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Polymerization Process and Morphology of Polyurethane/Vinyl Ester Resin Interpenetrating Polymer Networks 被引量:1
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作者 Dongyan TANG Xuelian WU Liangsheng QIANG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2007年第3期423-426,共4页
A series of polyurethane (PU)/vinyl ester resin (VER) simultaneous IPNs (interpenetrating polymer networks) with different component ratios and comonomers types introduced to VER were synthesized and the polymer... A series of polyurethane (PU)/vinyl ester resin (VER) simultaneous IPNs (interpenetrating polymer networks) with different component ratios and comonomers types introduced to VER were synthesized and the polymerization processes were traced by Fourier transform infrared spectroscopy (FTIR) to study the kinetics of IPNs and hydrogen bonding action within multi-component. Furthermore, the relationship of polymerization process with morphology was investigated in detail for the first time by the morphological information given by chemical action between two networks besides physical entanglement, atomic force microscope (AFM) observation and dynamic mechanical analysis (DMA). The results indicated that the degree of hydrogen bonding (Xb,UT,%), calculated from functional group conversional rate and fine structures gained from FT-IR spectra of two networks, were affected by PU/VER weight ratios and comonomer types of VER. The relationship of formation kinetics and morphology showed that the change of Xb,UT (%) values exhibited excellent consistency with that of phase sizes observed by AFM and detected by DMA. 展开更多
关键词 Polyurethane (PU) Interpenetrating polymer networks (IPNs) polymerization process MORPHOLOGY
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THE PROCESS OF THE EMULSIFIER-FREE POLYMERIZATION IN THE PRESENCE OF BARIUM SULFATE POWDER 被引量:1
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作者 Li CHEN Jing LIN Min LIN Hai Shui HUNG Department of Chemistry,Xiamen University,Xiamen 361005 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第9期825-826,共2页
The process of emulsifier-free copolymerization of the Styrene-Butyl Acrylate-K_sS_sO_s-water in the presence of Barium Sulfate(BS)powder was investigated under varied conditions within the range of BS powder quantity... The process of emulsifier-free copolymerization of the Styrene-Butyl Acrylate-K_sS_sO_s-water in the presence of Barium Sulfate(BS)powder was investigated under varied conditions within the range of BS powder quantity,initiator concentration and reaction temperature.Experimental results showed that the rate of polymerization is proportional to 0.3-power of the BS quantity and 1.3-power of the initiator concentration.There is a linear relationship of 2/3-power for the conversion and time.A process for the polymerization is propose to explain the experimental results. 展开更多
关键词 KPS RATE St THE process OF THE EMULSIFIER-FREE polymerization IN THE PRESENCE OF BARIUM SULFATE POWDER BA
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Novel High Performance Ziegler-Natta Catalyst for Ethylene Slurry Polymerization 被引量:9
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作者 郭子芳 陈伟 +1 位作者 周俊领 杨红旭 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第3期530-534,共5页
A novel high performance MgCl2/TiCl4 catalyst with tetrabutyloxsilicane as electron donor was pre-pared for ethylene slurry polymerization process. The properties of the catalyst such as particle size distribution, ca... A novel high performance MgCl2/TiCl4 catalyst with tetrabutyloxsilicane as electron donor was pre-pared for ethylene slurry polymerization process. The properties of the catalyst such as particle size distribution, catalytic activity, hydrogen responsibility and copolymerization performance were investigated and compared with commercial catalyst (imported catalyst). Copolymerization of ethylene and 1-butylene using the catalyst was stud-ied in a pilot plant. The composition, structure and property of the copolymer were characterized by 13C nuclear magnetic resonance (13C NMR) and gel permeation chromatography-Infrared (GPC-IR), and compared with those of the copolymer obtained from a commercial catalyst. In comparison with the commercial catalyst, the novel cata-lyst had a higher activity (up to 34.6 kg·g-1) and a better particle size distribution (PSD), and produced polymers having higher bulk density (up to 0.37 g·cm-3) with less fine resin. Meanwhile, the novel catalyst showed a higher hydrogen responsibility and better copolymerization performance. The results indicated that the copolymer obtained from the novel catalyst has a higher branch in the high molecular weight fraction and lower branch in the low mo-lecular weight fraction. 展开更多
关键词 Ziegier-Natta catalyst POLYETHYLENE slurry polymerization process structure and properties
