改性炭黑对天然橡胶/顺丁橡胶并用胶性能的影响

采用3种方法对传统炭黑进行表面改性,考察了改性前后炭黑表面形貌及结构的变化,并采用改性炭黑填充天然橡胶（NR）/顺丁橡胶（BR）并用胶,考察了改性炭黑对并用胶力学性能、硫化特性及动态力学性能等的影响。结果表明,与未改性炭黑相比,细化粒径、调高pH值及木质素改性处理后,炭黑表面的粗糙程度增加;且细化改性炭黑具有更高的比表面积,调高pH值改性炭黑具有更多疏松的二次结构,木质素改性炭黑粒径略有增加。对于炭黑填充NR/BR,用细化粒径及调高pH值方法处理的炭黑进行填充,NR/BR硫化胶的力学性能、耐磨性能及抗湿滑性均得到明显改善,但硫化延迟效应明显;木质素改性后,炭黑填充胶的力学性能、耐磨性能均出现不同程度的降低。     

改性热解炭黑的结构表征及其在丁苯橡胶中的应用研究

对比研究热解炭黑和改性热解炭黑的结构和性能及其在丁苯橡胶(SBR)中的应用。热解炭黑经浓硝酸和浓氢氟酸依次处理后得到改性热解炭黑,与热解炭黑相比,改性热解炭黑的DBP吸油值、挥发分含量增大,BET比表面积减小,二次结构粒径分布变宽、变大,表面羟基消失,羧基等极性基团增加不明显。与热解炭黑补强SBR相比,改性热解炭黑补强SBR混炼胶的门尼粘度增大,加工性能下降,焦烧时间延长,硫化速率减小;硫化胶的定伸应力增大20%~30%,拉伸强度增大10%,耐磨性能提高,压缩生热减小。     

改性热解炭黑的结构表征及其在丁苯橡胶中的应用

对比研究热解炭黑和改性热解炭黑的结构和性能及其在丁苯橡胶(SBR)中的应用。热解炭黑经浓硝酸和浓氢氟酸依次处理后得到改性热解炭黑,与热解炭黑相比,改性热解炭黑的DBP吸油值、挥发分含量增大,BET比表面积减小,二次结构粒径分布变宽、变大,表面羟基消失,羧基等极性基团增加不明显。与热解炭黑补强SBR相比,改性热解炭黑补强SBR混炼胶的门尼粘度增大,加工性能下降,焦烧时间延长,硫化速率减小;硫化胶的定伸应力增大20%~30%,拉伸强度增大10%,耐磨性能提高,压缩生热减小。     

废轮胎热解炭黑的改性

对废轮胎热解炭黑进行了硫酸酸洗以及酸洗后加入硬脂酸两种改性处理方法,测定了热解炭黑、酸洗炭黑和硬脂酸改性酸洗炭黑的粒径、比表面积和表面性质。研究表明：热解炭黑是由许多微米级的颗粒构成的,灰分含量很高,酸洗可明显减少灰分,酸洗后炭黑比表面积略有增加;酸洗及硬脂酸改性可以增加热解炭黑挥发分的含量。热解炭黑的表面覆盖有碳质沉积物,极性较低,更加亲油,改性后有部分极性官能团暴露出来,含氧官能团数量增加。     

不同类型偶联剂对热解炭黑的表面改性及应用研究

采用偶联剂Si69、钛酸酯类偶联剂、活化剂450和活化剂480对半钢子午线轮胎热解炭黑进行了干法表面改性,探究了改性热解炭黑在天然橡胶中的应用性能。结果表明,活化剂450对热解炭黑具有一定的改性效果,其硫化胶拉伸强度提高了5%左右,耐磨性提高了20%左右;其他活化剂对热解炭黑的改性效果不大,酞酸酯类偶联剂改性热解炭黑会降低硫化胶力学性能。     

三种煤系粉体对天然橡胶补强性能的对比研究

采用煤矸石和粉煤灰为原料,经活化改性制备天然橡胶补强材料,并与硅铝炭黑进行对比。3种粉体的化学组成相同,但含量差异明显,晶体结构也有不同。天然橡胶混炼胶的硫化特性和物理机械性能的测试结果表明,煤矸石粉填充天然橡胶混炼胶硫化速率最快,交联密度大;就拉伸强度而言,硅铝炭黑补强性能较好;煤矸石粉补强的300%定伸应力明显高于粉煤灰和硅铝炭黑补强天然橡胶。     

改性硬质高岭土在NR中的应用

研究硬脂酸改性硬质高岭土在NR中的应用，并与半补强炭黑进行对比。结果表明，硬脂酸改性硬质高岭土对NR补强性能优异；采用硬脂酸改性硬质高岭土部分替代SRF填充NR，硫化胶综合物理性能良好；硬脂酸改性低温煅烧硬质高岭土具有较高的白度，且对NR补强性能良好，可用于胶鞋白大底胶料。     

