丁腈橡胶/功能化氧化石墨烯复合材料的研究

用硅烷偶联剂KH590对氧化石墨烯进行功能化改性,得到的功能化氧化石墨烯再通过乳液共混和机械共混等工艺制备了丁腈橡胶/功能化氧化石墨烯复合材料.表征分析了功能化氧化石墨烯的结构和表面形态,研究了丁腈橡胶/功能化氧化石墨烯复合材料的机械性能.结果 显示,与氧化石墨烯相比,功能化氧化石墨烯的亲水性和表面形态均发生了较大变化...     

氧化石墨烯改性粉末丁腈橡胶-环氧树脂复合材料的研究

采用三辊研磨分散技术制备了氧化石墨烯改性粉末丁腈橡胶-环氧树脂三元复合材料,探讨了氧化石墨烯不同用量对复合材料机械性能的影响.结果 表明,当氧化石墨烯用量为0.3％时,复合材料的无缺口冲击性能和抗弯曲性能最好;随氧化石墨烯用量的增加,复合材料的热变形温度有所提升,但硬度变化不明显.     

氧化石墨烯改性粉末丁腈橡胶-环氧树脂复合材料的研究

采用三辊研磨分散技术制备了氧化石墨烯改性粉末丁腈橡胶-环氧树脂三元复合材料,探讨了氧化石墨烯不同用量对复合材料机械性能的影响。结果表明,当氧化石墨烯用量为0.3%时,复合材料的无缺口冲击性能和抗弯曲性能最好;随氧化石墨烯用量的增加,复合材料的热变形温度有所提升,但硬度变化不明显。     

功能化还原氧化石墨烯/天然橡胶导热复合材料的性能研究

采用2-巯基苯并咪唑(防老剂MB,以下简称MB)对氧化石墨烯(GO)进行还原及功能化,同时与采用抗坏血酸(VC)对GO进行还原对比,分别制得MB还原氧化石墨烯(rGO-MB)和VC还原氧化石墨烯(rGO-VC),并采用胶乳共混法制备rGO-MB/NR和rGO-VC/NR复合材料,对其性能进行研究。结果表明:MB成功还原了GO,MB接枝到了GO上;与rGO-VC/NR复合材料相比,rGO-MB/NR复合材料具有较低的Payne效应和较高的结合胶含量,拉伸强度和导热性能均明显提高。     

HDPE/功能化石墨烯复合材料制备及性能研究

氧化石墨烯(GO)具有较高的比表面积,层间距大,表面拥有丰富的官能团,可以很好地分散到聚合物中,但GO导电性差。研究对GO进行还原和表面修饰,以改善石墨烯和HDPE的相容性。采用熔融混炼法制备了HDPE/石墨烯复合材料,结合力学性能、导电性能、微观结构测试,考察不同HDPE/石墨烯复合材料的导电阈值,分析影响复合材料导电性的因素,进而得出较优化的制备工艺。研究发现石墨烯添加量为7.5%时,导电通路开始形成,当石墨烯含量达到7.5%时,拉伸强度提升22.14%,拉伸模量提升21.19%。     

用一步法原位制备氢化丁腈橡胶/还原氧化石墨烯纳米复合材料

将氢化丁腈橡胶(HNBR)与石墨烯二维纳米材料(GO)共混以提高其导电和导热性能,采用乳液一步法还原制备了HNBR/还原氧化石墨烯(RGO)纳米复合材料。结果表明,丁腈橡胶(NBR)乳液中分子链的碳碳双键和GO经水合肼/过氧化氢/硫酸铜催化体系产生的活性中心二酰亚胺被同时进行加氢和还原,这在改善HNBR性能的同时简化了RGO纳米复合材料的制备工艺,制备过程没有毒性大的有机溶剂。HNBR/RGO纳米复合材料的氢化度为61%,I_D/I_G为1. 36,说明NBR/GO中分子链双键和GO经一步法得到还原。采用一步法可将RGO在HNBR基质中均匀分散。HNBR/RGO纳米复合材料的力学性能和热性能因RGO的存在得以大幅度改善。     

