Flame-Retardant Ionic Conductive Elastomers with Multiple Hydrogen Bonds: Synthesis, Characterization, and Strain Sensing Applications
Abstract
:1. Introduction
2. Results and Discussion
2.1. Structure Characterization of CAIPX and PCAIPX
2.2. Flame-Retardant Property
2.3. Mechanical Property
2.4. Adhesion Performance
2.5. Application of PCAIPX Elastomers as Strain Sensors
3. Materials and Methods
3.1. Materials
3.2. Synthesis of Phosphorus–Nitrogen-Containing PCAIPX Elastomers
3.2.1. Preparation of ChCl/AA/IA (CAI) and ChCl/AA/IA/PA (CAIPX) PDES
3.2.2. Preparation of Elastomers via Photopolymerization of CAI and CAIPX
3.3. Characterization
3.3.1. Fourier Transform Infrared Spectroscopy (FT-IR)
3.3.2. Thermogravimetry Analysis (TGA)
3.3.3. Differential Scanning Calorimeter (DSC)
3.3.4. Mechanical Tests
3.3.5. Puncture Resistance Test
3.3.6. Electrochemical Impedance Spectroscopy (EIS)
3.3.7. Scanning Electron Microscope (SEM)
3.3.8. Flame-Retardant Test
3.3.9. Sensing Performance Test
3.3.10. X-Ray Photoelectron Spectroscopy (XPS) Test
4. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
- Dasari, A.; Yu, Z.-Z.; Cai, G.-P.; Mai, Y.-W. Recent developments in the fire retardancy of polymeric materials. Prog. Polym. Sci. 2013, 38, 1357–1387. [Google Scholar] [CrossRef]
- Liu, B.-W.; Zhao, H.-B.; Wang, Y.-Z. Advanced Flame-Retardant Methods for Polymeric Materials. Adv. Mater. 2022, 34, e2107905. [Google Scholar] [CrossRef] [PubMed]
- Lv, L.-Y.; Cao, C.-F.; Qu, Y.-X.; Zhang, G.-D.; Zhao, L.; Cao, K.; Song, P.; Tang, L.-C. Smart fire-warning materials and sensors: Design principle, performances, and applications. Mater. Sci. Eng. R Rep. 2022, 150, 100690. [Google Scholar] [CrossRef]
- Wang, Y.D.; Ma, L.; Yuan, J.; Zhu, Z.M.; Liu, X.M.; Li, D.S.; He, L.Q.; Xiao, F. Furfural-based P/N/S flame retardant towards high-performance epoxy resins with flame retardancy, toughness, low dielectric properties and UV resistance. Polym. Degrad. Stab. 2023, 212, 110343. [Google Scholar] [CrossRef]
- Rao, W.; Zhao, P.; Yu, C.; Zhao, H.-B.; Wang, Y.-Z. High strength, low flammability, and smoke suppression for epoxy thermoset enabled by a low-loading phosphorus-nitrogen-silicon compound. Compos. Part B 2021, 211, 108640. [Google Scholar] [CrossRef]
- Liang, J.; Yang, W.; Yuen, A.C.Y.; Long, H.; Qiu, S.; De Cachinho Cordeiro, I.M.; Wang, W.; Chen, T.B.Y.; Hu, Y.; Yeoh, G.H. Peanut Shell Derived Carbon Combined with Nano Cobalt: An Effective Flame Retardant for Epoxy Resin. Molecules 2021, 26, 6662. [Google Scholar] [CrossRef]
- Huo, S.; Sai, T.; Ran, S.Y.; Guo, Z.H.; Fang, Z.P.; Song, P.G.; Wang, H. A hyperbranched P/N/B-containing oligomer as multifunctional flame retardant for epoxy resins. Compos. Part B 2022, 234, 109701. [Google Scholar] [CrossRef]
- Qiao, H.; Chen, M.; Chen, B.; Zhang, H.; Zheng, B. Understanding the curing kinetics of boron-based hyperbranched polysiloxane reinforced and toughened epoxy resin by rheology. Chem. Eng. J. 2023, 467, 143542. [Google Scholar] [CrossRef]
