COMPOSITES PART B-ENGINEERING
·
2024
·
IF 12.7
Hongyang Deng,Lixian Guo,Keping Chen,Pingfeng You,Ping Zhang,Yewei Xu,Ningning Song,Chunrong Tian,Jianhua Wang,Shuen Liang
Polyurea (PU) elastomers have become increasingly popular in recent years due to their exceptional blast mitigation, ballistic protection, and wear resistance properties. However, their applications as protective materials are often limited as a result of their high flammability. In this study, aromatic dianhydrides (ArDAs) were employed to capture the thermal decomposing products of PU during combustion and facilitate the generation of highly heat-resistant aromatic polyimides (i.e., end group capturing effect), thus enhancing the material's char-forming ability and improving its flame retardancy. The ArDAs were found to significantly reduce the peak heat release rate (PHRR), total heat release (THR), total smoke release (TSR), and total CO release (TCO) of PU, and meanwhile increased the amount of char residue. At 20 wt% content of 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), PHRR, THR, TSR and TCO of PU were reduced by 70.6%, 32.5%, 44.7% and 58.8%, respectively, the char residue was increased by 405%, and the mechanical properties of PU were well maintained (88.5% tensile strength and 91.0% elongation at break of pure PU). These findings demonstrate that ArDAs could serve as a new kind of halogen/phosphorus-free flame retardant for PU elastomers.
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
PHARMAZIE
·
2021
·Vol. 76
·期 9
·412-415
·
IF 1.267
Xuan G. S.,Zhan J. H.,Zhang A. M.,Li W.,Zheng K.
A series of sulfonamide derivatives were synthesized, and the enzyme inhibitory activity of the synthesized compounds on carbonic anhydrase II was evaluated. Through molecular docking studies, it was found that compounds 1b, 1e, 2a, 2b, 3a have a strong
binding affinity to carbonic anhydrase II. The IC50 values of the four compounds 1e, 2b, 3a, and 3b were lower than that of the positive control drug acetazolamide. What's more, the compounds had a high inhibitory activity for A549 lung cancer cell growth,
among them, 1e and 3a could inhibit both carbonic anhydrase II and lung cancer cell proliferation.
研究领域:
药理学
·
肿瘤学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 130
·107793-107803
·
IF 3.84
Shanyou Liu,Yunhe Zhang,Xueping Wang,Haiwei Tan,Ningnig Song,Shaowei Guan
To investigate the properties of hyperbranched polyimides (HBPIs) for potential optical applications, novel fluorinated tetra-amine monomers with ether and sulfonyl groups, 4,4′-di[3,5-di(2-trifluoromethyl-4-aminophenoxy)phenoxy]sulfone, and five kinds of long-chain dianhydrides, have been designed and synthesized. A series of anhydride-terminated hyperbranched polyimides have been prepared via a two-step method with chemical imidization. The HBPIs possess outstanding solubility and show excellent thermal and optical properties. The glass transition temperatures (Tg) of the HBPIs range from 230–242 °C determined by differential scanning calorimetry (DSC), and 232–263 °C by thermomechanical analysis (TMA), depending on the dianhydride used. The 5% weight loss temperatures are in the range of 480–533 °C, showing high intrinsic thermal-resistant characteristics of the HBPIs. The HBPI films show good optical transparency, higher than 80% at 800 nm. The cast polyimide films have favorable mechanical properties with tensile strengths of 91–112 MPa, elongation at break of 5.99–7.99%, and initial modulus of 2.14–2.57 GPa. The polyimides exhibit average refractive indices of 1.5780–1.6271, and birefringence of 0.0065–0.0079 because of the hyperbranched structure. The PI derived from 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]hexafluoropropane possesses the lowest refractive indices due to the high fluorine content in the polymer chain.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2015
