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The Impact and Intervention of Handheld Tai Chi Water-Resistance Fitness Ball on Middle-Aged and Elderly Patients with Parkinson’s Disease
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作者 He Huang 《Health》 2024年第4期319-349,共31页
Through the use of a survey and statistical methods, this study explores the effects and interventions of handheld Tai Chi water resistance fitness balls on the elderly with Parkinson’s disease. Firstly, a questionna... Through the use of a survey and statistical methods, this study explores the effects and interventions of handheld Tai Chi water resistance fitness balls on the elderly with Parkinson’s disease. Firstly, a questionnaire on exercise compliance for patients with Parkinson’s disease was developed, and its reliability and validity were tested. Then, a survey was conducted to investigate the current status of exercise compliance among Parkinson’s disease patients, including general information, scoring status, and single and multiple factor analyses of influencing factors [1]. The results of the study show that through qualitative research, the dimensions and item pools of the questionnaire were initially constructed, and the reliability analysis of the questionnaire was conducted through Delphi expert consultation, with favorable results in terms of its reliability and validity [2]. Regarding the current status of exercise compliance among Parkinson’s disease patients, the study found that the level of exercise compliance needs improvement, and there are significant differences in exercise compliance levels among patients under different circumstances. Finally, the research results were discussed and conclusions were drawn. The innovation of this study lies in the development of a questionnaire on exercise compliance for patients with Parkinson’s disease and the preliminary qualitative research and Delphi expert consultation conducted on it, providing new ideas and methods for the study of exercise compliance. However, the study also has limitations as it did not examine the effects of other interventions on Parkinson’s disease, so further research should be conducted [3]. 展开更多
关键词 Parkinson’s Disease Exercise Compliance Tai Chi water Resistance Fitness Ball Influencing Factors Intervention Effectiveness
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High Water Resistance and Enhanced Mechanical Properties of Bio-Based Waterborne Polyurethane Enabled by in-situ Construction of Interpenetrating Polymer Network
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作者 Henghui Deng Jingyi Lu +5 位作者 Dunsheng Liang Xiaomin Wang Tongyao Wang Weihao Zhang Jing Wang Chaoqun Zhang 《Journal of Renewable Materials》 SCIE EI 2023年第3期1209-1222,共14页
In this study,acrylic acid was used as a neutralizer to prepare bio-based WPU with an interpenetrating polymer network structure by thermally induced free radical emulsion polymerization.The effects of the content of ... In this study,acrylic acid was used as a neutralizer to prepare bio-based WPU with an interpenetrating polymer network structure by thermally induced free radical emulsion polymerization.The effects of the content of acrylic acid on the properties of the resulting waterborne polyurethane-poly(acrylic acid)(WPU-PAA)dispersion and the films were systematically investigated.The results showed that the cross-linking density of the interpenetrating network polymers was increased and the interlocking structure of the soft and hard phase dislocations in the molecular segments of the double networks was tailored with increasing the content of acrylic acid,leading to enhancement of the mechanical properties and water resistance of WPU-PAA films.Notably,with the increase in content of acrylic acid,the tensile strength,Young’s modulus,and toughness of the WPU-PAA-110 film increased by 3 times,and 8 times,and 2.4 times compared with WPU-PAA-80,respectively.The WPU-PAA-100 film showed the best water resistance,and the water absorption rate at 96 h was only 3.27%.This work provided a new design scheme for constructing bio-based WPU materials with excellent properties. 展开更多
关键词 Bio-based waterborne polyurethane interpenetrating polymer network highly water resistance superior mechanical performance
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Preparation of Environmentally Friendly Urea-Hexanediamine-Glyoxal(HUG)Resin Wood Adhesive
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作者 Qianyu Zhang Shi Chen +4 位作者 Long Cao Hong Lei Antonio Pizzi Xuedong Xi Guanben Du 《Journal of Renewable Materials》 EI CAS 2024年第2期235-244,共10页
