浇铸尼龙的纳米复合抗静电改性研究

以膨胀石墨所固有的导电性能和蓬松多孔的层状结构为基础,借鉴插层复合方法,通过浇铸尼龙6(MCPA6)与石墨片层之间的纳米复合,提高MCPA6的导电性能,达到抗静电的要求。通过导电性能测试及XRD、OM和SEM分析,研究了浇铸尼龙6/膨胀石墨抗静电复合材料的纳米结构及导电机理。结果表明:当膨胀石墨质量分数为1.0％时,体积电阻率已下降到1.99×10~8Ω·cm,实现了抗静电目标。     

聚乙烯/膨胀石墨导电阻燃复合材料的研究

通过溶液插层法研究了聚乙烯/膨胀石墨复合材料的力学性能、电学性能、阻燃性能。结果表明,当膨胀石墨填充量为10～15份时,复合材料的体积电阻降为1×108Ω以下,当膨胀石墨含量为30份时,复合材料的氧指数达到22 8,具有一定的阻燃性。     

聚酰胺／纳米膨胀石墨／碳纤维高强导电复合材料及其制备方法

本发明公开了聚酰胺／纳米膨胀石墨／碳纤维高强导电复合材料及其制备方法,复合材料由主基体聚酰胺100份、膨胀倍数在100倍以上的膨胀石墨1～6份、增强体碳纤维1～20份组成。本发明在聚酰胺／纳米膨胀石墨复合体系中通过添加增强体碳纤维制备了高强度、高导电性的复合材料。     

聚芳醚／纳米膨胀石墨／碳纤维高强导电复合材料及其制备方法

聚芳醚／纳米膨胀石墨／碳纤维高强导电复合材料及其制备方法,该复合材料由主基体聚芳醚、增强体碳纤维和膨胀倍数100倍以上的膨胀石墨组成,各组分的质量份为：主基体聚芳醚100份、增强体碳纤维1～30份、膨胀石墨1～8份。     

聚芳醚／纳米膨胀石墨／碳纤维高强导电复合材料及其制备方法

聚芳醚／纳米膨胀石墨／碳纤维高强导电复合材料及其制备方法,该复合材料由主基体聚芳醚、增强体碳纤维和膨胀倍数100倍以上的膨胀石墨组成,各组分的质量份为：主基体聚芳醚100份、增强体碳纤维1～30份、膨胀石墨1～8份。     

镀银纳米石墨微片/丙烯酸酯导电压敏胶的研究

以天然EG(膨胀石墨)为原料,采用超声分散法制得NanoG(纳米石墨微片);然后采用化学镀法制备导电填料Ag-NanoG(镀银纳米石墨微片);最后采用溶液共混法制备丙烯酸酯类Ag-NanoG/PSA(镀银纳米石墨微片/导电压敏胶)。研究结果表明:NanoG表面镀上了一层均匀紧凑的金属Ag,Ag层厚度为250 nm左右,其质量分数为50.04%;导电填料Ag-NanoG已均匀分散在丙烯酸酯PSA基体中,并形成了导电网络;当w(Ag-NanoG)=40%时,Ag-NanoG/PSA的综合性能相对最好,其180°剥离强度为0.25 kN/m,剪切强度为0.133 MPa且电导率为2.5×10-2S/cm。     

一种可降解PBAT复合材料相容剂的合成及应用

以扩链剂ADR4370S 和硅烷偶联剂KH550为原料，合成了一种含硅相容剂（K-ADR）并应用于滑石增强PBAT基复合材料中。采用FTIR、1HNMR、TGA对K-ADR的结构进行了表征，通过转矩流变仪制备PBAT/K-ADR/滑石体系复合材料，并对复合材料的流变性能、力学性能、冲击断面微观形貌和元素分布进行了表征。结果表明，当相容剂K-ADR添加质量是体系质量的6‰时，PBAT/K-ADR/滑石复合材料拉伸强度、冲击强度和弯曲模量分别为19.11MPa、67.68KJ/m2和378.36MPa，相比于纯PBAT样品分别提高了5.3%、110.7%和346.7%。复合薄膜的水蒸气透过率系数（WVP）为5.70×10-12g·cm/cm2·s，氧气透过率系数（OP）为3.17×10-13cm3·cm/(cm2·s·Pa)，分别降低为纯PBAT样品的2.1％和1.0％。     

