In this manuscript, polyimide (PI) films with high strength and toughness are achieved by adjusting the stiffness and flexibility of the PI macromolecules utilizing rigid mixed diamine monomers, namely benzimidazole (PABZ) /benzoxazole (BOA) and flexible bisphenol A dianhydride (BPADA) monomer. Meanwhile, the stiffness of the PI is modulated as well by the coordination crosslinking between benzimidazole motifs of PABZ and Cu2+ validated by FTIR, XPS and UV-vis spectra, respectively which could boost the arrangement and packing of the PI molecules confirmed by the packing coefficient. The comprehensive properties of the polyimide film are synergistically increased by combining the rigidity/flexibility of the macromolecules and the reversible coordination effect, with a strength and toughness of the PI film reaching 132.43 ± 1.73 MPa and 21.24 ± 2.13 MJ/m3 respectively, as well as the decomposition temperature 5% weight loss (Td5%) and glass transition temperature (Tg) attaining at 514°C and 251°C. More interestingly, the PI films exhibit excellent wear resistance with the volume wear rate reduced from 15.578 × 10-6 mm3/Nm to 2.936 × 10-6 mm3/Nm which accounts for a reduction of 81.2% compared to neat PI. Therefore, high-strength/toughness, improved thermal stability and excellent wear-resistant PI films can be fabricated utilizing a synergistic strategy of stiffness-flexibility harmonization which is expected to provide a novel design strategy for the high-performance PI application.
ChengCLiaoXSilvaJMd. Se., et al.Polymeric fibers with high strength and high toughness at extreme temperatures. Adv Mater2024; 36(35): 2407712.
2.
LiuYTangATanJ, et al.Structure and gas barrier properties of polyimide containing a rigid planar fluorene moiety and an amide group: insights from molecular simulations. ACS Omega2021; 6(6): 4273–4281.
3.
RuanHZhangYLiS, et al.Effect of temperature on the friction and wear performance of porous oil-containing polyimide. Tribol Int2021; 157: 106891.
4.
WanBZhaJW. Dynamic polyimide dielectric film: a concept and application perspective. Adv Funct Mater2023; 34(13): 2312829.
5.
ShiTZhengZLiuH, et al.Configuration of multifunctional polyimide/graphene/Fe3O4 hybrid aerogel-based phase-change composite films for electromagnetic and infrared Bi-stealth. Nanomater2021; 11(11): 3038.
6.
NiHLiuJWangZ, et al.A review on colorless and optically transparent polyimide films: chemistry, process and engineering applications. J Ind Eng Chem2015; 28: 16–27.
7.
ParkESeoJHanH, et al.High-efficiency polymer:nonfullerene solar cells with quaterthiophene-containing polyimide interlayers. Adv Sci2018; 5(8): 1800331.
8.
ZhangMWangLXuH, et al.Polyimides as promising materials for lithium-ion batteries: a review. Nano-Micro Lett2023; 15(1): 135.
JiaYZhaiLMoS, et al.Effect of low-temperature imidization on properties and aggregation structures of polyimide films with different rigidity. Chin J Polym Sci2024; 42(8): 1134–1146.
11.
MushtaqNZhangYNazirM, et al.Ultra-high Tg colorless polyimide film with balanced optical retardation and coefficient of thermal expansion for flexible display. Polymer2025; 321: 128085.
12.
YuXLiangWCaoJ, et al.Mixed rigid and flexible component design for high-performance polyimide films. Polymers2017; 9(9): 9090451.
13.
LiuJLiJWangT, et al.Organosoluble thermoplastic polyimide with improved thermal stability and UV absorption for temporary bonding and debonding in ultra-thin chip package. Polymer2022; 244: 124660.
14.
HanSLiYHaoF, et al.Ultra-low dielectric constant polyimides: combined efforts of fluorination and micro-branched crosslink structure. Eur Polym J2021; 143: 110206.
15.
CaoKLiuG. Low-molecular-weight, high-mechanical-strength, and solution-processable telechelic poly(ether imide) end-capped with ureidopyrimidinone. Macromolecules2017; 50(5): 2016–2023.
16.
