Preparation of pitch precursor with excellent spinnability for general-purpose carbon fibre using coal tar pitch as raw material

Tetrahydrofuran(THF) extract of coal tar pitch(CTP) was used instead of blending CTP with pretreated pyrolysis fuel oil to prepare an isotropic pitch precursor with excellent spinnability for general-purpose carbon fibre through bromination-dehydrobromination. The feasibility and effectiveness of synthesising an isotropic pitch precursor derived from THF-soluble(CTP-THFs) is demonstrated in this study.The results show that CTP-THFs contains more light components than CTP;CTP-THFs and CTP monomer proportions were 62.52% and 45.32%, respectively. However, based on comparisons of CTP-THFsBr0 and CTPBr0 characterisations, CTP-THFs exhibits better polycondensation than CTP. Bromination-dehydrobro mination promotes polycondensation of pitch precursors, leading to greater carbon aromaticity in CTP-THFsBr5, CTP-THFsBr10, and CTP-THFsBr15 than that in CTP-THFsBr0 and CTPBr0. CTP-THFsBr5 and CTP-THFsBr10 have excellent spinnability even with softening points as high as 230 ℃. The pericondensed carbon and carbon aromaticity of CTP-THFsBr5 and CTP-THFsBr10 are high owing to the higher degree of polycondensation;however, they still possess a more linear molecular structure. The as-prepared carbon fibre exhibits homogeneity and uniformity, and the mechanical performance is comparable with that of commercial general-purpose carbon fibre products.

Feasibility Investigation of Bitumen Properties by Blending of Coal Tar Pitch

There are numerous methods and additives available to improve the durability and quality of road bitumen. A coal tar obtained by coal coking was distilled in a laboratory into fractions of initial boiling point IBP-180℃ (gasoline-like fuel), 180℃ - 360℃ (diesel-like fuel), and >360℃ (residue or coal tar pitch). The coal tar pitch was added into road bitumen by up to 1 - 5 wt% and investigated the alteration of physical and chemical properties. The physico-mechanical properties of coal tar pitch and bitumen blends, as well as the chemical group composition, were determined using standard techniques (MNS) and the SARA method, respectively. Results of 3% coal tar pitch addition into bitumen enhanced ductility by 12.4% and softening point by 1.6℃. We found that blending with bitumen coal tar pitch as a modifier could improve bitumen properties.

Mesophase formation of coal-tar pitches used for impregnant of C/C composites

By a polarized light optical microscopy with a hot stage, liquid phase nuclear magnetic resonance 13 C NMR and 1 H NMR, X ray diffractometry and scanning electron microscopy (SEM), the factors that affect the formation of mesophase in C/C composites, such as pressure, quinoline insolubles (QI) and heterocylic compounds, were analyzed. Further, the graphitizability of the resultant carbon was discussed. The results indicate that to some degree, QI contents accelerate the formation of mesophase at atmospheric pressure; while at high pressure, the coalescence and growth of mesophase spherules are impeded and the resultant coke produced from higher QI content pitch is harder to be graphitized. This is in agreement with the transfer of microstructure from domain anisotropy to fine grained mosaics.

Comparative Study of the Modification of Coal Tar Pitch for Higher Carbonization Yield and Better Properties

Parent coal tar pitch(CTP)was modified with boric acid(BA),cinnamaldehyde(CMA)and the mixture of BA and CMA,respectively.The parent CTP and three modified CTPs were characterized by elemental analysis,thermogravimetric analysis,Fourier transform infrared(FT-IR)spectroscopy and scanning electron microscopy.The four samples were carbonized at different temperatures and resultant carbonized products were characterized by FT-IR spectroscopy,X-ray diffraction and polarized-light microscopy.The results show that the morphologies and carbonization behaviors of the parent CTP and modified CTPs are quite different.The carbonization yield of the CTP modified with the mixture of BA and CMA is higher than that of CTP modified with BA or CMA only.In addition,the modification of CTP with 7 g of BA and 10 ml of CMA results in an increase in carbonization yield by5.64%.During the pyrolysis of modified CTPs,the dehydration of BA or the distillation of CMA occurs at the temperature lower than 300°C,and methyl and methylene groups of the modified CTPs disappear gradually as temperature rises.Furthermore,the modification of CTP by the mixture of BA and CMA results in more intensive mesophase spheres than other modified CTPs,and the modified CTP is easier to be carbonized to form graphitic carbon.

