RUBBER CHEMISTRY AND TECHNOLOGY
·
2021
·Vol. 94
·期 4
·759-773
·
IF 1.868
Lin Zhengwei,Zhao Haotian,Chen Yanlu,Mao Jie,Hoch Martin,Shi Xinyan
An EPDM terpolymer grafted with silane vinyl triethoxysilane (EPDM-g-VTES) was prepared by melt grafting, with dicumyl peroxide (DCP) as an initiator. Next, dibutyl tin dilaurate was added as a catalyst to promote moisture crosslinking of EPDM-g-VTES. By means of the rheological response of the rubber compound, Fourier transform infrared spectroscopy, and moving die rheometer, the VTES graft ratio and DCP partial crosslinking (pre-crosslinking) of EDPM-g-VTES were characterized to show the feasibility of moisture crosslinking. The mechanical properties of moisture crosslinked EPDM-g-VTES specimens were tested by universal material tester. The results showed that when the weight ratio of VTES to DCP was fixed at 15:1, the VTES graft ratio and DCP partial crosslinking of EDPM-g-VTES increased with the increase of VTES content. But the torque in the moisture crosslinking curve of EPDM-g-VTES increased significantly with the extension of crosslinking time, which proved that EPDM grafted with VTES was cured by moisture successfully. The tensile strength and elongation at break of EPDM-g-VTES were improved by moisture cure. Furthermore, the moisture cured specimen with 3 wt% VTES had the best mechanical performance.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
RUBBER CHEMISTRY AND TECHNOLOGY
·
2022
·Vol. 95
·期 3
·479-491
·
IF 2.081
Lin Zhengwei,Zhang Qinghong,Wang Gongliang,Mao Jie,Hoch Martin,Shi Xinyan
Moisture crosslinking of polyolefins has attracted increasing attention because of its high efficiency, low cost, and easy processing. However, the crucial shortcoming of moisture crosslinking is that the side reaction of peroxide scorch (precrosslinking) simultaneously occurs in silane grafting. It has been recognized that making peroxide precrosslinking useful is an effective way to broaden the application of moisture crosslinking. A novel foaming process combined with moisture crosslinking is proposed. The matrix of ethylene–propylene–diene terpolymer grafted with silane vinyl triethoxysilane (EPDM-g-VTES) was prepared by melt grafting, with dicumyl peroxide as initiator. Foaming was then carried out with azodicarbonamide (AC) as the blowing agent by making use of precrosslinking. Subsequently, the EPDM-g-VTES foams were immersed in a water bath to achieve moisture crosslinking with dibutyl tin dilaurate as the catalyst. The results showed that VTES was grafted onto EPDM and the EPDM-g-VTES foams were successfully crosslinked by moisture. The EPDM-g-VTES compounds with AC obtained great cells by compression molding with the help of precrosslinking. The mechanical property of the EPDM-g-VTES foam was improved by moisture crosslinking. The moisture-cured foam with 4 wt% AC had an expansion ratio of about three times, which could bear large deformation and showed a high energy-absorption effect.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
RUBBER CHEMISTRY AND TECHNOLOGY
·
2025
·
IF 1.5
Li Yutong,Xu Ruilong,Zheng Jiawang,Li Tiezhu,Pang Li,Zhao Shuai,Li Lin,Xin Zhenxiang
In order to further the design and use of flame retardants with a lower environmental impact, a large number of available, eco-friendly, bio-based and biocompatible flame retardants have begun to be used. This study explores the synthesis of a novel phosphorus-nitrogen synergistic flame retardant (PMO) using bio-sourced phytic acid (PA) and enteromorpha prolifera (EP), along with mineral-based modified sepiolite (OSEP) and melamine (MEL), to investigate its flame retardant and smoke suppression effects on ethylene-propylene-diene monomer rubber (EPDM). Experimental results demonstrate that compared to pure EPDM, EPDM with 50 phr PMO achieves a V-0 rating in UL-94 tests, with an increased Limiting Oxygen Index (LOI) to 31.1 %, Time to Ignition (TTI) extended from 6 s to 29 s, Peak Heat Release Rate (PHRR) reduced by 55.8 %, Total Heat Release (THR) decreased by 69.4 %, particularly Total Smoke Production (TSP) reduced by over 73 %, significantly enhancing the flame retardant performance of the rubber composite material. After loading with modified seafoam, the highly efficient PMO flame retardant was successfully prepared, which has a broad application prospect in general rubber materials.