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Ethylene Polymerization Using Improved Polyethylene Catalyst 被引量:6
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作者 朱孝恒 郭子芳 +1 位作者 岑为 毛炳权 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2011年第1期52-56,共5页
The study concerns the use of MgCl2-supported high-activity Ziegler-Natta catalysts for the polymerization of ethylene.In particular,two types of catalysts were investigated,which were N-catalyst(BRICI)and improved ... The study concerns the use of MgCl2-supported high-activity Ziegler-Natta catalysts for the polymerization of ethylene.In particular,two types of catalysts were investigated,which were N-catalyst(BRICI)and improved polyethylene catalyst.The effects of catalyst structure on kinetic behavior were examined.The distribution of active centers in these catalysts was investigated by energy dispersive analysis by X-rays(EDAX),and morphologies of catalyst particles and polymer products were examined by scanning electron microscope(SEM).Hydrogen response and copolymerization performance were investigated and compared with the two catalysts.The results were correlated with the kinetic behavior of the two catalysts and appropriate models for polymer particle growth were presented.The improved polyethylene catalyst showed higher activity,better hydrogen response and copolymerization performance. 展开更多
关键词 polyethylene catalyst POLYETHYLENE slurry polymerization process ethoxy group
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Effects of Processing Conditions on the Properties of Epoxy Resin Microcapsule 被引量:1
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作者 蔡秀兰 FU Datian QU Ailan 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第4期689-694,共6页
In order to improve the healing performance and increase the service life of the polymer matrix composites, microcapsules were prepared by interracial polymerization process with urea formaldehyde resin and epoxy resi... In order to improve the healing performance and increase the service life of the polymer matrix composites, microcapsules were prepared by interracial polymerization process with urea formaldehyde resin and epoxy resin E-51 as the wall material and core material separately. The effects of core/shell mass ratio and emulsifier on the distribution, topography and encapsulation rate of microcapsules were investigated. By optimizing the conditions, microcapsules with little particle size, well dispersion and compact surface were prepared. The distribution, topography, stability and compositions of the microcapsules were characterized using Nano-2s, optical microscope, scanning electron microscopy, thermal analysis and Fourier transform infrared spectroscopy. The osmosis performance of the microcapsules was evaluated. The experimental results showed that the ratio of core/shell materials (1:1) and 1% DBS as emulsifier were optimum preparation conditions and the encapsulation rate was 62.5%. The microcapsules can be synthesized successfully with mean diameter 548.6 nm and exhibit a good chemical stability below 225 ℃. The FTIR result indicated that urea-formaldehyde resin was formed and the core materials were successfully encapsulated in urea-formaldehyde shell. Osmosis performance evaluation showed that the microcapsules were well coated and slowly osmosed. 展开更多
关键词 epoxy resin MICROCAPSULE interfacial polymerization process
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Empirical correction of kinetic model for polymer thermal reaction process based on first order reaction kinetics 被引量:2
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作者 Zhaoxiang Zhang Fei Guo +2 位作者 Wei Song Xiaohong Jia Yuming Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第10期132-144,共13页
Based on the theory of first-order reaction kinetics,a thermal reaction kinetic model in integral form has been derive.To make the model more applicable,the effects of time and the conversion degree on the reaction ra... Based on the theory of first-order reaction kinetics,a thermal reaction kinetic model in integral form has been derive.To make the model more applicable,the effects of time and the conversion degree on the reaction rate parameters were considered.Two types of undetermined functions were used to compensate for the intrinsic variation of the reaction rate,and two types of correction methods are provided.The model was explained and verified using published experimental data of different polymer thermal reaction systems,and its effectiveness and wide adaptability were confirmed.For the given kinetic model,only one parameter needs to be determined.The proposed empirical model is expected to be used in the numerical simulation of polymer thermal reaction process. 展开更多
关键词 Thermal reaction Polymer processing Reaction kinetics Mathematical modeling Empirical correction