PP/POE/GNP导电复合材料的制备与性能研究

用油酸钠/乙醇溶液、邻二氯苯、N-甲基吡咯烷酮对膨胀石墨进行表面处理和分散改性并制备了纳米石墨微片(GNP),研究了其效果,确定了油酸钠/乙醇溶液作为分散介质和表面改性剂。将由该处理剂制得的GNP以不同添加量添加到聚丙烯/聚烯烃弹性体共混树脂(PP/POE)中,制得PP/POE/GNP复合材料。测试表明,GNP在基体中分散均匀,大部分达到纳米尺寸,与基体结合良好,复合材料的室温渗滤阈值为9%左右(对应GNP质量份数为10份),GNP质量份数超过10份之后复合材料成为半导体,最低体积电阻率为3.6×107Ω.cm。当GNP质量份数为20份时,复合材料仍然保持较佳力学性能,材料破坏方式为脆性断裂。     

膨胀石墨/丁腈橡胶复合材料的性能研究

膨胀石墨是一种层状材料,具有优异的导电性和导热性。本文采用机械共混的工艺方法制备了膨胀石墨/丁腈橡胶复合材料,考察了膨胀石墨对丁腈橡胶导电性能和力学性能的影响。实验表明,当加入20份高耐磨炭黑时,丁腈橡胶具有优异的综合力学性能,其最大拉伸强度为12.85 MPa,邵尔A硬度为 60.4 度。采用直接共混的方法制备膨胀石墨/高耐磨炭黑/丁腈橡胶复合材料,并与炭黑/丁腈橡胶复合材料进行比较,研究了材料的力学性能与导电性能。结果表明添加膨胀石墨后可大大的提高炭黑/丁腈橡胶复合材料的导电性能和力学性能。当不含膨胀石墨时,丁腈橡胶复合材料基本不表现出导电性能。     

镀镍石墨／三元乙丙橡胶导电复合材料的性能研究

研究镀镍石墨（NCG）用量对NCG/三元乙丙橡胶（EPDM）导电复合材料性能的影响,遴选出最佳硅烷偶联剂,研究其用量对复合材料导电稳定性的影响、,结果表明,随着NCG剧量的增大,复合材料的体积电阻率逐渐降低,当NCG用量超过240份时,复合材料的体积电阻牢降至10 Ω·cm以下、Al37足一种有效的硅烷偶联剂,当其用量为9份时,复合材料的各项性能较好。     

Structure and electrical properties of grafted polypropylene/graphite nanocomposites prepared by solution intercalation

A novel process was developed to prepare electrically conducting maleic anhydride grafted polypropylene (gPP)/expanded graphite (EG) nanocomposites by solution intercalation. The conducting percolation threshold at room temperature (Φ_c) of the nanocomposites was 0.67 vol %, much lower than that of the conventional conducting composites prepared by melt mixing (Φ_c = 2.96 vol %). When the EG content was 3.90 vol %, the electrical conductivity (σ) of the former reached 2.49 × 10^?3 S/cm, whereas the σ of the latter was only 6.85 × 10^?9 S/cm. The TEM, SEM, and optical microscopy observations confirmed that the significant decrease of Φ_c and the striking increase of σ might be attributable to the formation of an EG/gPP conducting multiple network in the nanocomposites, involving the network composed of particles with a large surface‐to‐volume ratio and several hundred micrometers in size, and the networks composed of the boards or sheets of graphite with high width‐to‐thickness ratio and particles of fine microscale or nanoscale sizes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1864–1869, 2003     

Synthesis and characteristics of poly(methyl methacrylate)/expanded graphite nanocomposites

In this work, we synthesized poly(methyl methacrylate) (PMMA)/expanded graphite (EG) nanocomposites by a new polymerization method. The volume electrical conductivity of the nanocomposite prepared by this way is very high (when the content of EG is about 8 wt %, the conductivity could reach 60 S/cm). The structure of the nanocomposite was investigated by SEM, TEM, IR, and XRD. And we found temperature and voltage were important parameters of governing the electrical conductivity of PMMA/EG nanocomposites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1427–1431, 2006     