- Chi, Z.Y.; Guo, Z.W.; Xu, Z.; Zhang, M.J.; Li, M.; Shang, L.; Ao, Y.H. A DOPO-based phosphorus-nitrogen flame retardant bio-based epoxy resin from diphenolic acid: Synthesis, flame-retardant behavior and mechanism. Polym. Degrad. Stab. 2020, 176, 109151. [Google Scholar] [CrossRef]
- Wan, C.; Duan, H.J.; Zhang, C.H.; Cao, J.F.; Zou, J.H.; Zhang, J.J.; Ma, H.R. A P/N/S-containing compound toward enhanced fire safety epoxy resin with well-balanced performance. Polym. Degrad. Stab. 2021, 192, 109698. [Google Scholar] [CrossRef]
- Cui, X.Y.; Wu, Q.; Sun, J.; Gu, X.Y.; Li, H.F.; Zhang, S. Preparation of 4-formylphenylboronic modified chitosan and its effects on the flame retardancy of poly(lactic acid). Polym. Degrad. Stab. 2022, 202, 110037. [Google Scholar] [CrossRef]
- Teng, N.; Dai, J.Y.; Wang, S.P.; Hu, J.Y.; Liu, X.Q. Hyperbranched flame retardant for epoxy resin modification: Simultaneously improved flame retardancy, toughness and strength as well as glass transition temperature. Chem. Eng. J. 2022, 428, 131226. [Google Scholar] [CrossRef]
- Qian, Y.X.; Luo, Y.B.; Li, Y.; Xiong, T.S.; Wang, L.Y.; Zhang, W.G.; Gang, S.F.; Li, X.; Jiang, Q.H.; Yang, J.Y. Enhanced electromagnetic wave absorption, thermal conductivity and flame retardancy of BCN@LDH/EP for advanced electronic packing materials. Chem. Eng. J. 2023, 467, 143433. [Google Scholar] [CrossRef]
- Yang, Q.S.; Wang, J.; Chen, X.; Yang, S.; Huo, S.Q.; Chen, Q.F.; Guo, P.Z.; Wang, X.; Liu, F.; Chen, W.; et al. A phosphorus-containing tertiary amine hardener enabled flame retardant, heat resistant and mechanically strong yet tough epoxy resins. Chem. Eng. J. 2023, 468, 143811. [Google Scholar] [CrossRef]
- Chen, W.H.; Liu, Y.S.; Liu, P.J.; Xu, C.; Liu, Y.; Wang, Q. The preparation and application of a graphene-based hybrid flame retardant containing a long-chain phosphaphenanthrene. Sci. Rep. 2017, 7, 8759. [Google Scholar] [CrossRef]
- Zhang, J.; Li, Z.; Qi, X.L.; Wang, D.Y. Recent Progress on Metal-Organic Framework and Its Derivatives as Novel Fire Retardants to Polymeric Materials. Nano-Micro Lett. 2020, 12, 173. [Google Scholar] [CrossRef]
- Huo, S.Q.; Guo, Y.; Yang, Q.S.; Wang, H.; Song, P. Two-dimensional nanomaterials for flame-retardant polymer composites: A mini review. Adv. Nanocompos. 2024, 1, 240–247. [Google Scholar] [CrossRef]
- Zhang, T.; Yan, H.Q.; Shen, L.; Fang, Z.P.; Zhang, X.M.; Wang, J.J.; Zhang, B.Y. A phosphorus-, nitrogen- and carbon-containing polyelectrolyte complex: Preparation, characterization and its flame retardant performance on polypropylene. RSC Adv. 2014, 4, 48285–48292. [Google Scholar] [CrossRef]
- Hou, B.Y.; Shan, X.Y.; Li, B.J.; Zhang, Y.; Xu, B.; Chen, Z.D.; Cui, Q.Q.; Li, J.C. Phosphorus-nitrogen-containing flame-retardant plasticizers derived from L-lactic acid for poly (lactic acid) improved toughness, flame retardancy and crystallization. Chem. Eng. J. 2024, 500, 157143. [Google Scholar] [CrossRef]
- Shi, Y.; Wang, L.; Zhao, Z.; Wu, M. Ecofriendly and durable flame-retardant cotton fabric based on alkyl/N/B/P modified meglumine with high efficiency. Prog. Org. Coat. 2023, 185, 107915. [Google Scholar] [CrossRef]
