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Experimental investigation on weak shock wave mitigation characteristics of flexible polyurethane foam and polyurea

Defence Technology（防务技术） 2024年第1期31卷 179-191页

作者： Shiyu Jia Cheng Wang Wenlong Xu Dong Ma Fangfang Qi State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Institute for Advanced Technology Shandong UniversityJinan250061China

In recent years,explosion shock wave has been considered as a signature injury of the current military conflicts.Although strong shock wave is lethal to the human body,weak shock wave can cause many more lasting consequences.To investigate the protection ability and characteristics of flexible materials and structures under weak shock wave loading,the blast wave produced by TNT explosive is loaded on the polyurethane foam with the density of 200.0 kg/m3(F-200)and 400.0 kg/m3(F-400),polyurea with the density of 1100.0 kg/m^(3)(P-1100)and structures composed of the two materials,which are intended for individual protection.Experimental results indicate that the shock wave is attenuated to weak pressure disturbance after interacting with the flexible materials which are not damaged.The shock wave protective capability of single-layer materials is dependent on their thickness,density and microscopic characteristics.The overpressure,maximum pressure rise rate and impulse of transmitted wave decrease exponentially with increase in sample thickness.For the same thickness,F-400 provides better protective capability than F-200 while P-1100 shows the best protective capability among the three materials.In this study,as the materials are not destroyed,F-200 with a thickness more than10.0 mm,F-400 with a thickness more than 4.0 mm,and P-1100 with a thickness more than 1.0 mm can attenuate the overpressure amplitude more than 90.0%.Further,multi-layer flexible composites are designed.Different layer layouts of designed structures and layer thickness of the single-layer materials can affect the protective performance.Within the research range,the structure in which polyurea is placed on the impact side shows the optimal shock wave protective performance,and the thicknesses of polyurea and polyurethane foam are 1.0 mm and 4.0 mm respectively.The overpressure attenuation rate reached maximum value of 93.3%and impulse attenuation capacity of this structure are better than those of single-layer polyurea and polyurethane foam with

关键词： Free-field explosion Weak shock wave mitigation Polyurea polyurethane foam Multi-layered composites

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Propagation Properties of Shock Waves in polyurethane foam based on Atomistic Simulations

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Defence Technology（防务技术） 2024年第1期31卷 117-129页

作者： Zhiqiang Hu Jianli Shao Shiyu Jia Weidong Song Cheng Wang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

Porous materials are widely used in the field of protection because of their excellent energy absorption characteristics.In this work,a series of polyurethane microscopic models are established and the effect of porosity on the shock waves is studied with classical molecular dynamics simulations.Firstly,shock Hugoniot relations for different porosities are obtained,which compare well with the experimental data.The pores collapse and form local stress wave,which results in the complex multi-wave structure of the shock wave.The microstructure analysis shows that the local stress increases and the local velocity decreases gradually during the process of pore collapse to complete compaction.Finally,it leads to stress relaxation and velocity homogenization.The shock stress peaks can be fitted with two exponential functions,and the amplitude of attenuation coefficient decreases with the increase of density.Besides,the pore collapse under shock or non-shock are discussed by the entropy increase rate of the system.The energy is dissipated mainly through the multiple interactions of the waves under shock.The energy is dissipated mainly by the friction between atoms under non-shock.

关键词： polyurethane foam Shock wave Attenuation Atomistic simulation

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Coal fly ash reinforcement for the property enhancement of crude glycerol-based polyurethane foam composites

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Waste Disposal and Sustainable Energy 2022年第4期4卷 271-282页

作者： Linda Zhang Weihong Zhang Mengyu Li Pan Li Xiaoyang Zheng Chun Chang Weihua Zou School of Chemical Engineering Zhengzhou UniversityZhengzhou450001China Henan Huakang Sugar Alcohol Technology Co.Ltd Jiaozuo454150China Henan Center for Outstanding Overseas Scientists Zhengzhou UniversityZhengzhou450001China