·Vol. 23
·期 3
·341-347
·
IF 1.671
Qian Shaoping,Mao Hailiang,Zarei Elmira,Sheng Kuichuan
To improve the interfacial interaction between poly(lactic acid) (PLA) and bamboo particles (BP), sodium hydroxide solution was employed to pretreat BP, and then maleic anhydride (MAH) was used to compatibilize PLA/BP biocomposites. The biocomposites were prepared through melt blending and hot-pressing. Effects of MAH concentration on the properties of BP and PLA/BP biocomposites were investigated using Fourier transform infrared spectroscopy, mechanical measurements, differential scanning calorimetric, melt flow rate (MFR) analysis and scanning electron microscope. Results showed that interfacial interaction between PLA and BP in the biocomposites was improved with MAH compatibilizer. Tensile strength and elongation at break of PLA/BP biocomposites, reached maximal values of 47.6 MPa and 6.22 %, respectively, when treated with 1.0 % MAH. Maximal flexural strength of 72.61 MPa and flexural modulus of 4.65 GPa were obtained with 0.5 % MAH treatment, and thermal properties were also improved at this concentration. MFR of the blends was enhanced with MAH compatibilization.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xiao Chen,Nannan Zhang,Huaming Wang,Ying Zhong,Tianming Lv,Changhai Liang
The continuous flow selective hydrogenation of maleic anhydride (MA) to γ-butyrolactone (GBL) over highly efficient and long-term stable catalysts is a considerable promising strategy for both lab-scale as well as industrial application. In this work, a PtPdCoNiCu/TiO 2 high-entropy alloy (HEA) catalyst is developed by the colloidal impregnation method, in which the HEA colloids are synthesized by lithium naphthalenide-driven reduction at mild conditions according to the redox potential of the various metals. The PtPdCoNiCu/TiO 2 catalyst exhibits highly efficient in the hydrogenation of MA with 91 % selectivity to GBL at full conversion of MA under the weighted hourly space velocity of 1.14 h −1 , 3 MPa H 2 , and 260 °C. Due to the present of oxygen vacancy in the TiO 2 support and the hydrogen spillover, the PtPdCoNiCu/TiO 2 HEA catalyst presents a low apparent activation energy (75 kJ mol −1 ), boosting the hydrogenolysis of C=O bonds for generating of GBL. The cocktail effect is presented in the PtPdCoNiCu/TiO 2 catalyst, and its catalytic activity is much better than that of corresponding monometallic and bimetallic catalysts. It realizes the reduction and substitution of precious metal catalysts. In addition, the PtPdCoNiCu/TiO 2 catalyst with sintering resistance and acid resistance shows excellent long-term stability within 132 h. This work is of great significance for understanding HEA catalysis at the atomic level and provides the possibility for developing low-cost and efficient precious metal industrial catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE RESEARCH
·
2014
·
IF 1.966
Yong-Fu Li,Yi-Ming Ha,Qin Guo,Qing-Peng Li
β-CD maleate (CDM) and β-CD itaconate (CDI) were prepared by esterification of β-cyclodextrin (β-CD) with maleic acid and itaconic acid using phosphate as a catalyst in a semi-dry process. The esterification of β-CD was carried out using [Itaconic acid ] or [Maleic acid ] 4 mol/mol of CD; M / L ratio 1:0.6; temperature 110 °C; [4-methoxyphenol] 2.5% amount of acid; reaction time 3.5 h. The esterification rates of CDM and CDI are 70.38% and 21.02%, respectively. We found that CDM and CDI were both monoesters. Here, we also established a new evaluation method for the rate of esterification.
