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Biodegradation of waste refrigerator polyurethane by mealworms

《环境科学与工程前沿（英文）》 2023年 第17卷 第3期 doi: 10.1007/s11783-023-1638-8

摘要：

● Waste refrigerator polyurethane (WRPU) was ingested and biodegraded by mealworms.

关键词： Waste refrigerator polyurethane     Mealworms     Biodegradation     Carbon balance     Gut microorganism    

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Effect of thermodynamic parameters on the performance of refrigerator-ejector

Lihong CAO, Yicai LIU, Chao WAN, Tianlong XIN, Qian HUANG, Mingyan ZHANG

《能源前沿（英文）》 2010年 第4卷 第4期   页码 517-521 doi: 10.1007/s11708-010-0004-2

摘要： A 3D calculation model of a refrigerator-ejector was built and simulated in a compression/injection hybrid refrigeration cycle system by using the FLUENT software of CFD. The effect of thermodynamic parameters (the pressure of primary fluid and secondary fluid) on the performance of the refrigerator-ejector was studied. The boundary conditions were set according to the actual operating condition and the parameters of refrigerator experimental sample. The numerical calculation results show that there is one optimal pressure of primary fluid, i.e., = 0.06612 MPa, corresponding to the maximum entrainment ratio, i.e., = 0.568; and there is one optimal pressure of secondary fluid, i.e., = 0.04837 MPa, corresponding to the maximum entrainment ratio, i.e., = 0.564.

关键词： refrigerator-ejector     FLUENT     thermodynamic parameters     entrainment ratio performance    

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Hyperbranched azo polyurethane synthesized through A + B scheme

CHE Pengchao, HE Yaning, WANG Xiaogong

《化学科学与工程前沿（英文）》 2008年 第2卷 第1期   页码 123-126 doi: 10.1007/s11705-007-0078-5

摘要： A hyperbranched azo polyurethane was synthesized by one-step polymerization of an A type monomer diphenylmethane-4,4′-diisocyanate and a B type monomer 4-(N,N′-bis(2-hydroxyethyl))amino-2′-hydroxyethoxyl-4′-nitro-azobenzene. The azo polymer was characterized by H nuclear magnetic resonance (NMR), ultraviolet-visible (UV-Vis) spectrum and thermal analysis. The of the polymer in dimethylformamide (DMF) solution is 488 nm. The number average molecular weight (M) determined by GPC is 9,300 with a polydispersion index 1.9. The glass transition temperature () of the polymer is 131°C observed from DSC thermogram. The results show that the azo polyurethane has been successfully synthesized through this scheme. Surface-relief-gratings (SRGs) were fabricated on the polymer film after being irradiated by interference pattern of Ar laser beams for 1,000 s. The surface modulation depth and the grating space period measured by AMF are 67 and 770 nm, respectively.

关键词： dimethylformamide     one-step polymerization     polyurethane     2-hydroxyethyl     diphenylmethane-4     4′-diisocyanate    

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Energy distribution between liquid hydrogen and liquid oxygen temperatures in a Stirling/pulse tube refrigerator

《能源前沿（英文）》 2023年 第17卷 第4期   页码 516-526 doi: 10.1007/s11708-022-0844-6

摘要： A two-stage gas-coupled Stirling/pulse tube refrigerator (SPR), whose first and second stages respectively involve Stirling and pulse tube refrigeration cycles, is a very promising spaceborne refrigerator. The SPR has many advantages, such as a compact structure, high reliability, and high performance, and is expected to become an essential refrigerator for space applications. In research regarding gas-coupled regenerative refrigerator, the energy flow distribution between the two stages, and optimal phase difference between the pressure wave and volume flow, are two critical parameters that could widely influence refrigerator performance. The effects of displacer displacement on the pressure wave, phase difference, acoustic power distribution, and inter-stage cooling capacity shift of the SPR have been investigated experimentally. Notably, to obtain the maximum first-stage cooling capacity, an inflection point in displacement exists. When the displacer displacement is larger than the inflection point, the cooling capacity could be distributed between the first and second stages. In the present study, an SPR was designed and manufactured to work between the liquid hydrogen and liquid oxygen temperatures, which can be used to cool small-scale zero boil-off systems and space detectors. Under appropriate displacer displacement, the SPR can reach a no-load cooling temperature of 15.4 K and obtain 2.6 W cooling capacity at 70 K plus 0.1 W cooling capacity at 20 K with 160 W compressor input electric power.