Carbon foams prepared from coal tar pitch for building thermal insulation material with low cost

A new approach is provided to resolve the large-scale applications of coal tar pitch. Carbon foams with uniform pore size are prepared at the foaming pressure of normal pressure using coal tar pitch as raw materials. The physical and chemical performance of high softening point pitch(HSPP) can be regulated by vacuumizing owing to the cooperation of vacuumizing and polycondensation. Results indicate that the optimum softening point and weight ratio of quinoline insoluble are about 292℃ and 65.7%, respectively. And the optimum viscosity of HSPP during the foaming process is distributed in the range of 1000-10000 Pa·s. The resultant carbon foam exhibits excellent performance, such as uniform pore structure, high compressive strength(4.7 MPa), low thermal conductivity(0.07 W·m^(-1) ·K^(-1)), specially, it cannot be fired under the high temperature of 1200 ℃.Thus, this kind of carbon foam is a potential candidate for thermal insulation material applied in energy saving building.

Comparative Studies of Thermal Stability of Coal Tar Pitches

In the present work, three medium softening point coal tar pitches were used for comparative thermal stability and under-storage stability investigation. Powders of the pitches were found to be different under storage： one of the pitches was caked and slumped after 7-day or longer storage. For thermal stability investigation the soft temperature treatment （265℃） of coal tar pitches was used. Detailed study of initial and treated pitches was carried out. Experimental results demonstrated that LMW-HC （high low-molecular-weight hydrocarbons） and oxygen content influence pitch quality characteristics in a negative way under long-term storage and lead to highest properties change after thermal stability treatment.

A strategy based on water soluble coal tar pitches to construct MnO_(2)@C composite materials with high electrochemical performance

The water soluble coal tar pitches(WS-CTPs)were successfully prepared and used to construct the MnO_(2)@C composite materials by a hydrothermal method.It is interestingly observed that the structures and morphologies of MnO_(2)@C materials can be controlled by controlling the dosages of WS-CTPs and KMnO4.Meanwhile,it is aware that MnO_(2)exists in the MnO_(2)@C materials in an amorphous state.Compared with MnO_(2),MnO_(2)@C materials output a remarkable improvement in electrochemical performance.For instance,MnO_(2)@C-0.3 shows the storage capacity at 965.7 mA h g^(−1)after 300 cycles at a current density of 0.1 A g^(−1).In addition,after 600 cycles at a current density of 1.0 A g^(−1),the storage capacity of MnO_(2)@C-0.3 still keeps 450.3 mA h g^(−1),indicating that MnO_(2)@C-0.3 owns tremendous cycle stability at a high current density.In view of the fact that the coal tar pitches possess great cost advantages,the strategy of using WS-CTPs as a carbon source to cover the metal oxides is a competitive way to expand the application of metal oxides in the fabrication of electrodes of LIBs.

Characterization of Coal Tar Pitch and Paving Pitch by UV,EA and NMR

In order to enlarge the use of coal tar pitch(CTP) in paving road,CTP and 60th paving pitch (PP) were extracted by n-heptane,toluene and ethanol step by step in a Soxhlet apparatus.The three fractions of CTP and PP were detected using UV-absorption(UV-A),elemental analyses(EA) and nuclear magnetic resonance(NMR) firstly as a whole unit after quality characterization of physical nature of CTP and PP were finished.The CTP had more saturate aliphatic and residue compounds dissolved in ethanol.On the other hand there were more continental type structures of aromatic ring than that of PP.There was almost no residue in PP after extracted by ethanol.The results explained why CTP was crisp in cold winter and was soften in summer.The following research will focus on how to change the chemical construction of CTP into the relative similar structures with those of PP through adding polymer.