Electrical properties of polycarbonate/expanded graphite nanocomposites

In present study, polymer matrix nanocomposites based on polycarbonate as matrix and expanded graphite (EG) as reinforcement were fabricated using a simple solution method followed by hot pressing. Scanning electron microscopy revealed almost uniform dispersion and three dimensional networks of EG particles in the matrix. The dc and ac electrical conductivities of the nanocomposites increased with increasing EG content in the matrix. The electrical percolation threshold was observed between 1 and 2 wt % EG. The improvement in the conductivity of 10 wt % nanocomposite was found more than 13 orders of magnitude higher than that of pure matrix. The dielectric constant (at 1 MHz) of the nanocomposite containing 10 wt % EG was increased to about 137. The significant increase in electrical conductivity, dielectric constant, and dissipation factor for the nanocomposites might be good for the applications in antistatic/electromagnetic interference shielding applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47274.     

Preparation of interfacially compatibilized PP‐EPDM thermoplastic vulcanizate/graphite nanocomposites: Effects of graphite microstructure upon morphology,electrical conductivity,and melt rheology

Electrically conductive PP/EPDM dynamically crosslinked thermoplastic vulcanizate (TPV)/expanded graphite (EG) has been successfully prepared via melt compounding of maleic anhydride grafted polypropylene (PP‐g‐MA)/EG masterbatch and a commercially available TPV material. Correlation between graphite microstructure, and electrical conductivity as well as melt rheological behavior has been studied. Natural graphite flake (NGF), graphite intercalated compound (GIC), and exfoliated graphite (EG) have been employed and compared. Scanning electron microscopy (SEM) showed the presence of 100–200 nm nanolayers in the structure of PP‐g/EG masterbatches, whereas thinner platelets (1.5–2.5 nm) were revealed by transmission electron microscopy (TEM). Better dispersion of the graphite nanolayers in the microstructure of TPV/PP‐g‐MA/EG composite was verified, as the 7.3 Å spacing between the aggregated graphite nanolayers could not be observed in the XRD pattern of this material. TPV/PP‐g/EG nanocomposites exhibited much lower conductivity percolation threshold (φ_c) with increased conductivity to 10^?5 S/cm at EG wt % of 10. Higher nonlinear and nonterminal melt rheological characteristics of dynamic elastic modulus (G′) at low frequency region was presented by the TPV/PP‐g/EG nanocomposites, indicating the formation of nanoscopic conducting multiple networks throughout the continuous TPV matrix. Maleated PP was found to be much more effective in separating EG nanolayers which is attributed to the higher interfacial interaction between PP‐g‐MAH and EG, synergized with its multiporous structure. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Fabrication of electrically conductive polymer composites for bipolar plate by two‐step compression molding technique

Electrically conductive polymer composites for bipolar plate were fabricated by two‐step compression molding technique. Raw materials consisted of natural graphite flakes (G), expanded graphite (EG), carbon black (CB), and phenol resin (PF). The G/EG/CB/PF composites were first compressed at a temperature lower than curing point (100°C) and then cured at a high temperature above curing point (150°C) and high pressure (10 MPa). Results showed that G and EG are oriented in the direction parallel to the composite plate surface. CB is dispersed not only in the phenol resin matrix but also in the packing and porous space of G and EG. The addition of EG and CB significantly increases number of the electrical channels and thus enhances the electrical conductivity of the composite. Under optimal conditions, electrical conductivity and flexural strength of the composite were 2.80 × 10⁴ S/m and 55 MPa, respectively, suggesting that the dipolar plates prepared by two‐step compression molding technique are adequate to meet the requirement of proton exchange membrane fuel cells. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2296–2302, 2013     

PE-HD／PANi／EG复合材料的制备

用过硫酸铵氧化原位聚合法成功制备了聚苯胺/膨胀石墨(PANi/EG)导电复合填料,用溶液法对高密度聚乙烯(PE-HD)填充复合,制备出PE-HD/PANi/EG复合材料,实现了PE-HD由绝缘体向半导体的转化。通过X射线衍射、扫描电镜、电导率测量对材料进行了表征,结果表明:PANi/EG复合填料XRD表征初级粒子尺寸小于28nm,SEM表征聚集体粒子尺寸约500nm左右,电导率高于0.5S/cm;复合导电填料质量分数为5%时,电导率达到10-10S/cm,接近抗静电材料的要求。     

