sci2023; 226: 112224. https://doi.org/10.1016/j.commatsci.2023.112224
15.
GeorgeJSPPVPonçotM, et al. Viscoelastic and rheokinetic behaviour of cellulose nanofiber/cloisite 30B hybrid nanofiller reinforced epoxy nanocomposites. Chem Eng J. 2024; 498: 155170. https://doi.org/10.1016/j.cej.2024.155170
16.
SunXLvJWangF, et al.Efficiency boost in all‐small‐molecule organic solar cells: insights from the re‐ordering kinetics. Adv Energy Mater2023; 14(3): 2302731. https://doi.org/10.1002/aenm.202302731
17.
WangYZhengXChenT, et al.Deciphering the morphology evolution of layer-by-layer processing via in situ spectroscopy measurement for high‐performance organic photovoltaics. Adv Energy Mater2026; 16(3): 2403162. https://doi.org/10.1002/aenm.202403162
18.
GeMMiaoJTLiangG, et al.Biobased epoxy resin with ultrahigh glass transition temperature over 400 °C by post-crosslinking strategy. Chem Eng J2024; 482: 148993. https://doi.org/10.1016/j.cej.2024.148993
19.
ZhaoYYanMJiaL, et al.Improving the comprehensive performances of epoxy coatings via poly(phthalazinone ether) modification. Appl Surf Sci2025; 714: 164465. https://doi.org/10.1016/j.apsusc.2025.164465
20.
ZhangJJiangQChengQ, et al.Cruciform-hinged conjugated polymers unlock the conductivity-hydrophilicity-insolubility triad for high-performance aqueous sodium-ion batteries. Chem2026: 102835. https://doi.org/10.1016/j.chempr.2025.102835
21.
LiSLiuHZhuH, et al.Mixed hyperbranched poly(aryl ether ketone) results in high toughness and excellent thermal resistance in epoxy resin. Eur Polym J2024; 210: 112951. https://doi.org/10.1016/j.eurpolymj.2024.112951
22.
YangWWangKShiF, et al.Enhancing toughness of epoxy resin through chain extending and end capping: an exploration of modifier influence. Eur Polym J2025; 235: 114092. https://doi.org/10.1016/j.eurpolymj.2025.114092
23.
ZhouYZhaoZZengY, et al.Ultra‐robust and tough epoxy resin enabled by pulley mechanism‐based curing agent for strong and reversible adhesion. Adv Funct Mater2025; 35(46): e17052. https://doi.org/10.1002/adfm.202517052
24.
MengJGuanHLiC, et al.One-pot interpenetrating epoxy thermosets from renewable dual biomass to high performance. Chem Eng J2023; 458: 141476. https://doi.org/10.1016/j.cej.2023.141476
25.
YuMDaiZHeM, et al.A phosphorus/silicon hybrid curing agent for epoxy resin: synergistically enhanced thermal resistance, flame retardancy, and toughness. Chem Eng J2025; 519: 164924. https://doi.org/10.1016/j.cej.2025.164924
26.
QianZZhaoSLiB, et al.Dual sacrificial strategy toward tough and recyclable CO2 ‐sourced epoxy thermosets. Angew Chem, Int Ed2025; 64(52): e19660. https://doi.org/10.1002/anie.202519660
27.
PalSDansukKGiuntoliA, et al.Predicting the effect of hardener composition on the mechanical and fracture properties of epoxy resins using molecular modeling. Macromolecules2023; 56(12): 4447–4456. https://doi.org/10.1021/acs.macromol.2c02577
28.
ValizadehKKoweyIRownaghiAA. Structure-guided design of 6FCDA-based copolyimide membranes for high-performance ethylene/ethane and propylene/propane separation. J Membr Sci2025; 736: 124663. https://doi.org/10.1016/j.memsci.2025.124663
29.
YangXFengYLiuP, et al.Achieving superior high-temperature capacitance performance in aromatic polyetherimide with bulky fluorine substituent. Energy Storage Mater2025; 77: 104206. https://doi.org/10.1016/j.ensm.2025.104206
30.
ZhouXLiuSSiddiqueA, et al.Construction of nanocomposite interphase with controllable thickness to relieve stress concentration and boost stress transfer from carbon fiber/epoxy resin interface. Chem Eng J2025; 505: 159542. https://doi.org/10.1016/j.cej.2025.159542
31.
LiuHWangCLiuS, et al.Enhancing interfacial properties of epoxy coatings via hyperbranched modification of SiC fillers: experimental and simulation insights. Chem Eng J2025; 511: 161841. https://doi.org/10.1016/j.cej.2025.161841
32.
NeuJOhJMukherjeeS, et al.Tuning the solubility parameters of conjugated polymers via side-chain engineering for all-polymer solar cells. Chem Mater2025; 37(10): 3788–3798. https://doi.org/10.1021/acs.chemmater.5c00515
33.
KhasbaatarAJonesALFernandoPS, et al.Tuning the solution aggregate structure of a PM7-Based conjugated polymer to enable green solvent processing of organic solar cells. Chem Mater2024; 36(6): 2819–2834. https://doi.org/10.1021/acs.chemmater.3c03055
34.
LiuYZhongXYuY. Gelation behavior of thermoplastic-modified epoxy systems during polymerization-induced phase separation. Colloid Polym Sci2010; 288(16-17): 1561–1570. https://doi.org/10.1007/s00396-010-2288-5
35.
GuanQYuanLZhangY, et al.Improving the mechanical, thermal, dielectric and flame retardancy properties of cyanate ester with the encapsulated epoxy resin-penetrated aligned carbon nanotube bundle. Composites, Part B Eng2017; 123: 81–91. https://doi.org/10.1016/j.compositesb.2017.05.029
36.
LiHWangKChenG, et al.Internal stress analysis of epoxy adhesively‐boned joints based on their thermomechanical properties at cryogenic temperature. J Appl Polym Sci2020; 137(43): 49311. https://doi.org/10.1002/app.49311