沥青基多孔炭材料制备及其双电层储能性能

多孔炭作为超级电容器电极的主要材料,具有导电性好、化学稳定性高、工作温度范围广等优点。以内蒙古煤沥青(CTP)为原料,分别以K_(2)CO_(3)和KOH为活化剂,通过化学活化法制备多孔炭材料,优化制备工艺并比较2种活化剂制备的多孔炭在结构和电化学性能方面的差异。结果表明,K_(2)CO_(3)活化和KOH活化最佳制备条件均为活化温度700℃、活化时间60 min、活化剂与CTP质量比为2∶1。2种活化剂制备的多孔炭在微观结构上有很大差异,KOH活化所得多孔炭(PH-T700)表面平整光滑并分布大量规则的圆孔,而K_(2)CO_(3)活化所得多孔炭(PC-T700)内部呈层叠交错的珊瑚状结构。与PH-T700相比,PC-T700具有更多中孔,离子扩散阻力更小。在1 A/g电流密度下,PC-T700和PH-T700的比电容量分别为252.90和261.02 F/g,PC-T700和PH-T700组装成纽扣型对称电容器,0.5 A/g时比电容量分别为226.01和225.51 F/g,且PC-T700表现出更优秀的倍率性能和循环稳定性。5000次充放电后,PC-T700和PH-T700的比电容量分别为初始值的103.77%和98.20%。输出功率达1038.46 W/kg时,PC-T700能量密度仍保持7.5 Wh/kg,实际使用价值高于PH-T700。

煤沥青交联改性处理对碳结构的影响

沥青基炭制品的碳结构高度依赖前驱体沥青的性质。采用化学交联的方法对沥青进行改性处理时,尽管化学交联的反应机理为亲电取代反应,但交联剂、催化剂的种类不同,沥青改性程度存在差异,进而影响炭制品结构。以中低温煤沥青为原料,探索3种交联剂(对苯二甲醇(PXG)、苯甲醛(BA)、对苯二甲酰氯(TPC))、5种催化剂(对甲苯磺酸、浓硫酸、浓硝酸、浓盐酸、硼酸)对沥青交联改性后炭制品结构的影响。通过TG-DTG、FT-IR研究交联改性后沥青热稳定性及沥青官能团的变化;借助XRD、Raman表征改性后沥青炭制品的微观结构差异。结果表明:交联剂和催化剂的存在促进了沥青分子的交联,有效阻止了热转化过程中轻组分挥发,提高了沥青的结焦值、软化点、热稳定等指标。以PXG为交联剂,沥青支链上亚甲基CH_(2)的H不易被取代;而以硼酸为催化剂时,支链末端甲基上的H易被取代;以BA为交联剂,取代氢的位置明显发生在芳香环上;以TPC为交联剂、浓硫酸为催化剂时,交联产品的C=0官能团含量增加,说明在这种组合下,TPC参加反应较多。无论与哪种交联剂相结合,浓盐酸为催化剂时,交联反应更易促进苯环上和支链上的C—H键发生取代反应。经过交联改性后的沥青,炭化过程中分子间较强的π-π相互作用减弱,有效阻止碳有序结构的形成,碳无序结构含量I_(D)/I_(G)增大。同时碳微晶层间距d_(002)明显增加,有序堆积平均堆积高度L_(c)减小,芳香层数降低,说明化学交联不仅影响有序碳结构排列,还可抑制碳微晶结构发育。其中硼酸作为催化剂时,催化效果更理想。获得的炭制品d_(002)在同组产品中最大。PXG、硼酸组合与沥青发生交联时,所得碳材料的d_(002)达0.377 nm。本研究为进一步定向调控和构筑沥青基碳材料奠定基础。

氢氧化镁-硼酸锌复合阻燃剂辅助制备产率高和电容性能优异的煤焦油沥青基多孔碳

以煤焦油沥青为前驱体,氢氧化镁-硼酸锌复合阻燃剂为助剂,直接在空气条件下高温碳化制备了煤沥青基多孔碳,并探究其电化学性能。得益于阻燃剂的阻燃协同其活化、掺杂功能化作用,得到了高产率(55.1%)、多原子(N、B、O)掺杂且具有分级多孔结构的多孔碳。将其作为超级电容器电极材料,在三电极体系中0.5 A·g^(-1)电流密度下比电容可达344 F·g^(-1)。此外,以制备的多孔碳和壳聚糖基氨基酸质子盐凝胶电解质组装的柔性对称电容器具有29.3 Wh·kg^(-1)的高能量密度,在50 000次循环后电容保持率为96.9%,且在-25~75℃温度区间内可正常工作,显示出宽的温度使用范围。