Using non-toxic,low-volatile glyoxal to completely replace formaldehyde for preparing urea-glyoxal(UG)resin adhesive is a hot research topic that could be of great interest for the wood industry.However,urea-glyoxal(U... Using non-toxic,low-volatile glyoxal to completely replace formaldehyde for preparing urea-glyoxal(UG)resin adhesive is a hot research topic that could be of great interest for the wood industry.However,urea-glyoxal(UG)resins prepared by just using glyoxal instead of formaldehyde usually yields a lower degree of polymerization.This results in a poorer bonding performance and water resistance of UG resins.A good solution is to pre-react urea to preform polyurea molecules presenting already a certain degree of polymerization,and then to condense these with glyoxal to obtain a novel UG resin.Therefore,in this present work,the urea was reacted with hexamethylene diamine to form a polyurea named HU,and then this was used to react it with different amounts of glyoxal to synthesize hexamethylenediamine-urea-glyoxal(HUG)polycondensation resins,and to use this for bonding plywood.The results show that the glyoxal can well react with HU polyuria via addition and schiff base reaction,and also the HUG resin exhibits excellent bonding strength and water resistance.The shear strength of the plywood bonded with this HUG at 160°C hot press temperature as high as 1.93 MPa,2.16 MPa and 1.61 MPa,respectively,which meets the requirement of the China national standard GB/T 9846-2015(≥0.7 MPa),and can be a good choice as a wood adhesive for industrial application. 展开更多
关键词 Urea-glyoxal resin hexamethylene diamine wood adhesives water resistance
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INFLUENCE OF SILOXANE CO-SEGMENT LENGTH AND CONTENT OF WATERBORNE POLYSILOXANE-URETHANE COPOLYMERS ON THEIR WATER RESISTANCE,THERMAL STABILITY AND MECHANICAL PROPERTIES 被引量:7
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作者 郑强 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2010年第2期219-229,共11页
A series of stable waterborne polysiloxaneurethane (WPSUR) dispersions were prepared using amino-terminated polydimethylsiloxane (NS), dimethylolpropionic acid (DMPA), castor oil, polypropylene glycol and toluen... A series of stable waterborne polysiloxaneurethane (WPSUR) dispersions were prepared using amino-terminated polydimethylsiloxane (NS), dimethylolpropionic acid (DMPA), castor oil, polypropylene glycol and toluene diisocyanate. Meanwhile, NS with different molecular weights was synthesized and used as the soft co-segment. Effects of types and contents of soft co-segments as well as chain extenders on the thermal degradation and stability for WPSUR films were examined. Results reveal that WPSUR films exhibit excellent water resistance and mechanical properties as compared with pure polyurethane (PU) films, and the NS soft co-segment possesses a remarkable effect on the second stage (stage Ⅱ), while the content of the hard segment is propitious to the initial stage (stage Ⅰ). Moreover, the highest temperature of stage Ⅱ (T2m) for WPSUR films using NS as soft co-segment is 413℃, approximately being 30℃ higher than that of those typical PUs using HDA and APDMS as the chain extenders, respectively. 展开更多
关键词 waterBORNE POLYSILOXANE Polyurethane Castor oil Thermal properties water resistance.
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RESEARCH ON THE WATER-RESISTANCE OF MAGNESIUM OXYCHLORIDE CEMENT——I:THE STABILITY OF THE REACTION PRODUCTS OF MAGNESIUM OXYCHLORIDE CEMENT IN WATER 被引量:9
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作者 张传镁 邓德华 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1994年第3期51-59,共9页
In this paper .the change of the crystalline phases in hardened magnesium oxychloride cement (MOC) paste in mater was analyzed by XRD. It was developed that the reaction products 5 phase or 3 phase of MOC are instable... In this paper .the change of the crystalline phases in hardened magnesium oxychloride cement (MOC) paste in mater was analyzed by XRD. It was developed that the reaction products 5 phase or 3 phase of MOC are instable in water and can be changed into Mg(OH)2 by the action of water, which causes the content of 5 phase or 3 phase to be less and less,the content of Mg(OH)2 to be more and more and the strength to be the lower the lower,after hardended MOC paste was immersed in water. The change of 5 pliase and 3 phase into Mg(OH)2 is not a dissolve process, but a hydrolysis process. The hydrolysis products of 5 phase and 3 phase are Mg(OH)2 precipitation and soluble Cl-,AIg+ ions and H2O. The hydrolysis is sponta-neous thermodynamically and its chemical kinatic equation is C = C,,e-k Thus .it is suggested that only by enhancing the stability of 5 phase or 3 phase in water and preventing 5 phase or 3 phase from the hydrolyzing can the water resistance of MOC be improved well. 展开更多
关键词 magnesitt籭. oxychloride cement stability of the reaction products water resistance hydrolysis.
