JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2012
·Vol. 113
·期 2
·939-945
·
IF 1.604
Chen Yan,Yang Liting,Wu Jiahui,Ma Lijun,Finlow David E.,Lin Shaoquan,Song Keming
A series of new modified epoxy resin (EP) cured products were prepared from epoxidized soybean oil and commercial epoxy resin, with methyl nadic anhydride as curing agent and 1-methylimidazole as promoting agent. The thermal properties of the resins were characterized by DMA and TG; DSC was used to determine the curing process. Fourier transform infrared spectroscopy was utilized to investigate their molecular structures and scanning electron microscopy was used to observe the micro morphology of their impact fracture surfaces. Tensile and impact testing was employed to characterize the mechanical properties of the cured products. The combination of commercial EP with 20 wt% ESO resulted in a bioresin with the optimum set of properties: 130.5 °C T
g , 396.9 °C T
50 % , 74.89 MPa tensile strength, and 48.86 kJ m −2 impact resistance.
研究领域:
高分子材料
·
复合材料科学
·
生物基聚合物
·
材料化学
·
热固性树脂
✓ 已验证
DOI
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2015
·Vol. 94
·期 3
·424-429
·
IF 1.231
Xia Gui,Ying Ding,Zhi Yun
An integrated approach was developed for preparing epoxy fatty acid methyl esters (EFAMEs) from cottonseed using a two-phase solvent extraction (TPSE) process followed by sequential base-catalyzed transesterification and epoxidation reactions. The TPSE process was performed to achieve simultaneous production of high-quality crude cottonseed oil and nontoxic cottonseed meal. The base-catalyzed transesterification of the cottonseed oil proceeded smoothly at 30 °C over 2 h to provide a high yield of fatty acid methyl esters (FAMEs). Subsequent epoxidation of the unsaturated FAMEs using petroleum ether as a non-polar solvent, H 3 PO 4 as a catalyst, 0.3 g/g H 2 O 2 as an oxygen donor, and HCOOH as an oxygen carrier gave the corresponding EFAMEs with a conversion to oxirane of 0.85 g/g. The order of effectiveness of catalysts was found to be H 3 PO 4 > TiO 2 > H 2 SO 4 > strong-acid cation exchange resin. The bio-based integrated process and new methods for the preparation of modified EFAMEs show great promise for comprehensive development and commercial applications of cottonseed with fewer steps and lower cost.
研究领域:
应用化学
·
油脂化学
·
生物基材料
·
绿色化工
·
天然产物转化
✓ 已验证
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 1
·377-388
·
IF 3.049
Tianyu Wu,Wenqing Zhang,Xin Jin,Xiangyi Liang,Gang Sui,Xiaoping Yang
Carbon fiber-reinforced polymer composites have been widely used in various fields and have inevitably produced large amounts of composite waste. The recycling of carbon fibers with high value has become an active research topic at related institutions and production enterprises. In this paper, the catalytic pyrolysis of T700 carbon fiber/epoxy composites in molten salt was studied. Due to the efficient solubility of molten ZnCl2 for the epoxy matrix and catalytic fracture of the C–N bonds by the action of Zn2+ ions, the epoxy composites can be completely degraded at 360 °C in 80 min under standard pressure, and the reclamation efficiency was significantly enhanced compared with conventional pyrolysis reclamation without a catalyst. The types and contents of the main oxygen-containing functional groups on the surfaces of the fibers reclaimed with ZnCl2 were similar to those of the virgin fibers, and the graphitization structure of the carbon fibers was not destroyed in the pyrolysis process. The tensile strength of a monofilament of the fibers reclaimed with ZnCl2 was obviously higher than that of fibers reclaimed in air; it reached a high retention rate that was about 95% that of the virgin fibers. The fibers reclaimed with ZnCl2 after sizing exhibited a desirable reinforcing effect on the flexure performance and interlaminar shear strength of unidirectional carbon fiber/epoxy composites which was close to the performance levels of composite samples containing commercial T700 carbon fibers. Therefore, efficient technology to reclaim high-quality carbon fibers from epoxy matrices has been devised.