煤制油沥青改性制备包覆沥青及其表征分析

以煤制油沥青(coal to oil asphalt,CTOA)为原料,加入乙烯焦油沥青(ethylene tar pitch,ETP)进行改性,采用热聚合法制备出高品质的包覆沥青。在最佳热聚合工艺条件下制备出200^(#)包覆沥青;利用元素分析仪、红外光谱仪、拉曼光谱仪、X射线衍射仪、扫描电子显微镜、热重分析仪等对包覆沥青的微观形貌、结构和组成进行分析。结果表明,相较于空气氧化法和催化交联聚合法,改性和热聚合所制备的200^(#)包覆沥青的QI和灰分质量分数显著降低,产品性能优异;微观结构和组成分析表明,包覆沥青分子具有较高的碳质量分数和芳香缩合度,分子中类石墨结构增多,碳微晶排列规整,热重分析结果进一步证实其热稳定性显著增强,可用作锂电负极包覆材料。

聚合物改性法脱除中温煤沥青中的苯并[a]芘效果分析

为降低煤沥青中致癌性多环芳烃的含量,实现其绿色化应用,分别采用聚氨酯单体、三聚甲醛、聚乙二醇、二乙烯基苯和环氧树脂中的一种或多种与煤沥青进行反应,以煤沥青中代表性致癌物苯并[a]芘(BaP)的脱除率作为评价指标,分析各单一改性剂及复合改性剂对煤沥青中BaP的影响。结果表明:选取的改性剂均能有效降低煤沥青中BaP的质量分数,单一改性剂脱毒效果从高到低依次为聚氨酯单体、三聚甲醛、聚乙二醇、二乙烯基苯、环氧树脂;复合改性剂的最优试验组合(质量分数)为6%聚氨酯单体+10%三聚甲醛+8%聚乙二醇,其在最佳反应条件下可使BaP的降低率达到82.16%。

SBS和EVA对炭沥青的改性研究

采用SBS和EVA对路用煤-石油基混合沥青进行改性处理，对SBS和EVA引起的炭沥青改性效果进行了研究。结果表明，SBS改性后的炭沥青具有更好的高温抗丰辙、低温抗裂性能和感温性能，采用4．5％～6％的SBS改性炭沥青（软化煤沥青比例为15％），所得性能最优。

三维氮掺杂分级多孔碳纳米片的制备及储锌性能

以MgO@ZIF-8为双模板和辅助碳源,KHCO_(3)为活化剂,煤沥青(CTP)为碳源,制备了三维氮掺杂分级多孔碳纳米片(N-CNs),探究了KHCO_(3)与CTP的质量比对N-CNs的结构、化学组成和锌离子储存性能的影响.结果表明,当KHCO_(3)与CTP的质量比为3∶1时,制备的样品(N-CN_(3))具有三维互连的碳纳米片结构、高比表面积(2360m^(2)/g)和吡咯氮含量.将N-CN_(3)作为锌离子混合电容器(ZHCs)正极时,其在2mol/LZnSO_(4)电解液中展现了出色的比容量(当电流密度为0.2A/g时,比容量为157.6mA·h/g)、高的能量密度(在176.1W/kg功率密度下能量密度为126.5 W·h/kg)和优异的循环稳定性(当电流密度为5 A/g时,经过20000次循环后容量仅衰减6.4%,库仑效率为99.6%).密度泛函理论计算结果证实,吡咯氮掺杂增加了电极材料对锌离子的吸附能,提高了N-CNs对锌离子的吸附容量.

