聚氨酯基聚合物电解质的研究进展

聚合物锂离子电池因具有能量密度高、绿色环保等优点备受关注,聚合物电解质作为锂离子电池的重要组成部分,发展高效聚合物电解质成为研究热点。聚氨酯由不相容的软硬两段组成,结构可设计性强,硬段部分作为物理交联点提供机械强度和热稳定性,软段部分溶解碱金属盐提供离子导电性,因而聚氨酯是作为锂电池聚合物电解质的优良材料。通过改进聚氨酯基聚合物电解质的电化学性能和增加聚氨酯基聚合物电解质的功能性两个方面综述了国内聚醚型、聚酯型、有机硅氧烷改性、聚氧化乙烯改性、聚乳酸改性和功能型聚氨酯基电解质的研究进展,并展望了未来聚氨酯基聚合物电解质的发展前景。     

超支化聚氨酯的改性研究进展

超支化聚氨酯具有端基种类丰富、无链缠绕、溶解性好和粘度低等优点,对其进行功能化改性后可应用于涂料、聚合物固体电解质、形状记忆材料、相变储能材料和阻尼材料等领域。文章从丙烯酸酯改性、有机硅改性、有机氟改性、纳米改性和环氧树脂改性等方面综述了超支化聚氨酯的改性方法,并对其发展方向进行了展望。     

聚有机硅氧烷改性聚氨酯的应用新进展

综述了聚有机硅氧烷改性聚氨酯在聚合物电解质基材、生物医学材料、膜材料等新领域的最新研究和应用进展。     

凝胶聚合物电解质的研究进展

介绍了几种聚合物高分子材料,常以其作为凝胶聚合物电解质基体。如聚氧化乙烯(PEO)、聚丙烯腈(PAN)、聚甲基丙烯酸甲酯(PMMA)、聚偏氟乙烯(PVDF)。对于凝胶聚合物电解质的研究,目前仍处于初级阶段,还存在许多问题。本文探讨了凝胶聚合物电解质的改性方法,主要有交联、共聚、共混或添加填料等,并展望了凝胶聚合物电解质的应用前景。     

碳纳米管增强聚合物纳米复合材料研究进展

综述了近几年国内外在碳纳米管增强聚合物纳米复合材料力学性能方面的研究进展,主要介绍了以聚氨酯和聚酰亚胺为基体的复合材料。讨论了碳纳米管的各种改性方法及其作用原理,并对各种改性和制备方法的有效性进行了比较。最后,对碳纳米管增强聚合物纳米复合材料的发展前景进行了展望。     

聚氨酯水分散体改性丙烯酸胶粘剂的性能

用聚氨酯改性的丙烯酸材料是近年来开发应用的一种新型材料,这种改性材料在涂料、油墨和胶粘剂等领域广泛应用。丙烯酸乳液具有和高弹性聚合物掺和性能好的特点。聚氨酯属高弹性聚合物类,它添加到丙烯酸乳液中去,能改进丙烯酸乳液的粘接、柔韧和延伸性能,且不使丙烯酸胶粘剂本身的特点受到影响。聚氨酯水分散体改性的丙烯酸树脂胶粘剂既能提高其粘接强度,又具有色     

聚氨酯改性有机硅的制备方法与应用展望

聚氨酯改性有机硅材料是一种性能优异的先进材料,在诸多领域具有广阔的应用空间。本文综述了聚氨酯改性有机硅的制备方法,包括共混改性、嵌段共聚改性、接枝共聚改性以及通过形成互穿聚合物网络进行改性,介绍了聚氨酯改性有机硅材料的性能与应用,并简要总结了目前在制备聚氨酯改性有机硅材料方面所面临的主要问题。     

基于大豆分离蛋白多孔材料的超级电容器的构建及性能研究

聚合物电解质作为固态超级电容器的重要组成部分成为了研究热点。本论文利用天然高分子大豆分离蛋白自身的乳化性,与EMPA交联制备了具有多孔结构的聚合物电解质基体材料,结合硫酸锂电解质,构建了大豆分离蛋白基聚合物电解质,并采用活性炭电极组装了双电层电容器,其单电极质量比电容在1.0 A/g的电流密度下能够达到113.59 F/g。     

聚硅氧烷电解质在锂电池中的应用研究进展

有机硅聚合物电解质具有较低的玻璃化转变温度、优异的热稳定性、较高的安全性,且其容易改性,因此可以通过简单的化学反应制备性能优异的聚合物固态电解质材料.介绍了有机硅材料(主要为聚硅氧烷和聚倍半硅氧烷)在锂电池聚合物电解质领域的应用,总结了不同有机硅材料对聚合物电解质性能的影响.     

