共混比对1,2-聚丁二烯/天然橡胶共混胶性能的影响

本工作研究了不同共混比的1,2 聚丁二烯/天然橡胶(1,2-PB/NR)共混胶的生胶、混炼胶和硫化胶的性能、实验表明,1,2-PB容易与NR共混,共混胶的辊筒行为良好。共混胶的门尼粘度和屈服强度随NR用量的增加而降低。NR的加入不仅使1,2-PB的挤出工艺行为得以改善,而且使其硫化胶的强伸性能和耐低温性能明显提高,同时对1.2-PB 的抗湿滑、低生热和耐热老化等性能无明显不良影响。     

腰果酚功能化液体1,2-聚丁二烯橡胶的制备及其对丁苯橡胶/白炭黑复合材料界面作用的增强

采用烯烃复分解法将生物基腰果酚（CA）接枝到1,2-聚丁二烯橡胶（1,2-PB）上制备了苯酚官能化的液体1,2-PB（1,2-PB-g-CA）。结果表明,CA成功接枝到聚丁二烯上,并且在开放体系下可得到官能度大于10%的接枝产物。将1,2-PB-g-CA作为白炭黑填充的丁苯胶轮胎胎面胶配方体系的增塑剂可提高白炭黑在基体中的分散性。同时,此改性低聚物羟基的存在有利于增加白炭黑和橡胶基体的相互作用。且该硫化胶具有较低的滚动阻力和生热性能。     

导电氯丁/天然橡胶复合材料力电响应特性

为了提升导电橡胶复合材料在结构健康监测中的应用潜力，通过开炼共混制备多壁碳纳米管(MWCNT)改性氯丁橡胶(CR)-天然橡胶(NR)共混复合材料，探讨CR/NR共混比(质量比)和MWCNT质量分数对复合材料导电性能、力学性能以及电阻-应变响应性能的影响机制。结果表明：当CR/NR共混比为5/5时，MWCNT质量分数的导电渗流阈值最低(仅为0.9%)。随着碳纳米管质量分数增加，材料的强度和刚度有所提升。复合材料在静态和循环载荷下表现出大应变范围(ε>350%)和良好动态电阻-应变响应重复性。最终通过理论模拟与实验结果的对比，建立基于隧道效应理论的电阻-应变定量关系模型。     

多壁碳纳米管对天然橡胶/丁腈橡胶阻尼材料性能的影响

研究了多壁碳纳米管(MWCNT)的用量对天然橡胶(NR)/丁腈橡胶(NBR)共混胶的硫化特性、力学性能及阻尼性能的影响。结果表明,随着MWCNT用量的增加,NR/NBR共混胶的最小转矩、最大转矩、最大转矩与最小转矩之差均增大,焦烧时间和正硫化时间缩短;扯断伸长率逐渐减小,撕裂强度、定伸应力和邵尔A硬度逐渐增大,回弹性下降,拉伸强度先增大后减小,当MWCNT用量为4.0份时拉伸强度达到最大值。拉伸/压缩-恢复过程中的滞后能量密度和阻尼系数增大。     

用巯基-烯点击法制备1,2-聚丁二烯包覆的白炭黑及其对丁苯橡胶的增强

采用巯基-烯点击法制备出1,2-聚丁二烯包覆的疏水性白炭黑（Silica-PBs）。红外光谱和X射线电子能谱分析表明,Silica-PBs表面被1,2-聚丁二烯所包覆,并且还有多余的乙烯基。将Silica-PBs与丁苯橡胶（SBR）共混制备的硫化胶相比于使用硅烷偶联剂改性制得的硫化胶具有更优异的综合性能。通过橡胶加工分析仪和电子显微镜分析均可以发现,Silica-PBs在SBR中具有更好的分散状态。Silica-PBs可以在填料与橡胶分子链之间形成一条“缓冲带”,为填料在橡胶分子链滑移时提供一定的缓冲作用。动态力学性能测试结果显示,Silica-PBs相比于传统白炭黑提高SBR/Silica-PBs复合材料的动态力学性能8%以上,可以作为一种理想的绿色轮胎用填料。     