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Impact of Die Materials on the Effect of New Polymer Processing Aids for Sharkskin Properties
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作者 Seyed Pooyan Sajjadi 《Journal of Materials Science and Chemical Engineering》 2016年第9期17-27,共12页
Flows of polymeric liquids undergo instabilities whose origins are quite different from those of Newtonian flows, due to their elastic character and the complexity of the fluid/solid boundary condition. One of these i... Flows of polymeric liquids undergo instabilities whose origins are quite different from those of Newtonian flows, due to their elastic character and the complexity of the fluid/solid boundary condition. One of these instabilities is well known as “shark-skin” which damages the surface appearance and properties of polymer extrudate while processing in blowmolding or piping, while it can be suppressed by employing various methods including coating the die surface and/or adding Polymer Processing Aid’s (PPA) to the polymer. In this article, the effect of various die materials on the properties of Polyethylene glycol (PEG) as a new type of PPA for suppressing the sharkskin phenomenon has been studied. 展开更多
关键词 Polymer processing Aids (PPA) PEG SHARKSKIN Extrusion Instabilities
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Viscosity reduction of tapioca starch by incorporating with molasses hydrocolloids
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作者 Xin Wan Hui Jiang +5 位作者 Zhen Ye Hang Zhou Yimin Ma Xuanrui Miao Xun He Kequan Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第9期165-172,共8页
As a low cost non-staple food resource,the high-viscosity paste and poor gel-forming ability of tapioca starch limit its industrial application.Herein,molasses hydrocolloids that is a by-product of the sugar refining ... As a low cost non-staple food resource,the high-viscosity paste and poor gel-forming ability of tapioca starch limit its industrial application.Herein,molasses hydrocolloids that is a by-product of the sugar refining process was applied as a blending modifier to reduce the viscosity of tapioca starch paste.The test results of paste and rheological properties show that molasses hydrocolloids exhibited a good physical viscosity-reducing effect on tapioca starch paste.The irregular network structure and high K^(+)/Ca^(2+)ion contents of molasses hydrocolloids exerted wrapping,adhesion,barrier,and hydration effects on starch,leading to the reduction of viscosity.The scanning electron microscope images and textural analysis demonstrated that this strategy also improve the structure of tapioca starch gel and enhanced its puncture strength by 75.46%.This work shows the great potential of molasses hydrocolloids as a lowcost and desirable material for the viscosity reduction of tapioca starch. 展开更多
关键词 BIOMASS MOLASSES Tapioca starch BLEND Starch gelatinization Polymer processing
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Nanosized Spinel Li4Ti5O12 Anode Material Prepared by Gel-polymer Method using Furfuryl Alcohol as Polymerizable Solvent
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作者 丁楚雄 白耀彩 +1 位作者 魏丛 陈春华 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2012年第4期457-462,I0004,共7页
Nanosized Li4Ti5O12 powders are synthesized by a polymerization-based method using ti- tanium butoxide and lithium nitrate as precursors and furfuryl alcohol as a polymerizable solvent. The prepared samples are charac... Nanosized Li4Ti5O12 powders are synthesized by a polymerization-based method using ti- tanium butoxide and lithium nitrate as precursors and furfuryl alcohol as a polymerizable solvent. The prepared samples are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Braunauer-Emmett-Teller (BET) analysis. The electrochemical performances of these Li4Ti5O12 powders are also studied. The effect of different surfactants including citric acid, polyvinylpyrrolidone, and cetyltrimethyl ammonium bromide on the structure and properties is also investigated. It is found that pure spinel phase of Li4Ti5O12 is obtained at an annealing temperature of 700 ℃ or higher. The use of surfactants can improve the powder morphology of nanosized particles with less agglomeration. With suitable annealing temperature and the addition of surfaetant, Li4Ti5O12 powders with high BET surface area and favorable electrochemical performance can be obtained. 展开更多
关键词 polymerization process Lithium ion battery LI4TI5O12 Nanoparticle Rate performance
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Chlorinated butyl rubber/two-step modified montmorillonite nanocomposites:Mechanical and damping properties 被引量:4
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作者 Keya Tang Jincheng Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第2期437-449,共13页
