Journal of Materials Chemistry A
·
2013
·Vol. 1
·期 16
·5081-5088
·
IF 0
Lijun Cao,Xiaoqing Liu,Haining Na,Yonggang Wu,Wenge Zheng,Jin Zhu
A bio-based epoxy monomer (GA-II) was synthesized from renewable gallic acid. The aromatic group contained made it capable of being absorbed onto the surface of graphene via strong π–π interactions, which was proven by Raman spectra and UV spectra. The GA-II anchored graphene was easily homogeneously dispersed in the epoxy resin. After solidification, the graphene/epoxy composites demonstrated superior performances in terms of good mechanical properties, excellent thermal conductivity, as well as high electrical conductivity. With the addition of only 2 wt% GA-II/graphene, the tensile strength, tensile modulus, flexural strength and flexural modulus of the composites were improved by 27%, 47%, 9% and 21%, respectively. The thermal and electrical conductivities were also improved by 12-fold (from 0.15 to 1.8 W m−1 K−1) and 8 orders (from 7.0 × 10−15 to 3.28 × 10−5 s cm−1), respectively. This work provided us with an environmentally friendly agent with high efficiency for graphene dispersion and demonstrated an efficient method for fabricating epoxy/graphene composites with superior properties.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
CHINESE JOURNAL OF POLYMER SCIENCE
·
2014
·Vol. 32
·期 11
·1550-1563
·
IF 1.42
Yan Hua,Lu Chun-xiang,Jing De-qi,Hou Xiang-lin
Chemical degradation of diglycidyl ether of bisphenol A (DGEBA) epoxy resin cured with an aliphatic amine in supercritical 1-propanol was investigated under different reaction temperature and time. The combination of GC-MS and LC-MS proved that the epoxy resin was decomposed to five main products including phenol, 4-isopropylphenol, 4-isopropenylphenol, bisphenol A, and 4,4′-(cyclopropane-1,1-diyl)diphenol. The 13 C-NMR results verified the chemical structures of the degradation products. The change of the products’ yield with time was evaluated by an effective means of HPLC. In addition, the GPC analysis confirmed the formation of soluble low molecular weight clusters during the degradation reaction. A possible free-radical reaction mechanism was proposed for chemical depolymerization of the epoxy resin in supercritical 1-propanol. After the homolytic cleavage of the aromatic ether linkages, the resulting bisphenol A biradical either produced 4,4′-(cyclopropane-1,1-diyl)diphenol after intramolecular rearrangement or generated bisphenol A after capturing hydrogen from 1-propanol.
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
POLYMER
·
2024
·
IF 4.1
Wenzheng Jiang,Guodong Zhang,Jiaqi Zhou,Bomin Liu,Junwei Yu,Chengrui Di,Bo Zhu,Kun Qiao
The epoxy resin composed of bisphenol A diglycidyl ether (DGEBA) and methyl tetrahydrophthalic anhydride (MeTHPA) has been found to enhance its thermal conductivity by increasing its molecular weight and crosslinking density. This was achieved through experiments and all-atom molecular dynamics simulations. Molecular dynamics was employed to calculate the root-mean-square displacement, free volume fraction, potential energy, density, and quantity of hydrogen bonds. The results showed the influence of molecular weight and crosslinking density on the system's thermal conductivity. The results showed that the high molecular weight epoxy resin system exhibited high thermal conductivity at elevated crosslinking densities. During the crosslinking process, the epoxy resin's thermal conductivity increased, starting with the center portion weakening and then strengthening. In addition, a simulation-verified free volume was found to have an inversely proportional connection with thermal conductivity. This study explored the thermal conductivity mechanism of epoxy resin by analyzing the structural changes at the micro level and correlating them with the changes in thermal conductivity at the macro level to enhance guidance for industrial production and practical application.