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Influence of Fly Ash and Silica Fume on Water-resistant Property of Magnesium Oxychloride Cement 被引量:5
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作者 李成栋 于红发 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2010年第4期721-724,共4页
By incorporation of fly ash or silica fume into magnesium oxychloride (MOC) cement, a high water resistance material can be formed for successful industrial applications. The influences of fly ash and silica fume on... By incorporation of fly ash or silica fume into magnesium oxychloride (MOC) cement, a high water resistance material can be formed for successful industrial applications. The influences of fly ash and silica fume on water-resistant property were investigated by SEM and EDS. It is found that the incorporation of fly ash or silica fume can improve the water-resistance of the MOC. The improvement of the water resistance of the MOC incorporated with fly ash or silica fume may be attributed to the alumino-silicate 5·1·8 gel or silicate 5·1·8 gel. 展开更多
关键词 magnesium oxychloride cement fly ash silica fume water resistance
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Synthesis of a Novel Core-shell Type Acrylic-polyurethane Hybrid Emulsion Containing Siloxane and Fluorine as well as Water and the Oil Resistances of Cured Film 被引量:7
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作者 Jing CHAO Xing Yuan ZHANG Jia Bing DAI Zhen GE Lin Lin FENG 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第8期1121-1124,共4页
Siliconated polyurethane (Si-PU) was synthesized using isophorone diisocyanate (IPDI), hydroxybutyl-terminated polydimethylsiloxane (PDMS), polytetramethylene ether glycol (PTMG), polypropylene glycol (PPG),... Siliconated polyurethane (Si-PU) was synthesized using isophorone diisocyanate (IPDI), hydroxybutyl-terminated polydimethylsiloxane (PDMS), polytetramethylene ether glycol (PTMG), polypropylene glycol (PPG), 1,6-hexanediol (HDO), dimethylol propionic acid (DMPA) and triethylamine (TEA). Based on butyl acrylate (BA), 2, 2, 2-trifluoroethylmethacrylate (TFEMA) and Si-PU as a seed emulsion, a novel core-shell type acrylic-polyurethane hybrid emulsion, containing siloxane and fluorine (F-Si-PU), was prepared by seeded emulsion polymerization. The contents of siloxane and fluorine were determined according to the feed ratio. Fourier transform infrared spectroscopy (FTIR) was used to identify the chain structures of Si-PU and F-Si-PU. Investigation of transmission electron microscopy (TEM) confirmed the core-shell structure of F-Si-PU emulsion. Measurement results of water contact angle and the swelling ratio in water and n-octane for cured film showed that the water and the oil resistances for F-Si-PU had been significantly improved at a suitable content of fluorine and siloxane. 展开更多
关键词 CORE-SHELL SILOXANE FLUORINE acrylic-polyurethane water and oil resistance.
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Water and Oil Resistance of Special Paperboard for Petroleum Packaging 被引量:5
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作者 YuJie Gao YanPing Zhang +1 位作者 XiaoJiao Yuan LiMin Gao 《Paper And Biomaterials》 2016年第1期51-55,共5页
The influence of different coating formulas and times on the water and oil resistance of paperboard was studied. The water and oil resistance of paperboard coated with a modified butadiene-styrene copolymer latex and ... The influence of different coating formulas and times on the water and oil resistance of paperboard was studied. The water and oil resistance of paperboard coated with a modified butadiene-styrene copolymer latex and fluorinated anion grease-proof agent was better than that coated with modified butadiene-styrene copolymer latex,where the modified butadiene-styrene copolymer latex was used as the pre-coating substrate and the F1516 fluorinated grease-proof agent was used as the top coating material. By coating modified butadiene-styrene copolymer latex with 30% solid content and F1516 fluorinated grease-proof agent with 24% solid content,the oil resistance of paperboard could reach anti-oil grade 12 and the water resistance could increased by98. 64%( compared with the base paperboard without any coating treatment). 展开更多
关键词 packaging paperboard coating agent greaseproof agent water resistance oil resistance
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Starch Grafted Water Resistant Polyvinyl Acetate-Based Wood Adhesive: A Review 被引量:1
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作者 Ravindra Vilas Indubai Gadhave 《Open Journal of Organic Polymer Materials》 CAS 2022年第2期17-30,共14页
