HIGH PERFORMANCE POLYMERS
·
2019
·
IF 1.584
Haoran Zhou,Xupeng Fan,Changwei Liu,Chunyan Qu,Zhen Yuan,Jiaqi Jing,Yao Tang,Daoxiang Zhao,Wanbao Xiao,Kai Su
The choice of basic epoxy resin (ER) is especially important for the design of epoxy adhesive formulations. In the present study, performance of several high-temperature ER systems, prepared using 4,4-diaminodiphenylsulfone as the curing agent by the same curing process, was investigated. The curing behavior was studied by dynamic rheometry and differential scanning calorimetry. The thermal properties of the cured resins were investigated by dynamic thermomechanical analysis, thermomechanical analysis, and thermogravimetric analysis. The peeling properties, mechanical behaviors, and moisture absorptivities of the cured resins were also studied. The results showed traditional diglycidyl ether of bisphenol A epoxy to be insufficient in heat resistance. Naphthalene-based ER and bifunctional cardo ER showed higher glass transition temperature values. However, the processability and adhesive properties may not comply with the application requirements. Biphenyl novolac ER has excellent performance in all aspects, which is suitable for use as a high-temperature adhesive.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2021
·
IF 5.161
Xiaomeng Li,Shuxue Zhou
The application of MXene in anticorrosion coatings has attracted recent research interest. Limited information exists on the effect of MXene functionalization on anticorrosion performance. In this work, epoxy-functionalized Ti 3 C 2 nanosheets (E-Ti 3 C 2 ) were prepared by grafting with (3-glycidyloxypropyl) trimethoxysilane and incorporated into solvent-borne epoxy coatings with low mass fractions of 0.3 wt%, 0.5 wt% and 0.7 wt%. The anticorrosion properties of the coatings were investigated by electrochemical impedance spectroscopy and salt spray tests. The highest impedance was achieved for the 0.5 wt% E-Ti 3 C 2 coating, at nearly three orders of magnitude higher than a pure epoxy coating. In contrast, the coating with unmodified Ti 3 C 2 yielded an impedance improvement of approximately one order of magnitude. Salt spray tests manifested the same anticorrosion results. The enhanced anticorrosion improvement by epoxy-functionalization should result from the better dispersibility and chemical bonding between the E-Ti 3 C 2 and matrix. The mechanical properties and adhesion force of the coatings were also evaluated. A better scratch resistance, higher adhesion force and reduced flexibility resulted after E-Ti 3 C 2 incorporation.
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
DOI
高影响因子
Applied Sciences-Basel
·
2023
·Vol. 13
·期 4
·2461
·
IF 2.7
Jianliang Jiang,Jingbo Shen,Xiao Yang,Dongqi Zhao,Yakai Feng
To improve the thermal and mechanical properties of epoxy resins, epoxy-functionalized POSS (E-POSS) and glass fiber (GF) were used to reinforce epoxy resin (E51) composites. The tensile, thermo-mechanical, fractured, and thermal tests were carried out to characterize these hybrid materials. The results show that E-POSS and GF could significantly improve the mechanical and thermal properties of epoxy resins due to high crosslink density of resin matrix and synergistic interaction between the epoxy resin, E-POSS, and GF. Compared with the pure E51 resin, the tensile strength of the E51 + E-POSS (10%) + GF (16%) sample increased by 257.6%, and the thermal decomposition temperature (Td5%) of the E51 + E-POSS (10%) + GF (16%) sample increased by 32 °C to 378 °C.Keywords:epoxy resin;epoxy-functionalized POSS;composites;glass fiber
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
MOLECULES
·
2025
·Vol. 30
·期 3
·583
·
IF 4.6
Guang-Zhao Li,Qiuhong Wang,Chongyu Zhu,Shuai Zhang,Fumei Wang,Lei Tao,Youqi Jiang,Qiang Zhang,Wenyan Wang,Rui Han
