氧化石墨烯/聚氨酯复合材料的制备及性能研究

采用溶液共混浇注成膜法制备氧化石墨烯/热塑性聚氨酯(TPU)复合材料,并对其结构和性能进行研究。结果表明:氧化石墨烯在TPU基体材料中分散较好;随着氧化石墨烯用量(0～5份)的增大,氧化石墨烯/TPU复合材料的拉伸强度增大,拉断伸长率未明显下降;当相同用量(均为1份)的氧化石墨烯、碳纳米管、石墨和炭黑分别填充TPU时,氧化石墨烯/TPU复合材料物理性能提高幅度最大,补强性能最好。     

水性聚氨酯/石墨烯柔性导电复合材料制备及性能

针对石墨烯在与聚合物基体复合中出现的难以均匀分散、易出现团聚的问题,通过采用不同的分散剂对石墨烯进行非共价键功能化改性,选取最佳分散剂,以制备稳定的石墨烯分散液。通过溶液共混法和流延浇铸法将石墨烯均匀分散在水性聚氨酯（WPU）基体中,制备了WPU/石墨烯柔性导电复合材料。溶剂分散效果及吸光度测试结果显示,聚乙烯醇（PVAL）水溶液对石墨烯的分散能力强,制备的石墨烯分散液较为稳定,且PVAL水溶液的最佳质量分数是15%,其吸光度达到2.943;导电性能测试结果发现,石墨烯含量为WPU质量的2%时,WPU/石墨烯柔性导电复合材料综合性能较好,其电导率为2.6×10^-7 S/m,并在此基础上,考察发现WPU∶PVAL水溶液质量比为80∶20时,复合材料的拉伸强度较未加分散剂的增加了116%,电导率为4.5×10^-5 S/m,较未加分散剂的增加了5个等级;扫描电子显微镜结果表明,加入PVAL水溶液后,石墨烯能均匀地分散在WPU基体中,表明PVAL水溶液对石墨烯具有良好的分散作用。     

磁性石墨烯复合材料的制备及应用研究进展

磁性石墨烯复合材料结合了纳米材料和磁性材料的优势,具有量子尺寸和宏观量子隧道等效应,被广泛应用于新能源、生物医学等领域。然而,磁性石墨烯复合材料的性能和应用受到其尺寸、形貌和晶体结构的影响,因此选择适当的制备方法对于开发出性能优越、应用广泛的磁性石墨烯复合材料至关重要。综述了近年来磁性石墨烯复合材料的制备方法及应用研究进展,重点介绍了制备方法的原理、优缺点及应用实例,并展望了未来的发展方向。     

三维石墨烯/聚氨酯复合材料的制备与特性

以氧化石墨烯(GO)为网络骨架的前驱体,通过水热还原、冷冻干燥制备了石墨烯气凝胶(GA);再以聚氨酯(PU)为复合材料的填充体,调节PU软硬度与流动性并真空浸渍气凝胶GA,两步法制备出互咬型三维石墨烯/聚氨酯(3DGP)复合材料。利用SEM、Raman、FTIR对GO、GA、3DGP的结构与形貌进行了表征,并采用TGA-DSC和自制压阻测试平台分析热稳定性和压阻特性。结果表明:6 g/L GO水溶液在还原剂乙二胺(EDA)作用下,GO片层间相互连接形成规整蜂窝状三维网络结构,其孔径约0.8mm,3DGP中PU与GA能很好地咬合;三维网络骨架的连续性为热运输载体声子提供了良好通道,使得3DGP热稳定性能显著提升,失重率5%时温度较PU提升了45℃;具有低迟滞性(8.7%)并且在压阻测量区间表现出两种压阻效应。     

聚氨酯/石墨烯纳米复合材料的研究进展

石墨烯以其独特的结构和优异的性质,使其聚氨酯纳米复合材料成为重要的研究领域。介绍了石墨烯/聚氨酯纳米复合材料的制备方法。讨论了石墨烯/聚氨酯纳米复合材料的结构与性能。综述了石墨烯/聚氨酯纳米复合材料的主要应用。     

微胶囊自修复复合材料的研究进展

微胶囊自修复复合材料是一种新型智能材料。本文对目前树脂基复合材料自修复的方法进行综述,着重介绍自修复复合材料用微胶囊的制备、表征方法,并详细介绍微胶囊在复合材料自修复中的应用及研究进展,讨论研究过程存在和急需解决的问题。     

离子液体改性石墨烯/聚氨酯弹性体复合材料的制备及形状记忆性能

采用1-丁基-3甲基咪唑四氟硼酸盐离子液体对石墨烯表面进行功能化修饰,用溶液共混法将离子液体改性石墨烯(IG)填入热塑性聚氨酯弹性体(TPU)制备IG/TPU复合材料,并考察了IG用量对IG/TPU复合材料形状记忆性能的影响.结果表明,纯TPU没有表现出光响应形状记忆性能,在激光照射下几乎没有回复.而IG的加入能显著提...     