Global energy issues and the reliance on hydrocarbon resources have resulted in the reduction of petroleum sources, and the focus of the chemical industries has shifted to substitute raw material sources. The major ra... Global energy issues and the reliance on hydrocarbon resources have resulted in the reduction of petroleum sources, and the focus of the chemical industries has shifted to substitute raw material sources. The major raw materials used in wood adhesives, such as hydrocarbons like polyvinyl acetate, would be gradually replaced by renewable natural polymers. Currently, polyvinyl alcohol has the limitation of petroleum origin, which is non-economical and it will be replaced by biopolymers. Conventionally available wood adhesive emulsions are colloid-like polyvinyl alcohol stabilized. Starch, being a naturally available polymer, has gained interest from researchers for replacing polyvinyl alcohol as a stabilizer. New research on sustainable, economical, biodegradable, renewable, and environmentally friendly starch grafted polyvinyl acetate emulsion that was synthesized by the graft polymerization of vinyl acetate monomer onto starch. However, starch grafted polyvinyl acetate emulsion-based adhesive’s properties, such as poor water resistance, weak adhesion, delayed drying rate and delayed setting speed, have resulted in limitations in its application as a wood adhesive. A detailed review of starch grafting on vinyl acetate and comonomers like acrylamides, and acrylic acid, and the addition of nano-fillers to enhance the water resistance and performance properties of sustainable adhesives has been explained. 展开更多
关键词 STARCH water Resistance GRAFTING Polyvinyl Acetate N-Methylol Acrylamide
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Layer regrouping for water-flooded commingled reservoirs at a high water-cut stage 被引量:2
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作者 Chuan-Zhi Cui Jian-Peng Xu +3 位作者 Duan-Ping Wang Zhi-Hong Liu Ying-song Huang Zheng-Ling Geng 《Petroleum Science》 SCIE CAS CSCD 2016年第2期272-279,共8页
Layer regrouping is to divide all the layers into several sets of production series according to the physical properties and recovery percent of layers at high water-cut stage, which is an important technique to impro... Layer regrouping is to divide all the layers into several sets of production series according to the physical properties and recovery percent of layers at high water-cut stage, which is an important technique to improve oil recovery for high water-cut multilayered reservoirs. Dif- ferent regroup scenarios may lead to different production performances. Based on unstable oil-water flow theory, a multilayer commingled reservoir simulator is established by modifying the production split method. Taking into account the differences of layer properties, including per- meability, oil viscosity, and remaining oil saturation, the pseudo flow resistance contrast is proposed to serve as a characteristic index of layer regrouping for high water-cut multilayered reservoirs. The production indices of multi- layered reservoirs with different pseudo flow resistances are predicted with the established model in which the data are taken from the Shengtuo Oilfield. Simulation results show that the pseudo flow resistance contrast should be less than 4 when the layer regrouping is implemented. The K-means clustering method, which is based on the objec- tive function, is used to automatically carry out the layer regrouping process according to pseudo flow resistances. The research result is applied to the IV-VI sand groups of the second member of the Shahejie Formation in the Shengtuo Oilfield, a favorable development performance is obtained, and the oil recovery is enhanced by 6.08 %. 展开更多
关键词 water-flooded reservoirs Layer regrouping.Flow resistance - High water cut Reservoir simulation
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Enhanced Water Resistance Performance of Castor Oil—Based Waterborne Polyurethane Modified by Methoxysilane Coupling Agents via Thiol-Ene Photo Click Reaction
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作者 Zhipeng He Junqi Xue +4 位作者 Yanzi Ke Ying Luo Qiming Lu Yuehua Xu Chaoqun Zhang 《Journal of Renewable Materials》 SCIE EI 2022年第3期591-604,共14页
Nowadays,waterborne polyurethanes(WPUs)prepared from renewable resources has attracted more and more attention.However,due to its structure,the prepared films easily swells in water and greatly affects the application... Nowadays,waterborne polyurethanes(WPUs)prepared from renewable resources has attracted more and more attention.However,due to its structure,the prepared films easily swells in water and greatly affects the application range of WPUs.Therefore,solving the problem of water resistance is a way to improve the application range of WPUs.In this study,a series of WPU dispersions were prepared using castor oil as the bio-based polyol.Besides,the thiol-ene photo click reaction was carried out on the WPU films for silane modification.The effect of the silane modification on the chemical structures of the WPU dispersions and the properties of the WPU films was investigated and discussed.The results revealed that the WPU dispersions had a smaller particle size and potential,showing excellent stability.In addition,the modified WPU films showed highly water resistance which 72 h water absorption could be reduced to 1.94%and the contact angle was up to 99.34?.Moreover,the modified WPU films also exhibited excellent solvent resistance(in acid and salt solution)and thermal stability.This study can provide a new way to improve the water-resistance,hydrophobicity,and thermal stability of bio-based waterborne polyurethane for potential application in painting,adhesives and inks. 展开更多
