POLYMER TESTING
·
2021
·
IF 4.282
Tongtong Zhang,Jihuai Tan,Xue Han,Qinghe Fu,Muhua Chen,Yong Xu,Xinbao Zhu
Families of bio-based hyperbranched epoxy (HBPEEs) were successfully prepared using renewable xylitol, bisphenol A and epichlorohydrin as feedstocks. The structure and physical performances of HBPEEs were characterized by FTIR, NMR, GPC and viscosity evaluation. Then, they were used as high efficient tougheners for diglycidyl of bisphenol A/diethylenetriamine (DGEBA/DETA) networks. The results indicated that the incorporation of HBPEEs into the DGEBA system can significantly enhance the mechanical properties and solvent resistance properties of the hybrid (HBPEEs/DGEBA). In particular, toughened hybrids with 15 wt% HBPEE-2 exhibited the outstanding impact strength than that of neat DGEBA (37.4 kJ/m 2 vs. 11.8 kJ/m 2 ) due to its excellent compatibility of with DGEBA. Simultaneously, the ductile fracture morphology of the modified hybrids was also confirmed by SEM. In addition, the activation energies of HBPEE-2/DGEBA hybrids calculated from the non-isothermal curing kinetics were lower than that of neat DGEBA. All of the results suggested that the bio-based HBPEEs could be used as efficient tougheners applied in epoxy resins industry.
研究领域:
高分子化学
·
材料科学
·
绿色化学
·
复合材料
·
聚合物改性
✓ 已验证
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2011
·Vol. 15
·期 1
·52-55
·
IF 2.827
Ben Qi,Lan-Lan Lou,Kai Yu,Wenyue Bian,Shuangxi Liu
A series of manganese oxides (MnO, Mn 3 O 4 , Mn 2 O 3 and MnO 2 ) were prepared and firstly applied as heterogeneous catalysts for the liquid phase epoxidation of alkenes with 30% H 2 O 2 in bicarbonate solution. Under our experimental conditions, MnO exhibited superior activity for the conversion of styrene to achieve ca. 100% with 92.4% selectivity of epoxide, compared to the other three manganese oxides as well as other metal oxides. Furthermore, recycling studies showed the good recyclability of MnO as a heterogeneous catalyst, which did not lose the catalytic activity after four reuses appreciably.
研究领域:
催化化学
·
有机合成
·
材料化学
·
绿色化学
·
工业化学
✓ 已验证
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2014
·
IF 2.633
Guang-Rui Xu,Miao-Jun Xu,Bin Li
The cyclotriphosphazene-based epoxy resin hexa-[4-(glycidyloxycarbonyl) phenoxy]cyclotriphosphazene defined as CTP-EP was successfully synthesized from hexachlorocyclotriphosphazene, p -hydroxybenzaldehyde and epichlorohydrin. Its chemical structure was characterized by Fourier transform infrared (FTIR) spectroscopy, 1 H NMR, 13 C NMR and 31 P NMR spectroscopy . The prepared compound was cured with diamino diphenyl methane (DDM), diamino diphenyl sulfone (DDS) and m -phenylenediamine (mPDA), respectively. The flame retardant properties, thermal degradation behavior and flame retardant mechanism of the cured CTP-EP were investigated. The LOI values of all cured CTP-EP samples increased from 19.9% for cured diglycidyl ether of bisphenol-A (DGEBA) to above 30% and successfully passed UL-94 V-0 rating, which demonstrated that the prepared CTP-EP thermoset exhibited excellent flame retardancy. The dynamic mechanical thermal analysis (DMA) test demonstrated that the glass transition temperature ( Tg ) enhanced from 155 °C for the cured DGEBA to 167 °C for CTP-EP thermoset . The results of thermogravimetric analysis/infrared spectrometry (TG-IR) tests suggested that the phosphazene group and high aromatic content in CTP-EP thermoset stimulated the dehydration of the matrix at earlier degradation process and the formation of char layer, which retarded the release of pyrolysis gas and enhanced the thermal stability of the cured CTP-EP at high temperature. The cone calorimeter tests (cone) test revealed that heat release rate (HRR), total heat release (THR), smoke production rate (SPR) and total heat production (TSP) of the cured CTP-EP decreased significantly compared with the cured DGEBA. The scanning electron microscopy (SEM) results showed that the phosphazene groups in CTP-EP obviously stimulated the formation of the intumescent, compact and stable char layer, which enhanced the flame retardancy of the matrix during combustion. Consequently, the underlying materials were protected from further degradation and combustion during a fire and result in the efficient flame retardancy of CTP-EP thermoset.