Coal fly ash(CFA)is the main combustion residue of fine ground coal in the process of coal-fired thermal power generation,and crude glycerol(CG)is the byproduct of biodiesel production.The novel polyurethane/CFA(PU/CFA)foam composites were prepared from CFA and CG.Two kinds of CFA,CFAI and CFAII were used as fillers for the property enhancement of PU/CFA composites,and the effects on foaming behavior and the reinforcement for the PU/CFA composites were investigated.It was found that the addition of CFA can prolong the rising time and tack-free time,and the maximum rising time and tack-free time increased to 40 s and 42 s.Meanwhile,the maximum compressive strength of PU/CFAI and PU/CFAII increased to 0.2186 MPa and 0.2284 MPa with the addition of CFA.The thermogravimetric analysis showed that the PU/CFA composites underwent three stages of thermal decomposition,and the amount of carbon residue increased from 23.11%to 67.91%with increasing CFA dosage.Moreover,the values of the limit oxygen index increased from 21.5%to 23.7%with the incorporation of CFA into the PU foam matrix,indicating that CFA improved the thermal stability and flame retardant performance of the composites.This study provided a new method for the recycling and high-value utilization of CG and CFA.

关键词： Coal fly ash Crude glycerol polyurethane foam Resource and recycling of waste

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polyurethane foam-supported three-dimensional interconnected graphene nanosheets network encapsulated in polydimethylsiloxane to achieve significant thermal conductivity enhancement

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Frontiers of Materials Science 2023年第3期17卷 145-153页

作者： Wenjing Li Ni Wu Sai Che Li Sun Hongchen Liu Guang Ma Ye Wang Chong Xu Yongfeng Li State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China

polyurethane(PU)foams are widely used in thermal management materials due to their good flexibility.However,their low thermal conductivity limits the efficiency.To address this issue,we developed a new method to produce tannic acid(TA)-modified graphene nanosheets(GTs)-encapsulated PU(PU@GT)foams using the soft template microstructure and a facile layer-by-layer(L-B-L)assembly method.The resulting PU@GT scaffolds have ordered and tightly stacked GTs layers that act as three-dimensional(3D)highly interconnected thermal networks.These networks are further infiltrated with polydimethylsiloxane(PDMS).The through-plane thermal conductivity of the polymer composite reaches 1.58 W·m^(−1)·K^(−1) at a low filler loading of 7.9 wt.%,which is 1115%higher than that of the polymer matrix.Moreover,the mechanical property of the composite is~2 times higher than that of the polymer matrix while preserving good flexibility of the polymer matrix owing to the retention of the PU foam template and the construction of a stable 3D graphene network.This work presents a facile and scalable production approach to fabricate lightweight PU@GT/PDMS polymer composites with excellent thermal and mechanical performance,which implies a promising future in thermal management systems of electronic devices.

关键词： graphene nanosheet polyurethane foam polymer composite thermal and mechanical property

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Zr-MOFs loaded on polyurethane foam by polydopamine for enhanced dye adsorption

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Journal of Environmental Sciences 2021年第3期33卷 177-188页

作者： Jingjing Zhao Linqiong Xu Yaozhuo Su Hongwei Yu Hui Liu Shaoping Qian Wenge Zheng Yongqing Zhao School of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China Ningbo Key Lab of Polymer Materials Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China School of Materials Science and Engineering Wuhan Institute of TechnologyWuhan 430205China