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DOI
高影响因子
RUBBER CHEMISTRY AND TECHNOLOGY
·
2024
·Vol. 97
·期 2
·190-203
·
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
·
环境科学
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DOI
高影响因子
RUBBER CHEMISTRY AND TECHNOLOGY
·
2016
·Vol. 89
·期 4
·700-711
·
IF 0.878
Hong Kan,Ni Xufeng,Shen Zhiquan
Organic supporter poly(styrene-co-divinylbenzene) (PS-DVB) was synthesized, and gas-phase polymerization of 1,3-butadiene was performed with PS-DVB–supported Nd(vers) 3 /Al 2 Et 3 Cl 3 /Al(i-Bu) 3 catalysts. Millimeter-sized granules of high cis -1,4 content (>98%) polybutadiene with an M n of 5.3–5.5 × 10 5 were obtained. Dispersants used in gas-phase polymerization of 1,3-butadiene have a significant influence on apparent activities of catalysts and appearance of products. The morphology of polybutadiene granules was also investigated by scanning electron microscopy.
研究领域:
高分子化学
·
催化化学
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DOI
高影响因子
RUBBER CHEMISTRY AND TECHNOLOGY
·
2022
·Vol. 95
·期 3
·450-464
·
IF 2.081
Wang Xiaolei,Pan Hongwei,Cao Lan,Wang Chunfu,Zong Chengzhong
Tea polyphenols and vitamin C are used as reducing agents that are introduced into nitrile–butadiene rubber (NBR) and NBR/graphene oxide (GO) latex systems, and the double bonds in the NBR and the GO sheet in NBR/GO are simultaneously hydrogenated and reduced through the synergistic hydrazine hydrate/hydrogen peroxide/copper sulfate catalytic system to prepare hydrogenated NBR (HNBR) and HNBR/reduced GO (RGO) nanocomposites. The degree of hydrogenation of the product is improved and the gel content of the product is reduced, which effectively solves the problems of the low degree of hydrogenation and high gel content in the diimide catalytic hydrogenation system. At the same time, the HNBR and HNBR/RGO nanocomposites, which are co-reduced by tea polyphenols and vitamin C, have good thermal stability and mechanical properties. Tea polyphenols are more likely to participate in the hydrogenation reaction. The degree of hydrogenation of the NBR double bonds is higher than the amount of reduction occurring within the GO sheet with the addition of tea polyphenols.
研究领域:
材料科学
·
化学工程
·
高分子化学
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DOI
高影响因子
RUBBER CHEMISTRY AND TECHNOLOGY
·
2024
·
IF 1.2
Li Y.,Yuan Y. Z.,Zhang Y.,Sun J. Y.,Tian X. H.,Jin J.,Wu W. B.
Antioxidants are usually added into NR to resist the oxidation caused by UV irradiation, whereas commonly used antioxidants are usually organic and prone to decomposition and migration. Inorganic UV absorbers such as titanium dioxide (TiO 2 ) and silicon dioxide (SiO 2 ) nanoparticles can maintain chemical stability under UV radiation, whereas the hydroxyl radicals from electron-hole pairs in TiO 2 would damage the NR matrix and the poor compatibility of TiO 2 with NR limited the process. Therefore, inert SiO 2 is coated on TiO 2 (TiO 2 @SiO 2 ) to reduce its photocatalytic activity, and polydopamine (PDA) is coated on rubber to improve stability. The strong light-absorbing properties of PDA could also improve the UV-resistant ability of NR. In addition, poly(sodium-p-styrenesulfonate) coating NR-PDA provides the matrix negative charge, and polydiallyl dimethyl ammonium chloride wrapped around TiO 2 @SiO 2 can give a positive charge, thereby moderating the compatibility between the filler and the matrix through electrostatic adsorption. The green UV-resistant natural composite NR-PDA-TiO 2 @SiO 2 was fabricated. The composites exhibited strong tensile strength and excellent UV-resistant properties, which particularly extend the service life of rubber products as UV-shielding materials, thus showing significant potential in extreme environments.
