乙烯渣油沥青的改性及表征

以乙烯渣油沥青为原料,通过常压空气氧化聚合处理对其进行改性,利用单因素方法考察了反应条件(反应温度、反应时间、空气流量)对改性沥青性质(软化点、喹啉不溶物、结焦值、甲苯不溶物、收率)的影响。结果表明,在反应温度370℃,反应时间5 h,空气流量24 L/h的条件下,可以获得软化点(SP)为233℃、喹啉不溶物(QI)为1.21%、结焦值(CV)为75.45%、甲苯不溶物(TI)为43.42%的改性沥青,其收率(Y)可达51.67%。通过元素分析、FTIR等手段对乙烯渣油沥青和改性沥青的芳香性指数(I_(ar))、支链化指数(CH_3/CH_2)进行计算,并利用TGA方法观察改性前后沥青的热稳定性变化。结果表明,乙烯渣油沥青和改性沥青的I_(ar)分别为0.39,0.53,CH_3/CH_2分别为0.88,1.08,说明改性过程中乙烯渣油沥青支链不断减少,芳香缩合度和热稳定性均有所提高。     

乙烯渣油沥青的改性及表征

以乙烯渣油沥青为原料,通过常压空气氧化聚合处理对其进行改性,利用单因素方法考察了反应条件(反应温度、反应时间、空气流量)对改性沥青性质(软化点、喹啉不溶物、结焦值、甲苯不溶物、收率)的影响。结果表明,在反应温度370℃,反应时间5 h,空气流量24 L/h的条件下,可以获得软化点(SP)为233℃、喹啉不溶物(QI)为1.21%、结焦值(CV)为75.45%、甲苯不溶物(TI)为43.42%的改性沥青,其收率(Y)可达51.67%。通过元素分析、FTIR等手段对乙烯渣油沥青和改性沥青的芳香性指数(I_(ar))、支链化指数(CH_3/CH_2)进行计算,并利用TGA方法观察改性前后沥青的热稳定性变化。结果表明,乙烯渣油沥青和改性沥青的I_(ar)分别为0.39,0.53,CH_3/CH_2分别为0.88,1.08,说明改性过程中乙烯渣油沥青支链不断减少,芳香缩合度和热稳定性均有所提高。     

低温交联法制备炭材料用改性沥青

以二乙烯基苯（DVB）为交联剂，在对甲苯磺酸（PTS）的作用下对中温煤沥青进行改性，制备出性能优良的炭材料用改性沥青，并对改性沥青的性能进行表征。结果表明，未固化沥青的软化点为112℃，残炭率达68.0%，而固化后沥青的残炭率高达74.2%；改性后的沥青中出现很多中间相小球体；与未改性的煤沥青相比，该沥青炭化产物的孔隙尺寸明显变小。     

有关炭材料生产用煤沥青的几个新概念

1中温改质沥青我国将煤沥青一般分为低温沥青(软化点为30～75℃,又称为软沥青)、中温沥青(软化点为75～95℃)、高温沥青(软化点为95～120℃,又称为硬沥青)和改质沥青(软化点为105～120℃)。GB/T2290—1994规定石墨电极生产用中温沥青的质量指标:软化点为80～90℃,甲苯不溶物含量为15%～25%,灰分不大于0.3%,水分小于5%,挥发分为58%～68%,喹啉不溶物含量小于10%;其他炭材料生产用中温沥青的质量指标:软化点为75～95℃,甲苯不溶物含量小于25%,灰分不大于     

煤液化沥青用于石墨电极黏结剂的性能研究

以煤液化沥青为原料,引入蒽油与其进行热聚合反应,得到了一种煤液化改性沥青,其软化点为83.3℃、甲苯不溶物含量21.97%、喹啉不溶物含量0.18%、结焦值50.95%。以此煤液化改性沥青作黏结剂,与针状焦进行混捏成型制备石墨电极,其热膨胀系数为1.1×10~(-6)/℃,电阻率6.4μΩ·m,抗压强度16 MPa,体积密度1.42 g/cm~3,真密度2.22 g/cm~3,灰分含量为0.03%。     

热聚合-氧化法制备高β树脂改性沥青

以中温沥青为原料,通过溶剂萃取沉降分离获得低喹啉不溶物含量(QI<0.1%)的精制沥青。对精制沥青进行热聚合-空气氧化改性处理,得到高β树脂含量的改性沥青。经特定热聚合条件处理后,研究了空气氧化阶段的反应温度、氧化时间和空气流量对沥青改性的影响。实验结果表明,在空气氧化阶段,当氧化温度为280℃,氧化时间为2h,空气流量为0.04m³/h时,可以获得软化点为220℃、甲苯不溶物为61.59% 、喹啉不溶物为4.35%、结焦值为78.44%,β树脂含量为57.24%的优质改性沥青。     

二乙烯基苯改性煤沥青的工艺及性能研究

以二乙烯基苯为交联剂,在酸性催化剂的作用下对煤沥青进行了改性,并对其工艺及性能进行了研究.采用不同溶剂对改性前后煤沥青的组分进行分析,并测定不同工艺改性沥青的软化点、残炭率及密度等性能;采用扫描电镜对改性煤沥青炭化产物的形貌进行观察.研究表明,改性工艺对改性煤沥青的组成和性能影响很大.     