丙烯酸酯橡胶柔性电极材料的制备及其性能研究

通过导电炭黑与多壁碳纳米管（MWCNT）并用制备丙烯酸酯橡胶（ACM）柔性电极材料,研究导电炭黑和MWCNT在ACM基体中的分散性及其并用比对柔性电极材料硫化特性、物理性能和导电性能的影响,并分析柔性电极材料与介电弹性体（DE）基体的粘合性能。结果表明：导电炭黑和MWCNT在ACM基体中具有良好的分散性;添加导电炭黑/MWCNT并用体系的ACM柔性电极材料的拉断伸长率远大于200%,满足DE发电机对于大形变的要求,且与仅添加导电炭黑的柔性电极材料相比,其硬度和弹性模量减小,柔韧性提高;随着MWCNT用量的增大,柔性电极材料的导电通路逐渐完善,导电性能提高;导电炭黑/MWCNT并用比为10/10的ACM柔性电极材料与ACM基DE基体共硫化后,两者的粘合强度达到5 N·mm^-1,且粘合稳定性较好。     

PP/MWCNT微孔发泡复合材料导电性能及电磁屏蔽效应的研究

通过溶液-熔融共混方法制备具有良好分散性的聚丙烯/多壁碳纳米管(PP/MWCNT)复合材料,利用超临界二氧化碳对其微观结构进行调控,并对其导电性能和电磁屏蔽效能进行研究.PP/MWCNT复合材料发泡后,随着MWCNT含量的增加,泡孔尺寸从13.27 μm降低至6.11 μm,发泡倍率则从3.85提高至5.56.对其导电...     

官能度宽域可调的羧基改性1，2-聚丁二烯的制备及性能

采用室温光引发巯基-烯点击化学法制备羧基功能化1,2-聚丁二烯（1,2-PB）。结果表明,3-巯基丙酸成功接枝到1,2-PB上,羧基官能度在0～46.2%宽域内可调。通过调节分子链上羧基含量可控制氢键的作用强度,使得聚合物的玻璃化转变温度从-2.1 ℃提高到26.3 ℃,未加填料增强的橡胶的拉伸强度可达15.5 MPa,扯断伸长率均大于350%;材料的有效阻尼温域从-8.28-3.83 ℃拓宽至23.63-73.03 ℃;1,2-PB/COOH中高的羧基接枝率赋予材料优异的金属黏附性能,分子链中剩余双键还可与丁苯橡胶基体共硫化,使其与橡胶层具有优异的黏附性能。     

聚丁二烯的类型对其与异成胶的共硫化胶结构和性能的影响

聚丁二烯的类型对其与异成胶的共硫化胶结构和性能的影响ЮловскаяВ．Д．等著袁抗译聚异戊二烯橡胶与顺式１，４及顺式１，２的聚丁二烯橡胶的共混胶，引起许多研究人员的注意。但是，关于的类型对这种共硫化胶结构和性能的影响，至今依然众说纷坛。已知，共混胶...     

氢化丁腈橡胶/氢化羧基丁腈橡胶/多壁碳纳米管共混胶的硫化特性及动力学

将多壁碳纳米管进行硝酸氧化处理得到酸氧化多壁碳纳米管(mMWNTs),通过傅里叶变换红外光谱和热重分析表征了mMWNTs,考察了mMWNTs用量对氢化丁腈橡胶(HNBR)/氢化羧基丁腈橡胶(HXNBR)共混胶硫化特性的影响,并采用经典的自催化反应模型研究了共混胶的硫化动力学。结果表明,mMWNTs的表面含有羟基和羧基官能团,纯度得到提高,热稳定性有所降低;随着mMWNTs用量的增加,共混胶的焦烧时间和正硫化时间缩短,交联密度和硫化速率逐渐增大,加快了硫化反应进程;采用自催化反应模型可以很好地描述共混胶的硫化动力学,mMWNTs的加入可略微提高共混胶的硫化反应级数,降低共混胶的硫化反应活化能。     

碳纳米管/纤维素在不饱和聚酯树脂中的分散性及力学性能研究

在超声改善MWCNT在不饱和聚酯树脂的分散性的基础上,通过非共价官能团化的方法引入处理过的天然填料柠檬酸化纤维素(CNFCA)来增强不饱和聚酯树脂,并采用偏光显微镜、旋转流变仪、透射电子显微镜、扫描电子显微镜、万能试验机等对不饱和聚酯树脂纳米复合材料的结构和性能进行了研究.结果表明,MWCNT的加入可以使不饱和聚酯复合...     

