Journal of Coatings Technology and Research
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2017
·Vol. 14
·期 3
·505-516
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IF 1.557
Huang Shan,Xiao Juan,Zhu Yan’an,Qu Jinqing
A series of multiarm star hydroxyl-terminated polyesters (MHPs) were synthesized through a “one-pot” method with di-trimethylolpropane as the core molecule, 2,2-dimethylolpropionic acid as the AB 2 -type monomer, ε-caprolactone, and monocarboxylic acids as modifiers. The influence of different monocarboxylic acids on the viscosities of polyesters and their 2K-PU films hardness was studied and it was found that MHPs prepared from lauric acid displayed the higher films hardness and lower viscosities. IR spectra of MHPs disclosed the ring-opening reaction between ε-caprolactone and hydroxyl groups occurred. 1 H NMR spectra demonstrated that the molecular structures of MHPs were irregular due to the multiplicity of reaction processes. The measured number-average molecular weights ( M
n ) of MHPs were around 715–1854 g/mol with the PDI of 1.45–2.05. MHPs exhibited lower viscosities in the range of 3304–9060 mPa s at 100% solid contents and possessed lower intrinsic viscosities compared with linear polymers of similar molecular weight. The cured films of MHPs exhibited excellent impact resistance, adhesion, flexibility, and high hardness and displayed good thermal stability with 5% weight loss at 280°C. The solution viscosities of MHPs were less than 450 mPa s at 80% solid contents, and the VOC contents of 2K-PU coatings obtained from MHPs were low to 300 g/L.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Journal of Materials Chemistry B
·
2013
·Vol. 1
·期 24
·3099-3106
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IF 0
Chunfeng Ma,Liguo Xu,Wentao Xu,Guangzhao Zhang
Degradable polyurethane (PU) with copolyester oligomer consisting of ε-caprolactone (CL) and glycolide (GA) as the soft segments has been prepared by a combination of ring-opening polymerization and condensation reaction. Enzymatic and hydrolytic degradation experiments demonstrate that the PU can degrade in seawater. Such a polyurethane exhibit a more rapid degradation in comparison with that with poly(ε-caprolactone) (PCL) soft segments because the introduction of GA can reduce the crystallinity, as revealed by differential scanning calorimetry (DSC) and polarizing optical microscope (POM). Marine field tests show that the degradable polyurethane has good antifouling ability due to its self-renewal property. Besides, such polyurethane can serve as a carrier and controlled release system for an antifoulant, and the incorporation of an antifoulant in the polyurethane can significantly improve the antifouling ability and duration.
研究领域:
材料科学
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海洋生物学
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生物医学工程
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DOI
PubMed
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2021
·
IF 6.064
Yafei Li,Xiaocheng Lan,Boyang Liu,Tiefeng Wang
A stable and highly efficient supported Cu-Ni catalysts for the conversion of ethyl levulinate (EL) to γ-valerolactone (GVL) was developed. The catalysts were characterized by XRD, TEM, TPD, TPR, and XPS. The support effect of metal oxides (Al 2 O 3 , SiO 2 , ZrO 2 , and TiO 2 ) revealed that Cu-Ni supported on Al 2 O 3 showed the highest activity for EL hydrogenation to ethyl 4-hydroxypentanoate (EHP) and the subsequent intramolecular esterification of EHP to GVL. EHP intramolecular esterification to GVL in the ethanol solution was a reversible reaction with an equilibrium constant of 24 at 453 K. A simplified reaction kinetic network was established. The solvent had a significant influence on the reaction equilibrium and the catalyst stability. Cu-Ni/Al 2 O 3 in n-hexane solvent gave a higher GVL yield than that in ethanol solvent, and showed better recyclability than that in toluene solvent. With optimizing the conditions, Cu-Ni/Al 2 O 3 gave 99.9% conversion and 98% selectivity to GVL with a space–time yield of 1.13 g GVL g cat -1 h −1 in n-hexane solvent with good recyclability.