LuLXuJLiJ, et al.High-toughness and intrinsically self-healing cross-linked polyurea elastomers with dynamic sextuple H-bonds. Macromolecules2024; 57(5): 2100–2109.
17.
ChenHHuangJZhangC, et al.Foldable polyimide/ionic liquid composite films with high transmittance and ultraviolet resistance benefiting from the intermolecular multipoint interaction. Chem Eng J2024; 490: 151598.
18.
LiJ-QLiW-SZhangW, et al.Enhancing molecular chain entanglement and π-π stacking toward the improvement of shape memory performance of polyimide. Chin J Polym Sci2023; 41(8): 1261–1268.
19.
MiyamaeKNakahataMTakashimaY, et al.Self-healing, expansion–contraction, and shape-memory properties of a preorganized supramolecular hydrogel through host–guest interactions. Angew Chem Int Ed2015; 54(31): 8984–8987.
20.
GanFJiangSZhouJ, et al.Architecting dual coordination interactions in polyimide for constructing structurally controllable high-performance nanofiltration membranes. Eur Polym J2022; 181: 111702.
21.
ChenTHeXLuQ. Comprehensive performance of polyimide reinforced by multiple hydrogen bonds for flexible electronics application. ACS Appl Polym Mater2023; 5(7): 5436–5444.
22.
LiYZhaoJZhaoF, et al.Synergistic enhancement of mechanical and dielectric properties in transparent polyimides by regulating hydrogen bonding and microbranched cross-linking structure. ACS Appl Polym Mater2024; 6(17): 10738–10749.
23.
GuoLShiYWuS, et al.Poly(hydrazide–imide) membranes with enhanced interchain interaction for highly selective H2/CO2 separation. Macromolecules2023; 56(9): 3430–3439.
24.
ZhouXZhaoXLiX, et al.Fabrication of shape memory polyimides with exploration of their activation mechanisms. Chem Eng J2023; 477: 146776.
25.
TianYLuoLYangQ, et al.Construction of stable hydrogen bonds at high temperature for preparation of polyimide films with ultralow coefficient of thermal expansion and high Tg. Polymer2020; 188(NO): 122100.
26.
LiuQXuSXiongS, et al.Coordination-crosslinked polyimide supported membrane for ultrafast molecular separation in multi-solvent systems. Chem Eng J2022; 427: 130941.
27.
PolotskayaGTianNFaykovI, et al.Novel design of Co-Poly(Hydrazide imide) and its complex with Cu(I) for membrane separation of methanol/dimethyl carbonate mixture. Membranes2023; 13(2): 160.
28.
ShiYLiangJBabu ShresthaB, et al.Enhancing the CO2 plasticization resistance of thin polymeric membranes by designing Metal-polymer complexes. Sep Purif Technol2022; 289: 120699.
29.
WuXWangJHuangJ, et al.Robust, stretchable, and self-healable supramolecular elastomers synergistically cross-linked by hydrogen bonds and coordination bonds. ACS Appl Mater Interfaces2019; 11(7): 7387–7396.
30.
JiangSBiZWangJ, et al.Construction of novel Cu-α-diimide interactions for enhancing thermal resistance and dimensional stability of polyimide films. J Mater Res Technol2023; 25: 1920–1930.
31.
JiangSZhouZZhangJ, et al.Fabrication of high-performance polyimide films by tailoring coordination bond and chain rigidity. Eur Polym J2024; 214: 113161.
32.
KimKJJoJHAnSJ, et al.Facile metal-ion infiltration into polyimide membranes with coordination crosslinking for efficient gas separation. Sep Purif Technol2023; 323: 124330.
33.
WangLPanBGaoJ, et al.Tribological behaviors of porous 3D graphene lubricant reinforced monomer casting polyamide 6 composite. Adv Eng Mater2020; 22(5): 1901170.
34.
YinQHuYQinY, et al.Construction of polyimide films with excellent dimensional stability and toughness via incorporating point-to-face multi-coordination structure. Composites Part B2021; 208: 108566.
35.
HuKChenPWengQ, et al.Preparation and properties of lateral monofluoro-substituted benzoxazole-based mesogenic compounds. Liq Cryst2015; 42(11): 1–9.