Surface modification of MWCNT to improve the mechanical and thermal properties of natural rubber nanocomposites

In this study, we focused on the synergistic effect between carbon black (CB) and multiwall carbon nanotube (MWCNT) hybrid fillers. In particular, the surface modification of pristine MWCNT (P-MWCNT) via an acid (oxidation) treatment was used to improve their dispersion, as well as the mechanical and thermal properties of their corresponding natural rubber (NR)-based nanocomposites. Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) were carried out to determine the presence of functional groups on the oxidized MWCNT (O-MWCNT). After vulcanization, dynamic mechanical analysis (DMA), tensile properties, hardness, thermal conductivity, swelling behaviour in toluene and SEM characterizations were performed on both NR/CB/P-MWCNT- and NR/CB/O-MWCNT-based nanocomposites. The results showed the positive effect of MWCNT surface oxidation on the fillers' dispersion and nanocomposites' properties.     

用于FDM的导电ABS/MWCNT复合材料的制备

采用熔融共混法将丙烯腈-丁二烯-苯乙烯共聚物(ABS)与多壁碳纳米管(MWCNT)复合,并对所得的复合材料进行了力学性能、热性能和电学性能分析。结果表明,添加MWCNT能够提高复合材料的力学性能、电导率和耐热性,力学性能在MWCNT添加量为2%时最佳,电导率随MWCNT添加量的增加而增大,MWCNT添加量为4%时,其电导率能达到4.35×10-6S/m。将添加4%MWCNT的复合材料拉丝,然后以三种打印方向进行熔融沉积(FDM)打印,研究了打印试样的力学性能,用扫描电镜(SEM)观察了其断面形貌。结果表明,水平方向打印的试样力学强度最好,侧向打印的试样次之,垂直方向打印的样品由于仅靠丝材的层间黏结,其力学强度比较差,与纯ABS丝材打印试样相比,复合丝材打印试样的拉伸强度和弯曲强度均有明显提高,冲击强度有所下降。     

Thermal‐Insulation,Electrical, and Mechanical Properties of Highly‐Expanded PMMA/MWCNT Nanocomposite Foams Fabricated by Supercritical CO2 Foaming

Foaming behavior of poly(methyl methacrylate) (PMMA)/multi‐walled carbon nanotubes (MWCNTs) nanocomposites and thermally‐insulating, electrical, and mechanical properties of the nanocomposite foams are investigated. PMMA/MWCNT nanocomposites containing various amounts of MWCNTs are first prepared by combining solution and melt blending methods, and then foamed using CO₂. The foaming temperature and MWCNT content are varied for regulating the structure of PMMA/MWCNT nanocomposite foams. The electrical conductivity measurement results show that MWCNTs have little effect on the electrical conductivity of foams with large expansion ratio. Thermal conductivities of both solid and foamed PMMA/MWCNT nanocomposites are measured to evaluate their thermally insulating properties. The gas conduction, solid conduction, and thermal radiation of the foams are calculated for clarifying the effects of cellular structure and MWCNT content on thermal insulation properties. The result demonstrates that MWCNTs endowed foams with enhanced thermal insulation performance by blocking thermal radiation. Moreover, the compressive testing shows that MWCNTs improve the compressive strength and rigidity of foams. This research is essential for optimizing environmentally friendly thermal insulation nanocomposite foams with enhanced thermal‐insulation and compressive mechanical properties.     

Mechanical,thermal and electrical properties of multi‐walled carbon nanotube/aluminium nitride/polyetherimide nanocomposites

A series of polyimide‐based nanocomposites containing polyimide‐grafted multi‐walled carbon nanotubes (PI‐g MWCNTs) and silane‐modified ceramic (aluminium nitride (AlN)) were prepared. The mechanical, thermal and electrical properties of hybrid PI‐g MWCNT/AlN/polyetherimide nanocomposites were investigated. After polyimide grafting modification, the PI‐g MWCNTs showed good dispersion and wettability in the polyetherimide matrix and imparted excellent mechanical, electrical and thermal properties. The utilization of the hybrid filler was found to be effective in increasing the thermal conductivity of the composites due to the enhanced connectivity due to the high‐aspect‐ratio MWCNT filler. The use of spherical AlN filler and PI‐g MWCNT filler resulted in composite materials with enhanced thermal conductivity and low coefficient of thermal expansion. Results indicated that the hybrid PI‐g MWCNT and AlN fillers incorporated into the polyetherimide matrix enhanced significantly the thermal stability, thermal conductivity and mechanical properties of the matrix. Copyright © 2012 Society of Chemical Industry     

