磨碎玻璃纤维增强环氧树脂复合材料的制备及力学性能研究

用硅烷偶联剂对磨碎玻璃纤维表面进行改性,并制备玻璃纤维/环氧树脂复合材料,采用超声分散对复合材料分散处理,探讨不同磨碎玻璃纤维粉质量比对环氧树脂基复合材料压缩、拉伸性能的影响。研究表明,添加磨碎玻璃纤维后,环氧树脂的强度和硬度显著增强。当磨碎玻璃纤维掺量在15%~25%之间时,复合材料的综合力学性能最好,其压缩强度、压缩模量、拉伸强度最高达到67.1 MPa、1.68 GPa、57.6 MPa,与纯环氧树脂相比提高了24%、35%、34%;断裂伸长率随着掺量的增加逐渐降低,当含量达到30%时比纯环氧树脂的降低了48%,表明添加玻璃纤维粉后环氧树脂脆性增强。目数小粒径较大的玻璃纤维粉对环氧树脂力学性能增强效果更优,但影响程度不如含量对复合材料力学性能的影响大。     

纳米粘土/环氧树脂复合材料的制备及力学性能研究

借助超声分散,采用固化处理制备了不同纳米粘土掺量(0,1%,3%,5%和7%(质量分数))的纳米粘土/环氧树脂复合材料,研究了纳米粘土掺量对复合材料性能的影响。通过X射线衍射(XRD)、力学性能测试、扫描电镜(SEM)等对复合材料进行了表征。结果表明,不同掺杂比例的纳米粘土和环氧树脂都均匀结合,纳米粘土掺量为7%(质量分数)的复合材料衍射峰强度最高,其结晶性能最佳;随着纳米粘土掺量的增加,复合材料的拉伸模量、极限抗压强度和断裂韧性KIC值整体均高于纯环氧树脂,而复合材料的破坏应变低于纯环氧树脂;当纳米粘土掺量为1%(质量分数)时,复合材料的极限抗拉强度略有提高,但随着纳米粘土掺量的继续增加,复合材料的极限抗拉强度逐渐降低;当纳米粘土掺量为5%(质量分数)时,复合材料的拉伸模量达到3 513 MPa,相比纯环氧树脂的3 300 MPa,增加了6.5%;当纳米粘土掺量为7%(质量分数)时,复合材料的断裂韧性KIC值达到1.97 MPa·m~(1/2),相比纯环氧树脂的1.60 MPa·m~(1/2),增加了23.1%;纯环氧树脂的断裂表面光滑无褶皱,断裂时裂纹没有产生无偏离的扩展,而复合材料的断裂表面随纳米粘土掺量的增加均趋于粗糙,裂纹在扩展过程中发生了偏移。     

碳纳米管对环氧树脂基纳米复合材料的力学和电学性能影响(英文)

以碳纳米管(MWCNT)为添加剂,制备出碳纳米管/环氧树脂复合材料,并探讨MWCNT质量分数对其力学和电学性能的影响。结果表明,当MWCNT含量分别为0.1%和0.25%时,该复合材料的拉伸强度和弯曲模量达到最大值。随着M WCNT含量的增加,拉伸模量增加和应变损坏率降低,这表明复合材料由塑性变形到脆性变形演变。当M WCNT含量为0.05%时样品弯曲强度最高;当M WCNT含量为0.5%时,样品出现电渗流阈值。M WCNT在环氧树脂基体中的良好分散对提高复合材料力学性能起重要作用。分散不均的MWCNT易团聚,会引起早期失效和电学性能降低。     

石墨烯/环氧树脂复合材料的制备及力学性能

分别通过超声共混法和原位还原法制备了石墨烯/环氧树脂复合材料。利用X射线光电子能谱(XPS)、X射线衍射(XRD)、光学显微镜和扫描电子显微镜(SEM)对复合材料的结构进行了表征,并对其力学性能进行了测试。结果表明,原位还原法制备的石墨烯/环氧树脂复合材料中,氧化石墨烯已经被成功地还原为石墨烯,并且石墨烯具有良好的分散性。力学性能测试结果表明,两种方法制备的复合材料的力学强度较纯环氧树脂明显提高。当石墨烯的量为m(GO)/m(EP)=0.3/100时,超声混合法制备的石墨烯/环氧树脂复合材料的拉伸强度和弯曲强度分别最大提高约29.2%和1.4%;而原位还原法制备的石墨烯/环氧树脂复合材料的拉伸强度和弯曲强度分别最大提高约40.5%和9.4%。     