改性玄武岩纤维对NR/SBR并用体系性能影响的研究

通过硅烷偶联剂如Si-69和KH550对玄武岩纤维进行表面改性,考察改性玄武岩纤维对NR/SBR并用胶各项硫化特性、物理机械性能和动态力学性能的影响。实验结果表明:改性玄武岩纤维使得并用胶正硫化时间有所提高,但焦烧时间缩短。其在胶料中分散性得到有效改善,提高了硫化胶的动态力学性能、物理机械性能,并有效降低压缩生热。用量在10~15份时效果最佳,是一种优良的填充补强材料。     

不同溶剂处理废轮胎热解炭黑在丁苯橡胶中的应用

采用丙酮、甲苯和硝酸3种不同溶剂对废轮胎热解炭黑(CBp)进行处理,将处理后的CBp应用到丁苯橡胶(SBR)中,考察其对SBR的补强效果。结果表明:CBp经丙酮抽提处理和甲苯索氏抽提处理后,附聚体变得疏松,原生粒子轮廓更加清晰,微孔和介孔体积增大;硝酸酸洗处理CBp经甲苯索氏抽提后比表面积大幅提高。将CBp丙酮抽提处理或硝酸酸洗脱灰处理后填充到SBR中,相应硫化胶的300%定伸应力、拉伸强度、撕裂强度和耐磨性能均有所提高。丙酮抽提处理CBp和酸洗处理CBp替代炭黑N660应用到SBR中,相应硫化胶的抗湿滑性能变化不大,滚动阻力下降。     

原位改性三元乙丙橡胶炭黑混炼胶与天然橡胶共混胶的性能

研究了三元乙丙橡胶(EPDM)炭黑混炼胶经偶联剂Si-69原位改性前后与天然橡胶(NR)共混胶的性能.结果表明,在EPDM炭黑混炼胶的原位改性过程中,Si-69在与炭黑表面作用的同时会与EPDM发生活性反应.这不仅增大了EPDM与炭黑间的亲和力,而且使EPDM的硫化反应活性增强,从而改善了共混硫化胶的物理机械性能.动态力学性能测试和扫描电子显微镜观察结果均表明,改性后的EPDM炭黑混炼胶与NR的硫化相客性增强.     

废轮胎热解炭黑的表面修饰及其在平版印刷油墨中的应用

Pyrolysis has the potential of transforming waste into valuable products. Pyrolytic carbon black （PCB） is one of the most important products resulting from the pyrolysis of used tires. One of the most significant applications of modified pyrolytic carbon black is its use as pigment for offset printing ink to obtain high added values. Inverse gas chromatography （IGC） results show that a large quantity of inorganic matters and carbonaceous deposit are removed by treating the pyrolytic carbon black with nitric acid solution. Plenty of active sites originally occupied by inorganic ash and coke are recovered. The surface energy of pyrolytic carbon black （TWPC） modified by titanate-coupling agent-especially the specific interaction γs^SP determined by the specific probe molecule, toluene-shows the strong interaction between the TWPC and the synthetic resins. The offset printing ink performance confirms the IGC prediction. And TWPC has the great potential of applications in printing ink industry as pigment.     

废轮胎热解炭黑与工业炭黑的粒径及化学组成

用激光粒度分析仪测定了废轮胎热解炭黑的粒径分布,用扫描电子显微镜、X-射线衍射法及X-射线光电子能谱法分析了热解炭黑和工业炭黑的形态、表面化学组成以及表面碳元素的结合状况。结果表明,热解炭黑的粒径分布是添加在轮胎中各种型号工业炭黑粒径分布的叠加。热解炭黑表面形态和组成接近于工业炭黑N660;热解炭黑的表面附着更多的有机物以及ZnO、ZnS等无机物,且随着热解温度的升高,附着的有机物含量减小,无机物中ZnO含量减小,ZnS含量增多。     

Surface modification of calcium carbonates studied by inverse gas chromatography and the effect on mechanical properties of filled polypropylene

Inverse gas chromatography (IGC) has been used to characterize the surfaces of a pure calcitic calcium carbonate as well as samples that had been treated with sodium polyacrylate and/or stearic acid. The dispersive components of the surface free energy for the pure material agreed well with related literature data. Polar contributions to the surface interactions with a range of probes were determined. The results show that the surface treatments reduced the polarities of the surfaces and that modification with stearic acid produced a non-polar, low-energy surface. Some mechanical properties of the polypropylene composites containing the modified calcium carbonates were found to correlate well with the filler surface energies. Copyright © 2004 Society of Chemical Industry     

Energy site distribution of carbon black surfaces by inverse gas chromatography at finite concentration conditions

Inverse gas chromatography (IGC) at finite concentration has been used to characterize the surface energy of a series of carbon blacks. It is known that there are many structural defects on carbon black surface and the surface energy is heterogeneously distributed. Using different molecular probes, IGC at finite concentration allows the determination of the surface energy sites distribution.     