关键词： Stirling/pulse tube refrigerator     displacer displacement     space application     phase shift     energy distribution    

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Preparation of lignin/TiO2 nanocomposites and their application in aqueous polyurethane coatings

Dongjie Yang, Shengyu Wang, Ruisheng Zhong, Weifeng Liu, Xueqing Qiu

《化学科学与工程前沿（英文）》 2019年 第13卷 第1期   页码 59-69 doi: 10.1007/s11705-018-1712-0

摘要： A simple method using a water soluble lignin quaternary ammonium salt (LQAS) and TiO has been developed for the preparation of lignin/TiO nanocomposites in an aqueous medium under mild conditions. The LQAS/TiO nanocomposites contain well-dispersed small particles with excellent ultraviolet (UV) shielding abilities and good compatibilities with waterborne polyurethane (WPU). When the LQAS/TiO nanocomposites were blended with WPU, the UV absorbance and the tensile ductility of the WPU increased significantly. The composite WPU hybrid film containing 6 wt-% LQAS/TiO nanocomposite had the highest visible light transmittance and had excellent ultraviolet aging properties. After 192 h of UV light irradiation, the tensile strength of the composite film was above 8 MPa and the elongation at break was 800%. This work highlights new possibilities for the utilization of alkali lignin.

关键词： lignin     TiO2     nanocomposite particle     polyurethane film    

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Microcellular injection molding process for producing lightweight thermoplastic polyurethane with customizable

Thomas ELLINGHAM, Hrishikesh KHARBAS, Mihai MANITIU, Guenter SCHOLZ, Lih-Sheng TURNG

《机械工程前沿（英文）》 2018年 第13卷 第1期   页码 96-106 doi: 10.1007/s11465-018-0498-6

摘要：

A three-stage molding process involving microcellular injection molding with core retraction and an “out-of-mold” expansion was developed to manufacture thermoplastic polyurethane into lightweight foams of varying local densities, microstructures, and mechanical properties in the same microcellular injection molded part. Two stages of cavity expansion through sequential core retractions and a third expansion in a separate mold at an elevated temperature were carried out. The densities varied from 0.25 to 0.42 g/cm3 (77% to 62% weight reduction). The mechanical properties varied as well. Cyclic compressive strengths and hysteresis loss ratios, together with the microstructures, were characterized and reported.

关键词： thermoplastic polyurethane     microcellular injection molding     cavity expansion     compressive strength     hysteresis loss ratio    

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3D finite element analysis of composite noise barrier constructed of polyurethane products

Ben DAEE,Hesham El NAGGAR

《结构与土木工程前沿（英文）》 2017年 第11卷 第1期   页码 100-110 doi: 10.1007/s11709-016-0364-8

摘要： This paper presents a numerical investigation on the structural performance of an innovative noise barrier consisting of poly-block, rigid polyurethane foam (RPF) and polyurea. The mechanical characteristics of RPF as well as the flexural resistance of the proposed wall system (poly-wall) were established and presented in another study. The experimental results are used in the current study to develop, calibrate and verify 3D finite element (FE) models of the wall system. The components of the poly-wall including steel rebars, poly-blocks and RPF cores were simulated and then verified using the results of experiments conducted on the wall components. The results of numerical analysis exhibited a satisfactory agreement with the experimental outcomes for the entire wall system. The verified numerical models were then used to conduct a parametric study on the performance of poly-wall models under uniform wind load and gravity load. The findings of the current study confirmed that the structural performance of poly-wall is satisfactory for noise barrier application. Simulation techniques for improvement of the numerical analysis of multi-martial 3D FE models were discussed.

关键词： 3D finite element     sound wall     rigid polyurethane foam     poly-wall     numerical model     calibration    

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ratio and the 1,6-hexanediol/dimethylol propionic acid molar ratio on the properties of waterborne polyurethane

Jiao Feng, Qiuhao Lu, Weimin Tan, Kequan Chen, Pingkai Ouyang

《化学科学与工程前沿（英文）》 2019年 第13卷 第1期   页码 80-89 doi: 10.1007/s11705-018-1763-2

摘要：

1,5-Pentamethylene diisocyanate, a novel aliphatic diisocyanate formed from bio-based 1,5-pentamethylenediamine, has been used as a hard segmented material to synthesize polyurethane. In this study, several waterborne polyurethane (WPU) dispersions have been successfully prepared by a prepolymer process from 1,5-pentamethylene diisocyanate poly(polyether) with different NCO/OH ratios and 1,6-hexanediol (HDO)/dimethylol propionic acid (DMPA) molar ratios. The Fourier transform infrared (FTIR) spectra, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, and a mechanical tensile test were used to investigate the structures, thermal stability, phase separation, crystallinity, mechanical properties, and adhesive performance of the WPU dispersions. The FTIR results indicate that the degree of hydrogen bonding and the numbers of urea groups increase as the NCO/OH ratio and HDO/DMPA molar ratio increase. Furthermore, the phase separation increases and the thermal stability decreases as the NCO/OH ratio increases or the HDO/DMPA molar ratio decreases. Finally, WPU3.0-2.4 (NCO/OH=3, HDO/DMPA=2.4) exhibits a maximum tensile strength and shear strength, pointing to its possible use as an adhesive. These results could provide a very valuable reference for industrial applications of WPU.