研究领域:
材料科学
·
化学工程
·
环境科学
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DOI
高影响因子
BIOPOLYMERS
·
2013
·Vol. 101
·期 5
·496-503
·
IF 2.879
Zhihong Zhang,Shunli Liu,Yu Shi,Jun Dou,Shaoming Fang
This study investigates the application of Plasma-polymerized pyrrole (ppPY) as bioactive platform for DNA immobilization and cell adhesion based on the fundamental properties of ppPY, such as chemical structure, electrochemical property, and protein adsorption. Variations in electrochemical properties of the ppPY film deposited under different plasma conditions before and after DNA immobilization were measured using electrochemical impedance spectroscopy (EIS). The equilibrium concentration of the probe DNA immobilized on the ppPY surface was deduced by detecting the variations in the surface charge transfer resistance ( R ct ) of the ppPY films after DNA immobilization with different concentrations. In addition, the detection limit of the target DNA hybridization with probe DNA, the association constant, K a , and the dissociation constant were deduced from Langmuir isotherm equations simulated using the experimental data collected by EIS. Moreover, inverted microscope was used to observe the cell adhesions onto the surface of the ppPY films prepared under different plasma conditions. Different adhesive behaviors of cells were observed, demonstrating that ppPY films could be an alternative biomaterial used as the sensitive layer for DNA sensor or cell adhesion. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 496–503, 2014.
研究领域:
生物材料
·
电化学
·
分子生物学
·
细胞粘附
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产品关联
DOI
PubMed
高影响因子
BMC Complementary Medicine and Therapies
·
2023
·Vol. 23
·期 1
·1-14
·
IF 3.9
Han Wenrun,Zhang Dandan,Zhang Peng,Tao Qianqian,Du Xiaoli,Yu Chunquan,Dong Pengzhi,Zhu Yan
IntroductionLiver X Receptor (LXR) agonists could attenuate the development of atherosclerosis but bring excess lipid accumulation in the liver. Danlou Recipe was believed to be a benefit for improving the lipid profile. Thus, it is unclear whether Danlou Recipe could attenuate hyperlipidemia without excess lipid accumulated in the liver of mice. This study aimed to clarify if Danlou Recipe could alleviate the progression of hyperlipidemia in mice without extra lipids accumulated in the liver.Methods Male murine macrophage RAW264.7 cells and murine peritoneal macrophages were used for the in vitro experiments. Cellular cholesterol efflux was determined using the fluorescent cholesterol labeling method. Those genes involved in lipid metabolism were evaluated by qRT‐PCR and western blotting respectively. In vivo, a mouse model of hyperlipidemia induced by P407 was used to figure out the effect of Danlou Recipe on reverse cholesterol transport (RCT) and hyperlipidemia. Ethanol extract of Danlou tablet (EEDL) was prepared by extracting the whole powder of Danlou Prescription from ethanol, and the chemical composition was analyzed by ultra-performance liquid chromatography (UPLC).Results EEDL inhibits the formation of RAW264.7 macrophage-derived foam cells, and promotes ABCA1/apoA1 conducted cholesterol efflux in RAW264.7 macrophages and mouse peritoneal macrophages. In the P407-induced hyperlipidemia mouse model, oral administration of EEDL can promote RCT in vivo and improve fatty liver induced by a high-fat diet. Consistent with the findings in vitro, EEDL promotes RCT by upregulating the LXR activities.Conclusion Our results demonstrate that EEDL has the potential for targeting RCT/LXR in the treatment of lipid metabolism disorders to be developed as a safe and effective therapy.
研究领域:
药理学
·
心血管疾病
·
脂质代谢
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产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2021
·Vol. 23
·期 38
·6668-6674
·
IF 3.545
Xianpei Ren,Qingbo Wei,Fei Wu,Yonghua Wang,Qiang Li
Transition metal sulfides, such as molybdenum sulfide and vanadium sulfide, have recently attracted substantial attention due to their potential application to the catalysis of the hydrogen evolution reaction (HER). Alloying is one of the powerful methods to exceed the intrinsic properties of pure metals. In this study, we report a simple one-step sintering method to synthesize MoS2, V1.5S2 and V–Mo–S alloys on carbon nanotubes (CNT/VMoS). Due to its compositional, morphological and electrical superiorities, the CNT/VMoS-2 catalyst recorded the optimal HER activity with a low overpotential of −146 mV at 10 mA cm−2, a low Tafel slope of 61 mV dec−1 and a very small Rct value of 8.8 Ω, which were superior to CNT/MoS2, CNT/V1.5S2 and other CNT/VMoS catalysts in acidic media, holding a great promise for practical water-splitting applications. We believe that the present work could broaden our horizon about the preparation of other transition metal sulfide alloys and provide a platform to understand the fundamental catalytic mechanism for improving HER performance.
研究领域:
材料科学
·
催化
·
能源材料
·
电化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）