Montmorillonite(MMT) was modified by ultrasound and castor oil quaternary ammonium salt intercalation method to prepare a new type of organic montmorillonite(OMMT). The surface structure, particle morphology, interlay... Montmorillonite(MMT) was modified by ultrasound and castor oil quaternary ammonium salt intercalation method to prepare a new type of organic montmorillonite(OMMT). The surface structure, particle morphology, interlayer distance, and thermal behavior of the samples obtained were characterized. The modified OMMT was then added to chlorinated butyl rubber(CIIR) by mechanical blending, and a composite material with excellent damping properties was obtained. The mechanical experiment results of CIIR nanocomposites showed that the addition of OMMT improved their tensile strength, hardness,and stress relaxation rate. Compared with pure CIIR, when the content of OMMT was 5 phr(part per hundred of rubber), the tensile strength of the nanocomposite was increased by 677% and the elongation at break was also increased by 105.4%. The enhancement of this performance was mainly due to the dispersion of the nanosheets in CIIR rubber and the chemical interaction between the organoclay and the polymer matrix, which was confirmed by morphology and spectral analysis. OMMT also endowed a positive effect on the damping properties of CIIR nanocomposites. After adding 5 phr of OMMT, the nanocomposite owned the best damping performance, and the damping factor, tanδmax, was 37.9% higher than that of pure CIIR. Therefore, the good damping and mechanical properties of these CIIR nanocomposites provided some novel and promising methods for preparing high-damping rubber in a wide temperature range. 展开更多
关键词 MONTMORILLONITE NANOSTRUCTURE Chlorinated butyl rubber Polymer processing COMPOSITES
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Morphology Dynamical Mechanical and Flame Retardant Properties of Nylon 1212/Organic Montmorillonite Nanocomposites Prepared by Melt Compounding 被引量:1
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作者 Anrong Huang Jing Sun +1 位作者 Shanshan Luo Heng Luo 《Journal of Electronic Research and Application》 2021年第2期11-17,共7页
Nylon 1212/organic montmorillonite(OMMT)nanocomposites were prepared using the melt compounding method.The morphology and dynamical mechanical properties of the nanocomposites were investigated using transmission elec... Nylon 1212/organic montmorillonite(OMMT)nanocomposites were prepared using the melt compounding method.The morphology and dynamical mechanical properties of the nanocomposites were investigated using transmission electron microscope(TEM)and dynamic mechanical analysis(DMA).The storage modulus of nylon 1212/OMMT nanocomposites was increased with increasing OMMT.The flame retardant properties were characterized by cone calorimetry,scanning electron microscope(SEM)and X-ray photoelectron spectroscopy(XPS).The flame retardant properties were characterized using cone calorimetry,whereby nylon 1212/OMMT nanocomposites were improved compared with pure nylon 1212 because of the carbonaceous-silicate granular materials which were formed during combustion,thus proposing the flame retardant mechanism. 展开更多
关键词 Mechanical properties NANOCOMPOSITES NYLON Polymer processing
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Achieving high dielectric energy-storage properties through a phase coexistence design and viscous polymer process in BNT-based ceramics
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作者 Yule Yang Juanjuan Wang +9 位作者 Ruiyi Jing Wenjing Shi Leiyang Zhang Chao Li Xinyu Zeng Fukang Chen Gang Liu Xiaolian Chao Yan Yan Li Jin 《Journal of Materiomics》 SCIE CSCD 2023年第6期1004-1014,共11页
In the last few decades,dielectric capacitors have gotten a lot of attention because they can store more power and charge and discharge very quickly.But it has a low energy-storage density(Wrec),efficiency(h),and temp... In the last few decades,dielectric capacitors have gotten a lot of attention because they can store more power and charge and discharge very quickly.But it has a low energy-storage density(Wrec),efficiency(h),and temperature stability.By adding Pb(Mg1/3Nb2/3)O3(PMN)and(Bi0$1Sr0.85)TiO3(BST)to a nonstoichiometric(Bi0$51Na0.5)TiO3(BNT)matrix,the goal is to change the phase transition properties and make the material more relaxor ferroelectric(RFE)by lowering the remnant polarization Pr and keeping the maximum polarization Pmax.A viscous polymer process(VPP)is used to improve the electric breakdown strength,which is also a key part of being able to store energy.By working together,ceramics with the formula 0.79[0.85BNT-0.15PMN]-0.21BST(BP-0.21BST)are made.The phase structure has been changed from a rhombohedral phase to a rhombohedral-tetragonal coexisted phase.This is beneficial for RFE properties and gives a Wrec of 6.45 J/cm^(3) and a h of 90%at 400 kV/cm.Also,the energy-storage property is very temperature stable between 30 and 150C.These results show that process optimization and composition design can be used to improve the energy storage properties,and that the dielectric ceramic materials made can be used in high-powder pulse dielectric capacitors. 展开更多