关键词 Castor oil waterborne polyurethane water resistance silane modification
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Effects of Concentration of(3-Aminopropyl)Triethoxysilane on Waterborne Polyurethane
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作者 郭恒义 刘岩 +2 位作者 彭晓晓 于运歌 辛斌杰 《Journal of Donghua University(English Edition)》 CAS 2022年第3期231-238,共8页
As a coupling agent,(3-aminopropyl)triethoxysilane(APTES)was used to synthesize a series of silanized waterborne polyurethanes(Si-WPUs)through the acetone process.The Fourier transform infrared spectroscopy(FTIR)toget... As a coupling agent,(3-aminopropyl)triethoxysilane(APTES)was used to synthesize a series of silanized waterborne polyurethanes(Si-WPUs)through the acetone process.The Fourier transform infrared spectroscopy(FTIR)together with the X-ray photoelectron spectroscopy(XPS)was utilized to measure both elements and structures of these samples.The scanning electron microscope(SEM)results explained that APTES would be agglomerate on the surface of WPU films when the mass fraction of the agent concentration was more than 8%.Besides,the contact angle of water(CAW)can be improved from 56.5°to 90.0°by adjusting APTES concentration in Si-WPU.The decomposition temperature of films was also improved with the increase of APTES,and a significant increase could be seen in the glass temperature from 51.00℃to 85.74℃. 展开更多
关键词 waterborne polyurethanes (3-aminopropyl)trirthoxysilane(APTES) AGGLOMERATION MODIFIED water resistant
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The Mixed-Alkali Effect on The Resistance of Glass to Water
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作者 雷家珩 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2001年第2期31-33,共3页
Based on the composition of float glass, the resistance of glassto water, in which a small amount of K_2O(0-1.0 wt/100)wassubstituted for equivalent amount of Na_2O, was investigated by meansof glass grains testing. T... Based on the composition of float glass, the resistance of glassto water, in which a small amount of K_2O(0-1.0 wt/100)wassubstituted for equivalent amount of Na_2O, was investigated by meansof glass grains testing. The components extracted from the glass andtotal alkalinities in extraction solution were de- termined by atomicabsorption spectroscopy and neutralizing method, respectively. Thecomposition of the glass was 14.4 K_2O+ Na_2O, 4.0 MgO, 8.2 CaO, 1.4Al_2O_3, 72.0 SiO, and the minimum extraction radio of oxides(maximum durability)occurred at a K_2O/Na_2O radio of 0.051(byweight)due to the presence of the mixed- alkali effect. 展开更多
关键词 glass mildewing chemical durability resistance to water
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Allyl Glycidyl Ether-modified Animal Glue Binder for Improved Water Resistance and Bonding Strength in Sand Casting
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作者 Chenchen Fan Qian Tang 《Organic Polymer Material Research》 2020年第2期1-7,共7页
This paper aims to develop a modified animal glue sand binder for foundry casting with improved water resistance and bonding strength.An efficient method is reported by using sodium hydroxide as the catalyst to improv... This paper aims to develop a modified animal glue sand binder for foundry casting with improved water resistance and bonding strength.An efficient method is reported by using sodium hydroxide as the catalyst to improve the operability of animal glue binder and allyl glycidyl ether as the modifier to improve the water resistance and bonding strength.Sand specimens prepared using allyl glycidyl ether-modified animal glue binder were cured by compressed air at room temperature.The proposed method saves energy and is environmentally friendly and inexpensive.Compared with unmodified animal glue binder,standard dog bone sand specimens with allyl glycidyl ether-modified animal glue binder had higher tensile strength of 2.58 MPa,flowability of 1.95 g,better water resistance(a lower decrease in tensile strength at 25°C and relative humidity of 60%),and good collapsibility.This allyl glycidyl ether-modified animal glue binder is suitable for practical application in the foundry industry. 展开更多