Zirconium-based metal-organic frameworks(Zr-MOFs)have attracted widespread attention due to their high specific surface area,high porosity,abundant metal active sites and excellent hydrothermal stability.However,Zr-MOFs materials are mostly powdery in nature and thus difficult to separate from aqueous media,which limits their application in wastewater treatment.In this study,PDA/Zr-MOFs/PU foam was constructed by growing Zr-MOFs nanoparticles on a dopamine-modified polyurethane foam substrate by in-situ hydrothermal synthesis as an adsorbent for removing dyes from wastewater.The results demonstrated that the polydopamine coating improves the dispersion of the Zr-MOFs nanoparticles on the substrate and enhances the interaction between the Zr-MOFs nanoparticles and the PU foam substrate.As a result,compared with Zr-MOFs/PU foam,the prepared PDA/ZrMOFs/PU foam exhibits higher adsorption capacity for crystal violet(CV)(63.38 mg/g)and rhodamine B(RB)(67.73 mg/g),with maximum adsorption efficiencies of CV and RB of 98.4%(pH=11)and 93.5%(pH=7),respectively,at a concentration of 10 mg/L.The PDA/Zr-MOFs/PU foam can simultaneously remove CV and RB from the mixed solution.Moreover,the PDA/ZrMOFs/PU foam still exhibits high stability and reusability after five cycles.

关键词： Metal-organic framework Polydopamine polyurethane foam Dye

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Electroless copper plating on microcellular polyurethane foam

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Transactions of Nonferrous Metals Society of China 2010年第S1期20卷 283-287页

作者：田庆华郭学益 School of Metallurgical Science and Engineering Central South University

In order to obtain substrates with good conductive foam for high porosity foam metal materials used in the metal electrodes,the technique of electroless copper plating on the microcellular polyurethane foam with pore size of 0.3 mm was investigated.The main factors affecting the deposition rate such as the solution composition,temperature,pH value and adding ultrasonic were explored.The results show that the optimum process conditions are CuSO4 16 g/L,HCHO 5 mL/L,NaKC4H4O6 30 g/L,Na2EDTA 20 g/L,K4Fe(CN)6 25 mg/L,pH value of 12.5-13.0 and temperature of 40-50℃.Under these technical conditions, the process has excellent bath stability.Adding ultrasonic on the process can elevate the deposition rate of copper by 20%-30%.The foam metal material with a porosity of 92.2%and a three-dimensional network structure,was fabricated by electro-deposition after the electroless copper plating.

关键词： electroless copper plating microcellular polyurethane foam deposition rate foam metal material

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Newly Designed Polypropylene Polyol with Terminated Primary Hydroxy Group and Application for polyurethane foam

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复旦学报（自然科学版） 2007年第5期46卷 741-页

作者： K.Maeda M.Kaku Y.Sakural K.Nishiyama H.Nakaminami Sanyo Chemical Industries Ltd.11-1Ikkyo Nomoto-choHigashiyama-kuKyotoJapan

1 Results Polypropylene polyol is very important chemical materials for polyurethane. We developed newly designed polypropylene polyol with terminated primary hydroxyl group. We focus on our new polypropylene polyol, and show its useful application for polyurethane foam. Polymerization of propyleneoxide is conventionally carried out in anionic polymerization process. In anionic process α-cleavage of propyleneoxide occurs rather than β-cleavage. Then the terminal hydroxyl group of the resulting polypropy...

关键词： polypropylene polyol primary hydroxy group polyurethane foam

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Porous polyurethane hydrogels incorporated with CMC for eliminating methylene blue from water

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International Journal of Smart and Nano Materials 2023年第1期14卷 57-76页

作者： Li Wang Qing Yang Yong Yang Kun Luo Ruqing Bai Peicong Zhang Department of Biomedical Engineering School of Big Health and Intelligent EngineeringChengdu Medical CollegeChengduChina College of Materials Chemistry&Chemical EngineeringChengdu University of TechnologySichuanP.R.China State Key Laboratory of Mechanical Transmission Chongqing University400044ChongqingChina College of Materials Chemistry&Chemical EngineeringChengdu University of Technology610059SichuanP.R.China

