Polymers
·
2022
·Vol. 14
·期 11
·2283
·
IF 4.967
Jing Wang,Jihu Wang,Song Wang,Shaoguo Wen,Kaimin Chen,Chen Xie,Chunping Yuan
The most notable features of polyurea are its fast reaction, energy-saving and high efficiency. In order to meet the needs of environmental protection, waterborne polyurea (WPUA) has become a research hotspot. However, the presence of hydrophilic groups in WPUA reduces its solvent resistance, heat resistance and mechanical properties. Therefore, it is necessary and valuable to develop a high-performance WPUA. In this study, epoxy-modified waterborne polyurea (WPUAE) emulsions were prepared using epoxy resin as a modifier. Fourier transform infrared spectroscopy (FT-IR) showed that E44 was successfully introduced into the molecular chain of WPUA. The WPUAE was tested for gel fraction, adhesion, contact angle, solvent resistance, tensile properties and thermal stability. The results showed that when the E44 content was 8 wt%, the performance of WPUAE was best, the adhesion of WPUAE coating film was 1.53 MPa, the gel fraction, water contact angle, water absorption, toluene absorption, tensile strength and decomposition temperature were 96.94%, 70.3°, 16.43%, 131.04%, 9.05 MPa and 365 °C, respectively. The results showed that epoxy resin as an emulsion modifier improved the comprehensive properties of WPUA.Keywords:waterborne polyurea;epoxy resin;solvent resistance;mechanical properties;thermal stability
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 10
·期 12
·6713-6723
·
IF 14.511
Yuan Lei,Yi Wang,Anqian Yuan,Shiwei Zhao,Yue Chen,Yao Xiao,Liang Jiang,Jingxin Lei
Great efforts have been devoted to solving the issue that covalent thermosetting polymers and their composites, unlike thermoplastic polymers, are unable to undergo reprocessing via secondary melting or recycling through injection or extrusion after curing, which prevents them from forming three-dimensional network structures. However, tremendous attention has been focused on introducing specific dynamic covalent bonds or noncovalent bonds into the molecular structures of thermosetting polymers, which requires choosing or synthesizing particular monomers, greatly limiting the industrial application potential. Herein, we have devised and prepared a series of conventional thermosetting polyurea elastomers (TPUEs) by utilizing the commercial raw materials of poly(propylene oxide)diamine and different diisocyanate monomers. These TPUEs have remarkable solvent resistance, great thermal stability, and outstanding transparency in the visible light range. In particular, the toughness, the breaking strength, and the elongation at break of TPUEs can reach maximum values of 300 MJ m−3, 31.4 MPa, and 1752%, respectively, making them superior to most dynamic materials and commercial elastomers that exhibit exceptional mechanical properties. Surprisingly, the TPUEs devised here have a superior dynamic nature owing to the classic urea bond, as confirmed via analysis of small molecules and dynamic properties, such as stress-relaxation and creep–recovery. These TPUEs can maintain remarkable mechanical properties, chemical stability, and solvent resistance after being recycled multiple times. Additionally, we propose a universal mechanism by which these TPUEs can simultaneously have mechanically robust properties in the range from the glass transition temperature of the soft segment (Tgs) to their topology freezing-transition temperature (Tv) (about −40 °C to 150 °C) and excellent recyclability at temperatures ranging from Tv to the thermal decomposition temperature (Td) (about 150 °C to 220 °C). Integration of mechanical robustness and a dynamic nature into one network can provide a facile way to solve the recyclability issues relating to conventional TPUEs.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2024
·
IF 6.5
Yuedong Xing,Xianwen Li,Jianben Xu,Faai Zhang
Conventional waterborne polyurethanes (WPUs) have limited their application as high-performance coatings due to low mechanical strength and poor solvent resistance. Organosilicon modification is important to improve the solvent and chemical resistance of WPUs. Herein, we prepared a double crosslinked WPUs with excellent performance using isophorone diisocyanate and polytetrahydrofuran as raw materials, and trihydroxy polyoxypropylene ether, pentaerythritol, and dihydroxy silicone oil as functional monomers. The solvent resistance and the mechanical properties of the coatings had improved after crosslinking of WPUs (tensile strength of 7.39 MPa, elongation at break of 1178 %). Furthermore, the coatings with excellent hydrophobicity (water contact angle of 94.5°). Meanwhile, medical gloves with organosilicon-modified WPUs showed excellent water, alcohol and salt immersion resistance. Based on the excellent comprehensive performance of organosilicon-modified WPUs, it is expected to be used as a surface coating in medical gloves.