褐煤焦油沥青改性的初步研究

通过热处理技术,对沥青进行改性试验,提高了沥青的软化点及甲苯不溶物含量,改性后沥青可满足建筑沥青使用要求。     

工艺条件对均四甲苯改性沥青性能和组成的影响

以均四甲苯为添加剂对沥青进行改性,初步考察了工艺条件（ 反应温度、反应时间、添加剂含量、体系压力等）对改性沥青软化点、残炭率及族组成的影响。发现均四甲苯的加入可促进沥青分子的反应,调整沥青的组成和结构分布;通过不同反应条件可控制沥青ＴＳ 组分和ＰＩ 组分以达到沥青组成设计的目的。     

改性沥青树脂及其复合材料的制备及相关性能

以煤沥青为原料、三聚甲醛为交联剂,在对甲苯磺酸的催化作用下合成了沥青树脂（COPNA树脂）,通过添加酚醛树脂对其进行了改性;分别以沥青树脂和改性树脂为原料,与石墨混合制备了复合材料。考察了酚醛树脂含量对改性树脂的残炭率、甲苯不溶物含量、喹啉不溶物含量、p树脂含量的影响,以及树脂含量对复合材料的电阻率,肖氏硬度的影响;采用FT—IR和H—NMR研究其反应机理;采用TG研究了沥青树脂和改性树脂的热行为。研究表明,酚醛树脂与沥青树脂可以在一定比例范围内进行复配,在加热混合过程中酚醛树脂与沥青树脂发生化学反应,提高了沥青树脂的耐热性。经酚醛树脂改性的沥青树脂具有更高残炭率、更高β树脂含量和更好耐热性。改性后的树脂复合材料具有更高的电阻率、更高的肖氏硬度和更高的耐磨性。     

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 by 5.64%. 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.     

Effect of erucic acid on the rheological and surface properties of coal tar pitch

Coal tar pitch (CTP) was modified using erucic acid, CH₃(CH₂)₇CH=CH(CH₂)₁₁COOH, and the rheological and surface properties of the modified CTP were evaluated. The effect of erucic acid was investigated using a rotational viscometer as well as by drop and weight tests. The modified CTPs were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy following a carbonization process. The results showed significant differences in several properties between the CTP and modified CTPs, such as decreases in viscosity, wetting temperature, and softening point when erucic acid content was 1–3 wt% of CTP. An improvement in bonding between the coke and the modified CTP can be achieved when the coke value remained 62%. Moreover, a modification mechanism was proposed to explain the physical plastification of CTP modified with erucic acid.     

中低温煤焦油沥青催化聚合制备改质沥青

以中低温煤焦油沥青为原料,采用催化聚合法制备改质沥青,并在中低温煤焦油沥青中加入乙烯焦油和蒽油进行调和来提高改质沥青的流变性能,分别考察反应时间、反应温度及催化剂和交联剂的加入量对改质沥青的软化点、结焦值、甲苯不溶物含量和喹啉不溶物含量的影响。结果表明:加入乙烯焦油和蒽油调和可以有效提高改质沥青的流变性能,催化剂和交联剂按照1∶1的质量比加入,可以有效降低改质沥青的软化点,这是因为酸性催化剂和交联剂之间形成相对均相的反应体系,解决了改质沥青软化点高的问题。采用调和中低温煤焦油沥青制备改质沥青,筛选出的最佳工艺条件为:反应温度370℃,反应时间7h,催化剂和交联剂的加入量2.5%,该条件下制备的改质沥青的性质符合工业标准YB/T 5194-2015的要求,改质沥青的软化点为120℃,结焦值为56.28%,甲苯不溶物含量为30.52%,喹啉不溶物含量为8.21%,β树脂含量为22.31%。采用傅立叶变换红外光谱仪和偏光显微镜对制备出的改质沥青和中低温煤焦油沥青进行分析,初步推断出改质沥青中化合物芳环上的取代基明显增加且烷基取代的化合物大多数为芳烃分子,且在偏光显微镜下改质沥青中出现小球体,表明中低温煤焦油沥青在制备成改质沥青的这一过程中其相对分子质量变大,稠环芳烃含量增多。     

对甲苯磺酸催化合成硼酸三乙醇胺酯

以硼酸和三乙醇胺(过量)为原料,以对甲苯磺酸作为酯化催化剂,采用潜溶剂法(适量甲苯作为带水剂,加热回流反应)合成制备硼酸三乙醇胺酯。实验中考察了原料配比对硼酸酯收率的影响。实验结果表明,随着原料配比的增加,硼酸三乙醇胺酯的收率也随之增加;当原料配比达到1∶5.5时,硼酸三乙醇胺酯的收率会随着它们的进一步增加而下降。     

Coating of graphite anode with coal tar pitch as an effective precursor for enhancing the rate performance in Li-ion batteries: Effects of composition and softening points of coal tar pitch

Effects of compositions and softening points of coal tar pitches (CTPs) on the electrochemical performances especially for first cycle Coulombic efficiency and rate performance, of the amorphous carbon coating on the graphite surface were closely examined. CTPs with higher softening points could afford the better homogeneous amorphous carbon coating on the graphite surface, resulting in the better enhancing rate performance of graphite anode without decreasing the first cycle Coulombic efficiency. CTP with almost complete absence of hexane soluble (HS) fraction always showed the good enhancing effect of the rate performance. HS fraction of CTP, which is a reason for inducing surface defects on the coated carbon, hindered the enhancing effect of electrochemical performances. CTP derived amorphous carbon coating could effectively decrease charge transfer resistance on the graphite electrode–electrolyte interface.     