研究领域:
高分子化学
·
材料科学
·
热分析
·
阻燃材料
·
聚合物化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2017
·
IF 2.714
Zhilin Xi,Zhenya Feng,Ang Li
For the control of pulverized coal, we propose a dust suppressant by applying a blend of mixed polyethylene oxide (g-PEO) and sodium dodecyl sulfate ( SDS ). In our experimental study, the thermal characteristics, critical micelle concentration ( CMC ), wettability and adhesion of the dust suppressant are investigated. It was found that g-PEO had a low fusing temperature and its combustion temperature was close to that of coal, thus, the solution containing g-PEO applied coal dust control did not affect the use of the coal. Based on steady-state fluorescence using pyrene as a fluorescent label, quantitative analysis revealed that the CMC s of g-PEO and SDS were 1 and 20 g/L in g-PEO& SDS solution, respectively. The solution containing SDS had the best wettability, but it only had a short-term effect. The solution containing g-PEO showed negligible wetting ability to wet coal dust. The solution containing g-PEO& SDS had better wetting ability and adhesion. Scanning electron microscopy showed that the coal dust covered by g-PEO& SDS on its surface could form a thin layer of armor by holding the particles together after air-drying. It was concluded that the g-PEO& SDS solution containing g-PEO for 1 g/L and SDS for 20 g/L could suppress coal dust and maintain a long-term effect.
研究领域:
环境工程
·
矿业安全
·
颗粒物控制
·
表面化学
·
燃烧科学
✓ 已验证
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·Vol. 11
·期 8
·7066-7075
·
IF 1.5
Jiheng Ding,Hongran Zhao,Lin Gu,Shengpei Su,Haibin Yu
This paper reports the synthesis of waterborne epoxy phosphate emulsion (WEP) through the reaction between epoxy resin E44 and phosphoric acid and ammonia neutralization. Synthesized WEP was characterized by FTIR for the confirmation of reaction between epoxy groups and phosphoric acid and SEM for morphology. WEP acted as a modifier in two-component epoxy anticorrosion coating on rusty steel substrate. The anticorrosion properties of the coating on rusty steel were investigated by electrochemical impedance spectroscopy (EIS) and Tafel polarization curve. Tafel polarization curve revealed that waterborne epoxy coating containing WEP had better protection ability which is clearly reflected by the protection efficiency (96.6%). EIS study also showed the higher impedance value for WEP containing coating as compared to pure waterborne epoxy coating.
研究领域:
材料科学
·
腐蚀与防护
·
高分子化学
·
表面工程
·
电化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 82
·67247-67257
·
IF 3.84
Huilong Guo,Yinwen Li,Jian Zheng,Jianqun Gan,Liyan Liang,Kun Wu,Mangeng Lu
In this work, a novel epoxy monomer denoted as 3,5′-di-t-butyl-5,3′-dimethyl biphenyl diglycidyl ether (t-BuMBPDGE) was synthesized and applied into in situ composites with 3,3′,5,5′-tetramethyl-4,4′-biphenyl diglycidyl ether (TMBPDGE), accompanied with curing agent aromatic amines. The liquid crystalline phase structure and the crosslink density of substituted biphenyl epoxies were determined by polarized optical microscopy, wide angle X-ray diffraction measurements and dynamic storage moduli data. The samples showed good mechanical properties and could recover quickly from a second state to their initial states with a shape fixity ratio higher than 98% and shape recovery ratio higher than 99%, owing to the oriented structure and increased crosslink network density caused by the orientation of biphenyl mesogenic. The high glass transition temperatures ranging from 160 to 178 °C and good water resistance could contribute to a stable fixed shape. The water resistance is analyzed by contact angles test. The samples exhibited contact angles of 92–98 degrees, which indicated that the water resistance was apparently better than that of conventional epoxy systems.
