BMI树脂/蒙脱土纳米复合材料(Ⅱ)——纳米复合材料的制备及表征

以烯丙基三苯基溴化(AP)作为界面改性剂对钠基蒙脱土进行改性,得到有机蒙脱土(OMMT),然后采用原位聚合方法制备二烯丙基双酚A改性二苯甲烷双马来酰亚胺(BMI)树脂/OMMT纳米复合材料。采用FT-IR、WAXD、TEM、TGA等研究了纳米复合材料的结构和性能。研究表明,AP中的烯丙基官能团能与BMI单体中酰亚胺环上的双键发生反应;当OMMT含量少时得到剥离型纳米复合材料,而当OMMT含量多时得到插层型纳米复合材料;复合材料体系的热性能明显优于基体树脂。     

七苯基倍半硅氧烷三硅醇改性双马来酰亚胺纳米复合材料

通过熔融共聚法制备了七苯基倍半硅氧烷三硅醇(POSS-triol)/双马来酰亚胺(BMI)/二烯丙基双酚A(BA)纳米复合材料.利用扫描电镜( SEM)、透射电镜(TEM)、动态力学分析(DMA)及热重分析(TGA)对BMI复合材料的结构形态与热性能进行了研究.实验结果表明,POSS-triol粒子能均匀分散于树脂体系...     

氧化石墨烯/双马来酰亚胺树脂纳米复合材料的制备及性能

通过溶剂超声剥离法制备氧化石墨烯/双马来酰亚胺(BMI)树脂纳米复合材料。采用X射线衍射(XRD)、透射电镜(TEM)和热重分析(TGA)对纳米复合材料进行表征,并对其力学性能进行研究。结果表明,在N,N-二甲基甲酰胺中超声能有效地将异氰酸苯酯改性的氧化石墨剥离成氧化石墨烯薄片;这种纳米复合材料比BMI树脂具有更好的力学性能和耐热性能,当氧化石墨烯含量为基体树脂的1%时,其拉伸强度、弯曲强度和冲击强度分别为87.7 MPa、142.1MPa、15.9 kJ/m2,当氧化石墨烯含量为1.25%时,其1000℃时的残炭率达41.3%。     

双马来酰亚胺/蒙脱土纳米复合材料的制备及表征EI北大核心CSCD

利用有机蒙脱土(OMMT)对双马来酰亚胺(BMI)树脂进行改性制备纳米复合材料。采用X射线衍射、透射电子显微镜对材料的微观结构进行表征,研究了纳米复合材料的弯曲性能、冲击性能以及动态力学性能。结果表明,当OMMT的质量分数为1%时,蒙脱土的片层被充分剥离,纳米复合材料的弯曲强度、弯曲模量和冲击强度均达到最大值,冲击断口形貌显示材料由改性前的脆性断裂转变为韧性断裂。同时,纳米复合材料的玻璃化转变温度(Tg)也得到提高。     

双马来酰亚胺/蒙脱土纳米复合材料的制备及表征

利用有机蒙脱土(OMMT)对双马来酰亚胺(BMI)树脂进行改性制备纳米复合材料。采用X射线衍射、透射电子显微镜对材料的微观结构进行表征,研究了纳米复合材料的弯曲性能、冲击性能以及动态力学性能。结果表明,当OMMT的质量分数为1%时,蒙脱土的片层被充分剥离,纳米复合材料的弯曲强度、弯曲模量和冲击强度均达到最大值,冲击断口形貌显示材料由改性前的脆性断裂转变为韧性断裂。同时,纳米复合材料的玻璃化转变温度(Tg)也得到提高。     

纳米Si_3N_4/双马来酰亚胺/氰酸酯树脂复合材料的性能

双马来酰亚胺树脂预聚体改性的氰酸酯树脂(BMI/CE)具有良好的机械性能和热性能,是一种多功能复合材料树脂基体。本文研究了纳米Si3N4的含量对BMI/CE复合材料力学性能和摩擦学性能的影响,并通过扫描电镜和透射电镜分析了复合材料的增韧机理、磨损机理以及纳米Si3N4在基体中的分散性。结果表明:纳米Si3N4可显著改善复合材料的力学性能和摩擦学性能。当纳米Si3N4含量为3.0wt%时,复合材料的力学性能和摩擦学性能最好。相对于BMI/CE树脂基体,复合材料的冲击强度提高了36.0%,弯曲强度提高了21.8%,摩擦系数降低了25.0%,磨损率降低了77.9%。纳米Si3N4粒子可较好地分散在树脂基体中,起到均匀分散应力的作用,从而增强材料的韧性;BMI/CE树脂为塑性变形和粘着磨损,而纳米Si3N4含量为3.0wt%时复合材料为粘着磨损。     