研究领域:
化学工程
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催化材料科学
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DOI
高影响因子
E-POLYMERS
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2022
·Vol. 22
·期 1
·147-155
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IF 3.074
Tao Xiong,Yi-Fu Zhang
The polycaprolactone diol (PCL diol) was prepared by ring-opening polymerization method, with hydroquinone bis(2-hydroxyethyl) ether as the reactive initiator and ε-caprolactone as the monomer. The polyurethane acrylate (PUA) was prepared with the self-made PCL diol. Then, PUA was used to prepare the ultraviolet curable coatings. The structure and molecular weight of PCL diol was characterized by Fourier transform infrared spectroscopy, gel-permeation chromatography, and hydroxyl value titration. The performance of the cured coating film was characterized by thermogravimetric analysis and scanning electron microscope. The flexibility and hardness of the cured coating film were tested. The results showed that the narrow molecular weight PCL diol was successfully synthesized. The UV curing coating film had the optimal performance with a hardness of 3H, flexibility of 1.5 mm, abrasion resistance of 0.028 g −1 , and adhesion of grade 1, all coating films showed good thermal properties.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Catalysts
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2023
·Vol. 13
·期 3
·478
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IF 3.9
Haiyue Xu,Qu Li,Yougui Yu,Qing Zheng
The development of low-alcohol Baijiu is consistent with demand for the industry’s sustainable development. However, the ester aroma of low-alcohol Baijiu is insipid and unstable—mainly due to the hydrolysis of esters during shelf life—thus reducing the industry scale of low-alcohol Baijiu to a significantly small range. An electrochemical method for improving low-alcohol Baijiu’s ester concentration and stability was investigated from the aspects of thermodynamics and kinetics. The key finding is that the new Baijiu’s ester content obtained through distillation is relatively high, exceeding its content in the thermodynamic equilibrium state. Thus, the ester will be hydrolyzed during shelf life. The idea of applying electrochemical catalytic esterification technology to the production of low-alcohol Baijiu in this study is directly derived from the production practice of Baijiu factories; it provides a direction for the further optimization of low-alcohol Baijiu to facilitate the production of an alternative product that will contribute to public health.Keywords:electrochemical esterification;low alcohol liquor;Baijiu;ester aroma
研究领域:
食品科学
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化学工程
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2014
·Vol. 132
·期 7
·
IF 1.64
Pan Dongdong,Tian Hengshui
Soluble and thermally stable polycarbonate polyurethane elastomers were synthesized through a solvent-free and nonisocyanate melt transesterification process. The conditions of this process were studied, and the optimum conditions were as follows: the catalyst dibutyltin oxide dosage was 0.125 wt %, the raw material molar ( n ) ratio of dimethyl 1,6-hexamethylene dicarbamate (HDC) to poly(carbonate macrodiol) (PCDL) was n (HDC)/ n (PCDL) = 1:0.99, the reactants were prepolymerized under 100°C for 1 h and then under 185°C and a high vacuum for 4 h. Three different PCDLs were selected to participate in the reaction under the conditions mentioned previously, and their structures were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. The products obtained from this process were still stable under 280°C. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41377.
研究领域:
高分子化学
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生物材料
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聚合物科学
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材料化学
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医用高分子
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DOI
高影响因子
Eco-Environment & Health
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2025
·Vol. 4
·期 2
·100139
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IF 17.6
Minghao Zhang,Yijin Lu,Zhuo Wang,Xiong Gao,Xuanhang Luo,Xin Shen,Weixiang Wu,Qingqing Mei
Ionic liquid-catalyzed methanolysis emerges as an efficient technique for transforming PET into premium-grade dimethyl terephthalate (DMT). However, incomplete depolymerization remains a major obstacle to the further industrial application of IL-catalyzed PET methanolysis. The proposed method utilized dimethyl carbonate (DMC) as the solvent for the complete methanolysis of waste PET under mild conditions, resulting in pure DMT and ethylene carbonate (EC) within 2.5 h. The use of 1-ethyl-3-methylimidazolium acetate ([EMIm][OAc]) as the IL catalyst significantly enhanced the reaction efficiency. Spectroscopic analyses using 1 H NMR and FT-IR confirmed the pivotal role of [EMIm][OAc] in establishing multiple hydrogen bonds with the reactants (PET, DMC, and MeOH) and the intermediate [ethylene glycol (EG)] during the catalytic process. This catalytic system exhibited remarkable performance, achieving complete conversion of PET, which resulted in the production of DMT and EC with yields of 99% and 91%, respectively. Moreover, this versatile approach is applicable to the upcycling of a wide variety of commercial polyesters and polycarbonates, underscoring its potential as a comprehensive solution for plastic waste management.
