废轮胎热解再生炭黑表面活性

为克服废轮胎常压热解再生炭黑(PC)表面碳质沉积物过多、表面活性差和不适于橡胶补强应用等缺点,本文以反相气相色谱法为分析手段,分别通过硝酸酸洗和硬脂酸-硝酸酸洗等方法改性处理PC,以期改善PC结构和提高其表面性能,继而改善PC填充天然橡胶硫化胶的机械性能.系统地考察了未改性PC以及硝酸酸洗改性热解炭黑(WPC)、硬脂酸-硝酸酸洗改性热解炭黑(SWPC)表面能色散分量、极性分量、热力学函数变化以及炭黑表面不同活性点的能量分布情况,并考察了改性处理对热解炭黑填充天然橡胶硫化胶机械性能的影响.实验结果表明,硝酸酸洗改性在炭黑表面引入较多的羟基和羧基等官能团,导致其表面能过高,不利于天然橡胶补强.而在硝酸酸洗基础上,通过加入硬脂酸再改性后,可以减少炭黑颗粒之间的团聚,降低表面能,改善炭黑在硫化胶中的分散性.通过硫化胶机械性能测试实验发现,与PC和WPC相比,填充SWPC的天然橡胶具有较高的拉伸强度、扯断伸长率、300%定伸应力,能基本达到半补强炭黑的应用标准.     

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。     

改性炭黑的表面性质与微观结构

通过氮气氛围下高温处理和双氧水H_2O_2,硝酸HNO_3氧化炭黑N234,利用氮吸附比表面积(BET),红外光谱(IR)和X射线光电子能谱(XPS)表征了上述改性炭黑的比表面积,表面的官能团和元素组成。高温处理炭黑表面氧元素含量降低,含氧官能团部分被除去,而双氧水和硝酸氧化炭黑表面氧元素含量增加,生成了很多C=O和C-O官能团。高分辨透射电镜(HR-TEM)结果显示,双氧水和硝酸改性的炭黑表面形成了很多结构上的缺陷,比表面积显著增加。     

玉米秸秆活性炭制备与NaOH改性对甲醛吸附的影响

以玉米秸秆为原料,在不同热解条件下制备活性炭,再运用BET模型和Boehm滴定法测定活性炭孔隙结构和表面性质,并选取性能较优的活性炭进行NaOH改性,研究其改性前后对甲醛的吸、脱附性能和表面结构与表面化学性质变化。结果表明:在最优热解参数60 min、650℃制备的玉米活性炭经NaOH改性后可使其对甲醛饱和吸附时间延长62%,饱和吸附量提高133.33%,比表面积增加3.02%,微孔容积增大0.6%,脱附峰面积和峰高明显增大,且其表面碱、酸性官能团含量分别提高了11.85%、5.51%,说明NaOH改性能提高活性炭的表面碱、酸性官能团含量,增大活性炭比表面积与孔径,从而提高其对甲醛等极性物质的吸附能力。     

废旧轮胎热解炭黑的研究进展

介绍废旧轮胎热解炭黑的改性和应用研究进展。目前热解炭黑的改性方法主要有表面改性剂改性、酸洗和复合改性等,热解炭黑主要用作橡胶填料和沥青填料以及用于耐火材料和混凝土中。热解炭黑的应用仍未从根本上实现,寻找能够使热解炭黑表面活性提高并能让热解炭黑在基体中分散均匀的方法以及拓展热解炭黑的应用是今后的重点课题。     

水热改性对半焦性质的影响

考察了在氢氟酸、氨水、氢氧化钠和过硫酸铵存在条件下水热改性对半焦表面酸碱性和碘吸附值等的影响。研究结果表明氨水和NaOH水热改性有利于半焦表面碱性官能团含量增加,而HF和过硫酸铵水热改性有利于半焦表面酸性性官能团含量增加;与原料半焦相比,NaOH水热改性半焦的碘吸附值有所增加,HF水热改性半焦的灰分含量最低。另外各种水热改性条件较大程度地影响了半焦的平均孔径,而对半焦的比表面积和孔容影响不是很大。     