关键词 BNT ENERGY-STORAGE Charge-discharge Viscous polymer process Relaxor ferroelectric
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Simultaneously enhanced energy storage performance and luminance resistance in (K_(0.5)Na_(0.5))NbO_(3) -based ceramics via synergistic optimization strategy
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作者 Yu Huan Diyu Gui +5 位作者 Changxiao Li Tao Wei Lingzhi Wu Xinjian Wang Xiaozhi Wang Zhenxiang Cheng 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2024年第1期34-43,共10页
The rapidly advancing energy storage performance of dielectric ceramics capacitors has garnered significant interest for applications in fast charge/discharge and high-power electronic techniques.Exploring the excepti... The rapidly advancing energy storage performance of dielectric ceramics capacitors has garnered significant interest for applications in fast charge/discharge and high-power electronic techniques.Exploring the exceptional electrical properties in harsh environments can further promote their practical applications.Defect carriers can be excited under luminance irradiation,thereby leading to degradation of energy storage performance.Herein,a synergic optimization strategy is proposed to enhance energy storage properties and luminance resistance of(K_(0.5)Na_(0.5))NbO_(3)-base(KNN)ceramics.First,the introduction of Bi(Zn0.5Ti0.5)O_(3) solid solution and La3+ions disrupts the long-range polar orders and enhances super paraelectric relaxation characteristics.Additionally,doping La3+ions can increase the band gap and reduce oxygen vacancy concentration,resulting in excellent luminance resistance.Finally,the viscous polymer process is employed to suppress the grain growth and promote chemical homogeneity.As a result,ultrahigh recoverable energy storage density(Wrec)of 8.11 J/cm3 and high efficiency(η)of 80.98%are achieved under an electric field of 568 kV/cm.Moreover,the variations in Wrec andηare only 12.45%and 1.75%,respectively,under 500 W xenon lamp irradiation compared to the performance under a dark environment.These findings hold great potential in facilitating the practical application of dielectric ceramic capacitors in luminance irradiation environments. 展开更多
关键词 potassium-sodium niobate energy storage performance illumination resistance oxygen vacancy viscous polymer processing
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Study on electrode process of myoglobin at a polymerized Toluidine Blue film electrode 被引量:1
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作者 DONG,Shao-Jun CHU,Qing-Hui Laboratory of Electroanalytical Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun,Jilin 130022 Present address:Applied Chemical Department,Fushun Petroleum Institute,Fushun,Liaoning 143001. 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1993年第1期12-20,共8页
This paper reports the use of an electrochemically polymerized Toluidine Blue (TB) film electrode.The film on platinum electrode surface was analyzed with ESCA.The heterogeneous electron transfer processes of myoglobi... This paper reports the use of an electrochemically polymerized Toluidine Blue (TB) film electrode.The film on platinum electrode surface was analyzed with ESCA.The heterogeneous electron transfer processes of myoglobin at the polymerized TB film electrode have been investigated using in situ UV-visible spectroelectrochemistry.The formal potential(E°′)and electron transfer number(n)of myoglobin were calculated as E°′=0.045 V(vs.NHE)and n=0.99.The exhaustive reduction and oxidation electrolyses are achieved in 130 s and 110 s respectively,during a potential step between-0.4 V and+0.4 V.A formal heterogeneous electron transfer rate constant(ksh)of 1.09× 10^(-4) cm/s and a transfer coefficient(α)of 0.47 were obtained by cyclic voltabsorptometry,which indicated that myoglobin underwent a quasi-reversible electrode process at the polymerized TB film electrode. 展开更多
关键词 TB POLY Study on electrode process of myoglobin at a polymerized Toluidine Blue film electrode
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BaTiO_(3)-based ceramics with high energy storage density 被引量:4
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作者 Yang Li Ming-Yang Tang +5 位作者 Zhong-Gang Zhang Qi Li Jing-Lei Li Zhuo Xu Gang Liu Fei Li 《Rare Metals》 SCIE EI CAS CSCD 2023年第4期1261-1273,共13页
