ACS Sustainable Chemistry & Engineering
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2019
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IF 6.97
Ganggang Zhang,Xinxin Zhou,Kuan Liang,Baochun Guo,Xiaolin Li,Zhao Wang,Liqun Zhang
Covalently cross-linked rubbers are indispensable in many important fields due to their unique entropic elasticity. For rubbers cross-linking, the addition of toxic curing agents, release of toxic volatile organic compounds (VOCs), and recycling of waste rubber are three important issues. A combination of green curing chemistry and efficient recycling into commercial polyolefin rubbers is of great importance. Herein, we demonstrate a facile and promising way to incorporate dynamic covalent bonds into ethylene-propylene-diene monomer (EPDM)/carbon black (CB) composites. The epoxy-functionalized EPDM (e-EPDM) was prepared using an in situ epoxidation reaction and then cured with biobased decanedioicacid (DA) through the reactions between the epoxy groups in e-EPDM and the carboxylic groups in DA. Because of the existence of exchangeable β-hydroxyl ester, the covalently cross-linked networks in e-EPDM/CB composites were able to rearrange their topological structure at high temperature, endowing the composites with recycled and reshaped abilities. More importantly, the recycled e-EPDM/CB composites still exhibit outstanding mechanical properties which can meet the needs of practical applications. This strategy may provide an efficient, green, and sustainable way to address the problems brought from rubbers cross-linking.
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
POLYMER
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2021
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IF 4.43
Haoran Feng,Chenru Tian,Ganggang Zhang,Liqun Zhang
Current adopted rubber curing methods undergo large amounts of environmental issues, such as the release of toxic volatile organic compounds (VOCs) during curing process and difficulties in recycling of end-of-life rubbers. Many new curing reactions and cross-linking structures have been developed to solve these problems. A green curing strategy based on epoxy-acid reactions and ester linkages could be a potential alternative to the current curing ones. However, the curing reactions between epoxy and carboxyl groups generally require a catalysis to improve curing rate, and the recycling process requires toxic organic solution or high temperature. It is of great desired to develop a real environmentally friendly crosslinking strategy for rubber materials. In this paper, we report a facile and high-efficiency green crosslinking strategy for the carboxyl-functionalized rubber. N,N,N′,N'-tetraglycidyl-4,4′-diaminodiphenylmethane (TGDDM) was selected as a multifunctional amine-type high-efficiency crosslinker for carboxylated nitrile rubber (XNBR). TGDDM-cured XNBR exhibit extremely fast crosslinking rate and high crosslinking efficiency due to the four epoxy terminated units and tertiary amine structure acting as an internal catalyst. Besides, the mechanical properties and crosslinking density of TGDDM-cured XNBR can be regulated by TGDDM content. Furthermore, the ester linkage formed by curing reaction could be selectively and efficiently cleaved in a mixed solution of ethanol and water under mild condition. The closed-loop recovered XNBR maintains chemical structure and molecular weight and exhibit good mechanical performance. This strategy offers a promising way for high-efficient crosslinking of diene rubber as well as a real cost-effective and environmentally friendly recovery of end-of-life rubber materials.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
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2022
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IF 9.879
Qianqian Wang,Pengwu Xu,Weijun Yang,Tianxi Liu,Martin Hoch,Piming Ma
The current cross-link method in rubber industry is suffering from the utilization of toxic curing packages and the release of volatile organic compounds (VOCs). In this work, we propose a green cross-link route to make robust rubber materials. To prove this concept, ethylene-vinyl acetate-glycidyl methacrylate copolymer (EVM-GMA) functionalized with silane groups, i.e., EVM-Si(OC 2 H 5 ) 3 as a model rubber was firstly designed by solvent-free compounding. Then, the silane groups of EVM-Si(OC 2 H 5 ) 3 rubber are hydrolyzed and cross-linked with water molecules. The cross-link density, tensile strength and hardness of the EVM-Si(OC 2 H 5 ) 3 rubber increased gradually with temperature up to 200 °C. Subsequently, the water cross-linked EVM-Si(OC 2 H 5 ) 3 rubber was reinforced with silica (SiO 2 ) that created a secondary network via an in situ interfacial reaction between the –OH groups of SiO 2 and the silane groups of EVM-Si(OC 2 H 5 ) 3 . As a consequence, the SiO 2 nanoparticles could be evenly dispersed in the rubber matrix with strong interfacial bonding . The tensile strength and elongation at break of the EVM-Si(OC 2 H 5 ) 3 /SiO 2 nanocomposites reached to 10.0 MPa and 800%, respectively at a SiO 2 loading of 30 phr. Thus, the new cross-link strategy addressed here may promote the development and application of rubber industry in some environmental-friendly domains.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
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2025
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IF 4.3
Chenru Tian,Ganggang Zhang,Jun Liu,Liqun Zhang
The conventional curing methods pose a significant environmental threat due to the use of toxic vulcanizing agents, the release of irritating volatile organic compounds, and the difficulties in recycling end-of-life rubber products. This work demonstrates a catalyst-free, facile, and eco-friendly crosslinking strategy based on the reaction between epoxy-functionalized ethylene-propylene-diene monomer (EEPDM) and dicarboxylic acids. The EEPDM was synthesized via a reusable reaction-controlled phase-transfer catalyst. Then, EEPDM could be effectively crosslinked by dicarboxylic acids without additional additives. The increased acidity of dicarboxylic acids could be conducive to improving the crosslinking rate. Moreover, the curing mechanism and the nature of the crosslinks were investigated, which is crucial for the recyclability of rubbers. The dicarboxylic acid-cured EEPDM exhibited undesirable side reactions, the extent of which showed a positive correlation with the acidity of carboxylic groups. This phenomenon could be primarily attributed to acid-catalyzed self-polymerization via epoxide ring-opening mechanisms, which would be detrimental to the reprocessability. Due to the formation of thermally stable ether linkages, the crosslinked EEPDM exhibited enhanced thermal-oxidative aging behavior. Hence, we envision that this catalyst-free, high-efficiency crosslinking strategy may offer a promising bridge between sustainable modification and high-performance for epoxy-functionalized rubbers, holding potential application in eco-friendly, low-odor automotive sealing strips.
研究领域:
高分子科学
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材料工程
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绿色化学
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橡胶技术
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化学合成
✓ 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）