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
POLYMER
·
2018
·
IF 3.483
Guodong Zhou,Weitao Wang,Mao Peng
Molecular composites using rigid-rod macromolecules as the reinforcement have attracted tremendous research interest. However, dispersion of rigid-rod macromolecules at molecular level in the matrix remains a great challenge. Herein, we report new epoxy (EP)-based molecular composites with sulfonated aromatic polyamides , poly( p -sulfophenylene terephthalamide) (sPPTA) and poly(benzidine-2,2′-disulfonic acid terephthamide) (PBDT), as the reinforcement, which disperse uniformly in epoxy. Covalent bonds formed by the reaction between the sulfonic acid groups of the polyamides and epoxy prevent reaction-induced phase separation during high temperature curing. The novel molecular composites exhibit extraordinarily high strength and toughness, with maximum tensile strength of sPPTA/EP and PBDT/EP (100.2 ± 4.8 MPa and 121.9 ± 12.5 MPa, respectively) increased by ∼81% and ∼120%, respectively. To the best of our knowledge, the improvement of mechanical properties surpasses those of molecular composites, nanofiller reinforced thermosets and liquid crystalline thermosets ever reported.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2018
·
IF 0
Lu Shen,Yong Li,Wenjie Zhao,Lijing Miao,Weiping Xie,Huanming Lu,Kui Wang
In order to hold the excellent corrosion resistance of zinc-rich epoxy coatings with reduced zinc content, five types of graphene modified zinc-rich epoxy coatings (G-ZRCs) were prepared. The effect of zinc content on the corrosion protection behaviors of G-ZRCs was investigated using electrochemical impedance spectroscopy (EIS). Open circuit potential (OCP) was also utilized to deepen the understanding of the anticorrosion mechanism of the as-prepared composite coatings. The results confirmed that addition of 0.3 wt % graphene could make the coating with 40 wt % (G-40ZRC) and 55 wt % zinc (G-55ZRC) provide cathodic protection for a short period of time. The EIS and OCP results showed a dominant physical barrier protection mechanism for the coatings without zinc (G-ZRC), while there was a mixed mechanism for G-40ZRC and G-55ZRC and a dominant cathodic protection mechanism for the coatings with 70 and 85 wt % zinc (G-70ZRC and G-85ZRC). Furthermore, the graphene modified zinc-rich coatings and corresponding corrosion products immersed in a 3.5% NaCl solution for 100 days were also characterized, which could further reveal anticorrosion mechanisms of the graphene modified zinc-rich coatings and the passivation effect of polyaniline (PANI).
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
产品关联
DOI
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 24
·52368
·
IF 3.057
Xiongfei Zhang,Tianhui Zhao,Ting Cao,Peiyu Liu,Chuang Ma,Pengyun Li,Dang Huang
In this paper, bisphenol A (BPA), epichlorohydrin (ECH), and isocyanate trimer (TDI-T) are used as raw materials to synthesize a high toughness/trimer epoxy resin by graft copolymerization. It was cured at room temperature with low molecular weight polyamide 650 (PA650)/isophorone diamine (IPDA) and low molecular weight polyamide 650/triethylene tetramine (TETA) composite curing system respectively. The cured products of the two compound systems were studied by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetry (TG), and mechanical property testing. The results show that with the increase of TETA and IPDA curing agents, the heat released during the curing process of the two systems also greatly increases, and the temperature rises from the initial 33.9–69.7°C and 52.8°C. The curing time is shortened from a few days to a few hours, and the controllability of the curing time is effectively realized. When the ratio of triethylene tetramine to low molecular weight polyamide 650 is 2.86:100, the compressive strength is the best, reaching 112.7 MPa, 12% higher than pure polyamide as curing agent, and the specimen can be completely restored to its original shape in a few minutes. When the ratio of TETA to PA650 is 2.86:100, the elongation at break reaches 21.4%.