Epoxy-terminated hyperbranched polymers (EHBPs) are a class of macromolecular polymers with a hyperbranched structure containing epoxy groups. They possess characteristics such as low viscosity, high functionality, and thermal stability, which endow them with broad application potential in materials science and chemical engineering. This study uses epoxidized soybean oil (ESO) as the raw material, which undergoes ring-opening reactions with glycerol and is esterified with 2,2-bis(hydroxymethyl)propionic acid (DMPA) to obtain epoxy soybean oil polyol (EGD) with a high hydroxyl value. Subsequently, four types of EHBPs are synthesized by incorporating epichlorohydrin (ECH) in mass ratios of 1:3, 1:4, 1:5, and 1:6 under strong alkaline conditions. The product structure is characterized using FT–IR and GPC. The degree of branching of EGD is calculated using1H NMR and13C NMR spectroscopy. The epoxy value of EHBPs is tested using the hydrochloric acid–acetone method, and the water contact angle, adhesion properties, rheological properties, and thermal properties of the EHBPs are also evaluated. The results show that the degree of branching of EGD is 0.45. The epoxy values of the EHBPs are 0.73, 0.79, 0.82, and 0.89 mol/100g, respectively. As the epoxy value and molecular weight of the epoxy hyperbranched polymers (EHBPs) increase, the water contact angle and adhesion strength of the EHBPs rise progressively and the viscosity decreases. Additionally, the glass transition temperature increases with the increase in the epoxy value. These epoxy hyperbranched polymers with low viscosity and high adhesion strength offer a promising approach for modifying surface coatings or formulating adhesives.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Bioresources and Bioproducts
·
2024
·
IF 20.2
Yunyi Liang,Yonghong Luo,Yingji Wu,Xiaona Li,Quyet Van Le,Jianzhang Li,Changlei Xia
The standard epoxy resin curing agents revealed are from unsustainable petroleum-based sources, which produce poisonous exhaust when cured. Amino acids, a bio-based epoxy curing agent with amino and carboxyl groups, are another potential curing agent. Water-soluble epoxy resins cured with lysine (Lys), glutamic acid (Glu), leucine (Leu), and serine (Ser) as amino acids were investigated. The results showed that the water-soluble epoxy resin (glycerol epoxy resins, GER) was cured with Lys and Glu after reacting. Fourier transform infrared (FT-IR) spectroscopic analysis of the GER-Lys showed that the amino and carboxyl groups of Lys primarily reacted with the epoxy groups of GER. The elongation at break of Lys-cured GER (GER-Lys) cured at 70 ℃ with a molar ratio of 1꞉0.75 was 75.32%. The fact that elongations at break of GER-Lys (79.43%) were higher than those of GER-Glu (17.33%), respectively supports the decrease of crosslinking density by the amino acid-cured GER reaction. The potential of Lys and Glu alternatives for petrochemical amines is demonstrated and provides promising opportunities for industrial application.
研究领域:
材料科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL CHEMISTRY
·
2024
·Vol. 79
·期 2
·233-240
·
IF 1
Wai Phyu Thin,Jiang Pingping,Lu Minjia,Cui Zhixuan,Feng Shan,Zhang Pingbo
High-resolution 1 H nuclear magnetic resonance ( 1 H NMR ) was advanced to determine both epoxy value and iodine value ( IV ) of vegetable oils that occur during their epoxidation. For calibration, rather than using a series of diluted stock samples, epoxidized soybean oils with a range of IV and epoxy value synthesized using entrapped peroxophosphotungstate as the catalyst under different reaction conditions were used. During the epoxidation reaction, IV and epoxy value were tracked with respect to time using 1 H NMR and conventional volumetric methods. The integrated peak area of the olefinic hydrogens (5.3–5.5 ppm) was used to calculate the absolute number of double-bonded protons. By comparison of IV obtained by 1 H NMR and the traditional Wijs-cyclohexane methods, the correlation coefficient was R 2 = 0.9997 for the regression equation y = 1.1314 x + 1.0035, where x was the result given by 1 H NMR. The average integrated peak areas related to the hydrogens of the epoxide groups located at chemical shifts of 2.9 ppm (monoepoxide) and 3.1 ppm (diepoxide) were used to determine the epoxy value. The quantification of the number of epoxides was carried out by 1 H NMR and the values obtained were correlated with epoxide content determined by the hydrochloric acid/acetone method. As a consequence, the correlation coefficient was R 2 = 0.9991 for the regression equation y = 0.0052 x + 1.7258, where x was the average integrated peak areas related to the hydrogens of the epoxide groups by 1 H NMR. The novelty of our study lies in the simultaneous correlation between IV and epoxy value obtained from conventional titrations, the integrated peak area related to olefinic protons, and the average integrated peak area located at the hydrogen of epoxide group, calculated using 1 H NMR. This approach is used to monitor and optimize the epoxidation reaction.