磁性石墨烯复合材料制备与应用研究进展

石墨烯具备多种优异的性能,但容易通过π-π堆积和范德华力作用产生聚集,重新堆叠成石墨。为了改善石墨烯的堆叠问题,提高石墨烯材料的应用性,越来越多的研究者将石墨烯及其衍生物和磁性纳米粒子复合,制备综合性能更优的新型材料。本文结合近年来国内外研究报道,总结了磁性石墨烯纳米复合材料的制备方法（水热/溶剂热、化学接枝法、微波辅助法等）,概述了磁性石墨烯复合材料在环境样品分离富集、催化、涂层耐腐蚀性、吸波材料及能源等方面的应用,指出了目前磁性石墨烯复合材料研究中存在的一些问题,例如磁性颗粒容易发生团聚、生物安全性有待验证、氧化石墨烯的还原导致其表面吸附位点减少等。目前（氧化）石墨烯的制备工艺正在得到改善,而未来最重要的发展方向是加强对磁性石墨烯的表面改性,从而可使其表面具有更丰富的吸附位点,同时也可使石墨烯表面的磁性纳米粒子的形态及分布更均匀,更有利于稳定发挥磁性石墨烯的功能性。     

碳纳米管/聚氨酯功能复合材料的制备与应用

介绍了碳纳米管的处理、碳纳米管/聚氨酯复合材料的制备方法：碳纳米管的处理方法有表面处理改性和局部活化改性2种; 碳纳米管/聚氨酯复合材料的制备方法有物理共混法和原位聚合法。结合碳纳米管和聚氨酯的特性,综述了碳纳米管/聚氨酯复合材料在力学性能的增强、电子材料、智能材料、生物医学材料和节能材料等方面的应用,并对CNTs/PU复合材料未来的研究工作提出了几点意见。     

Preparation and physical properties of functionalized graphene/waterborne polyurethane UV‐curing composites by click chemistry

Functionalized graphene nanoplatelets (f‐GNS) were modified with (3‐mercaptopropyl)trimethoxysilane (MPTMS) to enhance their compatibility with the polyurethane coating matrix. The results of Fourier transform infrared spectroscopy, AFM, Raman and XRD showed that the MPTMS was successfully attached onto the surface of the graphene nanoplatelets. Functionalized graphene/waterborne polyurethane acrylate (f‐GNS/WPUA) nanocomposites were fabricated by UV‐curing technology. The SEM and TEM images indicated that f‐GNS could be well dispersed in the polymer matrix and improved the interfacial adhesion. With the incorporation of 1 wt% f‐GNS, the thermal decomposition temperature of the composites was increased by 25 °C. Meanwhile, the conductivity, hydrophobicity and tensile strength were increased. When the load was further increased, the performance of the composites showed varying degrees of reduction. However, the dielectric loss tangent (tan δ) could be maintained at 0.08 or less and the electromagnetic shielding factor of the composites reached from 5 to 36 dB, showing a good electromagnetic shielding effect at a high content (2.5 wt% f‐GNS). It was considered that f‐GNS could disperse in the waterborne polyurethane well and crosslink with the polyurethane. © 2016 Society of Chemical Industry     

碳纳米管/聚氨酯复合材料的粘接性能

利用超声分散、酸处理以及表面活性剂分散的方法将碳纳米管分散到蓖麻油中,制备了蓖麻油型聚氨酯/碳纳米管(PUR/CNTs)复合材料,观察了该复合材料的微观结构,探讨了CNTs用量、酸处理时间以及表面活性剂的用量对复合材料粘接性能的影响。结果表明,随着蓖麻油中CNTs用量的增加,该复合材料的粘接强度不断提高,当增加到2%时,粘接强度提高84.4%;硝酸处理3 h的聚氨酯/碳纳米管复合材料的粘接强度最大,比未酸处理的复合材料增加15%;表面活性剂分散的聚氨酯/碳纳米管复合材料的粘接强度能得到进一步的提高。     

Exceptionally flame-retardant flexible polyurethane foam composites: synergistic effect of the silicone resin/graphene oxide coating

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

Preparation and properties of functionalized graphene/waterborne polyurethane composites with highly hydrophobic

The long‐chain functionalized graphene nanoplatelets (FGN) were functionalized by isophorone diisocyanate and then octadecylamine, the graphene functionalized/waterborne polyurethane (WPU) composites were prepared by solution mixture. The results showed that the FGN achieved good dispersion with exfoliated and intercalated nanostructure and strong interfacial adhesion with WPU, which made the nano–composites have a significant enhancement of thermal stability and mechanical properties at low FGN loadings. With 1.5% of FGN added, the tensile strength of the composites reached the maximum of 17 MPa, which improved by 41.6%, the water absorption of the composites is only 6.7%. With the incorporation of 2 wt % FGN, and the static contact angle of the composites reached to about 120°, showing the high hydrophobicity. At the same time, the volume resistivity of the composites was changed from 2.34 × 10¹² Ω·cm to 3.77 × 10⁹ Ω·cm. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42005.     