研究领域:
有机化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2025
·
IF 1.9
Mei Tang,Shunxin Liu,Ping Guo,Zhendi Ma,Xiaorong Hu
As a new class of porous materials, hyper-crosslinked polymers can adsorb heavy metal ions from aqueous solutions. This requires them to possess good surface hydrophilicity and active functional groups that can interact with heavy metals. In this research, three polymers, namely MAH-1, MAH-2, and MAH-3, were synthesized via the Friedel–Crafts alkylation reaction using phenyl maleic anhydride (MAH) as the monomer and dimethoxymethane (FDA), 1,4-p-dichloro-benzyl (DCX), and biphenyl dichlorobenzyl (BCMBP) as cross-linkers, respectively. The effect of the molecular size of the cross-linkers on polymer yields, morphology, and Pb2+ adsorption property was investigated. The yield of MAH-1 was low, and the product was soluble in methanol. This implied that when the cross-linker molecule was short, the steric hindrance caused by the substituents on the monomer benzene ring impeded polymer formation. MAH-2 formed nanoparticles that extended into thin sheets, while MAH-3 only formed nanoparticles, exhibiting clearly different morphologies. After alkalization, the maximum Pb2+ adsorption capacities of the two polymers, determined by the Langmuir adsorption isotherm, were 216 mg g−1 and 134 mg g−1, respectively. Both polymers were applied to treat Pb2+ in simulated battery wastewater with a concentration of 32 mg L−1, and both reduced the concentration to below 0.55 mg L−1, meeting the requirements of the Lead and Zinc Industrial Pollutant Discharge Standard GB 25466-2010 (National Standards of the People’s Republic of China). Additionally, the materials demonstrated good reusability and showed potential for treating lead-contaminated water.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2018
·
IF 2.829
Ming-Qiang Jia,Qi-Zheng Liu,Li-Juan Zhu,Yan Zhang,Zhong-Xiu Chen
Hydrolysis of fatty acid anhydrides involves fatty acid vesicle formation and autocatalytic hydrolysis. Previous studies focused on the effect of biopolymers on vesicle formation or on autocatalytic reactions , however, the influence of polysaccharides on a system where the self-assembly of fatty acid vesicles and the hydrolysis of fatty acid anhydrides coexist remains unknown. In this paper, three polysaccharides, sodium chondroitin sulfate (CSA), sodium alginate (SA) and 2-hydroxyethyl cellulose (2-HEC) were selected to investigate the effect of crowded media on the decanoic acid vesicle formation and the autocatalytic hydrolysis of decanoic anhydride . The results showed that the rate of hydrolysis of decanoic anhydride increased in CSA or SA but decreased in 2-HEC. Further investigation revealed that the size of vesicles in CSA decreased in the early stage of vesicle formation but increased in 2-HEC. In the CSA-vesicle system, elastic behavior dominates, while 2-HEC- and SA-vesicles show more viscous behavior. In addition, the significantly increased membrane fluidity in CSA or in SA supports self-assembly of decanoic acid vesicles and autocatalytic hydrolysis, which is the opposite in the case of 2-HEC. This research provides new insights into the self-assembly of fatty acid vesicles and vesicle-catalyzed reactions with polysaccharides in crowded conditions.
研究领域:
生物化学
·
分子生物学
✓ 已验证
DOI
高影响因子
PROCESS BIOCHEMISTRY
·
2015
·
IF 2.516
Guohua Jing,Fujun Pan,Bihong Lv,Zuoming Zhou
Carbonic anhydrase (CA) is the most efficient catalyst for CO 2 hydration and dehydration. In the present work, magnetic polymer microspheres functionalized with epoxy group were prepared, and CA enzyme was immobilized on the carries by selective covalent binding. The parameters affecting CA immobilization, such as pH, temperature and enzyme dose were investigated. Based on the investigation and the characterization of the microspheres, the kinetic parameters of the immobilized and the free CA were also evaluated. The value of the Michaelis–Menten constant ( K m ) and the maximum velocity ( V max ) of the immobilized CA was 8.077 mmol/L (mM) and 0.027 μmol/(min mL), while that of the free CA was 6.091 mM and 0.091 μmol/(min mL), respectively. Moreover, the performance of the thermal stability, storage stability and reusability of the immobilized CA confirmed that CA immobilized on the epoxy-functionalized magnetic polymer microspheres owned a stable and efficient catalytic ability on CO 2 hydration, which seemed to be a suitable candidate for CO 2 capture.