纳米改性聚氨酯弹性体

纳米级碳酸钙、二氧化硅、二氧化钛、粘土等材料用于聚合物的改性已取得不少的技术突破 ,一些厂家已成功制备了各种纳米聚合物复合材料。与普通改性聚合物相比 ,纳米改性材料的物性及加工性能都有较大提高。广州新力聚氨酯制品厂已开发成功纳米改性聚氨酯弹性体。该厂研制的有机或无机纳米材料增强的聚氨酯弹性体 ,具有高强度、高耐磨性及耐高温性能好的特点。例如在1 40℃下其 1 0 0 %及 30 0 %定伸强度仍能达到常温时时的 70 %左右。它的工作温度可比普通聚氨酯弹性体高 30～ 50℃ ,可用于高温高压聚氨酯密封圈、石油钻井泥浆泵皮碗、纺织…     

高锂盐含量聚氨酯基固态电解质的制备与性能

以异佛尔酮二异氰酸酯、聚碳酸酯二元醇和一缩二乙二醇为原料,合成硬段质量分数为30%的聚碳酸酯型聚氨酯(PCPU),将合成的聚氨酯和双三氟甲烷磺酰亚胺锂(LiTFSI)复合制得不同锂盐质量分数的固态聚合物电解质(SPE)。通过红外光谱分析了聚氨酯结构,采用TG、DSC测试了聚氨酯及电解质的热学性能,并采用交流阻抗、线性扫描伏安测试探究了不同LiTFSI质量分数对电解质电化学性能的影响。结果表明,随着LiTFSI质量分数的增加,聚氨酯基固态聚合物电解质的室温离子电导率呈现先增大后减小再增大的趋势,当锂盐质量分数为70%时,制备的电解质离子电导率达到最大值(1.28×10~(–8)S/cm),以此固态电解质与LiFePO4正极组装的固态电池在60℃、0.2 C电流密度时放电比容量为153 mA·h/g,循环100次容量保持率为84%。     

Composite polymer electrolytes based on the low crosslinked copolymer of linear and hyperbranched polyurethanes

Low crosslinked copolymer of linear and hyperbranched polyurethane (CHPU) was prepared, and the ionic conductivities and thermal properties of the composite polymer electrolytes composed of CHPU and LiClO₄ were investigated. The FTIR and Raman spectra analysis indicated that the polyurethane copolymer could dissolve more lithium salt than the corresponding polymer electrolytes of the non crosslinked hyperbranched polyurethane, and showed higher conductivities. At salt concentration EO/Li = 4, the electrolyte CHPU30‐LiClO₄ reached its maximum conductivity, 1.51 × 10^?5 S cm^?1 at 25°C. DSC measurement was also used for the analysis of the thermal properties of polymer electrolytes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3607–3613, 2007     

Synthesis and characterization of polyurethane/microcrystalline cellulose bionanocomposites

In this study, novel polyurethane/cellulose hybrid bionanocomposite films have successfully been prepared by dispersing microcrystalline cellulose in a polyurethane matrix. Incorporation of microcrystalline cellulose in a polyurethane matrix improved the mechanical properties significantly. The polyurethane/cellulose bionanocomposites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and transmission electron microscopy (TEM). The TEM results confirm that the nanoparticles were dispersed uniformly in polymer matrix. Additionally, thermogravimetric analysis data showed an improvement of thermal stability of novel nanocomposite films as compared to the neat polymer.     

超支化聚氨酯的研究进展

综述了国内外有关超支化聚氨酯的合成方法,介绍了超支化聚氨酯在涂料和聚合物固体电解质等方面的应用,并对其今后的研究重点提出了一些看法。     

Enhancement of ionic conductivity of PEO-LiTFSI electrolyte upon incorporation of plasticizing lithium borate

By dissolving plasticizing lithium borate (Salt A) and LiN(SO₂CF₃)₂ (LiTFSI) at different ratios in poly(ethylene oxide) (PEO), a series of solid-state mix-salt polymer electrolytes were prepared. Higher ionic conductivities were determined for the mix-salt polymer electrolytes than for the pure-salt counterparts. The optimum mixing ratio of the two salts was explored. The electrochemical stability and interfacial performance of the mix-salt polymer electrolytes were also investigated. A battery testing using LiNi_0.8Co_0.2O₂ as cathode material and lithium as anode material was executed to assess the cyclic performance of the electrolyte.     

In situ composite of nano SiO2-P(VDF-HFP) porous polymer electrolytes for Li-ion batteries

Nano SiO₂-P(VDF-HFP) composite porous membranes were prepared as the matrix of porous polymer electrolytes through in situ composite method based on hydrolysis of tetraethoxysilane and phase inversion. SEM, TEM, DSC and AC impedance analysis were carried out. It is found that the in situ prepared nano silica was homogeneously dispersed in the polymeric matrix, enhanced conductivity and electrochemical stability of porous polymer electrolytes, and improved the stability of the electrolytes against lithium metal electrodes. The in situ composite method was found to be much better than the direct composite method in lowering the interfacial resistance between electrolyte and lithium metal electrode. Moreover, cycle test of lithium batteries using lithium metal as anode and sulfur composite material as cathode showed that the electrolyte based on in situ composite of silica presented stable charge-discharge behavior and little capacity loss of battery.     