硝酸改性处理对活性炭性能的影响

研究了硝酸对活性炭改性处理后,活性炭灰分、pH值、表面元素含量以及表面结构的性能,结果表明硝酸对活性炭进行改性处理,能降低活性炭的灰分、pH值和比表面积,增加活性炭表面氧含量。     

不同牌号废轮胎裂解炭黑对SBR加工性能及硫化胶性能的影响

主要表征了不同工艺生产的废轮胎裂解炭黑的基本性质,并研究了不同裂解炭黑对丁苯橡胶(SBR)混炼胶、硫化胶性能的影响。实验结果表明,不同裂解炭黑在灰分含量、表面油含量和比表面积等方面有较大差异,比表面积大、灰分含量少的裂解炭黑填充的SBR混炼胶,其挤出物表面更为光滑,对SBR硫化胶的补强效果也更好。     

废轮胎裂解炭黑的酸洗改性及其在丁苯橡胶中的应用

采用HCl、H_2SO_4和HNO_3对废轮胎裂解炭黑(CBp)进行酸洗处理,研究了酸洗改性CBp(WCBp)的基本性质、微观形态和粒度分布,考察了3种WCBp对丁苯橡胶混炼胶的门尼黏度、硫化特性及硫化胶性能的影响。结果表明,酸洗后CBp的灰分明显减少,比表面积明显增大; 采用HNO_3处理的CBp粒径更小,粒子排列更加紧密,粒径分布变窄; 酸洗后CBp表面暴露出了部分极性官能团。填充WCBp的SBR混炼胶的门尼黏度均明显下降。填充WCBp的SBR硫化胶,其拉伸强度、300%定伸应力和撕裂强度均显著提高,耐磨性也有一定的改善。填充采用HNO3处理的WCBp的SBR混炼胶,焦烧时间和正硫化时间明显延长,储能模量趋于稳定时的测量值与初始测量值之差最小,拉伸强度为11.16 MPa,300%定伸应力为4.04 MPa,撕裂强度可达35.93 k N/m,磨耗体积为131.27 mm~3。     

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.     

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。     

废旧轮胎裂解炭黑的改性及其应用进展

废旧轮胎作为对环境有害的固体废弃物，其组成包括炭黑、白炭黑和胶粉等多种有价值的资源。在现有回收技术中，废轮胎热裂解技术可有效回收裂解油、炭黑和钢丝等，在国内获得了广泛应用。相对于已经普遍利用的热解油和钢丝来说，热解炭黑含有质量分数14-21%的灰分和胶质层，它的高价值利用是实现废旧轮胎循环回用的关键。很多研究者开展了热解炭黑不同的改性处理工艺研究，改性后的热解炭黑可被应用于多个领域。该文主要概括了热解改性炭黑在橡胶生产中的补强作用、改性活性炭吸附剂、电池材料、以及沥青和油墨填料等方面的应用，综述了上述应用领域内热解炭黑的处理和改性方法，并指出今后热解炭黑高价值回用的方向和改性方法。     

废旧轮胎裂解炭黑在橡胶地板中的应用

对比废旧轮胎裂解炭黑(CBp)和炭黑N330的理化性能,研究CBp部分替代炭黑N330对橡胶地板胶料性能的影响。结果表明:CBp灰分含量较大,结构度较低,其他理化性能与炭黑N330基本相当;在橡胶地板胶料中用CBp替代30%炭黑N330,胶料的硫化特性、硫化胶的物理性能和耐老化性能、橡胶地板的使用性能均符合普通橡胶地板的技术要求,且有效降低了生产成本。     

Preparation of Pyrolytic Carbon Black from Scrap Tire Rubber Crumb and Evaluation in New Rubber Compounds

Summary: Pyrolytic carbon black (CBp) has been prepared by rubber crumb pyrolysis under nitrogen flow at 700 °C. The CBp obtained by this process had an average surface area of 81 m² · g^?1 and was obtained in 43% yield over the starting rubber crumb. Although the CBp surface area can be increased up to 109 m² · g^?1 by washing away the Zn‐ and Si‐based ashes with HF treatment, the CBp was tested in a standard NR/SBR‐based formulation without any purification and ash extraction. CBp was tested at increasing loading levels as partial or full replacement of a standard N339 furnace carbon black. CBp depresses the physical properties of the rubber compound in a way which is directly proportional to the amount added. The reason of this result and the limited reinforcing effect is discussed in terms of low surface area and low structure in comparison to N339 carbon black as well as in terms of low surface activity, the interference of the ashes and the poor dispersion. Ideas of further development works are outlined.