Here,a series of polyurethane porous hydrogels(PUF-s)loaded with different sodium carboxymethyl cellulose(CMC)were successfully prepared by one-step foaming method.The physio-chemical prop-erties and morphologies were characterized.The effects of CMC content,adsorbent dosage,temperature,pH value and other fac-tors on the adsorption of methylene blue(MB)dye in water by CMC-PUF-s were also investigated through static adsorption experi-ments.The results showed that CMC-PUF-10 had excellent adsorp-tion performance for MB solution with removal rate of 81.47%,and the maximum adsorption capacity was 27.5 mg/g.In addition,the study of adsorption kinetics and adsorption isotherms showed that the adsorption of MB by CMC-PUF was more consistent with Langmuir isotherm adsorption model and pseudo second-order kinetic model.The adsorption thermodynamics study suggested that the adsorption process of MB by CMC-PUF-10 was sponta-neous and exothermic at room temperature.The results of cyclic adsorption experiment demonstrated that the removal rate of MB reached above 70%after five cycles,indicating the foams with excellent recyclability.Finally,a low-cost,environmentally friendly and recyclable MB adsorbent was synthesized in this study.As polyurethane foam was synthesized by one-step foaming method,this adsorbent can be prepared on site in practical application and reduce the transportation cost.

关键词： Carboxymethyl cellulose polyurethane foam hydrogel methylene blue adsorption

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Passive air sampling of organochlorine pesticides in a northeastern state of India,Manipur

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Journal of Environmental Sciences 2011年第5期23卷 808-815页

作者： Ningombam Linthoingambi Devi Shihua Qi Paromita Chakraborty Gan Zhang Ishwar Chandra Yadav State Key Laboratory of Biogeology and Environmental Geology School of Environmental Studies China University of Geosciences Wuhan 430074 China. E-mail: nldevi.cug@*** State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of sciences Guangzhou 510640 China tate Key Laboratory in Marine Pollution Department of Biology and Chemistry City University of l-long Kong Hong Kong Chin Center of Advanced Study in Botany Banaras Hindu University Varanasi-221005 Uttarpradesh India

Thirty-six polyurethane foam disk passive air samplers （PUF-PAS） were deployed over a year during January to December, 2009 at three locations, i.e., Imphal （urban site）, Thoubal （rural site） and Waithou （alpine site） of Manipur, to assess the seasonal local atmospheric emission of selected organochlorine pesticides （OCPs）. The average concentration of HCHs monitored at mountain site during hot season （Mar, Apr, and May） and rainy seasons （Jun, Jul, Aug, and Sep） were 403 and 349 pg/m3, respectively. DDTs had a high concentration with 384 pg/m3 at rural site and 379 pg/m3 at urban site during hot seasons. Endosulfans and chlordane were found high in concentration during hot seasons （260 pg/m3） and low during retreating monsoon seasons （44 pg/m3） at rural site. Most of the OCPs concentrations were high during cultivation period. The OCP concentrations of rainy season were highly correlated （p 〈 0.01） with OCPs of hot seasons. Further, positive correlation （p 〈 0.05） was also obtained between cold seasons and retreating monsoon. Principal component analysis showed a significant correlation among the four seasons and distribution pattern of OCPs in air. Back trajectory analysis by using HYPSLIT model showed a long range air transport of OCPs to the present study area. Present OCP levels at Manipur is an outcome of both local emission and also movement of air mass by long range atmospheric transport.

关键词： organochlorine pesticides polyurethane foam urban rural mountain Manipur

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Biodegraded and polyurethane Drape-formed Urea Fertilizer

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Journal of Wuhan University of Technology(Materials Science) 2005年第2期20卷 12-14页

作者：王勇 School of Materials Science and Engineering Wuhan University of Technology Wuhan 430070 China Prof

Natural water absorbent konjac flour participates in synthesizing biodegraded and polyurethane foamed drape, which is used to release urea slowly.The experimental results indicate that the slowly-releasing velocity of urea nitrogen and the degrading velocity of the drape can be controlled by regulating the thicknesses of drapes, the amount of konjac flour and the water content. In addition, the biodegradability of the drape was investigated by burying the specimens in earth afterwards,and results show this drape can be degraded naturally.

关键词： polyurethane foam konjac flour slowly-releasing urea biodegradation

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