研究领域:
分析化学
·
高分子科学
·
有机化学
·
光谱学
·
化学反应工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2018
·
IF 3.997
Xian-peng Zhang,Jian Luo,Tong-fang Jing,Da-xia Zhang,Bei-xing Li,Feng Liu
Microcapsules (MCs) prepared with diverse wall material structures may exhibit different properties. In this study, MCs were fabricated with three kinds of epoxy phenolic novolac resins (EPNs), which possessed unique epoxy values as wall-forming materials by interfacial polymerization. The effects of the EPN types on the surface morphology, particle size distribution, encapsulation efficiency, thermal stability as well as release behavior and bioactivity of the MCs were investigated. In all three samples, the MCs had nearly spherical shapes with fine monodispersities and sizes in the range of 7–30 μm. Scanning electron microscopy (SEM) images showed that some small pores (ranging from 50 nm to 400 nm) appeared on the microcapsule surfaces and that the porosity decreased with an increasing of epoxy value. The X-ray diffractometer (XRD) analysis indicated that the cured EPN shells had larger degrees of crosslinking with higher epoxy values, leading to better thermal stabilities. Moreover, the release rate of the core material (pendimethalin) decreased with an increasing of epoxy value and thus resulted in a lower herbicidal control efficacy. The results of our research will enhance the potential application of EPNs as smart wall-forming materials to prepare porous MCs for controlled release.
研究领域:
材料科学
·
化学工程
·
农业科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemSusChem
·
2013
·Vol. 7
·期 2
·555-562
·
IF 7.475
Songqi Ma,Xiaoqing Liu,Libo Fan,Yanhua Jiang,Lijun Cao,Zhaobin Tang,Jin Zhu
Graphical An epoxy on both your houses! A trifunctional bio-based epoxy resin (denoted TEIA) is synthesized from itaconic acid. Its curing reaction with poly(propylene glycol) bis(2-aminopropyl ether) (D230) and methyl hexahydrophthalic anhydride (MHHPA) is investigated. As a result of high epoxy value and low viscosity, TEIA shows high performance and good processability. A bio-based epoxy resin (denoted TEIA) with high epoxy value (1.16) and low viscosity (0.92 Pa s, 25 °C) was synthesized from itaconic acid and its chemical structure was confirmed by 1 H NMR and 13 C NMR spectroscopy. Its curing reaction with poly(propylene glycol) bis(2-aminopropyl ether) (D230) and methyl hexahydrophthalic anhydride (MHHPA) was investigated. For comparison, the commonly used diglycidyl ether of bisphenol A (DGEBA) was also cured with the same curing agents. The results demonstrated that TEIA showed higher curing reactivity towards D230/MHHPA and lower viscosity compared with DGEBA, resulting in the better processability. Owing to its high epoxy value and unique structure, comparable or better glass transition temperature as well as mechanical properties could be obtained for the TEIA-based network relative to the DGEBA-based network. The results indicated that itaconic acid is a promising renewable feedstock for the synthesis of bio-based epoxy resin with high performance.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SYNTHETIC METALS
·
2019
·
IF 2.87
Yujuan Jing,Pingquan Wang,Qiangbin Yang,Yi He,Yang Bai
Epoxy coatings play an important role in preventing the corrosive medium penetrating into the base metal, but improving its durability in harsh environments is still a challenge. Nanomaterial introduced in epoxy coatings is an effective improvement measure, especially, the use of two-dimensional nanomaterial can effectively block the corrosion medium. In this paper, we use two-dimensional molybdenum disulfide (MoS 2 ) hybrid materials as nanofiller to improve the corrosion resistance of epoxy coatings. MoS 2 hybrid materials were obtained by an effective method based on self-oxidation of dopamine and functionalized silane (KH560) grafting. The poly(dopamine) and epoxy groups on the surface of MoS 2 enhanced the interaction with EP matrix. The anticorrosive performance of composite epoxy coating with the different content of MoS 2 hybrid materials was investigated in detail. An appropriate content (0.8 wt%) in the epoxy coating was obvious to improve its anti-corrosion performance.