氧化石墨烯/羧基丁腈橡胶纳米复合材料的制备及其耐有机溶剂渗透性能的研究

采用改进Hummers法制备氧化石墨烯（GO）,并以聚乙烯亚胺为“桥接分子”制备GO/羧基丁腈橡胶（XNBR）纳米复合材料,考察GO/XNBR纳米复合材料的微观形貌、力学性能和耐有机溶剂渗透性能。结果表明：GO与XNBR基体结合良好且分散均匀;GO/XNBR纳米复合材料的拉伸强度由纯XNBR胶料的3.9 MPa提高到7.2 MPa(GO用量为0.7份),提高了约1.8倍;随着GO用量增大,GO/XNBR纳米复合材料对有机溶剂的耐渗透时间明显延长。     

氧化石墨烯填充羧基丁腈橡胶复合材料的热稳定性及降解动力学

采用改进的Hummers法制备了不同氧化程度的氧化石墨烯(GO),并采用乳液混合法制备了GO/羧基丁腈橡胶(XNBR)复合材料,表征了GO的微观结构及其在复合材料中的分散状况,考察了GO的氧化程度对复合材料热稳定性的影响,分别采用Kissinger法和Ozawa法计算了复合材料的热分解活化能。结果表明,GO表面含有羧基、羰基和环氧基的含氧基团,氧化程度随着氧化剂高锰酸钾用量的增加而提高;GO氧化程度的提高可以有效改善GO在XNBR基体中的分散效果及复合材料的热稳定性,但是氧化程度过高会使热稳定性下降;采用Kissinger法和Ozawa法计算得到的热分解活化能虽不相同,但其大小顺序与GO氧化程度一致。     

氧化石墨烯的功能化及其生物相容性研究

利用改进Hummers法合成纳米级氧化石墨烯(GO),并将羧基和氨基化聚乙二醇(PEG-NH2)共价交联到GO表面,形成功能化的氧化石墨烯(PGO)。考察PGO在水、PBS和生理溶液中的稳定性,并以肝脏细胞为研究对象,结合MTT细胞毒性检测,评价PGO的生物相容性。结果表明,PGO在生理溶液中最稳定,且对肝脏细胞的毒性小,具有良好的生物相容性。     

氧化石墨烯的氧化程度对羧基丁腈橡胶纳米复合材料力学性能的影响（英文）

采用一种改进的Hummers方法,通过在浓硫酸中加入不同量的高锰酸钾,制备了不同氧化程度的氧化石墨烯(GO)。并将不同氧化程度的GO添加到羧基丁腈橡胶(XNBR)中,制备了XNBR/GO复合材料。结果表明,GO氧化程度的增加,使得XNBR/GO复合材料中橡胶与填料之间的相互作用变强。橡胶与填料之间强烈的相互作用促进XNBR/GO复合材料中的应力传导。当高锰酸钾/石墨的质量比为3.0时,XNBR/GO复合材料的拉伸强度、100%定伸应力、300%定伸应力和撕裂强度达到最大,相比于XNBR分别提高了114.6%、111.2%、269.3%和88.5%。     

Observation of mechanical percolation in functionalized graphene oxide/elastomer composites

We have covalently functionalized graphene oxide (GO) with octadecylamine (ODA) to form GO–ODA. This material can be dispersed in tetrahydrofuran (THF) and subsequently formed into composites with polymers such as thermoplastic polyurethane (TPU). We have characterized the mechanical properties of composites of GO–ODA in TPU. No increase in stiffness was observed at loading levels below 2.5 vol%. Reinforcement appeared to start sharply at this volume fraction and subsequently increased as a power law with increasing volume fraction. This behavior is typical of percolation and shows that the low-strain stress is not increased until the functionalized graphene flakes form a percolating network. Slightly different behavior is observed for properties related to material failure. The ultimate tensile strength increased linearly with graphene content up to the percolation threshold before subsequently falling off. Similarly the strain at break was constant below the percolation threshold but fell off dramatically above it. This work shows the importance of network formation in the reinforcement of elastomeric materials.     