石墨烯-多壁碳纳米管协同增强环氧树脂复合材料的低温力学性能

为了提高环氧树脂的低温力学性能,采用石墨烯与多壁碳纳米管(MWCNTs)协同改性环氧树脂,系统研究了石墨烯-MWCNTs/环氧树脂复合材料的室温(RT)和低温(77K)力学性能。结果表明:当石墨烯的质量分数为0.1wt%,MWCNTs的质量分数为0.5wt%时,纳米填料的加入可同时改善环氧树脂的低温拉伸强度、弹性模量和冲击强度;在此最佳含量下,石墨烯-MWCNTs/环氧树脂复合材料在RT和77K时的拉伸强度皆达到最大值,比纯环氧树脂的拉伸强度分别提高了11.04%和43.78%。石墨烯和MWCNTs能协同提高环氧树脂的低温力学性能。     

石墨烯增强室温硫化硅橡胶复合材料的制备及力学性能

采用机械共混法制备了石墨烯(GNS)/室温硫化硅橡胶(RTV)复合材料。用扫描电镜(SEM)、透射电镜(TEM)、红外光谱(FT-IR)、拉曼光谱(Raman)和X射线衍射(XRD)对GNS的微观结构以及GNS在RTV硅橡胶基体中的分布情况进行了表征和分析,同时研究了GNS/RTV硅橡胶复合材料的力学性能。结果表明,石墨烯在基体硅橡胶中的分布较均匀,极少出现团聚现象;随着填料石墨烯含量的增加,复合材料的拉伸模量逐渐增大,拉伸强度和断裂伸长率均出现极大值后渐渐减少;当石墨烯的质量分数为0.925%时,复合材料的拉伸强度和断裂伸长率均达最大值,分别为0.8387MPa和195.78%,比纯RTV硅橡胶提高了159.86%和55.32%;此时拉伸模量比纯RTV硅橡胶提高了157.44%。     

稀释剂对DDM/E-51环氧树脂体系力学性能的影响

以乙二醇二缩水甘油醚(EGDGE)为活性稀释剂,4,4’-二氨基二苯甲烷(DDM)为固化剂,采用模具浇铸法制备了高力学性能的环氧固化物,详细研究了稀释剂含量对其拉伸、弯曲和冲击强度等力学性能的影响。结果表明,随着稀释剂含量的增加,环氧树脂的拉伸和弯曲强度及模量先增加后减小,添加40%(质量分数,下同)稀释剂时,拉伸和弯曲强度分别达到最大值96.7MPa和168.3MPa,比不添加稀释剂时提高了24.3%和19.2%;拉伸和弯曲模量也分别达到最大值1958.6MPa和3573.9MPa,比不添加稀释剂时提高77.8%和19.8%。添加20%稀释剂时,冲击强度达到最大值37.43kJ/m2,比不添加稀释剂时提高23.1%。     

原位制备还原氧化石墨烯增强环氧树脂基复合材料及其形状记忆性能

采用原位法制备不同含量还原氧化石墨烯(r GO)/环氧树脂(EP)复合材料。研究r GO含量对r GO/EP复合材料力学性能和形状记忆性能的影响。结果表明,通过溶剂热还原,填充到环氧树脂单体中的GO原位还原成r GO,并可均匀分散在EP基体中。该复合材料的拉伸强度、弹性模量和储能模量均随r GO含量增加呈先升后降态势,在w(r GO)=0.2%(相对于环氧树脂的质量而言)时相对最大;随着r GO含量增加,复合材料的玻璃化转变温度随之增加。当w(r GO)=0.6%时,玻璃化转变温度Tg相对纯环氧树脂提高约45℃,达到102℃,热稳定性显著提高。相应的复合材料具有良好的形状记忆性能,变形可以完全恢复,且r GO/EP复合材料相对纯环氧树脂具有更高的形状固定率与形状恢复温度。     

包裹氧化石墨烯的PMMA微球改性环氧树脂研究

自制聚甲基丙烯酸甲酯(PMMA)微球和氧化石墨烯(GO),将GO包裹在PMMA微球上,用包裹了GO的PMMA微球改性环氧树脂,包裹在PMMA微球上的GO更容易在环氧树脂中分散,能显著提高环氧树脂的导热性;利用包裹GO的PMMA微球制备的环氧树脂复合材料拉伸强度和拉伸模量在GO质量分数为0.5%时具有最大值,弯曲强度和弯曲模量随GO含量的增加而减小。     

CIP/GF/CF/EP吸波复合材料的制备及力学性能

为制备兼具力学性能和电磁吸收性能的结构型吸波材料,采用真空辅助成型工艺设计制备一种以羰基铁粉(CIP)为吸收剂,玻璃纤维(GF)为透波层,碳纤维(CF)为反射层,环氧树脂(EP)为基体的吸波复合材料。研究了不同质量比CIP/EP对吸波复合材料力学性能和微波吸收性能的影响。通过FTIR和DSC分析可知CIP未与EP发生化学反应。SEM结果表明CIP能够在EP树脂基体中均匀分散,不趋向于纤维表面。力学测试分析结果显示:当CIP/EP质量比达到30%时,CIP/GF/CF/EP复合材料的力学性能最佳,拉伸强度为347.56MPa,拉伸模量为25.99GPa,较纯GF/CF/EP复合材料提升了4.3%和5.7%;弯曲强度为339.6MPa,弯曲模量为23.7GPa,较纯GF/CF/EP复合材料提升了18.2%和71.2%。矢量网络分析可知复合吸波板的吸波性能随CIP含量的增加而增加,且吸波损耗反射峰值朝低频段移动。     