研究领域:
材料科学
·
腐蚀防护
✓ 已验证
产品关联
DOI
高影响因子
PHYTOCHEMISTRY
·
2024
·
IF 3.2
Hao-Dong Yang,Yuan-Gui Yang,Zhi-Shu Tang,Kang Ma,Hong-Bo Xu
Acanthopanacis cortex (the dried root bark of Acanthopanax gracilistylus W. W. Smith) has been used for the treatment of rheumatic diseases in China for over 2000 years. Four previously undescribed lignans ( 1 – 4 ) and 12 known lignans ( 5 – 16 ) were isolated from Acanthopanacis cortex. In this study, the inhibitory activities of compounds 1 – 16 against neutrophil elastase (NE), cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) are reported. The results show that compounds 1 – 16 exhibit weak inhibitory activities against NE and COX-1. However, compounds 2 , 6 – 8 and 13 – 16 demonstrate better COX-2 inhibitory effects with IC 50 values from 0.75 to 8.17 μ Μ. These findings provide useful information for the search for natural selective COX-2 inhibitors.
研究领域:
药理学
·
中药学
·
天然产物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-10
·
IF 15.7
Dong Hao,Luo Ran,Zhang Gong,Li Lulu,Wang Chaoxi,Sun Guodong,Wang Hongyi,Liu Jiachang,Wang Tuo,Zhao Zhi-Jian,Zhang Peng,Gong Jinlong
Direct electrochemical ethylene (C 2 H 4 ) epoxidation with water (H 2 O) represents a promising approach for the production of value-added ethylene oxide (EO) in a sustainable way. However, the activity remains limited due to the sluggish activation of C 2 H 4 and the stiff formation of *OH intermediate. This paper describes the design of a Ag/SnO 2 electrocatalyst to achieve efficient electrochemical C 2 H 4 epoxidation with a high faradaic efficiency of 39.4% for EO and a high selectivity of 91.5% at 25 mA/cm 2 in a membrane electrode assembly. Results of in situ attenuated total reflection infrared spectra characterizations and computational calculations reveal that the Ag/SnO 2 interface promotes C 2 H 4 adsorption and activation to obtain *C 2 H 4 . Moreover, electrophilic *OH is generated on the catalyst surface through H 2 O dissociation, which further reacts with *C 2 H 4 to facilitate the formation of *C 2 H 4 OH, contributing to the enhanced electrochemical epoxidation activity. This work would provide general guidance for designing catalysts for electrochemical olefin epoxidation through interface engineering.
研究领域:
材料科学
·
电化学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMPOSITES COMMUNICATIONS
·
2024
·
IF 6.5
Qianqian Fan,Jiahui Li,Qi Cao,Chengwen Gu,Qian Liu,Xigao Jian,Zhihuan Weng
Liquid crystal epoxy resin, as an ideal toughening agent, combines the features of liquid crystal ordering and network cross-linking, which can effectively optimize the comprehensive performance of blended epoxy resins and achieve an ideal balance of rigidity and toughness. Here we successfully synthesized rigid and flexible bio-based liquid crystal epoxy resin (THBR-EP) by finely tuning the length of alkyl side chains. Using aromatic diamine as curing agent, a homogeneous network without phase separation was constructed by taking advantage of the different activity but good compatibility with ordinary epoxy resins, which significantly improved the toughness of the blended system. Specifically, only a small amount of THBR-EP(2.5 wt%) was required to exhibit a maximum impact strength of 48.8 kJ/m 2 . Moreover, the increase in system toughness was accompanied by a benign improvement in flexural strength, modulus and thermal stability. The ordered structure of the liquid crystals and their good compatibility with the resin matrix enhanced the ability to inhibit crack extension and energy dissipation. The feasibility to simultaneously achieve effective toughening and other property improvements of common resins broadens the application of resins under various demanding scenarios.
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
危险品化学品经营许可证（带存储）