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 MOLECULAR GRAPHICS & MODELLING
·
2023
·
IF 2.9
Bingyue Yan,Wei Yang,Yuyao Zhong,Qijun Duan,Jun Xie
With the development of alternate electrical power system and the improvement of voltage level, the operation conditions faced by epoxy resin (ER) insulation materials are becoming more and more complex. The traditional ER materials have been difficult to meet the increasingly stringent requirements. In this paper, the thermal and mechanical properties of DGEBA/TDE-85/MTHPA blend system were studied by molecular dynamics (MD) simulation and experiment. The results show that the addition of TDE-85 can significantly improve the thermal and mechanical properties, and the comprehensive improvement effect is the best when the molar ratio of DGEBA and TDE-85 is about 8:2. The experimental results are consistent with the simulation results. Further analysis of the micro-parameters of the monomer and the cross-linking network found that the torsional energy barrier of TDE-85 is higher than DGEBA. And the compatibility of the two ER is better when the ratio is 8:2. In addition, TDE-85 can introduce high-stability Y-nodes into the system, making the cross-linked network more stable, which has a significant effect on improving the thermal and mechanical properties. The research provide a reference for the blending modification of high-performance ER for high-voltage insulation.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
PubMed
高影响因子
Polymer Chemistry
·
2022
·Vol. 13
·期 37
·5325-5336
·
IF 5.364
Jieyuan Zheng,Yuquan Cai,Yang Hu,Jialong Zhu,Jiao Wei,Yuanchuan Ma,Jintao Wan,Hong Fan
Conventional epoxy thermosets lack toughness, and conventional methods to toughen them are at the cost of decreasing other properties of the materials, such as the mechanical modulus, strength and transparency. Herein, hydrogenated MQ silicone resins (H–MQ) of various M/Q ratios, where M and Q denote R3SiO1/2 and SiO4/2, respectively, are synthesized from co-hydrolytic condensation of siloxane precursors. Then, these H–MQ resins are bonded with two epoxy monomers, bio-based eugenol glycidyl ether (EG) and allyl glycidyl ether (AG), through hydrosilylation to afford EG–MQ and AG–MQ, respectively, with tailored organic segments and M/Q ratios. The obtained epoxy-functionalized MQ silicone resins will have increased compatibility with the epoxy matrix. Compared with neat DGEBA thermosets, the addition of 20% EG-1.2MQ (M/Q ratio = 1.2 : 1) leads to marked increases in impact, tensile, and flexural strengths by 90%, 3%, and 3%, respectively, as well as increases in tensile and flexural strains by 55% and 100%. The epoxidized organic segments are found to be critical for enhancing the mechanical properties of the obtained epoxy composites. The EG–MQ/epoxy composites show better mechanical properties than AG–MQ/epoxy systems due to the improved compatibility of EG–MQ with DGEBA due to the aromatic EG moieties attached. Furthermore, the thermal stability and residual yield are increased by adding these silicone resins, with an increased water contact angle from 80 to as high as 110°. Our contribution provides a new avenue for integrating such good properties as impact toughness, mechanical properties, thermal stability and water repellance into the obtained epoxy thermosetting materials, without compromising the transparency.
研究领域:
材料科学
·
高分子化学
·
复合材料
✓ 已验证
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2018
·
IF 4.92
Ruisong Li,Yucang Zhang,Zengheng Xiong,Fengyi Zheng,Fanrong Meng
A typical method of synthesizing epoxy composites is to incorporate diglycidyl ether of bisphenol-A (DGEBA) into a bio-based epoxy resin. In this strategy, pure liquefied biomass is typically used as feedstock and is blended with DGEBA. Liquefied banana pseudo stem (LBPS), a bio-based active mixture obtained by liquefaction with phenol as the solvent, was directly utilized without depuration or additional DGEBA to develop a composite blend epoxy resin (cb-LBPSER). The blending process based on an incorporation of phenol-based epoxy resin (PER) was investigated by Fourier transform infrared spectroscopy, gel permeation chromatography , and thermogravimetric analysis . The cb-LBPSER presented a lower molecular weight and an improvement of 38.45% for shear strength than the pure LBPS-based epoxy resin (LBPSER). Also, the cured cb-LBPSER adhesive displayed a thermal stability comparable to that of PER. In addition, the curing behaviour, the activation energy , and the glass transition temperature were analyzed by diffrential scanning calorimetry and dynamic mechanical analysis . The blend bio-based epoxy composites exhibited an improved performance, confirming its potential as a suitable alternative to commercial PER.