研究领域:
高分子化学
·
材料科学
·
复合材料
·
热固性树脂
·
功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2016
·
IF 5.557
Sikuai Xue,Chengcai Li,Jiuming Li,Hailin Zhu,Yuhai Guo
To improve hydrophilicity and anti-fouling property of the polytetrafluoroethylene (PTFE) flat microfiltration (MF) membrane, a facile method was developed to modify the membrane via the co-deposition of catechol (CA) and polyethyleneimine (PEI) followed by surface mineralization of γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH560). The surface chemical composition, surface morphology, hydrophilicity and filtration performance of the PTFE flat membrane were investigated by ATR-FTIR, XPS, FESEM, WCA and pure water flux measurements, respectively. After using this low-cost and simple modification method, the PTFE flat membrane was endowed with excellent hydrophilicity, high water permeation flux and superior anti-fouling property. Then, the oil/water separation tests were conducted using the modified PTFE flat membranes. The size distribution of the oil droplets is between 0.12–1.44 µm and the mean pore size of pristine PTFE flat MF membrane is 0.22 µm. The as-prepared hydrophilized PTFE flat membranes possess an excellent oil resistant ability with oil rejection ratio near 99%. Finally, the surface stability of the modified membrane was studied and the mineralized membrane showed excellent acid resistant ability. Therefore, this facile strategy holds attractive potential practical application in water environmental remediation.
研究领域:
材料科学
·
环境工程
·
膜技术
·
表面化学
·
水处理
✓ 已验证
DOI
高影响因子
COMBUSTION AND FLAME
·
2023
·
IF 4.4
Xiaodong Wang,Lili Ye,Xiaoyuan Zhang,Zhihe Zhang,Jiuzhong Yang,Long Zhao
Acetaldehyde, ethylene oxide , and vinyl alcohol are three C 2 H 4 O isomers that are ubiquitous in combustion over a wide temperature range. A comprehensive reaction kinetics study has been performed for reactions that occur on the same C 2 H 4 O potential energy surface , mainly including the unimolecular reactions of three C 2 H 4 O isomers and the recombination reaction of CH 3 with HCO. Temperature- and pressure-dependent rate coefficients were updated or newly predicted by performing quantum chemical calculations coupled with RRKM/master equation simulations. The dominance of C C bond fission is reconfirmed for acetaldehyde decomposition at higher temperatures. The negligible contribution of CH 4 + CO channel from usual tight intramolecular H-shift transition state provides indirect evidence for previously reported roaming mechanism that was proposed to explain the observation of CH 4 + CO in acetaldehyde pyrolysis . For ethylene oxide pyrolysis , current experiment and kinetic prediction have a good consistency in branching ratios between the formation of acetaldehyde and vinyl alcohol products. The radicals of CH 3 + HCO can also be directly generated from ethylene oxide through a well-skipping reaction mechanism especially at higher temperatures. For CH 3 + HCO recombination, we highlight the importance of CH 3 CO + H channel that was often overlooked previously. Kinetic simulations show that the incorporation of updated rate coefficients and newly identified channels results in a measurable influence on C2 chemistry , indicating the possibility and necessity of further improvement of core mechanism in combustion kinetic models .
研究领域:
物理化学
·
燃烧化学
·
反应动力学
·
量子化学计算
·
分子反应机制
✓ 已验证
DOI
高影响因子
Journal of Renewable Materials
·
2022
·Vol. 11
·期 4
·1731-1743
·
IF 2.115
Hongying Chu,Huabei Li,Xiaoyan Sun,Yaowang Zhang
The application of phthalate plasticizers has been restricted around the world due to their poor migration and potential harm to the human body. Hence, producing functional bio-based plasticizers via exploiting clean and reusable resources meets the satisfaction of current demands. In this study, flame-retardant rubber seed oil-based plasticize (FRP) was prepared via epoxidation reaction and ring opening addition reactions, which was used as a flame-resistant plasticizer for polyvinyl chloride to replace petroleum-based phthalate plasticizer. When DOP was replaced with FRP, the torque of PVC blends increased from 11.4 to 18.4 N⋅m, the LOI value increased from 24.3% for PVC-FRP-0% to 33.1% for PVC-FRP-20. The THR value diminished from 39 MJ/m 2 (pertaining to PVC-FRC-0) to 22 MJ/m 2 Tg increased from 23°C to 47°C, the weight loss of plasticized PVC blends significantly reduced from 22.6% to 2.8% in leaching tests. The study provided a new way to prepare flame retardant plasticizer using rubber seed oil as raw material.