用杜仲胶/碳纳米管改性环氧树脂制备导电防腐涂料及其性能

以杜仲胶(EUG)和环氧树脂(E-51)为涂层基质、碳纳米管为导电填料制备了导电防腐涂料,考察了 EUG用量对复合涂层导电性和耐腐蚀性的影响.采用差示扫描量热仪和动态热机械分析仪研究了复合涂层的热性能,用四探针测试仪研究了导电性能,分别通过电化学阻抗谱及盐雾测试和附着力测试研究了耐腐蚀性和附着力.结果表明,当EUG用量...     

聚醚醚酮/多壁碳纳米管复合材料力学及阻燃性能研究

通过熔融共混法将聚醚醚酮（PEEK）与多壁碳纳米管(MWCNT)混合,利用模压法制备了MWCNT增强型PEEK复合材料,研究了MWCNT对PEEK性能的影响。结果表明,添加一定比例的MWCNT能够提高PEEK的力学和阻燃性能;当MWCNT含量为5%（质量分数,下同）时,PEEK的弯曲强度提高了53%;当MWCNT含量为1%时,锥形量热法测得的热释放速率峰值最低,燃烧性能指数值最大,热重分析显示初始分解温度较纯PEEK提高了13℃,表明MWCNT有效地提高了PEEK的阻燃和热稳定性能。     

喷雾干燥法制备聚氨酯/碳纳米管复合材料的结构与性能

通过喷雾干燥法制备了聚氨酯/碳纳米管复合材料。扫描电子显微镜和透射电子显微镜观察结果表明,碳纳米管在聚氨酯基体中分散较好。X-射线衍射测试表明,碳纳米管对复合材料的微相结构影响较小。随着碳纳米管用量的增加,动态力学性能测试表明复合材料的耐热性有了显著的改善。另外,该复合材料还表现出多功能特性,如高导电性和导热性。随着碳纳米管体积分数的增加,聚氨酯/碳纳米管复合材料的电导率逐渐提高,填充碳纳米管的聚氨酯复合材料的导电逾渗值约为5%。     

基于磷杂菲衍生物多组分无卤阻燃天然橡胶的制备及性能

将磷杂菲/三嗪双基协同阻燃剂（TGD）、甲基膦酸二甲酯（DMMP）、可膨胀石墨（EG）及氢氧化铝（ATH）复配添加到天然橡胶（NR）中制备阻燃NR硫化胶,考察了TGD/DMMP/EG/ATH复配阻燃剂对NR硫化胶的阻燃性能、热稳定性及物理机械性能的影响。结果表明,TGD/DMMP/EG/ATH复配阻燃剂可有效提升NR硫化胶的阻燃性能和热稳定性,并降低燃烧过程中的热释放速率。当TGD/DMMP/EG/ATH复配阻燃剂的用量为60份（质量）时,NR硫化胶的极限氧指数可达28.4%,残炭质量分数可达25.61%,热释放速率可降低95%,总热释放量可降低21%。TGD/DMMP/EG/ATH复配阻燃剂对NR硫化胶的物理机械性能影响不大。     

Preparation and properties of polyurethane/multiwalled carbon nanotube nanocomposites by a spray drying process

A spray drying approach has been used to prepare polyurethane/multiwalled carbon nanotube (PU/MWCNT) composites. By using this method, the MWCNTs can be dispersed homogeneously in the PU matrix in an attempt to improve the mechanical properties of the nanocomposites. The morphology of the resulting PU/MWCNT composites was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM and TEM observations illustrate that the MWCNTs are dispersed finely and uniformly in the PU matrix. X‐ray diffraction results indicate that the microphase separation structure of the PU is slightly affected by the presence of the MWCNTs. The mechanical properties such as tensile strength, tensile modulus, elongation at break, and hardness of the nanocomposites were studied. The electrical and the thermal conductivity of the nanocomposites were also evaluated. The results show that both the electrical and the thermal conductivity increase with the increase of MWCNT loading. In addition, the percolation threshold value of the PU composites is significantly reduced to about 5 wt % because of the high aspect ratio of carbon nanotubes and exclusive effect of latex particles of PU emulsion in dispersion. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012