研究领域:
高分子材料
·
功能材料
·
化学工程
·
材料科学
·
纳米复合材料
·
智能材料
✓ 已验证
DOI
高影响因子
POLYMER
·
2019
·
IF 3.771
Wenbo Shen,Ling Wang,Gang Chen,Chunxin Li,Lanying Zhang,Zhou Yang,Huai Yang
A liquid crystalline epoxide was synthesized and its curing reactivity was compared with that of the conventional epoxy monomers . By utilizing the difference in curing reactivity between the liquid crystalline epoxide and non-liquid crystalline epoxy monomers, a coexistent system of polymer-dispersed and polymer-stabilized liquid crystal (LC) in the intelligent films can be obtained by two-step thermal curing method. If the later curing process was undertaken under an external electric field , the ordered microstructure of liquid crystalline epoxy polymer (LCEP) network can be implanted into the conventional epoxy resin. The competition of the anchoring effect on the LC molecules from the LCEP network and the conventional epoxy resin matrix was crucial to the electro-optical performance of the films. Moreover, the performance of the films can be adjusted by controlling the content of liquid crystalline epoxide and the external electric field applied during later curing. This approach can provide a facile route to regulate the electric-optical performance of polymer-dispersed liquid crystal films for practical applications.
研究领域:
材料科学
·
高分子化学
·
功能材料
·
光电工程
·
智能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 44
·e56156
·
IF 2.7
Hao Sun,Qinghua Yang,Detao Kong,Yanrui Li,Yaolong He,NengHui Zhang,Hongjiu Hu
Polyethylene oxide (PEO)-based solid polymer electrolytes are regarded as promising electrolyte materials because of their safety and flexibility. However, low ionic conductivity at ambient temperature and poor mechanical properties have been a hindrance to its development. In this work, we thermally compressed the PEO-based electrolytes and explored the ionic conductivity, mechanical performance, free volume, and thermal properties of the electrolyte under different thermal pre-compressing strains (TPC-strains). The results show that TPC-strain can significantly improve the ionic conductivity, in-plane strength, stiffness, and cell specific capacity as well as the mechanical integrity of solid polymer electrolytes within the battery environment. However, it also results in a reduction in the modulus and stiffness of the SPEs in the through-plane. In particular, applying a TPC-strain of 10%–20% to the SPEs by thermal compressing may be a suitable option, which can increase the ionic conductivity of the through-plane to a factor of 3.4 compared with the uncompressed electrolyte, and increase the in-plane strength by up to 141%, resulting in better mechanical integrity during charging/discharging processes. At the same time, the compression modulus can be maintained at 80% or higher.
研究领域:
材料科学
·
电化学
·
高分子物理
·
能源存储
·
固态离子学
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2020
·Vol. 31
·期 11
·2480-2491
·
IF 2.578
Po Hu,Xinyu Zheng,Jiwei Zhu,Baolin Wu
Chicken feather keratin (CK), a biomaterial that contains a large amount of nitrogen is extracted from chicken feathers and has significant potential for use as a flame retardant. In this study, CK and 9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide (DOPO) were added in different amounts to an epoxy resin (EP), and their flame retardancy and smoke suppression effects were studied. The results showed that CK exhibits a good flame-retardancy effect and better smoke suppression characteristics than those of DOPO when added to EP. Furthermore, it greatly reduces the CO yield in smoke. While the EP samples with DOPO showed better flame-retardancy properties than those of the samples with CK, they also produced more smoke, which had a higher CO content. Furthermore, when CK and DOPO were added to EP together, the flame-retardancy characteristics of the samples varied with the CK/DOPO ratio. Then the pyrolysis of all samples was divided into two stages based on thermokinetics analysis and the activation energies of these samples in the two stages were investigated. Finally, the flame-retardancy mechanism was discussed. When samples burn, the PO· free radicals derived from DOPO combine with H· and OH· to induce a quenching effect. In addition, the phosphate resulting from the decomposition of DOPO promotes the formation of the char layer. At the same time, the noncombustible gases generated during the pyrolysis of CK cause the char layer to expand and remove some of the heat. Thus, CK and DOPO synergistically improved the flame retardancy of EP.