研究领域:
材料科学
·
化学工程
·
高分子科学
·
生物复合材料
✓ 已验证
产品关联
DOI
高影响因子
POLYMER TESTING
·
2020
·
IF 3.275
Weiqi Xie,Donglin Tang,Shumei Liu,Jianqing Zhao
The development of high-performance biomass-derived epoxy thermosets with excellent flame resistance is vital to various applications (i.e., composites, coatings and adhesives). Herein, a difunctional epoxy monomer bis(2-methoxy-4-(oxiran-2-ylmethyl)phenyl) phenyl phosphate (BEU-EP) was synthesized from abundant and biobased eugenol . In addition, BEU-EP was cured by 4,4′-diaminodiphenyl methane (DDM) and the cured resin diglycidyl ether of bisphenol A (DGEBA)/DDM was used as a reference. Results indicated that BEU-EP/DDM not only showed a 58.1%, 28.8% and 35.1% increase in residual char (at 700 °C), flexural and storage modulus (at 30 °C) compared with DGEBA/DDM, but also exhibited excellent flame resistance and smoke suppression. BEU-EP/DDM passed V-0 rating (in UL-94 testing) with limiting oxygen index (LOI) of 38.4% and greatly decreased the peak heat release rate (pHRR) and total smoke production (TSP) by 84.9% and 80.5%, respectively. The mechanism analysis confirmed that the phosphorus-containing group and aromatic structure from BEU-EP contributed both the gas and condensed-phase flame retardation of BEU-EP/DDM network. This work provides an efficient and scalable route for synthesizing biobased epoxy thermosets with high integrated performance and superior flame resistance.
研究领域:
材料科学
·
化学工程
·
高分子科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2023
·
IF 5.9
Yuan Zhang,Xinyu Zhang,Peng Wang,Yudie Liu,Mengting Wan,Kan Zhang
The fabrication of bio-based epoxy resins having better intrinsic flame retardancy and mechanical performances than petroleum-based epoxy thermosets is important for alleviation of energy and health concerns. In this study, bio-based monomer of diglycidyl ether of curcumin (DGEC) was successfully synthesized from a natural and renewable curcumin through a facile one-step process. The biocompatible epoxy resin obtained was then cured with 4,4′-diaminodiphenyl sulfone (DDS) and compared with petroleum-based diglycidyl ether of bisphenol A (DGEBA). The DGEC/DDS exhibited a higher glass-transition temperature (300 °C) than DGEBA/DDS (215 °C), indicating the outstanding heat resistance. The tensile strength of DGEC/DDS was 65.9 MPa, higher than that of DGEBA/DDS (56.1 MPa). Furthermore, DGEC/DDS showed excellent charring ability with char yield of 50.15% at 800 °C in N 2 , which was approximatively 3.5 times as much as that of the cured DGEBA/DDS (14.68%). Microscale combustion calorimeter (MCC) test demonstrated that the DGEC/DDS possessed lower heat release capacity (HRC, 130 J/gk), peak heat release rate (PHRR, 115.0 W/g) and total heat release (THR, 9.9 kJ/g), which were reduced by 80.2%, 74.8% and 59.4%, respectively, compared to those of DGEBA/DDS (658 J/gk, 457.3 W/g, 24.4 kJ/g). The DGEC/DDS passed the UL-94 test and attained the V-0 rating, revealing the good flame retardancy. This work provided an opportunity to prepare bio-based epoxy resins with better properties than DGEBA, which exhibited promising applications in high heat and flame retardancy fields.
研究领域:
材料科学
·
化学工程
·
可持续化学
✓ 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）