关键词： 1     5-pentamethylene diisocyanate     polyurethane     water based    

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Available energy analysis of new tandem double-capillary tube refrigeration system for refrigerator-freezers

HE Maogang, ZHANG Ying, SONG Xinzhou, ZHANG Jiantao

《能源前沿（英文）》 2008年 第2卷 第1期   页码 36-42 doi: 10.1007/s11708-008-0013-6

摘要： A new tandem double-capillary tube refrigeration system for refrigerator-freezers is proposed. A capillary tube was added between the two evaporators in the fresh and frozen food storage chests to raise the evaporation temperature of the refrigerating chamber, and reduce the heat exchange temperature difference and the available energy loss. Peng-Robinson (P-R) equation of state was adopted to calculate the thermodynamic properties of the refrigerants, and the available energy analysis of the vapor compression refrigeration cycle was programmed to calculate the thermodynamic performances of the new and the conventional refrigeration cycle of the refrigerator-freezer. The calculation results show that the available energy efficiency of the conventional refrigeration cycle of the refrigerator-freezer is 21.20% and 20.57%, respectively when the refrigerant is R12 and R134a, while that of the double-capillary tube refrigeration cycle of the refrigerator-freezer is 23.97% and 23.44%, respectively. By comparison, the available energy efficiency of the new refrigeration system increases by 13.07% and 13.95%, respectively.
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Optimization of polyurethane-bonded thin overlay mixture designation for airport pavement

Xianrui LI; Ling XU; Qidi ZONG; Fu JIANG; Xinyao YU; Jun WANG; Feipeng XIAO

《结构与土木工程前沿（英文）》 2022年 第16卷 第8期   页码 947-961 doi: 10.1007/s11709-022-0836-y

摘要： This research explored the application potential of PUM thin-overlay technology on airport rapid maintenance. The rapid curing process of polyurethane binder determines the limited time window for mixing and construction of polyurethane-bonded mixture (PUM), which presents significant difference with hot-mix asphalt (HMA) technology. Therefore, this research investigated and optimized the mix design of PUM for airport thin-overlay technology based on its thermosetting characteristics. First, limestone and basalt were comprehensively compared as an aggregate for PUM. Then, the effects of molding and curing conditions were studied in terms of mixing time, molding method, molding parameters and curing temperature. Statistical analysis was also conducted to evaluate the effects of gradation and particle size on PUM performances based on gray relational analysis (GRA), thus determining the key particle size to control PUM performances. Finally, the internal structural details of PUM were captured by X-ray CT scan test. The results demonstrated that it only took 12 hours to reach 75% of maximum strength at a curing temperature of 50 °C, indicating an efficient curing process and in turn allowing short traffic delay. The internal structural details of PUM presented distribution of tiny pores with few connective voids, guaranteeing waterproof property and high strength.

关键词： polyurethane-bonded mixture     mix design optimization     airport pavement     thin overlay     gray relational analysis    

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High-gravity-assisted emulsification for continuous preparation of waterborne polyurethane nanodispersion

Weihong Zhang, Dan Wang, Jie-Xin Wang, Yuan Pu, Jian-Feng Chen

《化学科学与工程前沿（英文）》 2020年 第14卷 第6期   页码 1087-1099 doi: 10.1007/s11705-019-1895-z

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surface modified mixed metal oxide nanoparticles on the electrochemical and mechanical properties of polyurethane