- Vahabi, H.; Wu, H.; Saeb, M.R.; Koo, J.H.; Ramakrishna, S. Electrospinning for developing flame retardant polymer materials: Current status and future perspectives. Polymer 2021, 217, 123466. [Google Scholar] [CrossRef]
- Qin, P.F.; Yi, D.Q.; Hao, J.W.; Ye, X.M.; Gao, M.; Song, T.L. Fabrication of melamine trimetaphosphate 2D supermolecule and its superior performance on flame retardancy, mechanical and dielectric properties of epoxy resin. Compos. Part B 2021, 225, 109269. [Google Scholar] [CrossRef]
- Sun, J.H.; Zhang, D.; Wang, B.T.; Xia, Y.; Zhang, Y.H.; Guo, Z.H.; Fang, Z.P.; Li, J.; Chen, P. Flame retardancy and toughness of epoxy resin induced by a star-shaped flame retardant containing P/Si/B. React. Funct. Polym. 2023, 190, 105649. [Google Scholar] [CrossRef]
- Qi, Y.Z.; Ye, X.L.; Huan, X.Y.; Xu, Q.; Ma, S.K.; Bao, D.M.; Zhou, G.Y.; Zhang, D.H.; Zhang, Y.P.; Du, H.J. P/N/S flame retardant based on DOPS-triazine groups for improving the flame retardancy, char formation properties and mechanical properties of epoxy resin. Eur. Polym. J. 2024, 202, 112634. [Google Scholar] [CrossRef]
- Huo, S.Q.; Song, P.; Yu, B.; Ran, S.Y.; Chevali, V.S.; Liu, L.; Fang, Z.P.; Wang, H. Phosphorus-containing flame retardant epoxy thermosets: Recent advances and future perspectives. Prog. Polym. Sci. 2021, 114, 101366. [Google Scholar] [CrossRef]
- Qiu, S.; Ma, C.; Wang, X.; Zhou, X.; Feng, X.; Yuen, R.K.K.; Hu, Y. Melamine-containing polyphosphazene wrapped ammonium polyphosphate: A novel multifunctional organic-inorganic hybrid flame retardant. J. Hazard. Mater. 2018, 344, 839–848. [Google Scholar] [CrossRef]
- Mao, Y.W.; Wang, W.B.; Huang, W.Y.; Cai, H.P. Flame retardant, transparent, low dielectric and low smoke density EP composites implemented with reactive flame retardants containing P/N/B. Polym. Degrad. Stab. 2024, 230, 111078. [Google Scholar] [CrossRef]
- Wang, Y.D.; Liu, L.Y.; Ma, L.; Yuan, J.; Wang, L.X.; Wang, H.; Xiao, F.; Zhu, Z.M. Transparent, flame retardant, mechanically strengthened and low dielectric EP composites enabled by a reactive bio-based P/N flame retardant. Polym. Degrad. Stab. 2022, 204, 110106. [Google Scholar] [CrossRef]
- Wang, S.H.; Jiang, Y.C.; Tong, X.; Li, Y.J.; Sun, J.; Qian, L.J.; Li, H.F.; Gu, X.Y.; Zhang, S. The fabrication of a boron nitride/ammonium polyphosphate skeleton based on ice template method for thermal conductive and flame retardant epoxy. Polym. Degrad. Stab. 2024, 219, 110606. [Google Scholar] [CrossRef]
- Xu, Y.J.; Zhang, K.T.; Wang, J.R.; Wang, Y.Z. Biopolymer-Based Flame Retardants and Flame-Retardant Materials. Adv. Mater. 2025, e2414880. [Google Scholar] [CrossRef]
- Ridard, H.; Duvigneau, J.; Mayer-Gall, T.; Ali, W.; Wurm, F.R. Biobased Flame-Retardant Polylactic Acid Foams through Lignin-Based Nanocarriers Encapsulating Deoxyribonucleic Acid. ACS Sustain. Chem. Eng. 2024, 12, 14866–14878. [Google Scholar] [CrossRef]
- Song, K.; Bi, X.; Yu, C.; Pan, Y.T.; Xiao, P.; Wang, J.; Song, J.I.; He, J.; Yang, R. Structure of Metal-Organic Frameworks Eco-Modulated by Acid-Base Balance toward Biobased Flame Retardant in Polyurea Composites. ACS Appl. Mater. Interfaces 2024, 16, 15227–15241. [Google Scholar] [CrossRef] [PubMed]