研究领域:
生物化学
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
·
2012
·Vol. 90
·期 2
·265-272
·
IF 1.773
Chengsheng Gui,Xiaoqing Liu,Di Wu,Tuo Zhou,Guyue Wang,Jin Zhu
The most commonly used curing agents for soy-based adhesives are polyamines, which have the problem of low solid content and/or high viscosity. To overcome this problem, a new type of polyamidoamine (PADA) resin was synthesized and applied to soy flour-based adhesives to improve their water resistance. The PADA solution obtained had a high solid content of 50 wt% and low viscosity of 270 cP. The optimum weight ratio of soy flour/PADA/maleic anhydride to prepare adhesive was 40/7/1.68. The wet strength of plywood prepared at the optimum weight ratio was 0.82 MPa, which meant the plywood could be used as type II plywood according to the Chinese National Standard GB/T 9846.7-2004. The results of water-insoluble solid content measurement and SEM observation demonstrated that cured soy flour–PADA–maleic anhydride adhesive had a 16 % greater water-insoluble solid content than soy flour–NaOH adhesive. The cross-linking network formed by the reactions of PADA and MA would increase the water-insoluble solid contents and improve water resistance of cured soy flour-based adhesives.
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
FOOD CHEMISTRY
·
2018
·
IF 4.946
Yao Zhang,Lunan Guo,Dan Xu,Dandan Li,Na Yang,Feng Chen,Zhengyu Jin,Xueming Xu
This research aimed at investigating the effects of different weight-average molecular weights ( M w : T10, T70, T250, T750, T2000) of dextran (α-(1 → 6)-linked linear backbone, α-(1 → 3)-linked branching) on wheat sourdough bread qualities. Texture analyzer showed that dextran contributed to a significant inhibition of bread staling, particularly dextran T2000. Pasting profiles (Rapid visco-analysis) and steady rheological properties (steady shear measurements) of samples indicated that dextran T2000 suppressed the swelling and gelatinization of wheat starch granules and bound a great amount of water, thus retarding the aging process. Dextran T2000 markedly improved the elastic properties of sourdough-containing dough. Wheat sourdough breads containing dextran T10 exhibited unexpected less firm crumb structure. The improvement of bread qualities was a function of the M w of dextran. Dextran with high M w values has the potential for improving the quality of wheat sourdough breads, especially extending shelf life.
研究领域:
食品科学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2020
·Vol. 26
·期 53
·12233-12241
·
IF 4.857
Chunlei Tan,Na Wang,Qichang Pan,Yan Li,Yu Li,Qiannan Ji,Xiaoping Fan,Fenghua Zheng,Hongqiang Wang,Qingyu Li
Graphical Butyric anhydride was used as carbonate-based electrolyte additive to construct a thin, uniform cathode–electrolyte interphase (CEI) film that can alleviate the decomposition of the electrolyte and prevent the dissolution of metal ions to maintain the structural stability of LiNi 0.5 Mn 1.5 O 4 (LNMO) during the cycling process, and improve the electrochemical performance of LNMO cathodes in carbonate-based electrolytes. Butyric anhydride (BA) is used as an effective functional additive to improve the electrochemical performance of a high-voltage LiNi 0.5 Mn 1.5 O 4 (LNMO) cathode. In the presence of 0.5 wt % BA, the capacity retention of a LNMO/Li cell is significantly improved from 15.3 to 88.4 % after 200 cycles at 1 C. Furthermore, the rate performance of the LNMO/Li cell is also effectively enhanced, and the capacity goes up to 112 mAh g −1 even at 5 C, which is considerably higher than that of a LNMO/Li cell in electrolyte without BA additive (95.4 mAh g −1 at 5 C). Linear sweep voltammetry and cyclic voltammetry results reveal that the BA additive can be preferentially oxidized to construct a stable cathode electrolyte interphase (CEI) film on the LNMO cathode. Subsequently, the BA-derived CEI film can alleviate the decomposition of the electrolyte and the dissolution of Mn and Ni ions from the LNMO cathode as well as maintain the structural stability of LNMO during the cycling process; this leads to outstanding electrochemical performance. Thus, this work provides an effective and low-cost functional electrolyte for high-voltage LNMO-based LIBs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
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