Fabrication and mechanical properties of well-dispersed multiwalled carbon nanotubes/epoxy composites

Multiwalled carbon nanotubes (MWCNTs)/epoxy nanocomposites were fabricated by using ultrasonication and the cast molding method. In this process, MWCNTs modified by mixed acids were well dispersed and highly loaded in an epoxy matrix. The effects of MWCNTs addition and surface modification on the mechanical performances and fracture morphologies of composites were investigated. It was found that the tensile strength improved with the increase of MWCNTs addition, and when the content of MWCNTs loading reached 8 wt.%, the tensile strength reached the highest value of 69.7 MPa. In addition, the fracture strain also enhanced distinctly, implying that MWCNTs loading not only elevated the tensile strength of the epoxy matrix, but also increased the fracture toughness. Nevertheless, the elastic modulus reduced with the increase of MWCNTs loading. The reasons for the mechanical property changes are discussed.     

混合型固化剂对环氧树脂室温和低温力学性能的影响

研究了一种刚性和柔性胺混合型固化剂（芳香胺DETD和聚醚胺D-400）固化环氧树脂浇铸体的力学性能、材料断裂表面的微观形貌和玻璃化转变温度等性能。结果表明:当D-400加入量占固化剂总量的40%时,其室温拉伸强度呈现最大值,为82.52 MPa,弹性模量为2.30 GPa,与未加D-400的体系相比分别提高了6.3%和14.4%,其低温冲击强度提高了14%。对冲击断面形貌进行扫描电子显微分析表明:D-400的加入致使断口形貌变得粗糙,抗开裂能力得到提高。热分析实验结果显示,体系的玻璃化转变温度随着D-400含量的增加而降低。此外,还探讨了环氧树脂体系低温增韧机制。      

A new method of reinforcing graphene nanoplatelets in glass/epoxy composites

This research aims to develop a method for the amalgamation of graphene nanoplatelets in glass/epoxy composites. The poor interface bonding between the fiber and matrix is critical and hinders the full performance of the composites. Glass fabric and epoxy were used as reinforcement and matrix in the composite, respectively. Graphene nanoplatelets were utilized as an additional nano-materials filler for the composites. Glass/graphene/epoxy and glass/epoxy composites were fabricated via vacuum infusion molding. The new method of applying graphene nanoplatelets as secondary reinforcement in the composite was developed based on proper functionalization in the sonication process. The physical, tensile, flexural, and short beam interlaminar properties of fabricated composites were examined to analyze the method's effectiveness. The results showed that density decreased by around 5 %; however, thickness increased by around 34 % after introducing graphene nanoplatelets into the composites. The tensile strength and modulus of the composites declined by approximately 19 %, on the other hand, flexural strength and modulus increased by around 63.3 % and 8.3 %, respectively, after the addition of graphene nanoplatelets into the composites. Moreover, interlaminar shear strength of the composite was enhanced by approximately 50 %.     

Effect of matrix glass transition on reinforcement efficiency of epoxy-matrix composites with single walled carbon nanotubes,multi-walled carbon nanotubes,carbon nanofibers and graphite

This study compares the mechanical and thermal properties of glassy and rubbery epoxy–matrix composites reinforced with 1 and 4 wt.% single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), graphite, and carbon nanofibers (CNFs). The tensile modulus of most glassy composites was higher than that of the epoxy and increased with higher filler concentration and 4% graphite/epoxy and 4% SWCNT/epoxy exhibited approximately the same highest tensile modulus. The elongation of glassy composites was significantly lower than that of the epoxy and decreased with increasing filler loading. Most rubbery composites showed a higher tensile modulus and elongation than the epoxy and the modulus increased with rising filler content and 4% SWCNT/epoxy showed the highest tensile modulus and tensile strength. In the rubbery regime, glassy and rubbery composites displayed a higher storage modulus than the corresponding epoxy and 4 wt.% SWCNT/epoxy composites showed a 300% improvement in storage modulus compared to the epoxy.     