- Zhang, X.Y.; Yan, X.X.; Zeng, F.L.; Zhang, H.; Li, P.Y.; Zhang, H.Y.; Li, N.; Guan, Q.B.; You, Z.W. Low-Cost Intrinsic Flame-Retardant Bio-Based High Performance Polyurethane and its Application in Triboelectric Nanogenerators. Adv. Sci. 2025, 12, e2412258. [Google Scholar] [CrossRef]
- Li, Z.Q.; Zhu, Y.L.; Niu, W.W.; Yang, X.; Jiang, Z.Y.; Lu, Z.Y.; Liu, X.K.; Sun, J.Q. Healable and Recyclable Elastomers with Record-High Mechanical Robustness, Unprecedented Crack Tolerance, and Superhigh Elastic Restorability. Adv. Mater. 2021, 33, e2101498. [Google Scholar] [CrossRef]
- Yao, Y.; Liu, B.; Xu, Z.Y.; Yang, J.H.; Liu, W.G. An unparalleled H-bonding and ion-bonding crosslinked waterborne polyurethane with super toughness and unprecedented fracture energy. Mater. Horiz. 2021, 8, 2742–2749. [Google Scholar] [CrossRef]
- Ou, F.Y.; Xie, T.; Li, X.Z.; Zhang, Z.C.; Ning, C.; Tuo, L.; Pan, W.Y.; Wang, C.S.; Duan, X.Y.; Liang, Q.H.; et al. Liquid-free ionic conductive elastomers with high mechanical properties and ionic conductivity for multifunctional sensors and triboelectric nanogenerators. Mater. Horiz. 2024, 11, 2191–2205. [Google Scholar] [CrossRef]
- Hao, X.-Y.; Yu, B.; Li, L.; Ju, H.; Tian, M.; Cao, P.-F. Semi-Interpenetrating Polyurethane Network with Fatigue Elimination and Upcycled Mechanical Performance. Macromolecules 2024, 57, 5063–5072. [Google Scholar] [CrossRef]
- Luo, Y.L.; Chen, J.L.; Situ, G.H.; Li, C.C.; Zhang, C.R.; Li, F.Z.; Li, C.-H.; Luo, Z.Y.; Zhang, X. Aromatic disulfide-induced self-reinforcing polyurethane elastomer with self-healability. Chem. Eng. J. 2023, 469, 143958. [Google Scholar] [CrossRef]
- Shang, X.; Jin, Y.; Du, W.N.; Bai, L.; Zhou, R.; Zeng, W.H.; Lin, K.Y. Flame-Retardant and Self-Healing Waterborne Polyurethane Based on Organic Selenium. ACS Appl. Mater. Interfaces 2023, 15, 16118–16131. [Google Scholar] [CrossRef]
- Deng, H.H.; Xie, F.; Shi, H.B.; Li, Y.F.; Liu, S.Y.; Zhang, C.Q. UV resistance, anticorrosion and high toughness bio-based waterborne polyurethane enabled by a Sorbitan monooleate. Chem. Eng. J. 2022, 446, 137124. [Google Scholar] [CrossRef]
- Liu, B.; Chen, X.; Spiering, G.A.; Moore, R.B.; Long, T.E. Quadruple Hydrogen Bond-Containing A-AB-A Triblock Copolymers: Probing the Influence of Hydrogen Bonding in the Central Block. Molecules 2021, 26, 4705. [Google Scholar] [CrossRef] [PubMed]
- Man, Y.Y.; Liu, Y.Y.; Miao, H.Y.; Huang, G.; Han, L.; Tong, L.L.; Fu, X.B.; Zheng, C.Y.; Huang, X.J.; Zhang, X.; et al. Stretchable and high sensitive ionic conductive hydrogel for the direction recognizable motion detection sensor. Giant 2023, 16, 100199. [Google Scholar] [CrossRef]
- Chang, K.Q.; Zhang, C.; Liu, T.X. A Comprehensive Review on Fabrication and Structural Design of Polymer Composites for Wearable Pressure Sensors. Polym. Sci. Technol. 2025, 1, 3–24. [Google Scholar] [CrossRef]
- Gong, S.; Lu, Y.; Yin, J.L.; Levin, A.; Cheng, W.L. Materials-Driven Soft Wearable Bioelectronics for Connected Healthcare. Chem. Rev. 2024, 124, 455–553. [Google Scholar] [CrossRef]