关键词 Quartz sand Modified animal glue Casting binder Allyl glycidyl ether water resistance
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THE PROPERTIES OF SILICA FUME-MAGNESIUM OXYCHLORIDE CEMENT MATERIALS 被引量:4
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作者 H.F.Yu 1) ,P.Q.Liu 1) and W.H.Wang 2) 1) Department of Materials Science and Engineering, Shenyang Architectural and Civil Engineering Institute,Shenyang 110015,China 2) Department of Airport, CAAC Eastnorth Management, Shenyang 110043,Chin 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1999年第5期1038-1040,共3页
The properties of a new magnesium Oxychloride cement (MOC) material formed by silica fume uniformly mix in MOC paste was presents. The influence of silica fume on the water resistance and compressive strength of MOC p... The properties of a new magnesium Oxychloride cement (MOC) material formed by silica fume uniformly mix in MOC paste was presents. The influence of silica fume on the water resistance and compressive strength of MOC paste was invesigated in this study. It is shown that when 30 weight percent of silica fume is added to the MOC paste, a high strength and water resisting new material with 112MPa compressive strength and 1 00 water resisting coefficient could by obtained. 展开更多
关键词 silica fume magnesium oxychloride cement (MOC) compressive strength water resistance
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Interfacial Interaction Between Polyurethane/Poly(Methacrylateco-Styrene) Coating and the Regenerated Cellulose Film 被引量:1
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作者 Gong Ping, Yang Guang, Zhang Lina(Department of Chemistry, Wuhan University, Wuhan 430072, China) 《Wuhan University Journal of Natural Sciences》 EI CAS 1998年第1期92-97,共6页
Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St... Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St) copolymer on tensile strength (dry and wet states), vapor permeability, size stability, and water resistivity of the coated films were studied. The interfacial interaction between cellulose and the PU/P (MA-St) coating was analyzed using infrared (IR), ultraviolet (UV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA), and electron probe microanalysis (EPMA). The results indicated that the mechanical properties and water resistivity of the coated films significantly enhanced, and the biodegradability was displayed, when the ratio of PU to P (MA-St) was 8∶2 by weight. The chemical bonds and hydrogen bonds between the cellulose, PU, and the copolymer exist in the coated films. It is regarded that PU/P (MA-St) semi-interpenetrating polymer networks (IPNs) were formed, and a shared network of PU with both the cellulose and the coating in the coated film occurred simultaneously resulting in a strong bonding between the coating layer and the film. 展开更多
关键词 Key words regenerated cellulose films water resistivity interfacial interaction coating IPNS
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State of Research and Trends in the Development of Polyvinyl Acetate-Based Wood Adhesive 被引量:4
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作者 Ravindra Vilas Indubai Gadhave Pritam V. Dhawale 《Open Journal of Polymer Chemistry》 CAS 2022年第1期13-42,共30页
Synthetic wood adhesives, consisting of urea-formaldehyde resins (UF), phenol-formaldehyde resins (PF), melamine-formaldehyde resins (MF), and polyurethane resins, are widely used. For UF and MF, most investigations a... Synthetic wood adhesives, consisting of urea-formaldehyde resins (UF), phenol-formaldehyde resins (PF), melamine-formaldehyde resins (MF), and polyurethane resins, are widely used. For UF and MF, most investigations are concerned with reducing free formaldehyde content;for PF, most studies focused on finding new alternative chemicals to replace phenol. These adhesives come under the Carcinogenic, Mutagenic, and Reprotoxic chemicals (CMR) category. Due to global energy issues and dependency on petroleum sources, the focus has shifted to look for alternative and renewable raw material sources for wood adhesives. Conventionally available wood adhesives are polyvinyl alcohol (PVA) stabilized, with drawbacks like poor water resistance, poor heat resistance, low-temperature workability, and it’s based on petroleum resources. Polyvinyl acetate (PVAc) is non-resistant to moisture polymer, and if such adhesive joints are exploited in a moist environment, its strength substantially decreases. Sufficiently moisture-resistant adhesive joints are obtained by modifying PVAc dispersion with special compounds like reactive comonomer, Silanes, and modified PVA. To improve the workability at low temperature, Vinyl acetate (VAc) is copolymerized with specific comonomers like butyl acetate without affecting the performance properties. Here, we aim to present an overview of the research trend of PVAc-based adhesives in the wood industry. The review summarizes the current state of research PVAc-based adhesives. 展开更多