研究领域:
应用化学
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高分子科学
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绿色化学
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DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2016
·Vol. 134
·期 15
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IF 1.866
Shuangbao Peng,BinShuang Wu,Linbo Wu,Bo-Geng Li,Philippe Dubois
It is indispensable to investigate hydrolytic degradation behavior to develop novel (bio)degradable polyesters. Biobased and biodegradable copolyesters poly(butylene adipate- co -butylene furandicarboxylate) (PBAF) and poly(butylene succinate- co -butylene furandicarboxylate) (PBSF) with BF molar fraction (ϕ BF ) between 40 and 60% were synthesized in this study. The hydrolytic degradation of film samples was conducted in a pH 7.0 PBS buffer solution at 25 °C. Slight mass loss (1–2%) but significant decrease in intrinsic viscosity (35–44%) was observed after 22 weeks. The apparent hydrolytic degradation rate decreased with increasing ϕ BF and initial crystallinity. Meanwhile, PBAFs degraded slightly faster than PBSFs with the same composition. The ϕ BF and crystallinity increased slowly with degradation time, suggesting the aliphatic moiety and the amorphous region are more susceptible to hydrolysis. And high enough tensile properties were retained after hydrolysis degradation, indicating PBAF and PBSF copolyesters are hydrolytically degradable, with tunable hydrolytic degradation rate and good balance between hydrolytic degradability and durability. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44674.
研究领域:
材料科学
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环境科学
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高分子化学
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产品关联
DOI
高影响因子
SCIENCE AND ENGINEERING OF COMPOSITE MATERIALS
·
2021
·Vol. 28
·期 1
·528-539
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IF 1.295
Su Xiaofeng,Yu Yitao,Li Bing,Wang Jing,Lu Chuan,Zong Jianping,Li Jinhui,Wang Feng
In order to prepare polyurethane–polysiloxane block copolymers, α,ω-hydroxyalkyl polysiloxanes with methacrylate side chain and α,ω-bis(2-methyl-3-hydroxypropyl)polymethyl(2-methyl-methylpropanoate) siloxanes, were synthesized and characterized in this study. The syntheses process included hydroxyl protection, hydrosilylation, deprotection, and ring-opening equilibrium reactions. The intermediates and target products were characterized by Fourier transform infrared spectroscopy and 1 H nuclear magnetic resonance methods. The characterization results showed that each step was successfully carried out in all the cases. Then the waterborne polyurethane–polysiloxane block copolymers were prepared via step-growth polymerization. The properties of the block copolymer films were characterized by thermal gravimetric analysis, differential scanning calorimetry, and dynamic thermomechanical analysis methods in detail. The experimental results showed that the block introduction of hydroxyalkyl polysiloxane could reduce the water absorption of waterborne polyurethane from 62 to 11%, and significantly improve the water resistance of polyurethane. With the introduction of polysiloxane, the tensile strength decreased and the elongation at break increased. At the same time, with the increase of the polysiloxane content, the glass transition temperature of the soft segment decreased to −56.4°C and the thermal decomposition temperature increased to 300°C. The results revealed that the introduction of polysiloxane could effectively improve the comprehensive performance of polyurethane–polysiloxane block copolymer films.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
TOXICOLOGY LETTERS
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2011
·
IF 3.581
Zhaobin Zhang,Chengxia Jia,Ying Hu,Libei Sun,Jian Jiao,Liang Zhao,Desheng Zhu,Jun Li,Yonglu Tian,Huicheng Bai,Ruobao Li,Jianying Hu