研究领域:
高分子材料科学
·
阻燃化学
·
热分析
·
环境友好材料
·
生物基添加剂
✓ 已验证
DOI
高影响因子
POWDER TECHNOLOGY
·
2018
·
IF 3.23
Zhilin Xi,Liwei Jin,J.Y. Richard Liew,Ding Li
A foam sol clay (FSC) mixture, mainly composed of fly ash (FA), surfactant ( n -amylamine) and polyethylene oxide (PEO), was proposed for coal dust control. The FA surface, modified by a FSC solution, stability and foamability were investigated. It was found that the FA surface in alkaline solution was deprotonated to form a negative charge, which could be adsorbed by the polar head group of n -amylamine via electrostatic interactions . As a result, with increasing surfactant, the particles gradually converted from hydrophilic to hydrophobic and attached at gas-liquid interfaces so that the contact angle, zeta potential , froth stability and foamability increased. At a surfactant concentration (c a ) of 35 g/L, a monolayer three-dimensional network was formed and the maximum foamability and half-life were obtained. Upon further increasing c a , a bilayer and particle clusters were formed by surfactant chain-chain interaction, resulting in particles becoming hydrophilic again, and the FSC solution having stronger mechanical resistance against flowing, so that the viscosity rapidly increased and the diffusion of free surfactant molecules was hindered at the froth surfaces. Thus, the contact angle, froth stability and foamability decreased. PEO could bond sodium dodecyl sulfate and water to form a dual adsorption layer and hydrogen, respectively, which enhanced the wettability of the FSC on coal dust surfaces. PEO could adsorb and curl FA particles to form a thin layer of armor after froth air-drying. It was concluded that the froth generated by the FSC solution, including 200 g/L FA, 35 g/L c a and 1 g/L PEO, could control coal dust with a long-term effect.
研究领域:
环境工程
·
矿物加工
·
胶体与界面化学
·
粉尘防治
·
资源利用
✓ 已验证
DOI
高影响因子
Nano Energy
·
2016
·
IF 11.553
Jingxian Zhang,Ning Zhao,Miao Zhang,Yiqiu Li,Paul K. Chu,Xiangxin Guo,Zengfeng Di,Xi Wang,Hong Li
Solid-state electrolytes with high ionic conductivity , large electrochemical window, good mechanical properties , and easy processability are needed for high-energy solid-state lithium batteries . In this work, composite membranes consisting of lithium garnet (i.e. Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 , LLZTO) particles and Li-salt-free polyethylene oxides (PEOs) are produced as solid-state electrolytes. Li-ion-conducting particles in nano-scale are crucial for the enhancement of conductivity and the membranes containing ~40 nm LLZTO particles exhibit conductivities nearly two orders of magnitude larger than those with the micro-scale ones, which is attributed to the difference in specific surface area related to the percolation effect. Compared to the conventional PEO doped with lithium salt, the insulating PEO in PEO:LLZTO membrane electrolyte is conducive to the suppression of lithium dendrite growth owing to prohibition of current flow. With PEO:LLZTO membrane electrolytes in conductivity of 2.1×10 −4 S cm −1 at 30 °C and 5.6×10 −4 S cm −1 at 60 °C, the solid-state LiFePO 4 /PEO:LLZTO/Li and LiFe 0.15 Mn 0.85 PO 4 /PEO:LLZTO/Li cells deliver energy densities of 345 Wh kg −1 (662 Wh L −1 ) and 405 Wh kg −1 (700 Wh L −1 ) (without the package weight or volume) with good rate capability and cycling performance. This study suggests that the conjunction of nano-scale Li-ion-conducting particles and an insulating polymer provides a promising solution to produce powerful solid-state electrolytes for high-performance solid-state lithium batteries .
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子科学
·
固态电池技术
✓ 已验证
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2020
·
IF 6.444
Baowei Qiu,Tong Sun,Muxuan Li,Yang Chen,Shengtai Zhou,Mei Liang,Huawei Zou
The interface performance of carbon fiber (CF) reinforced polymer composites (CFRPs) is one of the key factors that affect their properties. In order to improve the interface adhesion between CF and epoxy (EP), a green method is proposed. Carboxymethyl cellulose (CMC) and graphene oxide (GO) are introduced to the CF surface through the hydrogen bonds, and they can form high micromechanical interlocking composite architectures, which can enhance the micromechanical interaction in the interface of CF and EP. It is found that CMC and GO can significantly improve the interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) of EP/CF composite. This means that it has great potential to improve the interface of CFRPs and strengthen their performance by natural cellulose fibers. This modification method does no harm to CF and is environmental friendliness, which lays a research foundation for using natural cellulose to enhance the interface performance of CFRPs.
研究领域:
复合材料科学
·
高分子材料
·
界面工程
·
纳米材料
·
绿色制造
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）