硼酸对水玻璃基保温材料性能影响研究

水玻璃基保温材料具有轻质、导热系数低的优点,但其耐水性较差的问题亟待改善。将硼酸作为改性剂加入到水玻璃中,采用中温烧结法制备保温材料,通过对样品微观结构的表征和物理性能的测试,以及耐水性浸出试验,研究硼酸对水玻璃基保温材料性能的影响效果。结果表明,硼酸能够调节材料中Si—O四面体的框架结构,有效降低结构中的羟基数量,并抑制溶液中硅酸根离子和钠离子的浸出,提高材料的软化系数和耐水性能。当硼酸质量添加量为1.00%时,软化系数从改性前的0.519增至0.701,增加了35%。同时,硼酸的加入能够使材料内部孔径分布更加均匀,提高材料的抗压强度,但是材料的导热系数和表观密度也会增加。经0.75%(质量分数)硼酸改性后的保温材料导热系数、表观密度和抗压强度分别为0.052 W/(m·K)、128 kg/m³和0.442 MPa,满足保温材料的性能要求。     

2-乙基-1，3-己二醇萃取硼酸的传质系数

单液滴法因其测量结果精确与实验设备简单等优点广泛应用于萃取过程中的传质研究。应用此方法研究了硼酸在2-乙基-1,3-己二醇-甲苯/卤水体系中的传质系数。结果表明：传质系数随着有机相2-乙基-1,3-己二醇浓度、卤水相硼酸浓度及温度的增加而增大。通过双膜传质理论分析,并引入修正的传质系数关联式,将双膜传质模型应用到此萃取体系中,建立了新的针对此体系的传质系数模型。新模型的计算值与实验值的平均相对误差为7.59 %,两者吻合良好,因此,该模型可用于2-乙基-1,3-己二醇-甲苯体系萃取硼酸过程的设计与放大。     

对伞花烃裂解氧化产物苯甲酸的水相酯化方法研究

对伞花烃裂解氧化产物苯甲酸与硫酸二甲酯的反应可以采用水相酯化法。实验室小试结果显示,苯甲酸的转化率平均为89.97%,苯甲酸甲酯的得率平均为83.16%;车间放大试验结果显示,苯甲酸甲酯的得率为89.00%。水相酯化法与有机相酯化法相比,甲苯的单耗降低38.69%,硫酸二甲酯的单耗下降32.14%,废水量下降35.85%,耗时减少66.67%,设备利用率和生产能力显著提高,氧化催化剂也可以得到回收。     

缓凝剂对氯氧镁水泥水化历程的影响

为了拓展氯氧镁水泥(MOC)的使用范围,研究了缓凝剂(柠檬酸、硼酸、葡萄糖酸钠)对氯氧镁水泥凝结时间、抗压强度、电阻率、水化热和耐水性的影响,同时采用X射线衍射仪分析了氯氧镁水泥改性后的水化产物。结果表明,掺入缓凝剂会延长氯氧镁水泥的凝结时间,当缓凝剂掺量达到0.75%(质量分数,下同)时,各组试样的28 d抗压强度较空白组分别下降了19.3%、16.7%和20.2%。缓凝剂的掺入降低了水泥浆体电阻率速率曲线和内部温度曲线的峰值,推迟了水化放热速率曲线第二峰值出现时间,即降低了氯氧镁水泥的水化速率,改善了氯氧镁水泥放热集中的现象。缓凝剂能提高氯氧镁水泥的耐水性,当硼酸掺量为0.75%时,软化系数可达到0.79。     

Comparative studies of the modification of coal-tar pitch

Properties of coal-tar pitches modified by sulfur addition, air blowing, and nitrogen blowing were compared to find an appropriate method of preparing a matrix precursor for carbon/carbon (C/C) composites. Raw and modified pitches were characterized by softening point, thermal analysis (TGA), elemental analysis, solubility in toluene and quinoline, and gel permeation chromatography. Both sulfur addition and air blowing very effectively increased softening point and coke yield by dehydrogenative polymerization of pitch molecules. Air-blown pitch, however, had less thermal stability than the pitch with added sulfur and showed more weight loss at high temperatures. Property changes in nitrogen-blown pitch were mainly induced by eliminating volatile matter of low molecular weight. Sulfur addition is suggested to be the most promising method for preparing matrix precursor because it had the highest yield among those with similar softening points.