Acid-base method for the demineralization of pyrolytic carbon black

The carbon black material used as reinforcing filler in tires was recovered by vacuum pyrolysis at a temperature of 500°C and a total pressure of 20 kPa. The pyrolytic carbon black obtained (CBp) was contamined by various additives of the original tire. Contaminants were also produced by chemical reactions occurring in the pyrolysis reactor. The contamination is reflected by the high content of ash and gritty materials (coke) present in the CBp. A characterization of the recovered carbon black was performed and a possible reduction of the ash content by sulfuric acid and sodium hydroxide treatment was investigated. The variables which were studied included the ratio of reactant to carbon black, the reactant concentration, the treatment temperature and the reaction time. Properties of the commercial carbon black filler grade N539 were compared to those of the CBp recovered before and after the demineralization treatment.     

Microscopic investigation of carbonaceous deposits formed in a solvent-treated coal reactor

The mode of occurrence and optical characteristics of the carbonaceous deposits from a 3 t/d process development unit solvent-treated coal reactor were investigated by optical microscopy to increase understanding of the formation and development of reactor blockage materials such as mesophase and semicoke. The solid deposits showed a layered texture consisting of mesophase matrix as a binder, particles of non-plastic coal, pyrolytic carbon and mineral matter. The layered appearance of the deposits was due to variations in the proportions of the microscopic constituents and pores. The variations in reflectance values of the carbonaceous deposits from the centre of the reactor to the wall provided evidence of the thermal alteration after deposition. Based on these results, the formation and sedimentation of carbonaceous deposits and subsequent secondary alteration processes are discussed.     

Analysis of whitening phenomenon of EPDM article by humid aging

An ethylene–propylene–diene terpolymer (EPDM) article used for a car component was aged in 80°C humid air (60% relative humidity) for 30 days and in 80°C tap water for 7 days. The aged sample surfaces were changed to white. The aged sample surfaces were analyzed using GC/MS, image analyzer, SEM, EDX, and ATR‐FTIR. Calcium stearate was found on the aged sample surface. To confirm the whitening phenomenon, three sulfur‐cured EPDM composites with different reinforcing systems (talc/carbon black, calcium carbonate/carbon black, and clay/carbon black) and one resole‐cured EPDM composite were prepared and aged in 90°C tap water for 7 days. The sulfur‐cured EPDM composites contained stearic acid, whereas the resole‐cured EPDM composite did not contain stearic acid. Whitening occurred in the sulfur‐cured EPDM samples irrespective of the filler systems but the aged resole‐cured EPDM composite surface was not changed. The whitening was due to the formation of calcium stearate as a result of reaction between calcium cation and stearic acid. The calcium cation came from humid air and tap water, while the stearic acid came from the sulfur‐cured EPDM samples. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Mechanical enhancement of C/C composites via the formation of a machinable carbon nanofiber interphase

C/C composites with improved mechanical strength were synthesized using a filler constituted by a carbon felt covered with catalytically grown carbon nanofibers (CNFs) and a carbonaceous matrix generated by the pyrolysis of a phenolic resin. First, the synthesis method of the filler allows the homogeneous deposition and anchorage of CNFs on the host microfilaments at a rapid densification rate. Carbon nanofibers grown this way lead to the formation of numerous micro- and nanobridges between the microfilaments, conferring a significant improvement of the mechanical resistance of the CNF/C system allowing one to tailor its dimensions and shape. Thus, further fabrication of C/C composites can be achieved: the CNF/microfilament structure was infiltrated with a phenolic resin and carbonized at 650 °C to generate a carbonaceous matrix by thermal decomposition. Similar experiments on the microfilaments carried out at the same synthesis time, without catalyst and at higher reaction temperatures led to the deposition of a pyrolytic carbon sheath and to poor mechanical enhancements. This clearly indicates the advantage of using CNF growth as an efficient densification process before infiltration. Such C/C composites exhibit high-quality bonding between the two carbon phases, the matrix and the CNF/microfilament filler, via the formation of a considerable amount of CNF interphase.     

Elastomer–carbon black interaction: Influence of elastomer chemical structure and carbon black surface chemistry on bound rubber formation

The contribution of elastomer polarity and reactivity to bound rubber formation has been investigated. In this study, a number of elastomers of different chemical nature have been tested. The surface of the carbon black (N110) has also been modified by nitric acid oxidation in order to increase the concentration of surface functional groups. The experimental results have shown that the bound rubber formation is barely related to the polarity of the polymers. It is the reactive sites in both the elastomer and carbon black which are mainly responsible for bound rubber formation. It therefore appears that the elastomer/carbon black interaction leading to the formation of bound rubber is essentially a chemical process involving primary bond formation between elastomer and carbon black. The oxidized carbon black exhibits a higher surface activity which may be due to an increased concentration of oxygen-containing reactive surface sites, namely, phenolic hydroxyl, carboxyl, lactone, and quinone groups. © 1995 John Wiley & Sons, Inc.