研究领域:
高分子材料
·
阻燃化学
·
绿色化学
·
生物基材料
·
塑料加工
✓ 已验证
DOI
高影响因子
Asia-Pacific Journal of Chemical Engineering
·
2021
·Vol. 16
·期 6
·e2702
·
IF 1.447
Shiyuan Xiong,Xiaole Huang,Wennian Xu,Xiaoping Guo,Shuan Liu
In previous work, the corrosion performance and anti-corrosion mechanism of galvanized steel wire embedded in vegetation-growing concrete under marine environment was highlighted. In this work, a graphene-modified epoxy coating was developed and applied to the protection of galvanized steel in vegetation-growing concrete under a marine environment. The effect of dispersed graphene on the anticorrosion performance of the epoxy coatings was evaluated. The composite coatings displayed outstanding barrier properties against H 2 O molecules compared to the pure epoxy coating. Salt spray test results revealed superior corrosion resistance offered by the prepared graphene-modified epoxy coating on galvanized steel.
研究领域:
材料科学
·
腐蚀与防护
·
土木工程材料
·
复合材料
·
环境耐久性
✓ 已验证
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2019
·
IF 3.571
Xu Xu,Fuhao Dong,Xinxin Yang,He Liu,Lizhen Guo,Yuehan Qian,Aiting Wang,Shifa Wang,Jinyue Luo
The absorbent materials synthesized from biosources with low cost and high selectivity for oils and organic solvents have attracted increasing attention in the field of oil spillage and discharge of organic chemicals. We developed a convenient surface-grafting method to prepare efficient and recyclable biobased aerogels from epoxidized soybean oil (ESO)-modified cellulose at room temperature. The porous network-like structure of the cellulose aerogel was still fully retained after undergoing hydrophobic modification with ESO. Moreover, the modified aerogels possessed excellent hydrophobicity with a water contact angle of 132.6°. Moreover, the absorbent ability of the hydrophobic cellulose aerogels was systematically assessed. The results showed that modified aerogels could retain more than 90% absorption capacity even after 30 absorption–desorption cycles, indicating that the ESO-grafted cellulose aerogels have practical applications in the oil–water separation from industrial wastewater and oil-leakage removal.
研究领域:
材料科学
·
环境工程
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2016
·Vol. 122
·期 5
·515
·
IF 1.444
Huang Liang,Zhu Pengli,Li Gang,Sun Rong
The partial reduced graphene oxide (P-rGO) sheets-wrapped nickel foams (NF@P-rGO) were prepared by hydrothermal method, and then their epoxy composites were fabricated via a simple drop-wetting process. The P-rGO sheets on the metal networks could effectively improve the compatibility between nickel foam and epoxy resin, thus greatly accelerate the wetting of epoxy resin on the foams and avoid cracks in the network–polymer interface. Owing to the existence of high-efficiency conductive metal networks, the NF@P-rGO/epoxy composite has a high thermal conductivity of 0.584 W m −1 K −1 , which is 2.6 times higher than that of neat epoxy resin. Additionally, owing to the improved wetting ability, NF@P-rGO-10 wt% boron nitride (BN) microsheets/epoxy composites could be fabricated and have a further higher thermal conductivity of 0.71 W m −1 K −1 . We believe the use of P-rGO as a novel surface modifier and the following liquid polymer drop-wetting could be an effective method to obtain novel and outstanding metal foam/polymer composites.
研究领域:
材料科学
·
高分子复合材料
·
热管理材料
·
表面与界面工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）