     

A comparison of surface morphology and chemistry of pyrolytic carbon blacks with commercial carbon blacks

The surface morphology and chemistry of CBp obtained by pyrolysis of waste tyres at 500 and 700 °C, respectively was studied compared with a commercial tyre carbon blacks by laser particle size analyzer, X-ray diffractogram (XRD) and electron spectroscopy for chemical analysis (ESCA). The distribution of CBp aggregates was the mixed particle distribution of commercial carbon blacks added to tyres in fabrication. The concentration of inorganic compounds and carbonaceous deposits (the organic compounds deposited on the surface of the CBp) depends on the pyrolysis temperature. The chemical nature of the CBp from pyrolysis at 700 °C was found to be closer to the commercial tyre carbon blacks than the CBp from pyrolysis at 500 °C.     

基于BP神经网络优化制备化学改性脱硫灰/丁苯橡胶复合材料

以化学改性脱硫灰取代部分炭黑与丁苯橡胶复合制备化学改性脱硫灰/丁苯橡胶复合材料,运用均匀设计结合BP神经网络建立制备工艺参数与力学性能的BP神经网络优化模型,获得制备最优化学改性脱硫灰/丁苯橡胶复合材料的工艺参数,对最优复合材料进行了表征. 结果表明,最优化学改性脱硫灰/丁苯橡胶复合材料的制备参数为促进剂N-叔丁基-2-苯并噻唑次磺酰胺用量1.2 g、硫磺用量1.3 g、硬脂酸用量1.1 g、氧化锌用量2.4 g、硫化时间27 min,该条件下所制复合材料的拉伸强度为20.31 MPa、撕裂强度为45.68 kN/m、邵氏A硬度为66,最优实测值与最优模型预测值吻合较好,相对误差为3.03%~3.22%.     

A ultra-low viscosity stearic acid emulsion prepared by lauric acid as waterproof agent for cement mortar

Safe building structures cannot be achieved without reliable waterproofing engineering. To address the susceptibility of concrete materials to water leakage, a low-viscosity stearic acid emulsion has been developed as a waterproofing agent for mortar. By introducing lauric acid, the formation of stearic acid crystals in water could be effectively prevented, resulting in a stearic acid emulsion with a viscosity of only 24 mPa·s. It is found that the best overall performance was achieved when the ratio (R) of lauric acid to stearic acid was 2/3. This emulsion has the least effect on mortar fluidity and setting time. The as-prepared modified mortar possessed the highest compressive strength (127% of the blank) and the lowest water absorption at 48 h (37% of the blank). X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive x-ray spectroscopy (EDS), scanning electron microscopy (SEM), dynamic light scattering (DLS) particle size analysis, and water contact angle measurements were used to investigate the mechanism of stearic acid emulsion's modification. It is determined that the stearic acid emulsions successfully modified the internal and external hydrophobicity of the mortar by chemical action with calcium hydroxide.     

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     

酸浸法高镁炉渣制备白炭黑的研究

以非淬水高镁炉渣为原料,采用酸浸法利用其中的二氧化硅制备白炭黑产品。采用红外光谱对白炭黑进行定性分析,采用X射线荧光光谱仪对白炭黑进行含量分析。考察了盐酸浓度、反应时间、反应温度和洗涤次数对白炭黑制备的影响。得到制备白炭黑的最佳工艺条件：盐酸浓度为4.0 mol/L、反应温度为55 ℃、反应时间为2.5 h、洗涤次数为6次,在该工艺条件下,从20 g炉渣中可制备白炭黑产量为10.90 g,白炭黑产品纯度达到90.2%。