沥青工血清ras P21蛋白水平检测

为了解职业性肺癌高发人群沥青工血清ｒａｓＰ２１蛋白水平，用ＷｅｓｔｅｒｎＢｌｏｔｉｎｇ法对２４名沥青工和１２名对照血清Ｐ２１蛋白进行了检测；发现沥青工Ｐ２１均值（３５５８７）明显高于对照（１２７０７）（Ｐ＜００１）；对沥青工按工龄、是否吸烟分组并比较，均未发现组间Ｐ２１的显著性差异。此结果提示，煤焦沥青可使接毒者癌蛋白Ｐ２１水平提高。

锂电池负极材料改性石墨CGS制备工艺研究

采用煤焦油沥青和石油沥青的混合物为包覆剂制备了碳包覆锂离子电池负极材料,对材料进行了SEM、压实密度,以及大电流放电倍率、循环等测试。制备的碳负极材料为类球状,形貌规整,压实密度提高,循环500周后容量保持率大于80%。

沥青工、焦炉工血清 ras p21 水平的研究

为了解职业性肺癌高发人群沥青工和焦炉工血清ｒａｓｐ２１癌蛋白水平，从分子水平阐明毒物作用于机体后的反应；用ＷｅｓｔｅｒｎＢｌｏｔｉｎｇ法对２４名沥青工、２５名焦炉工和１２名正常对照组血清ｐ２１水平进行了研究。结果发现接触组ｐ２１均值（３６６８．６）明显高于对照（１２７０．７，Ｐ＜０．０１）。按工种分层分析，沥青工和焦炉工血清ｐ２１均值明显高于对照组（Ｐ＜０．０１）；焦炉工中的炉顶工ｐ２１水平明显高于其它工种（Ｐ＜０．０５）；接触组按工龄分组、是否吸烟分组进行比较，未发现ｐ２１的显著性差异。此结果提示。

中低温煤焦油沥青组分的热解特性及动力学研究

中低温煤焦油沥青(MLP)为人造炭材料的重要原料,研究其组分的热解特性及动力学对高品质中低温煤焦油沥青基炭材料的制备具有重要意义。以中低温煤焦油沥青为原料,分别采用正丁醇(BA)和二甲基亚砜(DMSO)为萃取剂以获得4种沥青组分,通过热重分析仪对中低温煤焦油沥青和4种族组分的热解行为进行研究,利用Flynn-Wall-Ozawa法、Kissinger-Akahira-Sunose法和Satava-Sestak法计算热解活化能以及热解动力学参数。结果表明:MLP、DMSOS、BAI组分的热解反应机理符合随机成核及其后续增长模型,最佳热解机理函数分别为G(α)=[-ln(1-α)]^(4/3)、G(α)=[-ln(1-α)]^(4)、G(α)=[-ln(1-α)]2,活化能分别为73.99、180.20、46.09 kJ/mol,lg A分别为5.82、13.57、3.32;BAS组分的热解反应机理符合二维扩散模型,最佳热解机理函数为G(α)=α+(1-α)ln(1-α),E=85.36 kJ/mol,lg A=6.18;DMSOI组分的热解反应机理符合二维扩散或三维扩散模型,最佳热解机理函数为G(α)=[1-(1-α)^(1/3)]^(2),E=64.42 kJ/mol,lg A=4.00。

煤焦沥青烟提取物对BEAS-2B细胞Nrf2及NQO1表达的影响

目的:研究煤焦沥青烟提取物对人肺支气管上皮细胞(BEAS_2B)Nrf2、NQO1mRNA及Nrf2蛋白表达的影响。方法:煤焦沥青烟提取物以0.00、1.25、2.50、5.00、10.00μg/ml分别染毒BEAS_2B细胞24h后,提取细胞总RNA和总蛋白。采用RT_PCR检测Nrf2、NQO1mRNA的相对表达量,Westernblot测定Nrf2蛋白相对表达量。结果:染毒组BEAS_2B细胞Nrf2mRNA及蛋白相对表达量均低于对照组,差别均有统计学意义(P均<0.05),在1.25～5.00μg/ml浓度范围内,随着染毒浓度的增加,Nrf2mRNA和蛋白表达呈递增趋势,而当染毒浓度为10.00μg/ml时,Nrf2mRNA和蛋白表达量均有所减少(P<0.05)。随着染毒浓度的增加,NQO1基因表达水平升高,在5.00、10.00μg/ml时NQO1基因相对表达量比对照组高(P<0.05)。结论:在煤焦沥青烟提取物浓度较低时(1.25～5.00μg/ml),随染毒浓度增加Nrf2表达水平升高,可能上调NQO1基因的表达,增强BEAS_2B细胞氧化应激能力。