Enhanced mechanical and thermal properties of polyurethane/functionalised graphene oxide composites by in situ polymerisation

ABSTRACT

Isocyanate-functionalised graphene (iGO) was prepared and incorporated into a thermoplastic polyurethane via an in situ polymerisation. Firstly, graphene oxide was successfully modified using a mixture of isocyanate- and diisocyanate-containing compounds, leading to the formation of good dispersions of resulting functional graphene oxide in organic solvents, such as N,N-dimethylacetamide and N,N-dimethylformamide. The addition of iGO into polyurethane matrix improved both mechanical and thermal properties in the polyurethane/iGO composites relative to neat polyurethane. An addition of only 0.03?wt-% of functionalised graphene into the polyurethane increased Young’s modulus by 1.4 times and tensile strength by two times. Meanwhile, the elongation at break was similar to that of the neat polymer. In addition, dynamic mechanical analysis also confirmed the improvement in storage modulus of the polymer composites especially at high-temperature range. We believe that the developed modification approach for graphene oxide and polyurethane/graphene composites presented herein could be useful in polymer/graphene composite development.     

热塑性聚氨酯/石墨烯改性聚氨酯注浆材料的制备与性能研究

采用石墨烯、热塑性聚氨酯（TPU）复合改性聚氨酯注浆材料,并添加少量的粉煤灰、炉底渣及碱性激发剂制备一种低密度、高强度、快硬性的TPU/石墨烯改性聚氨酯注浆材料。借助聚氨酯弹性体材料密度测试仪、万能材料试验机、渗透系数测试仪、荧光显微镜对TPU/石墨烯改性聚氨酯注浆材料的密度、膨胀倍数、抗压强度、阻燃性能、渗透系数及微观形貌进行表征,深入分析了石墨烯和TPU的种类和含量对聚氨酯注浆材料基本物理性能、力学性能及微观结构的影响。结果表明,TPU/石墨烯改性聚氨酯注浆材料的密度为0.24~1.25 g/cm³,膨胀倍数最高可达38倍,抗压强度为15.0~43.8 MPa,相比普通聚氨酯注浆材料,改性聚氨酯注浆材料抗压强度提升1倍以上。酒精灯燃烧试验显示注浆材料无焰燃烧时间均小于20 s。石墨烯和TPU均可提高聚氨酯的强度和耐久性,改善TPU的微观形貌。TPU/石墨烯改性聚氨酯注浆材料表现出良好的强度、耐久性及弹性,是一种性能优异的注浆材料。     

Enhanced mechanical and thermal properties of rigid polyurethane foam composites containing graphene nanosheets and carbon nanotubes

The comparative study of rigid polyurethane foam (RPUF) nanocomposites based on graphene nanosheets (GNSs) and carbon nanotubes (CNTs) has been reported. A GNS content of 0.3 wt% in polyol turns to be optimal for its foamability with the isocyanate component, as verified by rheology measurements. Scanning electron microscopy and transmission electron microscopy observations reveal a homogeneous dispersion of GNSs and CNTs in the RPUF nanocomposites. Only 0.3 wt% loading of GNSs and CNTs led to 36% and 25% improvement respectively in the compressive modulus of the RPUF nanocomposites. Meanwhile, 16 °C and 14 °C improvements in the glass transition temperature confirm the important role of both the nanofillers in the heat resistance of RPUF nanocomposites. These results additionally indicate that GNSs work more effectively than CNTs in mechanical property and heat resistance enhancement of the RPUF nanocomposites. The superiority of GNSs over CNTs can be attributed to their wrinkled surface structure, unique two‐dimensional geometrical morphology and higher specific surface area, which results in stronger interaction and restriction of segmental motion at the interface between the GNSs and the RPUF matrix. In addition, changes in the thermal conductivity of the nanocomposites are negligible, indicating that incorporation of GNSs and CNTs will not hinder the application of RPUF nanocomposites as thermal insulators. On the contrary, the enhancement in mechanical properties and heat resistance will undoubtedly expand the application range of polyurethane foam materials. Copyright © 2012 Society of Chemical Industry