- Luo, C.; Huang, Z.K.; Guo, Z.H.; Yue, K. Recent Progresses in Liquid-Free Soft Ionic Conductive Elastomers. Chin. J. Chem. 2023, 41, 835–860. [Google Scholar] [CrossRef]
- Yan, C.C.; Li, W.Z.; Liu, Z.Y.; Zheng, S.J.; Hu, Y.; Zhou, Y.J.; Guo, J.N.; Ou, X.; Li, Q.N.; Yu, J.T.; et al. Ionogels: Preparation, Properties and Applications. Adv. Funct. Mater. 2024, 34, 2314408. [Google Scholar] [CrossRef]
- Jin, Y.T.; Li, J.T.; Zhang, M.Z.; He, J.L.; Ni, P.H. Unexpected mechanically robust ionic conductive elastomer constructed from an itaconic acid-involved polymerizable DES. Chem. Commun. 2023, 59, 12998–13001. [Google Scholar] [CrossRef]
- Qian, Z.Y.; Pan, C.L.; Chen, H.; Zhang, M.Z.; He, J.L.; Ni, P.H. Development of an Ionic Conductive Elastomer from the Photocopolymerization of a Ternary Polymerizable Deep Eutectic Solvent for Human Motions Sensing. Macromol. Rapid Commun. 2025, 46, e2400798. [Google Scholar] [CrossRef]
- Li, R.A.; Fan, T.; Chen, G.X.; Xie, H.J.; Su, B.; He, M.H. Highly Transparent, Self-Healing Conductive Elastomers Enabled by Synergistic Hydrogen Bonding Interactions. Chem. Eng. J. 2020, 393, 124685. [Google Scholar] [CrossRef]
- Zhang, K.L.; Li, R.A.; Chen, G.X.; Yang, J.M.; Tian, J.F.; He, M.H. Polymerizable Deep Eutectic Solvent-Based Mechanically Strong and Ultra-Stretchable Conductive Elastomers for Detecting Human Motions. J. Mater. Chem. A 2021, 9, 4890–4897. [Google Scholar] [CrossRef]
- Ding, X.-P.; Mao, Y.-J.; Huang, J.-F.; Lin, H. Fabrication of a Flexible and Transparent All-Solid-State Ionic Conductive Elastomer and Its Sensing Properties. Ind. Eng. Chem. Res. 2025, 64, 5720–5728. [Google Scholar] [CrossRef]
- Xu, W.K.; Shen, T.; Ding, Y.T.; Ye, H.J.; Wu, B.Z.; Chen, F. Wearable and Recyclable Water-Toleration Sensor Derived from Lipoic Acid. Small 2024, 20, e2310072. [Google Scholar] [CrossRef] [PubMed]
- Wang, D.Y.; Lu, W.N.; Qu, J.Q. Rapid Preparation of High Strength, High Stretchability, Transparent, Self-Healing Conductive Elastomers for Strain Sensors by Photo-Initiated Copolymerization of Two Novel Polymerizable Deep Eutectic Solvents. Eur. Polym. J. 2024, 210, 112999. [Google Scholar] [CrossRef]
- Du, D.Y.; Zhou, J.H.; Shi, D.J.; Dong, W.F.; Chen, M.Q. Cross-Linked, Transient Ionic Conductive Elastomer with Extreme Stretchability, Healability, and Degradability for Detecting Human Motions. ACS Appl. Polym. Mater. 2022, 4, 4972–4979. [Google Scholar] [CrossRef]
- Aierken, Y.; Xu, Y.S.; Xiang, S.F.; Peng, W.J.; Zhang, X.M.; Hakkarainen, M.; Ma, P.M. Reprocessable, Highly Transparent Ionic Conductive Elastomers Based on Beta-Amino Ester Chemistry for Sensing Devices. ACS Appl. Mater. Interfaces 2024, 16, 25374–25384. [Google Scholar] [CrossRef]
- Wen, X.; Xu, J.H.; Wang, H.B.; Du, Z.L.; Wang, S.; Cheng, X. High Strength, Self-Healing, and Anti-Freezing Polyurethane Ionogel Based on Multiple Hydrogen Bonding for Wearable Strain Sensor. Polym. Eng. Sci. 2022, 62, 3132–3143. [Google Scholar] [CrossRef]
- GB/T 2406.2-2009; Plastics—Determination of Burning Behaviour by Oxygen Index—Part 2: Ambient-Temperature Test. National Standards of People’s Republic of China: Beijing, China, 2009.