氧化石墨烯纳米片/环氧树脂复合材料的制备与性能

氧化石墨烯(GO)是石墨烯重要的衍生物之一,通过氧化和超声波分散制备了GO纳米片/环氧树脂复合材料。采用XRD、拉曼光谱、FTIR和TEM表征了GO纳米片的结构与形貌,研究了GO纳米片用量对GO纳米片/环氧树脂复合材料热稳定性、力学性能及介电性能的影响。结果表明:GO纳米片的加入提高了GO纳米片/环氧树脂复合材料失热稳定性;随着GO纳米片填充量的增加,GO纳米片/环氧树脂复合材料的冲击强度和抗弯性能先提高后降低,其介电常数和介电损耗则先减小后增加。GO纳米片填充量为0.3wt%的GO纳米片/环氧树脂复合材料的失重5%时的热分解温度由纯环氧树脂的400.2℃提高到424.5℃,而冲击强度和弯曲强度分别在GO纳米片填充量为0.2wt%和0.3wt%时达到最大,冲击强度由纯环氧树脂的10.5kJ/m2提高到19.7kJ/m2,弯曲强度由80.5 MPa提高到104.0 MPa。     

石墨烯添加量对铜基复合材料性能的影响

采用一步化学还原法结合放电等离子烧结工艺制备石墨烯增强铜基复合材料,利用XRD、SEM、拉曼光谱、拉伸试验机、纳米压痕仪、涡流电导率仪等研究石墨烯含量对复合材料微观组织、力学性能和导电性能的影响。结果表明:石墨烯在复合材料基体中均匀分布,石墨烯的添加能显著增强铜基体的力学性能。与纯铜相比,添加0.025%(质量分数)的氧化石墨烯,可使其屈服强度提高219.8%,抗拉强度提高35.9%,弹性模量提高6.9%,此外,其导电率仍有93.1%IACS。随着石墨烯含量的增加,复合材料的屈服强度、抗拉强度及弹性模量均有所下降,这是因为高石墨烯含量复合粉体中部分石墨烯纳米片未能被铜颗粒包覆,其与铜基体界面结合强度低,石墨烯的剪切应力转移强化效果降低。     

Properties of graphene nanopowder and multi-walled carbon nanotube-filled epoxy thin-film nanocomposites for electronic applications: The effect of sonication time and filler loading

Graphene nanopowder (GNP) and multi-walled carbon nanotube (MWCNT)-filled epoxy thin-film composites were fabricated using ultrasonication and the spin coating technique. The effect of sonication time (10, 20 and 30 min) and GNP loading (0.05–1 vol%) on the tensile and electrical properties of GNP/epoxy thin-film composites was investigated. The addition of GNP decreased the material’s tensile strength and modulus. However, among the tested samples, the GNP/epoxy composites produced using 20 min of sonication time had a slightly higher tensile strength and modulus, with a lower electrical percolation threshold volume fraction. The effect of sonication time was supported by morphological analysis, which showed an improvement in GNP dispersion with increased sonication time. However, GNP deformation was observed after a long sonication time. The GNP/epoxy composites at different filler loadings showed higher electrical properties but slightly lower tensile properties compared with the MWCNT/epoxy composites fabricated using 20 min of sonication time.     

石墨烯与多壁碳纳米管增强环氧树脂复合材料的制备及性能

对多壁碳管(MWCNTs)进行改性处理得到酸化碳管(MWCNTs-COOH)和环氧化碳管(MWCNTs-Epon828), 将石墨烯(Graphene)与不同的碳管分别混合, 制备出三种Graphene-MWCNTs/环氧树脂(EP)复合材料。通过拉伸和热重实验研究了石墨烯与MWCNTs的协同作用、 两者的含量以及MWCNTs功能化方法对复合材料力学和热学性能的影响。结果表明: 石墨烯与MWCNTs的协同增强明显优于MWCNTs单独增强。当石墨烯和MWCNTs质量分数仅为0.1%时, Graphene-MWCNTs-Epon828/EP的拉伸强度达最大值, 其拉伸强度、 弹性模量和断裂伸长率分别较纯EP增加了35%、 65%和34%。石墨烯和MWCNTs的加入使Graphene-MWCNTs/EP复合材料的热稳定性均有所提高。     

The reinforcing effect of graphene nanosheets on the cryogenic mechanical properties of epoxy resins

The reinforcing effect of graphene in enhancing the cryogenic tensile and impact properties of epoxy composites is examined at a weight fraction of 0.05–0.50%. The micro-structure and cryogenic mechanical properties of the graphene/epoxy composites are investigated using scanning electron microscopy, transmission electron microscopy, small-angle X-ray scattering and mechanical testing techniques. The results show that the graphene dispersion in the epoxy matrix is good at low contents while its aggregation takes place and becomes severer as its content increases. And the cryogenic tensile and impact strength at liquid nitrogen temperature (77 K) of the composites are effectively improved by the graphene addition at proper contents. The cryogenic Young’s modulus increases almost linearly with increasing the graphene content. Moreover, the results for the mechanical properties at room temperature (298 K) of the graphene/epoxy composites are also presented for the purpose of comparison.