丁腈橡胶/石墨纳米复合材料的制备、结构及性能研究

采用乳液共混、直接共混及溶液共混等方法制备了丁腈橡胶/石墨复合材料,并用电子显微镜和X-射线进行了观察和衍射测试。结果表明,采用乳液共混可以制备出同时具有插层和剥离结构的纳米复合材料。随着石墨用量的增加,所得复合材料的力学性能(特别是小应变下的应力)逐渐提高,同时动态力学性能也有了显著的改善。另外,该复合材料还表现出多种优异的功能特性,如高气密性、高导电性和高导热性、低的摩擦系数和较好的耐磨损性能。     

Improvement in thermal conductivity and mechanical properties of ethylene‐propylene–diene monomer rubber by expanded graphite

Thermally conductive fillers are usually employed in the preparation of rubber composites to enhance thermal conductivity. In this work, ethylene‐propylene‐diene monomer rubber (EPDM)/expanded graphite (EG) and EPDM/graphite composites with up to 100 phr filler loading were prepared. Compared to EPDM/graphite compounds with the same filler loading, stronger filler network was demonstrated for EPDM/EG compounds. Thermal conductivity and mechanical properties of EPDM/graphite and EPDM/EG composites were compared and systematically investigated as a function of the filler loading. The thermal conductivity of both EPDM/graphite and EPDM/EG composites increased with increasing volume fraction of fillers, and could be well fitted by Geometric Mean Model. The thermal conductivity as high as 0.910 W · m⁻¹ · K⁻¹ was achieved for the EPDM/EG composite with 25.8 vol% EG, which was ∼4.5 times that of unfilled EPDM. Compared to EPDM/graphite composites, EPDM/EG composites exhibited much more significant improvement in thermal conductivity and mechanical properties, which could be well correlated with the better filler‐matrix interfacial compatibility and denser structure in EPDM/EG composites, as revealed in the SEM images of tensile fracture surfaces. POLYM. COMPOS., 38:870–876, 2017. © 2015 Society of Plastics Engineers     

膨胀石墨改性氢化苯乙烯-丁二烯-苯乙烯嵌段共聚物/聚丙烯弹性体的制备与性能

分别采用膨胀石墨和纳米Fe₃O₄插层膨胀石墨改性氢化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS)/聚丙烯(PP)弹性体材料,探讨了膨胀石墨用量及纳米Fe₃O₄插层复合膨胀石墨对弹性体拉伸性能、回弹性和导电性能的影响规律。结果表明,膨胀石墨的加入可有效提高SEBS/PP弹性体的回弹性和导电性能,当膨胀石墨用量为3.5份(质量)时,弹性体的回弹性最佳,表面电阻率最低,但其拉伸强度有所下降。采用纳米Fe₃O₄插层膨胀石墨改性SEBS/PP弹性体可有效改善其拉伸性能,并可进一步降低表面电阻率和体积电阻率。     

High electrical conductive polymethylmethacrylate/graphite composites obtained via a novel pickering emulsion route

In this work, high electrically conductive Polymethylmethacrylate/graphite (PMMA/G) composites with a specific core-shell structure were synthesized via Pickering emulsion (solid-stabilized emulsion) route. The electrical conductivity of the core-shell composites was measured by a four-point probe resistivity determiner and a very high value of 9.8?×?10^?3 S/cm (10¹³ times higher than virgin PMMA) was obtained at 30 wt% graphite. However, the electrical conductivity of the PMMA/G composites gained through traditional blend process was relatively lower and the value only reached 9.4?×?10^?9 S/cm at same graphite loading fraction. Contact angle measurement was applied to determine the surface free energy of the modified graphite which was cladded by Al(OH)₃. The morphology of the core-shell composites was observed by SEM and optical microscopy. Dynamic rheology analysis was employed to study the structural change by the interconnection of the graphite flakes and the formation of the networks in the composites. The interconnected networks of the core-shell composites were more easily constructed when compared with the composites obtained by the traditional blending process.