Samples | PA (wt%) | UL-94 Test | LOI (%) | |
---|---|---|---|---|
Dripping/Ignition of Cotton | Rating | |||
PCAI | 0 | Yes/Yes | V-2 | 25.0 ± 1.0 |
PCAIP5 | 5 | No/No | V-0 | 31.8 ± 1.6 |
PCAIP7.5 | 7.5 | No/No | V-0 | 40.4 ± 2.4 |
PCAIP10 | 10 | No/No | V-0 | 52.0 ± 1.0 |
PCAIP12.5 | 12.5 | No/No | V-0 | 54.6 ± 6.3 |
Samples | TTI a (s) | pHRR b (kw/m2) | THR c (MJ/m2) | pARHE d (kw/m2) | TML e (g/m2) |
---|---|---|---|---|---|
PCAI | 19 | 225.9 | 93.1 | 166.5 | 5170 |
PCAIP5 | 34 | 199.9 | 44.2 | 71.1 | 3314 |
PCAIP7.5 | 35 | 134.4 | 25.5 | 59.4 | 3263 |
PCAIP10 | 36 | 130.4 | 15.1 | 42.8 | 3190 |
PCAIP12.5 | 37 | 120.5 | 15.3 | 40.0 | 3187 |
Samples | m (ChCl, g) | m (AA, g) | m (IA, g) | m (PA, g) |
---|---|---|---|---|
PCAI | 4.84 | 5 | 1.35 | 0 |
PCAIP5 | 1.12 | |||
PCAIP7.5 | 1.68 | |||
PCAIP10 | 2.24 | |||
PCAIP12.5 | 2.80 | |||
PCAIP7.5-0 | 0 | 1.48 | ||
PCAIP7.5-0.1 | 0.45 | 1.54 | ||
PCAIP7.5-0.2 | 0.90 | 1.61 | ||
PCAIP7.5-0.3 | 1.35 | 1.68 |
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Li, S.; Chen, H.; Zhao, C.; He, J.; Zhang, L. Flame-Retardant Ionic Conductive Elastomers with Multiple Hydrogen Bonds: Synthesis, Characterization, and Strain Sensing Applications. Molecules 2025, 30, 1810. https://doi.org/10.3390/molecules30081810
Li S, Chen H, Zhao C, He J, Zhang L. Flame-Retardant Ionic Conductive Elastomers with Multiple Hydrogen Bonds: Synthesis, Characterization, and Strain Sensing Applications. Molecules. 2025; 30(8):1810. https://doi.org/10.3390/molecules30081810
Chicago/Turabian StyleLi, Sen, Hao Chen, Chen Zhao, Jinlin He, and Lijing Zhang. 2025. "Flame-Retardant Ionic Conductive Elastomers with Multiple Hydrogen Bonds: Synthesis, Characterization, and Strain Sensing Applications" Molecules 30, no. 8: 1810. https://doi.org/10.3390/molecules30081810
APA StyleLi, S., Chen, H., Zhao, C., He, J., & Zhang, L. (2025). Flame-Retardant Ionic Conductive Elastomers with Multiple Hydrogen Bonds: Synthesis, Characterization, and Strain Sensing Applications. Molecules, 30(8), 1810. https://doi.org/10.3390/molecules30081810