Evaluation of the engineered polysaccharide alpha-1,3 glucan in a thermoplastic polyurethane model system

Enzymatic polymerization is under development as novel scalable process technology to convert sucrose to engineered polysaccharides. Similar to established monomer-based polymerization processes, this approach allows for the synthesis of glucose-based polymers with controlled polymer linkage, structure, and material morphology. Using enzymatic polymerization, alpha-1,3-polyglucose (glucan) can now be produced from sugar on scales required for industrial applications. This alpha-1,3 glucan material, with accessible primary and secondary hydroxyl groups within the overall defined particle morphology, is especially of interest as a partially reactive component in polyurethane chemistry. This study explores the impact of alpha-1,3-glucan as additive in a thermoplastic polyurethane model system and the improvement in mechanical properties of these composites. Glucan was effectively first mixed with a polyether polyol diol, forming a stable dispersion with narrow particle size distribution, followed by reaction with diisocyanate and chain extender to form the polyurethane matrix. The analysis of the generated polyurethane matrix indicates that the hydroxyl groups of the dispersed glucan particles directly react with isocyanate. Tetrahydrofuran solubility of the formed polyurethane compound decreased with the addition of glucan, providing evidence of covalent bonding of glucan leading to cross-linking of the polyurethane matrix. Thermal analysis of this model system suggests that the glucan additive induces hard segment crystallization, resulting in increased hardness and tensile modulus compared with the reference. Based on the observed property enhancements, engineered polysaccharides provide a sustainable performance additive for polyurethane materials.     

Dye-sensitized solar cells employing polymers

Dye-sensitized solar cells (DSSCs) are of interest due to their potential use as inexpensive and environmentally friendly photovoltaic (PV) devices with acceptable power conversion efficiency (PCE). Platinum (Pt) metal is, traditionally, the preferred material for the counter electrode (CE) component of DSSCs, however, further development of iodide/triiodide (I⁻/I₃⁻) based liquid-electrolyte DSSCs using Pt remains challenging due to the high cost of this scarce metal and its susceptibility to corrosion. Additional concerns include solvent leakage and low chemical stability resulting from volatile liquid electrolyte used in DSSCs. In order to counteract this issue, polymer electrolytes or hole-transporters with higher mobilities are employed as a replacement for liquid electrolytes. In this regard, polymers can serve as efficient CE materials by replacing the platinized electrode in liquid-electrolyte DSSCs, while also substituting for the liquid electrolytes as polymer electrolytes or hole-transporters in solid-state or quasi solid-state DSSCs. Considering the fragility and shape restrictions of glass substrates, polymer substrates may also be used to replace rigid glass substrates, providing more flexible DSSCs. Herein, applications of the polymers as cell components (CEs, polymer electrolytes or hole-transporter, and plastic substrates) in DSSCs are discussed, with special focus on the role that polymers play in DSSCs and widely accepted reports of PV performance. The current understanding of the factors and strategies involved in improving the performance of polymers in DSSCs are reviewed and analyzed. In addition, the benefits, challenges and potential utility of polymers for use in DSSCs are assessed.     

Excellent Mechanical and Transparency Properties of Cationic Waterborne Polyurethane Films Modified by Boehmite Sol

The strategies for nanosol from metal alkoxide have enabled production of ultratransparent and mechanically robust polymer nanocomposites at extremely high loading. Herein, a simple approach to fabricate high‐performance polyurethane‐based nanocomposites via unmodified boehmite nanoparticles is reported. Evaluating their physical properties, the uniform dispersion of boehmite in the matrix caused nanocomposites retains ultrahigh transparency. Hydrogen bonding and intermolecular entanglement between boehmite and polyurethane brings about the mechanical properties of the nanocomposites material enhanced, i.e., strength, stiffness, and toughness. Optimized strength, stiffness, and toughness of Boehmite/Cationic waterborne polyurethane at 40 wt% (BNC40) are up to 58.1 MPa, 1096.7 MPa, 249.5 MJ m^?3, respectively. Furthermore, the feasibility and mechanism of polymer strengthening and toughening by inorganic rigid nanoparticles is explored from the aspects of crystallinity and micromorphology.     

Engineered polysaccharide alpha-1,3 glucan as isocyanate-reactive component in viscoelastic polyurethane foams

Enzymatic polymerization is emerging as scalable method to convert sucrose to engineered polysaccharides. Polymer architecture and material properties can be controlled selectively to produce novel differentiated biomaterials. One first example for such an engineered polysaccharide is alpha-1,3-polyglucose (alpha-1,3-glucan) synthesized using glucosyltransferase (GTF) enzymes. Stable dispersions of alpha-1,3-glucan in polyether polyols were prepared with narrow particle size distributions, which are reactive with isocyanate allowing for covalent bonding to the hard segment of the polyurethane polymer matrix. This study further explored the use of alpha-1,3-glucan (PS) in the preparation of viscoelastics (VE) polyurethane foams. The introduction of alpha-1,3-glucan into the polyurethane polymer matrix was found to increase the load-bearing properties of VE foams without impacting the density. Other key performance properties of VE foams were effectively unchanged, including resilience, tensile, and tear strength. Cell size and morphology were also unaffected. The glass transition of these VE foams was not impacted; however, the overall thermal dimensional stability was improved as considerable reduction in compression set was observed. The results of this study indicated that alpha-1,3-glucan disperses in polyether polyols to improve performance characteristics of the VE foams, as well as other flexible polyurethane foams properties.