联苯聚芳醚酮-双马来酰亚胺复合树脂的分相行为和流变行为

离位复合增韧技术是本征脆性的热固性树脂基纤维复合材料提高韧性的有效解决方案,为了更好地结合离位增韧技术和树脂传递模塑(RTM)工艺制备高性能双马来酰亚胺(BMI)树脂基复合材料,本文面向新型热塑性联苯聚芳醚酮(PAEK-B),研究了PAEK-B在BMI树脂及碳纤维复合材料中的分相行为及PAEK-B/BMI复合树脂的流变特性。结果表明,PAEK-B在BMI树脂的注射窗口温度保持一定时间后会发生分相行为,并在RTM工艺制备的碳纤维(CF)/PAEK-B/BMI复合材料中保持了分相结构。BMI树脂的注射温度会影响到PAEK-B在其中的溶解特性,注射温度升高会使BMI树脂的初始黏度变小,但PAEK-B/BMI复合树脂的黏度拐点时间会缩短;PAEK-B/BMI复合树脂符合Winter-Chambon准则,复合树脂的tanδ对频率没有依赖性,且复合树脂的凝胶活化能随着PAEK-B含量的增加逐渐增大。      

SiO2-苯并噁嗪/双马来酰亚胺树脂的固化反应动力学

为改善双马来酰亚胺树脂(BMI)脆性过大、耐热性不足的缺点,以末端含有氨基的纳米SiO₂(SiO₂-NH₂)为原料,通过溶剂法制备出结构中含有SiO₂的苯并噁嗪树脂单体(SiO₂-BOZ),作为改性体系加入到BMI中进行共混,制备出一种耐热性能、韧性良好的新型SiO₂-BOZ/BMI树脂材料,并详细研究了SiO₂-NH₂的添加对BMI固化反应动力学的影响。结果表明,当SiO₂-BOZ添加量达到15.0wt%时,SiO₂-BOZ/BMI树脂复合材料的表观活化能较纯BMI树脂得到了一定程度的降低,SiO₂-BOZ/BMI的弯曲强度达到最大值166.12 MPa,较纯BMI 增加了32.3%,且具有比BMI更好的耐热性能。      

氰酸酯树脂/氧化石墨烯纳米复合材料的制备及表征

通过溶液插层的方法制备氰酸酯树脂/氧化石墨烯纳米复合材料,采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和热重分析(TGA)研究纳米复合材料的结构和性能,采用电子万能试验机研究纳米复合材料的力学性能。研究表明,异氰酸苯酯改性氧化石墨在二甲基甲酰胺中经超声处理后剥离形成氧化石墨烯薄片;添加氧化石墨烯后纳米复合材料的力学性能和耐热性显著改善。当氧化石墨烯的含量为基体树脂的1%时,纳米复合材料的拉伸强度、弯曲强度和冲击强度分别为82.9 MPa、148.6 MPa和12.9 kJ/m2,1000℃时的残炭率达45.1%。     

NanoG/BMI纳米减摩复合材料的制备及其性能

利用扫描电子显微镜(SEM)和X射线衍射(XRD)手段研究纳米石墨薄片(NanoG)制备条件对层间结构与润滑性能影响,首次以NanoG为润滑剂制备的NanoG/BMI纳米减摩复合材料,研究其减摩性能和耐热性能及力学性能.研究表明:NanoG主要是由具有石墨的标准002特征峰的多层碳-碳六方平面结构的“亚结构单元“构成,其润滑性能主要是由于这些多层“亚结构单元“之间易相对滑动的结果;3%～5%NanoG或NanoG MoS2制备的NanoG/BMI或NanoG MoS2/BMI纳米减摩复合材料减摩性能优于20%石墨粉制备的传统减摩复合材料或与其相当,而前者的力学性能远优于后者,且均具有较好的耐热性能.     

Mechanical,tribological and heat resistant properties of fluorinated multi-walled carbon nanotube/bismaleimide/cyanate resin nanocomposites

Bismaleimide containing cyanate resin(BMI/CE) pre-ploymer was used as resin matrix. Fluorinated multiwalled carbon nanotubes(F-MWCNTs) were used as fillers to prepare F-MWCNT/BMI/CE nanocomposites via a solution intercalation method. The influence of F-MWCNT content on the mechanical, tribological and heat resistant properties of the nanocomposites was investigated. The morphology of the fracture surface and the wear surface of nanocomposites were characterized by scanning electron microscopy.Results show that the addition of F-MWCNTs is beneficial to improving the mechanical and tribological properties of the nanocomposites. It's worth noting that when the content of F-MWNTs was 0.6 wt%, the performances of nanocomposite are optimized(i.e., highest impact strength, lowest frictional coefficient and wear rate). In addition, the nanocomposites exhibit good thermal stability in comparison with BMI/CE.     