《化学科学与工程前沿（英文）》 2023年 第17卷 第1期   页码 1-14 doi: 10.1007/s11705-022-2176-9

摘要： Newly synthesized functional nanoparticles, 3-amino-1,2,4-triazole (ATA)/SiO2–TiO2 were introduced to the polyurethane (PU) matrix. Electrochemical techniques were used to investigate the barrier properties of the synthesized PU–ATA/SiO2–TiO2 nanocomposite coated steel specimen. In natural seawater, electrochemical impedance spectroscopy experiments indicated outstanding protective behaviour for the PU–ATA/SiO2–TiO2 coated steel. The coating resistance (Rcoat) of PU–ATA/SiO2–TiO2 was determined to be 2956.90 kΩ·cm–2. The Rcoat of the PU–ATA/SiO2–TiO2 nanocomposite coating was found to be over 50% higher than the PU coating. The current measured along the scratched surface of the PU–ATA/SiO2–TiO2 coating was found to be very low (1.65 nA). The enhanced ATA/SiO2–TiO2 nanoparticles inhibited the entry of electrolytes into the coating interface, as revealed by scanning electron microscopy/energy dispersive X-ray spectroscopy and X-ray diffraction analysis of the degradation products. Water contact angle testing validated the hydrophobic nature of the PU–ATA/SiO2–TiO2 coating (θ = 115.4°). When the concentration of ATA/SiO2−TiO2 nanoparticles was 2 wt %, dynamic mechanical analysis revealed better mechanical properties. Therefore, the newly synthesised PU–ATA/SiO2–TiO2 nanocomposite provided excellent barrier and mechanical properties due to the addition of ATA/SiO2–TiO2 nanoparticles to the polyurethane, which inhibited material degradation and aided in the prolongation of the coated steel’s life.

关键词： SiO2/TiO2 nanoparticle     nanocomposite coatings     dynamic mechanical analysis     electrochemical techniques     corrosion     colloids and interfaces    

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Hemocompatible polyurethane/gelatin-heparin nanofibrous scaffolds formed by a bi-layer electrospinning

Heyun WANG, Yakai FENG, Marc BEHL, Andreas LENDLEIN, Haiyang ZHAO, Ruofang XIAO, Jian LU, Li ZHANG, Jintang GUO

《化学科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 392-400 doi: 10.1007/s11705-011-1202-0

摘要： In this paper, a scaffold, which mimics the morphology and mechanical properties of a native blood vessel is reported. The scaffold was prepared by sequential bi-layer electrospinning on a rotating mandrel-type collector. The tubular scaffolds (inner diameter 4 mm, length 3 cm) are composed of a polyurethane (PU) fibrous outer-layer and a gelatin-heparin fibrous inner-layer. They were fabricated by electrospinning technology, which enables control of the composition, structure, and mechanical properties of the scaffolds. The microstructure, fiber morphology and mechanical properties of the scaffolds were examined by means of scanning electron microscopy (SEM) and tensile tests. The PU/gelatin-heparin tubular scaffolds have a porous structure. The scaffolds achieved a breaking strength (3.7±0.13 MPa) and an elongation at break (110±8%) that are appropriate for artificial blood vessels. When the scaffolds were immersed in water for 1 h, the breaking strength decreased slightly to 2.2±0.3 MPa, but the elongation at break increased to 145±21%. In platelet adhesion tests the gelatin-heparin fibrous scaffolds showed a significant suppression of platelet adhesion. Heparin was released from the scaffolds at a fairly uniform rate during the period of 2 day to 9 day. The scaffolds are expected to mimic the complex matrix structure of native arteries, and to have good biocompatibility as an artificial blood vessel owing to the heparin release.

关键词： electrospinning     artificial blood vessels     scaffold     polyurethane     gelatin     nanofiber     hemocompatibility    

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Exceptionally flame-retardant flexible polyurethane foam composites: synergistic effect of the silicone

Qian Wu, Jincheng Zhang, Shengpeng Wang, Bajin Chen, Yijun Feng, Yongbing Pei, Yue Yan, Longcheng Tang, Huayu Qiu, Lianbin Wu

《化学科学与工程前沿（英文）》 2021年 第15卷 第4期   页码 969-983 doi: 10.1007/s11705-020-1988-8

摘要： A facile strategy was developed to fabricate flexible polyurethane (PU) foam composites with exceptional flame retardancy. The approach involves the incorporation of graphene oxide (GO) into a silicone resin (SiR) solution, which is then deposited onto a PU foam surface via the dip-coating technique and cured. Fourier-transform infrared spectroscopy, scanning electron microscopy, and Raman spectroscopy measurements demonstrated that the SiR and GO were successfully coated onto the PU skeleton and the intrinsic porous structure of the PU foam remained intact. The effects of SiR and GO on the mechanical and thermal stability and flame retardancy of PU composites were evaluated through compression tests, thermogravimetric analysis, vertical combustion tests, and the limiting oxygen index. The measurement results revealed that the composites (PU@SiR-GO) showed superior flame retardancy and thermal and mechanical stability compared to pristine PU or PU coated with SiR alone. The mechanical and thermal stability and the flame-retardant properties of the PU composites were enhanced significantly with increasing GO content. Based on the composition, microstructure, and surface morphology of PU@SiR-GO composites before and after combustion tests, a possible flame-retardance mechanism is proposed. This work provides a simple and effective strategy for fabricating flame-retardant composites with improved mechanical performance.