BaTiO_(3)ceramics are difficult to withstand high electric fields,so the energy storage density is relatively low,inhabiting their applications for miniaturized and lightweight power electronic devices.To address this... BaTiO_(3)ceramics are difficult to withstand high electric fields,so the energy storage density is relatively low,inhabiting their applications for miniaturized and lightweight power electronic devices.To address this issue,we added Sr_(0.7)Bi_(0.2)TiO_(3)(SBT)into BaTiO_(3)(BT)to destroy the long-range ferroelectric domains.Ca^(2+)was introduced into BT-SBT in the form of CaTiO_(3)(CT),which has the effect of inhibiting the movement of A-site defects to reduce dielectric loss and refining the grains to increase the breakdown field strength.In addition,we have increased the density and grain uniformity of ceramics by repeated rolling of the green samples through the viscous polymer processing(VPP),to further increase the breakdown electric field.The BT-SBT-CT ceramics exhibit the high recoverable energy storage density of 4.0 J·cm^(-3)under electric field of 480 kV·cm^(-1).Its recoverable energy storage density varies by less than 8%in the temperature range of 30-150℃,indicating good temperature stability of the energy storage performance.In this work,the energy storage performance of barium titanate-based ceramics was greatly improved by transforming ferroelectrics into relaxor ferroelectrics and VPP method,which can bring new inspiration for the research of energy storage ceramics. 展开更多
关键词 Barium titanate Energy storage Viscous polymer processing(VPP)
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Improved energy storage performance of bismuth sodium titanate-based lead-free relaxor ferroelectric ceramics via Bi-containing complex ions doping 被引量:3
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作者 Wen-Jing Shi Lei-Yang Zhang +5 位作者 Yu-Le Yang D.O.Alikin V.Ya.Shur Xiao-Yong Wei Hong-Liang Du Li Jin 《Rare Metals》 SCIE EI CAS CSCD 2023年第5期1472-1482,共11页
Lead-free dielectric ceramics can be used to make quick charge-discharge capacitor devices due to their high power density.Their use in advanced electronic systems,however,has been hampered by their poor energy storag... Lead-free dielectric ceramics can be used to make quick charge-discharge capacitor devices due to their high power density.Their use in advanced electronic systems,however,has been hampered by their poor energy storage performance(ESP),which includes low energy storage efficiency and recoverable energy storage density(Wrec).In this work,we adopted a combinatorial optimization strategy to improve the ESP in(Bi_(0.5)Na_(0.5))TiO_(3)(BNT)-based relaxor ferroelectric ceramics.To begin,the Bi-containing complex ions Bi(Mg_(2/3)Nb_(1/3))O_(3)(BMN)were introduced into a BNT-based matrix in order to improve the diffuse phase transition,increase Bi-O bond coupling,avoid macro domain development,and limit polarization response hysteresis.Second,the viscous polymer process was employed to reduce sample thickness and porosity,resulting in an apparent increase in breakdown strength in(1-x)[0.7(Bi_(1/2)Na_(1/2))TiO_(3)]-0.3SrTiO_(3)-xBi(Mg_(2/3)Nb_(1/3))O_(3)(BS-xBMN)ceramics.Finally,in x=0.20 composition,an amazing Wrecof 5.62 J·cm^(-3)and an ultra-high efficiency of 91.4%were simultaneously achieved at a relatively low field of 330 kV·cm^(-1),together with remarkable temperature stability in the temperature range of 30-140℃(3.5 J·cm^(-3)±5%variation).This research presents a new lead-free dielectric material with superior ESP for use in pulsed power capacitors. 展开更多
关键词 Relaxor ferroelectric Energy storage performance(ESP) Viscous polymer process (Bi_(0.5)Na_(0.5))TiO_(3)(BNT)
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Biaxial stretching of polytetrafluoroethylene in industrial scale to fabricate medical ePTFE membrane with node-fibril microstructure 被引量:2
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作者 Gang Wang Yusheng Feng +12 位作者 Caiyun Gao Xu Zhang Qunsong Wang Jie Zhang Hongjie Zhang YongqiangWu Xin Li Lin Wang Ye Fu Xiaoye Yu Deyuan Zhang Jianxiong Liu Jiandong Ding 《Regenerative Biomaterials》 SCIE EI CSCD 2023年第1期1161-1177,共17页
Expanded polytetrafluoroethylene(ePTFE)is promising in biomedical fields such as covered stents and plastic surgery owing to its excellent biocompatibility and mechanical properties.However,ePTFE material prepared by ... Expanded polytetrafluoroethylene(ePTFE)is promising in biomedical fields such as covered stents and plastic surgery owing to its excellent biocompatibility and mechanical properties.However,ePTFE material prepared by the traditional biaxial stretching process is with thicker middle and thinner sides due to the bowing effect,which poses a major problem in industrial-scale fabrication.To solve this problem,we design an olive-shaped winding roller to provide the middle part of the ePTFE tape with a greater longitudinal stretching amplitude than the two sides,so as to make up for the excessive longitudinal retraction tendency of the middle part when it is transversely stretched.The as-fabricated ePTFE