一种耐高温加成固化型酚醛树脂作为复合材料基体的评价

制备了烯丙基化程度可达 173%的烯丙基酚醛树脂(AN173),并与双马来酰亚胺(BMI)以 1 ∶1 的质量比进行共聚,制备了双马改性的烯丙基酚醛树脂(BMAN173) 。研究了该树脂工艺性,确定了其固化制度,考察了该树脂石英布复合材料层合板的耐热性和力学性能。实验结果表明,BMAN173 树脂具有良好的工艺性,适合于RTM、模压成型等多种成型工艺。BMAN173树脂固化物表现出良好的耐热性,其储能模量起始下降温度约为390℃, 起始热分解温度超过430℃。与传统酚醛树脂相比,该树脂的复合材料的高温力学性能优异,350℃弯曲强度和层间剪切强度保留率分别约为57%和62%;复合材料具有优异的热性能,其储能模量起始下降温度约为410℃,玻璃化转变温度超过了450℃。BMAN173树脂是耐高温复合材料的理想候选基体树脂。     

Effect of interfacial interaction between graphene oxide derivatives and poly(vinyl chloride) upon the mechanical properties of their nanocomposites

In this work, graphene oxide (GO) and poly(methyl methacrylate) (PMMA) grafted GO reduced by dopamine (rGO@PDA-g-PMMA) were employed to determine the key factor responsible for the improved mechanical properties of poly(vinyl chloride) (PVC). Dopamine was utilized to reduce GO and simultaneous coating of polydopamine (PDA) on the GO surface. rGO@PDA-g-PMMA was prepared by a combination of mussel-inspired chemistry and surface-initiated atom transfer radical polymerization techniques. The resulting derivatives were characterized by thermogravimetric analysis, Fourier transforms infrared spectroscopy, X-ray diffraction, and Raman spectroscopy. PVC nanocomposites containing GO derivatives were prepared by solution blend and the nanocomposite films were obtained using a casting method. The mechanical properties of the nanocomposites were studied using both dynamic mechanical thermal analysis and tensile testing. The results revealed that the vital components responsible for the improved mechanical properties and thermal stability of rGO@PDA-g-PMMA/PVC nanocomposites compared to pure PVC are the interfacial interactions between the GO derivatives and the PVC matrix.     

Click coupled stitched graphene sheets and their polymer nanocomposites with enhanced photothermal and mechanical properties

The chemically stitched graphene oxide (GO) sheets were obtained using a click chemistry reaction between azide-functionalized GO and alkyne-functionalized GO. The click coupled GO (GO-click-GO) sheets showed the largely increased electrical conductivity and near infrared laser-induced photothermal properties compared to the GO sheets, which result from formation of triazole ring as a bridging linker between the GO sheets. The polyurethane (PU) nanocomposites incorporating the GO-click-GO sheets exhibited enhanced mechanical properties of breaking stress and modulus than the GO/PU nanocomposites. The modulus of GO-click-GO/PU nanocomposites was higher than that of the GO/PU nanocomposites at the same filler loading of 0.1 and 0.5 wt%. The GO-click-GO/PU nanocomposites also showed a significantly improved photothermal properties compared to the GO/PU nanocomposites at the same filler loading. The click coupled stitched GO sheets in this study can be used as the superior reinforcing fillers for mechanically and photothermally high performance polymer nanocomposites.     

界面强度对柔性环氧树脂/粘土纳米复合材料热/力学性能的影响

先合成反应型BBDMP30-clay有机化粘土和非反应型CPDMP30-clay有机化粘土,然后以其为纳米增强体分别制备了两种界面强度不同的环氧树脂/粘土纳米复合材料。用透射电子显微镜(TEM)、拉伸实验表征这两种环氧树脂/粘土纳米复合材料并进行动态力学分析(DMA),研究了界面强度对其力学性能的影响。结果表明：这两种纳米复合材料具有几乎相同的无规剥离结构,反应型BBDMP30-clay比非反应型CPDMP30-clay能更有效地提高材料的热/机械性能。粘土质量分数为3.5%时BBDMP30-clay可使纳米复合材料的拉伸强度提高250%,而CPDMP30-clay只能使材料的拉伸强度提高190%。BBDMP30-clay使纳米复合材料的玻璃化转变温度(T_g)提高了6.5℃,而CPDMP30-clay只能使材料的T_g提高2.5℃。这些不同都可归因于这两种纳米复合材料界面强度的差异。     

The effects of the variations of carbon nanotubes on the micro-tribological behavior of carbon nanotubes/bismaleimide nanocomposite