淀粉/NBR复合材料的性能研究

采用共沉法和直接混合法制备淀粉/NBR复合材料,并对其性能进行对比研究.结果表明,与直接混合法制备的淀粉/NBR复合材料相比,共沉法制备的淀粉/NBR复合材料的拉伸强度和撕裂强度提高,淀粉在NBR中的分散性变好且两者间有一定的界面结合;随着淀粉用量的增大,共沉法制备的淀粉/NBR复合材料中淀粉的分散性变差,出现团聚现象,但复合材料的耐油性能提高.     

氧化石墨烯/密胺树脂导电复合材料的制备与性能研究

采用的改进的Hummers法和组合剥离技术制备了氧化石墨烯(GO),并以氧化石墨烯、甲醛溶液、三聚氰胺为原料,采用原位合成技术制备石墨烯/密胺树脂导电复合材料(GO/MF)及含有水合肼的氧化石墨烯/密胺树脂复合材料(GO/MF+N_2H_4),并对其结构、热稳定性和导电性等进行研究分析。试验结果表明:GO/MF+N_2H_4试样的热稳定性最佳,氧化石墨烯的加入,提高了密胺树脂材料的导电性,且添加质量分数0.9%GO的GO/MF+N_2H_4试样出现导电临界值,体积电阻率达到1.5×10~4Ω·m,为制备具有抗静电性能和导电性能的密胺树脂新型复合材料提供一定的基础理论参考。     

Kevlar oligomer functionalized graphene for polymer composites

Kevlar oligomer functionalized graphene (FGS) was prepared by simple grafting of amino-terminated Kevlar oligomer on graphene oxide (GO) followed by reducing with hydrazine hydrate. The incorporation of FGS shows pronounced effect on the host polymers. High-level reinforcement of both PMMA and PI is observed with low content of FGS (≤0.2 wt %), in this lower loading range, the tensile modulus and strength of composites increase almost linearly as a function of the adding amount of FGS. But no further improvement is obtained as the content of FGS further increased (>0.2 wt %). The mechanism under the reinforcement effect against the FGS loadings is discussed based on the morphological characterizations of the composites. The thermal properties of the composites were also investigated. The glass transition temperature and thermal stability of PMMA were dramatically increased even with the addition of only a small amount of FGS.     

Improvement of interfacial properties in bismaleimide composites using functionalized graphene oxide grafted carbon fiber

A hierarchical reinforcement, which was used to improve the interfacial properties of bismaleimide (BMI) composites, was prepared by grafting functionalized graphene oxide (GO) onto a carbon fiber surface. The GO and carbon fibers were first functionalized separately to create interactional functional groups on their surfaces. The grafting process was then realized by an amidation reaction of the amine and acyl chloride function groups formed on GO and carbon fibers, respectively. The surface groups of functionalized GO and carbon fibers were identified by an X‐ray photoelectron spectroscopy (XPS). The resulting reinforcement was further characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and dynamic contact angle analysis. Experimental results showed that the functionalized GO were successfully grafted onto the carbon fibers surfaces and significantly increased the surface energy of carbon fibers. The study also indicated that the prepared hierarchical reinforcement could significantly improve the interfacial adhesion of resulting BMI composite. POLYM. ENG. SCI., 58:886–893, 2018. © 2017 Society of Plastics Engineers     

Thermal conductivity and structure of non-covalent functionalized graphene/epoxy composites