36.
LiuSZhouMZhangG, et al.The effect of benzoxazole unit on the properties of cyclic thiourea functionalized triphenylamine dye sensitizers. Dyes Pigments2021; 187: 109093.
37.
AlmansourAArumugamNSuresh KumarR, et al.Synthesis, spectroscopic, X-ray diffraction and DFT studies of novel benzimidazole fused-1, 4-oxazepines. Molecules2016; 21(6): 21060724.
38.
ZhuangYLiuXGuY. Molecular packing and properties of poly(benzoxazole-benzimidazole-imide) copolymers. Polym Chem2012; 3(6): 1517.
39.
LiuTHuangHWangY, et al.Super strong and tough polybenzimidazole/metal ions coordination networks: reinforcing mechanism, recyclability, and anti-counterfeiting applications. Macromol Rapid Commun2021; 43(3): 2100643.
40.
OkadaTIshigeRAndoS. Effects of chain packing and structural isomerism on the anisotropic linear and volumetric thermal expansion behaviors of polyimide films. Polymer2018; 146: 386–395.
41.
LiuTZhengFDingTM, et al.Design and synthesis of a novel quinoxaline diamine and its polyimides with high-Tg and red color. Polymer2019; 179: 121612.
42.
SlonimskiiGLA, AAAskadskiiAAKitaigorodskiiA. The packing of polymer molecules. Polym Sci1970; 12(3): 556–577.
43.
LuoLZhangJHuangJ, et al.The dominant factor for mechanical property of polyimide films containing heterocyclic moieties: in-plane orientation, crystallization, or hydrogen bonding. J Appl Polym Sci2016; 133(39): 44000.
44.
LiYLiangQXuR, et al.Preparation of aromatic polyamide with ultra-high intrinsic breakdown strength via layered stacking structure induced by coplanar monomer. Polymer2022; 255: 125170.
45.
ZhongALiJZhangG, et al.Adhesion and interface studies of the structure-controlled polyimide with smooth copper for high-frequency communication. Adv Mater Interfac2022; 9(5): 202101745.
46.
ChenHDaiFHuM, et al.Heat-resistant polyimides with lowCTEand water absorption through hydrogen bonding interactions. J Polym Sci2021; 59(17): 1942–1951.
47.
FangYHeXKangJ, et al.Terphenyl-based colorless and heat-resistant polyimides with a controlled molecular structure using methyl side groups. Polym Chem2022; 13(35): 5105–5115.
48.
FangYHeXKangJ, et al.Colorless transparent and thermally stable terphenyl polyimides with various small side groups for substrate application. Eur Polym J2024; 202: 112640.
49.
GuanTWangXZhaoX, et al.Reversibly cross-linking polyimide and cyclophosphazene toward closed-loop recyclable plastics with high mechanical strength, excellent flame retardancy, and chemical resistance. CCS Chem2024; 6(4): 976–987.
50.
HariharanRBhuvanaSMalbiMA, et al.Synthesis and characterization of polyimides containing pyridine moiety. J Appl Polym Sci2004; 93(4): 1846–1853.
51.
QianGHuMZhangS, et al.Synthesis of superheat-resistant polyimides with enhanced dielectric constant by introduction of Cu(ΙΙ)-Coordination. Polymers2020; 12(2): 12020442.
52.
WanBZhengMSYangX, et al.Recyclability and self-healing of dynamic cross-linked polyimide with mechanical/electrical damage. Energy Environ Mater2022; 6(1): e12427.
53.
WuSLiangJShiY, et al.Design of interchain hydrogen bond in polyimide membrane for improved gas selectivity and membrane stability. J Membr Sci2021; 618: 118659.
54.
ZhangMLiuWGaoX, et al.Preparation and characterization of semi-alicyclic polyimides containing trifluoromethyl groups for optoelectronic application. Polymers2020; 12(7): 1532.
55.
ZhuangYSeongJGDoYS, et al.Effect of isomerism on molecular packing and gas transport properties of poly(benzoxazole-co-imide)s. Macromolecules2014; 47(22): 7947–7957.