membrane has,as designed,uniform thickness and node-fibril microstructure.In addition,we examine the effects of mass ratio of lubricant to PTFE powder,biaxial stretching ratio and sintering temperature on the performance of the resultant ePTFE membranes.Particularly,the relation between the internal microstructure of the ePTFE membrane and its mechanical properties is revealed.Besides stable mechanical properties,the sintered ePTFE membrane exhibits satisfactory biological properties.We make a series of biological assessments including in vitro hemolysis,coagulation,bacterial reverse mutation and in vivo thrombosis,intracutaneous reactivity test,pyrogen test and subchronic systemic toxicity test;all of the results meet the relevant international standards.The muscle implantation of the sintered ePTFE membrane into rabbits indicates acceptable inflammatory reactions of our sintered ePTFE membrane fabricated on industrial scale.Such a medical-grade raw material with the unique physical form and condensed-state microstructure is expected to afford an inert biomaterial potentially for stent-graft membrane. 展开更多
关键词 biomedical polymer medical-grade raw material expanded polytetrafluoroethylene olive roller polymer processing biaxial stretching
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EFFECT OF FINAL HEATING TEMPERATURE ON CRYSTALLIZATION OF ISOTACTIC POLYPROPYLENE NUCLEATED WITH AN ARYL AMIDE DERIVATIVE AS β-FORM NUCLEATING AGENT 被引量:4
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作者 于建 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2011年第3期308-317,共10页
An aryl dicarboxylic acid amide compound TMB-5 is an efficient β-form nucleating agent for isotactic polypropylene (iPP). Because of the solubility of TMB-5, superstructure and morphology of iPP crystals changed wi... An aryl dicarboxylic acid amide compound TMB-5 is an efficient β-form nucleating agent for isotactic polypropylene (iPP). Because of the solubility of TMB-5, superstructure and morphology of iPP crystals changed with melting conditions. Effects of final heating temperature (Tf) on heterogeneous nucleation of iPP/TMB-5 were investigated. It was discovered that the crystallization temperature increased with decreasing Tf value. The optical microscopic images indicated that when TMB-5 partially dissolved in iPP melt, the remaining (non-dissolved) TMB-5 facilitated the recrystallization of dissolved nucleating agent from the melt, which promoted crystallization. Complete solubility of nucleating agent caused the decreasing efficiency. TMB-5 recrystallized in the form of tiny needles, whose aggregates induced dendritic iPP crystals. 展开更多
关键词 Isotactic polypropylene Heterogeneous nucleation CRYSTALLIZATION Polymer processing Melting temperature.
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Current advances and future perspectives of additive manufacturing for functional polymeric materials and devices 被引量:6
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作者 Chuhong Zhang Yijun Li +2 位作者 Wenbin Kang Xingang Liu Qi Wang 《SusMat》 2021年第1期127-147,共21页
Three-dimensional(3D)printing has received extensive attention due to its unique multidimensional functionality and customizability and has been recognized as one of the most revolutionary manufacturing technologies.F... Three-dimensional(3D)printing has received extensive attention due to its unique multidimensional functionality and customizability and has been recognized as one of the most revolutionary manufacturing technologies.Functional 3D printed products represent an important orientation for next-generationmanufacturing and attract a great spotlight for the application in sensors,actuators,robots,electronics,and medical devices.However,the lack of functions of printing polymeric materials dramatically limits the development of functional 3D printing.Different from traditional processing,the physical properties,such as geometry and rheological behavior,of the polymericmaterialsmust match the printing process,making the selection of printable materials limited.More importantly,challenges in large-scale production of such materials further stifle the development of functional 3D printing industry.In this review,we aim to outline recent advances in polymeric materials and methodologies for the functional 3D printing technology.The reports are classified based on functionalities,including electronic conductive,thermally conductive,electromagnetic interference shielding,energy storage,and energy harvesting materials.This study attempts to provide a comprehensive overview of the challenges and opportunities for 3D printing functional polymeric materials/devices,also seeks to enlighten the orientation of future research in this field. 展开更多
关键词 3D printing polymeric functional materials and devices polymer processing
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