关键词 Polyvinyl Acetate Emulsion Polyvinyl Alcohol Bio-Polymers WOOD water Resistance Adhesives
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Preparation and Properties of Aqueous SCNTs Dispersion based on A UV-curable Polymeric Dispersant 被引量:1
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作者 袁妍 WU Haiqiang +3 位作者 LIU Jingcheng LUO Jing LIU Ren LIU Xiaoya 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第2期485-491,共7页
A novel photosensitive copolymer P(SS-co-AA-g-GMA)(PSAG) was synthesized and utilized to noncovalently functionalize pristine single-walled carbon nanotubes(SCNTs). PSAG was highly effective for the solubilizati... A novel photosensitive copolymer P(SS-co-AA-g-GMA)(PSAG) was synthesized and utilized to noncovalently functionalize pristine single-walled carbon nanotubes(SCNTs). PSAG was highly effective for the solubilization of SCNTs in water and validated by UV-vis absorption spectra experiments, resulting in homogeneous and stable PSAG-SCNT aqueous dispersion. The microstructure of SCNTs was observed through Raman spectroscopy and transmission electron microscopy. In addition, compared with the two common polymeric dispersants of Triton X-100 and PSS, PSAG demonstrated more effective performances for dispersing SCNTs under identical conditions. Furthermore, the photosensitive PSAG-SCNTs can be crosslinked after UV irradiation, leading to significant improvement in the water resistance of SCNT films. UV-cured films can be transferred to plastic wrap to form a flexible film with high electrical conductivity. 展开更多
关键词 single-walled carbon nanotubes(SCNTs) polymeric dispersant UV-curable conductive water resistance
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Effects of Heat Treatment on Dimension Stability of Larch Pallet Decks 被引量:1
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作者 Xue-Chun Yang Bing Wang +2 位作者 Jin-Zhuo Wu Xiao-Qi Xing Shi-Jun Yang 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2013年第3期75-80,共6页
The useful life of wooden pallets is lower because of the defects in lumbers. The quality of lumber can be significantly enhanced by heat treatment. In this paper,the larch pallet decks samples were heat-treated under... The useful life of wooden pallets is lower because of the defects in lumbers. The quality of lumber can be significantly enhanced by heat treatment. In this paper,the larch pallet decks samples were heat-treated under the conditions of different time and temperatures. The quantity of water uptake has reduced 16. 8% under the condition of 250 ℃ for 150 min. The resistance of water absorption efficiency increases 165. 34% under the condition of 175 ℃ for 90 min. The anti-shrink efficiency increases 72. 08% under the condition of 250 ℃ for 90min. The results showed that the dimension stability of larch panels can be improved by heat treatment. The condition of 250 ℃ for 180 min is the best heat treating condition to improve the dimension stability. 展开更多
关键词 larch pallet heat treatment resistance of water absorption efficiency anti-shrink efficiency dimension stability
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Research Progress of Soybean Protein Adhesive:A Review
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作者 Yantao Xu Yufei Han +5 位作者 Jianzhang Li Jing Luo Sheldon QShi Jingchao Li Qiang Gao An Mao 《Journal of Renewable Materials》 SCIE EI 2022年第10期2519-2541,共23页
Traditional formaldehyde-based adhesives rely excessively on petrochemical resources,release toxic gases,and pollute the environment.Plant-derived soybean protein adhesives are eco-friendly materials that have the pot... Traditional formaldehyde-based adhesives rely excessively on petrochemical resources,release toxic gases,and pollute the environment.Plant-derived soybean protein adhesives are eco-friendly materials that have the potential to replace the formaldehyde-based adhesives used to fabricate wood-based panels.However,the poor water resistance,high brittleness,and poor mildew resistance of soybean protein adhesives limit their industrial applications.This article reviews recent research progress in the modification of soybean protein adhesives for improving the bonding performance of adhesives used for wood-based panel fabrication.Modification methods were summarized in terms of water resistance,solid content,and mildew resistance.The modification mechanisms and remaining problems were also discussed.Finally,the current industrial applications and the future research direction of soybean protein adhesives are discussed. 展开更多
关键词 Soybean protein adhesive bonding performance water resistance solid content mildew resistance
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