研究领域:
材料科学
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高分子化学
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涂料研究
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Xiwei Guo,Ronan Brown,Yue Dong,Haoyu Feng,Yang Xiang,Dongxu Wang,Qi Zhang,He Zhu,Shiping Zhu
Elastomers are essential for a variety of demanding applications, but their performance is significantly compromised under harsh conditions, such as extremely low temperatures and serious aging. Herein, a novel polyurethane elastomer (PFTA) is presented, having perfluoropolyether as the soft segment and catechol-containing molecules synthesized via Schiff base reaction as the chain extender, where the perfluoropolyether segments confer outstanding low-temperature and solvent resistance and the catechol groups provide exceptional anti-aging properties to the material. As a result, the obtained elastomer achieves an ultralow glass transition temperature of approximately −115 °C, demonstrating remarkable flexibility at extremely low temperatures, even in a liquid nitrogen environment, and possesses good aging and solvent resistance. These results highlight that the combination of catechol functionalization and perfluoropolyether segments provides a promising platform for the development of elastomers suitable for extreme environmental applications, such as aerospace and polar exploration.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
BIOMACROMOLECULES
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2022
·
IF 6.978
Guangchao Zheng,Wei Gao,Xue Li,Zhiqiang Wu,Lin-An Cao,Enke Feng,Zhiming Yang
Gel polymers are widely used in different fields due to their unique properties, especially in flexible electronic devices. However, developing multienvironmentally-tolerant (antifreezing, antidrying, and solvent-resistant) gel polymer-based soft electronics is still a significant challenge. Herein, a binary solvent system-based versatile organohydrogel is designed and successfully prepared, which exhibits superior stretchability, favorable self-adhesive properties, prominent temperature tolerance, and excellent solvent-resistant capabilities. Furthermore, the as-assembled organohydrogel-based sensor demonstrates a satisfied sensitivity (GF = 1.8), wide strain range (5–500%), and outstanding human motion detection. Meanwhile, the obtained organohydrogel can also serve as an all-weather sensor for achieving precise and reliable mechanical sensing in a wide temperature range from −50 to 50 °C and diverse liquid media consisting of water, toluene, and carbon tetrachloride. Interestingly, the organohydrogel displays a repeatable transmittance change behavior in water and dimethyl sulfoxide, based on this feature, which could realize the functional applications for recording and erasing information. It is envisioned that these superior performances render the as-prepared organohydrogel suitable to develop future advanced soft electronics with multienvironmental tolerance.
研究领域:
材料科学
·
柔性电子学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2023
·Vol. 224
·期 17
·2300083
·
IF 2.5
Shibiao Jin,Tao Ai,Yong Jiang,Xuanxuan Wu,Kun Yang,Ying Liu,Yue Cheng
Traditional chemically cross-linked polymer materials may cause severe environmental pollution and economic losses due to the difficulty of recycling. Vitrimers containing reversible dynamic covalent bonds are processable, recyclable, and self-healing. In this article, a bio-based epoxy resin curing agent is synthesized by hydrolysis using cellulose as raw material. The results show that the epoxy vitrimers with the best ratio have a lower topological transition temperature and a fast relaxation time at 140 °C. After soaking in solvent for 90 days, the gel content of the material is greater than 81%. The glass transition temperature of the sample measured by differential scanning calorimetry （DSC) is 83 °C. It also has a high initial decomposition temperature (350 °C) with good flexibility and solvent resistance, showing its good performance as a coating paint.