Non-covalent functionalization was used to functionalize graphene nanosheets (GNSs) through π–π stacking of pyrene molecules with a functional segmented polymer chain, which results in a remarkable improvement in the thermal conductivity of GNS-filled polymer composites. The functional segmented poly(glycidyl methacrylate) containing localized pyrene groups (Py-PGMA) was prepared by atom transfer radical polymerization, and Py-PGMA was characterized by nuclear magnetic resonance spectroscopy. Raman spectra, X-ray photoelectron spectroscopy and thermogravimetric analysis reveal the characteristics of Py-PGMA–GNS. Differential scanning calorimetry indicated that the functional groups on Py-PGMA–GNSs can generate covalent bonds with the epoxy matrix, and further form a cross-linked structure in Py-PGMA–GNS/epoxy composites. The Py-PGMA on the GNS surface not only plays an important role to facilitate a homogeneous dispersion in the polymer matrix but also improves the GNS–polymer interaction, which results in a high contact area. Consequently, the thermal conductivity of integrated Py-PGMA–GNS/epoxy composites exhibited a remarkable improvement and is much higher than epoxy reinforced by multi-walled carbon nanotubes or GNSs. The thermal conductivity of 4 phr Py-PGMA–GNS/epoxy has about 20% (higher than that of pristine GNS/epoxy) and 267% (higher than pristine MWCNT/epoxy).     

Thermal and mechanical properties of liquid silicone rubber composites filled with functionalized graphene oxide

To improve the thermal and mechanical properties of liquid silicone rubber (LSR) for application, the graphene oxide (GO) was proposed to reinforce the LSR. The GO was functionalized with triethoxyvinylsilane (TEVS) by dehydration reaction to improve the dispersion and compatibility in the matrix. The structure of the functionalized graphene oxide (TEVS‐GO) was evaluated by Thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectra, X‐ray diffraction (XRD), and energy dispersive X‐ray spectroscopy (EDX). It was found that the TEVS was successfully grafted on the surface of GO. The TEVS‐GO/LSR composites were prepared via in situ polymerization. The structure of the composites was verified by FTIR, XRD, and scanning electron microscopy (SEM). The thermal properties of the composites were characterized by TGA and thermal conductivity. The results showed that the 10% weight loss temperature (T₁₀) increased 16.0°C with only 0.3 wt % addition of TEVS‐GO and the thermal conductivity possessed a two‐fold increase, compared to the pure LSR. Furthermore, the mechanical properties were studied and results revealed that the TEVS‐GO/LSR composites with 0.3 wt % TEVS‐GO displayed a 2.3‐fold increase in tensile strength, a 2.79‐fold enhancement in tear strength, and a 1.97‐fold reinforcement in shear strength compared with the neat LSR. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42582.     

NBR/革屑复合材料性能研究

将制革工艺中的削匀革屑（LS）与丁腈橡胶（NBR）混炼并压板制备成复合材料（NBR/LS）,通过测定复合材料物理力学性能考察工艺条件对材料性能的影响。分别对NBR纯胶和NBR/LS复合材料的热性能进行了表征。测试结果表明：NBR/LS复合材料制备中压板时间、温度和革屑含量均对NBR/LS复合材料有较大影响;最佳力学性能出现在压板时间为30 min,温度为150℃,革屑用量为15份的工艺条件下;革屑的加入使得NBR的玻璃化转变温度（Tg）从-33.6℃升高至-31.0℃,复合材料的tanδ峰值和损耗模量明显降低;NBR/LS复合材料比NBR纯胶有较好的热稳定性能。     

多孔胺基化氧化石墨烯基材料对CO2的吸附性能研究

以乙二胺(EDA)、二乙烯三胺(DETA)、四乙烯五胺(TEPA)、聚乙烯亚胺(PEI)等多胺基化合物为表面改性剂,氧化石墨烯(GO)材料为载体,采用嫁接法辅以超声处理制备了表面胺基功能化多孔吸附材料,用于CO₂气体的吸附捕集。所制备的多孔吸附材料孔径约为1.35~4.34 nm,比表面积约为98.032~210.465 m²/g。制备的四种吸附材料中,以PEI功能化吸附材料对CO₂的吸附容量最大,70℃下达到了1.5 mmol/g,且经过20次循环吸附/脱附实验后,其CO₂吸附量基本不变。吸附过程的吸附等温线线型为Ⅰ型优惠型,另外吸附实验数据与Avrami模型模拟结果符合性较好。