Two kinds of original multiwalled carbon nanotubes (MWCNTs) with different diameters, and one carboxyliated MWCNTs were used to prepare three kinds of MWCNTs/bismaleimide (BMI) nanocomposites. The effects of the diameter, concentration and functional group of MWCNTs used in the composites on the micro-tribological behavior of the MWCNTs/BMI nanocomposites were investigated in this paper. The microhardness, the morphology of the worn surface, the glass transition temperature and dynamic mechanical properties of the MWCNTs/BMI nanocomposites were also measured to figure out the possible main wear mechanism of the composites. Results show that the addition of MWCNTs in BMI resin decreases the friction coefficient of the resin no matter what kind of MWCNTs is added. Moreover, the wear loss rate of all nanocomposites considerably decreases with the increasing of nanotube content until the content reaches 2.5 wt%. Functionalization of MWCNTs changes the main wear mechanism of the MWCNTs/BMI composite from adhesive wear (for pure BMI resin) to abrasive attrition by changing the self-lubricating property of the wore surface, the dispersion of MWCNTs in the BMI matrix, the interfacial strength between MWCNTs and the matrix as well as the internal strength of the materials.     

氧化石墨烯改性碳纤维/环氧树脂复合材料的湿热性能及微观形貌

采用湿法预浸技术和模压工艺制备了氧化石墨烯(GO)改性碳纤维/环氧树脂(CF/EP)复合材料,研究了GO在室温干态及湿热处理后对CF/EP复合材料动态热力学性能和层间剪切性能的影响,并通过微观形貌分析了复合材料的改性机制。结果表明,当GO添加量分别为0.5%和0.8%时,GO-CF/EP复合材料的玻璃化转变温度(T_g)得到明显提高,由CF/EP复合材料的184.4℃分别提高到197.7℃和199.5℃;GO-CF/EP复合材料经湿热处理后,GO-CF/EP复合材料的T_g的保持率比CF/EP略低。GO添加量分别为0.05%和0.1%时,GO-CF/EP复合材料的层间剪切强度由CF/EP复合材料的59.7 MPa分别提高到70.2 MPa和72.2 MPa;GO-CF/EP复合材料进行湿热处理后,GO添加量为0.05%的GO-CF/EP复合材料和GO添加量为0.1%的GO-CF/EP复合材料层间剪切强度较CF/EP复合材料高,但GO-CF/EP复合材料的湿热后层间剪切强度保持率均低于CF/EP复合材料。力学损耗分析表明,GO有效提高了CF与EP基体间的界面黏结作用。微观形貌分析表明,GO的存在可有效分散裂纹能量并使裂纹发生偏转,使GO-CF/EP复合材料抵抗裂纹扩展的能力提高。      

单层氧化石墨烯改性水性聚氨酯

采用一种新型高效的铁系强氧化剂成功制备出单层氧化石墨烯(GO),通过衰减全反射红外光谱、X射线衍射、拉曼光谱、原子力显微镜、场发射电子显微镜表征了这种单层GO的形态和性质。通过超声将GO分散于去离子水中,于水性聚氨酯(WPU)合成的乳化阶段共混制备出GO-WPU复合材料,测试了其拉伸性能、热学性能、疏水性的变化,同时利用透射电镜和场发射电子显微镜分别对乳液粒子形态与涂膜截面形貌进行了观察。结果表明,单层GO在乳化阶段的加入所制备的复合材料的拉伸强度得到了明显的改善,由原来的10 MPa增加到24 MPa,当GO质量分数为0.30%,复合聚氨酯的初始热分解温度(T_(d5))从245℃上升到272℃,同时,随着GO用量的逐步增加,复合膜的接触角则由70.3°提高到了95.2°从而实现了疏水性的改善。     

Fabrication and characterization of OMMt/BMI/CE composites with low dielectric properties and high thermal stability for electronic packaging

Thermostable nanocomposites based on interpenetrating polymer network bismaleimide/cyanate ester (BMI/CE) copolymer, derived from bisphenol A dicyanate, 4,4′-bismaleimidodiphenyl methane, and doped by 1–5 wt% organo-modified 2D montmorillonite (OMMt) nanoparticles were synthesized and characterized using a dielectric strength tester, concept 40 impedance analyzer, scanning electron microscope (SEM), dynamic mechanical analysis, and thermogravimetric analysis techniques. OMMt improves the dispersibility, alignment and interfacial strength of these nanocomposites, the electrical conductivity increase with increasing OMMt loading, and a suitable addition of OMMt can enhance the mechanical properties and dielectric property of BMI/CE copolymer. SEM analysis shows distinct characteristics of a ductile fracture of the blends. In addition, the OMMt/BMI/CE nanocomposites have a better thermal stability and a higher thermal conductivity compared to those of BMI/CE resin with the increasing of OMMt content. All of these changes in properties are closely correlated with the OMMt/BMI/CE nanocomposites, which could form an interaction interface structure in the system.