关键词： flame retardancy     flexible polyurethane foam     graphene oxide     silicone resin    

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Integrated approach to winery waste: waste generation and data consolidation

Margarida OLIVEIRA,Elizabeth DUARTE

《环境科学与工程前沿（英文）》 2016年 第10卷 第1期   页码 168-176 doi: 10.1007/s11783-014-0693-6

摘要： The winemaking process involves the generation of a significant amount of waste and wastewater. These residues should be addressed for recycling or treatment before being returned to environment. As each winery is unique in waste generation and disposal, plans for environmentally friendly waste management are not universal and should be tested for their effectiveness. In this study, a diagnostic was made during three years, in different wineries, throughout Portugal, in order to quantify and characterize the waste and the wastewater produced. The results showed that solid waste and wastewater are mainly produced during the harvest period, corresponding to 74% and 87%, respectively. One ton of processed grape approximately produce 0.13 t marc, 0.06 t lees, 0.03 t of stalks and 1.65 m of wastewater. No significant differences ( ≤0.05) were observed for grape marc, lees and wastewater ratios, between years or wineries. With respect to the stalk ratio, there was no effect of year but the winery significantly affected this ratio ( ≤0.05). During the study period the treated wastewater, since diluted, revealed suitable characteristics for irrigation representing an additional source of water. In this regard, the data acquisition and consolidation ensure the transfer of information and experience which constitute an essential step in a support decision tool design.

关键词： waste management     wastewater reuse     winery wastewater    

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标题 作者 时间 类型 操作

Biodegradation of waste refrigerator polyurethane by mealworms

期刊论文

Effect of thermodynamic parameters on the performance of refrigerator-ejector

Lihong CAO, Yicai LIU, Chao WAN, Tianlong XIN, Qian HUANG, Mingyan ZHANG

期刊论文

Hyperbranched azo polyurethane synthesized through A + B scheme

CHE Pengchao, HE Yaning, WANG Xiaogong

期刊论文

Energy distribution between liquid hydrogen and liquid oxygen temperatures in a Stirling/pulse tube refrigerator

期刊论文

Preparation of lignin/TiO2 nanocomposites and their application in aqueous polyurethane coatings

Dongjie Yang, Shengyu Wang, Ruisheng Zhong, Weifeng Liu, Xueqing Qiu

期刊论文

Microcellular injection molding process for producing lightweight thermoplastic polyurethane with customizable

Thomas ELLINGHAM, Hrishikesh KHARBAS, Mihai MANITIU, Guenter SCHOLZ, Lih-Sheng TURNG

期刊论文

3D finite element analysis of composite noise barrier constructed of polyurethane products

Ben DAEE,Hesham El NAGGAR

期刊论文

ratio and the 1,6-hexanediol/dimethylol propionic acid molar ratio on the properties of waterborne polyurethane

Jiao Feng, Qiuhao Lu, Weimin Tan, Kequan Chen, Pingkai Ouyang

期刊论文

Available energy analysis of new tandem double-capillary tube refrigeration system for refrigerator-freezers

HE Maogang, ZHANG Ying, SONG Xinzhou, ZHANG Jiantao

期刊论文

Optimization of polyurethane-bonded thin overlay mixture designation for airport pavement

Xianrui LI; Ling XU; Qidi ZONG; Fu JIANG; Xinyao YU; Jun WANG; Feipeng XIAO

期刊论文

High-gravity-assisted emulsification for continuous preparation of waterborne polyurethane nanodispersion

Weihong Zhang, Dan Wang, Jie-Xin Wang, Yuan Pu, Jian-Feng Chen

期刊论文

surface modified mixed metal oxide nanoparticles on the electrochemical and mechanical properties of polyurethane

期刊论文

Hemocompatible polyurethane/gelatin-heparin nanofibrous scaffolds formed by a bi-layer electrospinning

Heyun WANG, Yakai FENG, Marc BEHL, Andreas LENDLEIN, Haiyang ZHAO, Ruofang XIAO, Jian LU, Li ZHANG, Jintang GUO

期刊论文

Exceptionally flame-retardant flexible polyurethane foam composites: synergistic effect of the silicone

Qian Wu, Jincheng Zhang, Shengpeng Wang, Bajin Chen, Yijun Feng, Yongbing Pei, Yue Yan, Longcheng Tang, Huayu Qiu, Lianbin Wu

期刊论文

Integrated approach to winery waste: waste generation and data consolidation

Margarida OLIVEIRA,Elizabeth DUARTE

期刊论文