CONSTRUCTION AND BUILDING MATERIALS
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2024
·
IF 7.4
Chengbin Wang,Bin Wang,Xinghua Su,Rui He
Due to the excellent strength, ultra-high specific surface area and extremely small size of graphene, it is an ideal modification component for cementitious materials. However, the conventional production methods of graphene are often time-consuming, energy-intensive, and expensive, which limits its development in cementitious materials to a certain extent. Recently, flash joule heating (FJH) has been shown to be an effective and green method to synthesize graphene. Therefore, the present paper attempts to prepare graphene from waste rubber powder by FJH and study its effect on the properties of cementitious materials. The results demonstrate that the study successfully converted waste rubber powder into multilayer graphene with minimal defects. Raman spectroscopy and XRD analyses revealed characteristic peaks of graphene, while the results of TGA show that graphene have excellent thermal stability. XPS analysis indicate that the purity of graphene can reach about 87.33 %. SEM and TEM reveal its multi-layered lamellar structure. Moreover, we synthesized graphene-enhanced cement mortar, which exhibited improved mechanical properties. The pore structure was optimized, with decreased porosity and mean pore size. Microscopically, the presence of graphene led to a denser arrangement of hydration products, fewer pores, and cracks. AFM results demonstrated that graphene effectively enhanced the average elastic modulus at the nanoscale interface. This study contributes to the advancement of sustainable development by recycling waste rubber and proving the potential of graphene in cement composites.
研究领域:
材料科学
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可持续发展
·
土木工程
✓ 已验证
DOI
高影响因子
RUBBER CHEMISTRY AND TECHNOLOGY
·
2024
·Vol. 97
·期 2
·190-203
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IF 1.2
Gao Lining,Li Li,He Rui,Zheng Xinqiu,Qin Ruihao
The recycling of waste rubber is very important for environmental protection, but the compatibility problem restricts the recycling and application of waste rubber powder (WRP). Devulcanization of WRP has been proven to be an effective method to improve the solubilization effect. The use of environmentally friendly nontoxic solvents can not only improve the devulcanization effect but also avoid secondary pollution. Thus, in this article, an environmentally friendly deep eutectic solvent (DES) is first prepared and then applied to the devulcanization treatment of WRP. The results show that the prepared DES has a positive devulcanization effect, and the devulcanization rate can reach 50%. The devulcanization mechanism can be divided into two aspects: (1) adsorption and removal of sulfur-containing low-molecular compounds and (2) destruction of the crosslinking structure and improvement of fluidity. Observation of the microstructure showed that the rougher the surface of the desulfurized rubber powder, the more conducive to the crosslinking reaction with the matrix material to form a uniform whole. The devulcanization mechanism of DES is divided into destroying the sulfur-containing cross-linked structure and adsorbing the sulfur-containing low-molecular compounds. The surface of WRP after DES treatment is rougher and more porous, which is beneficial to the crosslinking reaction with the matrix material. Finally, the optimum process conditions for the de-crosslinking effect are determined by orthogonal test as follows: liquid-solid ratio 15∶1, temperature 120°C, time 0.5 h.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
Journal of Rubber Research
·
2019
·Vol. 23
·期 1
·41-46
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IF 0.281
Liao Xiao-Xue,Wei Yan-Chan,Zhang Hui-Feng,Zheng Ting-Ting,Luo Ming-Chao,Liao Shuangquan
Waste rubber with three-dimensional structure is insoluble and non-melting, which creates recycling problem. The technique called “high-pressure high-temperature sintering” (HPHTS) can convert vulcanized rubber powder into usable rubber products. However, reversion occurs when vulcanizates are exposed to a prolonged treatment at high temperature. This reversion results in the decrease of mechanical properties of sintered waste rubber powder (WRP) samples. To address this problem, a method of enhancing the mechanical properties of sintered WRP by incorporating different content of maleic anhydride (MA) and N , N ′- m -phenylene bismaleimide (BMI) is discussed in this paper. The results show that BMI and MA can slow down the formation of the conjugated double bonds. Through Diels–Alder reaction, BMI inhibits conjugated double bonds formation and improves the adhesion between particles and particles, which is beneficial to improvement of final properties. Therefore, BMI improves the mechanical properties of sintered WRP greatly.
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
MACROMOLECULAR RESEARCH
·
2018
·Vol. 26
·期 5
·403-409
·
IF 1.767
Wang Xiaoping,Du Jianghua,Zhang Xin,Jia Deming
A mechano-chemical modification process for waste rubber powder (WRP) was investigated in this paper. 2-Mercatobenzothiozole (accelerator M) was introduced as a peptizer to improve plasticity of WRP, and 3-aminopropyltriethoxysilane (silane coupling agent KH550) was used as a surfactant to further modify the surface of plasticized rubber powder (PRP) to improve interfacial bonding with epoxidized natural rubber (ENR). Infrared spectrums showed that the WRP generated more oxygen-containing groups by mechanical forces in the presence of accelerator M and then grafted amino groups with KH550. The mechano-chemical process with accelerator M changed the structure of WRP obviously shown by sol fraction and microstructure of PRP, which increased the mechanical properties and crosslink density of full rubber powder vulcanizates. After further modified by KH550, the modified rubber powder (MRP) had a positive chemical interfacial bonding with ENR, changing the fracture surface and improving the mechanical properties of vulcanizates. The cure characteristics of the vulcanizates also illustrated that accelerator M and KH550 participated in the vulcanization process increasing the curing efficiency. The best mechanical properties of ENR/MRP vulcanizates were better than the neat ENR vulcanizates. It indicated that the mechano-chemical process with accelerator M and KH550 will be a potential method to reclaim WRP.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2013
·Vol. 129
·期 4
·2313-2320
·
IF 1.395
Mingchao Luo,Xiaoxue Liao,Shuangquan Liao,Yanfang Zhao
Waste rubber powder (WRP) was modified by microwave, sol–gel method, and both microwave and sol–gel method, respectively. The mechanical and dynamic mechanical properties of natural rubber (NR)/modified WRP composite were investigated. The influence of bis-(3-(triethoxysilyl)-propyl)-tetrasulfide (TESPT) content on curing characteristics and mechanical properties of vulcanizate was also studied. The results showed that NR/WRP modified by both microwave and sol–gel method composite owned the best mechanical properties. Rubber processing analyzer was used to characterize the interaction between silica and rubber chains and the dispersion of silica. With increase of TESPT content, the Payne effect decreased. Scanning electron microscopy indicated the coherency and homogeneity of in situ generated silica filled vulcanizate. Dynamic mechanical analyzer showed that NR/WRP modified by both microwave and sol–gel method composite with 5 phr TESPT exhibited the lower tan δ at temperature range of 50–80°C, compared with composite without TESPT and the higher tan δ at temperature of 0°C, compared with the conventional modification of WRP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
研究领域:
高分子材料科学
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橡胶工程
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复合材料学
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材料化学
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高分子物理
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功能材料
·
可持续材料技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）