Salicylate esters (SEs), a class of chemicals extensively used as flavor and fragrance additives in foods, beverages and a wide variety of consumer products, are suspected to have estrogenic activity based on chemical analysis of in silica molecular docking. We evaluated the estrogenic potentials of phenyl salicylate (PhS), benzyl salicylate (BzS), phenethyl salicylate (PES), ethyl salicylate (ES) and methyl salicylate (MS) using an in vitro human estrogen receptor α (hERα)-coactivator recruiting assay and in vivo immature rodent uterotrophic bioassays. We found that PhS, BzS and PES showed obvious in vitro hERα agonistic activities; BzS in particular exhibited a higher estrogenic activity compared to bisphenol A (BPA). The uterine weights were significantly increased in mice treated with 11.1, 33.3, 100 and 300 mg/kg/day BzS and 33.3 mg/kg/day PES and rats treated with 3.7, 11.1, 33.3 and 100 mg/kg/day BzS for 3 days ( P < 0.05). Finally, we transformed the daily intakes and the dermal exposures of SEs in the real world into estradiol equivalent concentrations (EEQs). We found that the EEQ of BzS daily intake in consumers in the U.S. and the EEQs of dermal BzS and PES exposure among high-volume users worldwide were higher than the maximum secure daily estradiol intake recommended by the U.S. Food and Drug Administration (FDA). In particular, the EEQ for dermal BzS exposure was up to 162 ng EEQ/kg, which is 3.3 times higher than the maximal acceptable daily E 2 intake recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).
研究领域:
毒理学
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环境科学
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食品科学
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药理学
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DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2020
·
IF 2.888
Jing Fan,Shuangshuo Liu,Qinglong Meng,Fenhong Song
In order to provide the basic thermophysical property data for the research of alternative clean fuels, the liquid thermal conductivity of methyl myristate, methyl laurate and methyl caprate which are considered as the main compounds of biodiesel was reported. The measurements of three fatty acid esters, covering a temperature range from (292 to 372) K and pressure up to 15 MPa, have been performed by a transient hot-wire technique with a bare platinum hot wire. The relative uncertainty of the experimental results was estimated to be ± 2.0% (in the 0.95 confidence level). The present thermal conductivity data were correlated as a polynomial function of temperature and pressure for the purpose of interpolation.
研究领域:
能源科学
·
物理化学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES
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2020
·
IF 2.671
Yongxia Ren,Yunsheng Dong,Ruoning Yang,Youwei Yao
Ultraviolet (UV)/thermal dual-curable polyurethane acrylate (PUA) mixtures were prepared using a PUA oligomer , tripropylene glycol diacrylate (TPGDA), benzoyl peroxide (BPO), 2,4,6-trimethylbenzoyldiphenyl phosphine oxide (TPO), and cobalt isooctanoate. For purposes of comparison, a UV-curable PUA mixture was prepared by mixing the PUA oligomer, TPGDA, and TPO. When placed under a UV lamp (400 W, 50 mW/cm 2 ), the surface drying time of each curable mixture was approximately 2 s. The content of volatiles during UV curing (the intensity of the lamp was 100 mW/cm 2 ) was less than 0.3 wt%, and the content of potential volatiles (the test condition was heating at 110 °C for 1 h after UV curing) was below 1.0 wt%. Compared with the UV-cured sample, the UV/thermal dual-cured sample containing cobalt isooctanoate had more favorable properties, that is: (1) better acid and alkali resistance; and (2) better thermal stability and higher gel content. The temperature at 5 wt% weight loss ( T 5wt.% ) and the gel fraction of the UV-cured sample (the curing condition was 1 min of UV irradiation) were 269.4 °C and 94.6%, respectively. The T 5wt.% and the gel fraction of the UV/thermal dual-cured sample (cured at 100 °C for 10 min after 1 min of UV irradiation) were 318.2 °C and 99.8%, respectively. BPO and cobalt isooctanoate had little effect on the surface drying rate of the curable mixtures, and the performance of the cured samples was improved by thermal treatment following irradiation with UV. Considering the dyeing effect of BPO, this system provides a more practical approach to the complete curing of colored UV-curable resins.
研究领域:
材料科学
·
聚合物化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）