研究领域:
材料科学
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生物化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2023
·
IF 4.6
Mao Chen,Shuyi Duan,Lin Zhou,Zhongtao Chen,Yinyu Zhang,Yeping Wu,Qing Zhu,Kuibao Zhang,Xiuli Zhao
Polymer-bonded explosives (PBXs) that make up of high explosives and polymeric materials have been widely used as propellants, explosives and pyrotechnics in various industry. However, due to the cross-linked networks of polymers, the inflammable and toxic PBXs wastes that cannot be degraded and recycled are commonly burned or buried, leading to environmental pollution and economic loss. Due to the ultra-high sensitivity and high solid content of PBXs, it is a great challenge to achieve recyclable cross-linked PBXs. Herein, a thiol-cured disulfide-based epoxy vitrimer was prepared to bond high explosives of HMX, resulting in vitrimer-bonded explosives (VBXs). Due to the neutral and mild properties of disulfide epoxy monomers and thiol curing agents , the epoxy vitrimers exhibited good compatibility with the ultra-sensitive HMX. Meanwhile, intrinsic properties and dynamic properties of the epoxy vitrimers were both investigated. Moreover, the VBXs that consisted of 82 wt% HMX and 18 wt% epoxy vitrimers exhibited outstanding solvent resistance and excellent mechanical properties , while the compression strength was up to ∼35.1 MPa. Besides, the VBXs were successfully degraded by the neutral thiol solutions and the HMX was recycled from the VBXs non-destructively, which was confirmed by 13 C NMR. To the best of our knowledge, it is the first time to achieve recyclable PBXs relying on vitrimer materials, which will provide a new insight for the green development of energetic composites, while the thiol-cured disulfide-based epoxy vitrimer will have the potential for more other demanding applications.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2023
·
IF 5
Xiaobo Xu,Xiaozhen Ma,Xiaolin Wang,Jin Zhu,Jinggang Wang,Ning Yan,Jing Chen
Using sustainable biomass feedstock to prepare biobased chemical products is attracting increasing attention. Betulin is a natural cyclic aliphatic diol that can be extracted in large quantities from the bark of birch trees. In this study, a series of bio-based polyurethane (PU) elastomers with excellent mechanical properties, solvent resistance, and thermal stability were synthesized under catalyst-free conditions using betulin and castor oil (CO) as the bio-based polyols. The chemical structure and properties of the bio-based PU elastomers were systematically investigated according to the effect of the hydroxyl ratio between betulin and CO. Due to the presence of abundant hydrogen bonds and rigid ring planes in the PU structure, and a higher cross-link density, the obtained PU elastomers had excellent mechanical properties. They achieved a maximum tensile strength of 31.6 MPa with the tensile strain reaching more than 200% and were able to withstand 1 × 105 times their weight. The thermal decomposition temperature of the betulin-derived PUs was over 300 °C. This study showcased a strategy to synthesize sustainable high-performance PU materials with a high biomass content (>75%).
研究领域:
材料科学
·
化学工程
·
可持续性
·
聚合物化学
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2021
·Vol. 23
·期 22
·9061-9070
·
IF 10.182
Hongzhi Feng,Songqi Ma,Xiwei Xu,Qiong Li,Binbo Wang,Na Lu,Pengyun Li,Sheng Wang,Zhen Yu,Jin Zhu
Dynamic covalent polymer networks (DCPNs) can address the recycle or reuse issue of thermosets due to their network rearrangement from the dynamic bond exchange. However, developing DCPNs combining fast reprocessability and high performance through a facile and green method is still a huge challenge. Herein, a facile and green method (in situ polymerization and dynamic cross-linking (ISPDC)) was utilized to produce hemiacetal ester-based DCPNs which exhibited fast reprocessability and high performance. No solvent and no purification were required, and the facile synthesis process also showed readily regulated performance for the DCPNs. The obtained DCPNs could be continuously reprocessed by extrusion as well as compression remolding; meanwhile their solvent resistance, thermo-physical and mechanical properties are excellent on account of their high cross-link density. The small-molecule model reactions and theoretical calculation demonstrated that hemiacetal ester exchange follows a dissociative mechanism without or with an extra carboxyl group. This work studied DCPNs which showed great potential to be efficiently recycled via reprocessing and scaled up. It tallies with sustainable development and contributes to carbon neutrality.
研究领域:
材料科学
·
聚合物化学
·
可持续材料
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2020
·Vol. 12
·期 21
·2727-2734
·
IF 2.596
Yuhong Zhou,Qian Liang,Zhilun Zhang,Zhaodi Wang,Mingxian Huang
A hybrid silica monolith containing vinyl groups was synthesized by a sol–gel method, and then ground and treated, yielding silica particles with a 3–5 μm particle size and a 10–20 nm pore size. Cellulose derivatives containing 3,5-dimethylphenylcarbamate groups and methacrylate groups regioselectively were then immobilized onto the surface of the above particles by the thiol–ene click reaction using an alkanedithiol as the crosslinking agent, thus forming a solvent-resisting crosslinked network structure attached onto the surface of the particles. The immobilization degree was more than 80%, and the back pressure of the chiral stationary phase (CSP) packed column was relatively low and was maintained at around 3.0 MPa. The as-prepared CSPs were shown to be able to effectively separate various enantiomers with different mobile phases.
研究领域:
分析化学
·
材料科学
·
色谱学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）