尿素法合成甲苯二氨基甲酸苯酯过程中间体的制备、表征和定量分析

尿素与2,4-甲苯二胺以及苯酚反应合成甲苯二氨基甲酸苯酯为一复合反应体系。制备了其较好反应路径的中间产物氨基甲酸苯酯及甲苯-2-氨基-4-氨基甲酸苯酯,借助熔点测定、红外表征、元素分析以及核磁共振等手段对中间产物进行了表征;建立了高效液相色谱分析方法,液相色谱分析条件为:流动相甲醇-水(体积比1∶1),流速0.4mL/min,紫外光检测波长254nm。在一定的质量浓度范围内,氨基甲酸苯酯及甲苯-2-氨基-4-氨基甲酸苯酯的线性相关系数均大于0.999,相对标准偏差均小于1.0%。     

尿素法合成甲苯-2,4-二氨基甲酸正丙酯反应

以2,4-二氨基甲苯（TDA）、尿素和正丙醇（PrOH）为原料,非催化合成了甲苯-2,4-二氨基甲酸正丙酯（TDC-P）,考察了反应条件对该合成反应的影响,并基于反应产物的液相色谱 质谱分析结果,推测了可能的反应路径。结果表明,该反应适宜的反应条件为n(TDA)/n(Urea)＝1/3、n(TDA)/n(PrOH)＝1/84、反应温度170℃、反应压力0.6 MPa、反应时间4 h。此时,TDA转化率95.3%,TDC-P产率66.1%、选择性69.4%。合成TDC-P可能的反应路径有3条,（1）经过氨基甲酸正丙酯和3-氨基-4-甲基苯氨基甲酸正丙酯或2-甲基-5-氨基苯氨基甲酸正丙酯生成TDC-P的反应路径;（2）以2,4-甲苯二脲为中间产物的反应路径;（3）以3-脲基-4-甲基苯氨基甲酸正丙酯或2-甲基-5-脲基苯氨基甲酸正丙酯为中间产物的反应路径。     

基于TMC路径尿素法合成甲苯-2,4-二氨基甲酸甲酯的热力学计算和路径考察

以2,4-二氨基甲苯(TDA)、尿素和甲醇(MeOH)为原料,合成了甲苯-2,4-二氨基甲酸甲酯(TDC)。在对以3-氨基-4-甲基苯氨基甲酸甲酯(TMC)为中间产物的反应路径进行热力学分析的基础上,考察了催化剂及反应条件对基于TMC合成TDC反应的影响,筛选出活性较高的碱式碳酸铜催化剂,确定了适宜的反应条件。结果表明,由TDA、尿素和甲醇经TMC合成TDC的反应在热力学上可行。在TDA与碱式碳酸铜、尿素和甲醇的摩尔比为1∶0.07∶5∶80,反应温度463.15K,反应压力3.0 MPa,反应时间6h条件下,TDA的转化率为97.3%,TDC的收率和选择性分别为48.0%和49.3%。     

异氰酸酯功能单体的封闭与解封闭

用己内酰胺作封闭剂,研究了(3-异氰酸酯基-4-甲基)苯氨基甲酸-2-丙烯酯(TAI)功能单体的封闭和解封闭。用化学滴定法和傅里叶变换红外光谱表征封闭反应前后异氰酸酯基的变化情况,采用热失重分析确定封闭产物的解封闭温度。结果表明,封闭的最佳条件为:反应温度80℃,n(封闭剂):n(单体)=1.1:1,反应时间4～5 h,封闭率可达97%。解封闭反应起始温度为160℃,异氰酸酯解封闭速率最快时所对应的温度为200℃。     

催化加氢法合成2,5-二氨基甲苯

以2-氨基偶氮甲苯为原料,催化加氢合成2,5-二氨基甲苯。考察了催化剂类型、原料浓度、催化剂用量、反应温度和反应压力等对反应的影响。结果表明,介孔碳负载钯催化剂Pd/MC具有高活性和稳定性。经单因素实验考察,确定优化工艺条件为:采用甲醇-水(体积比3∶7)溶液作为溶剂,原料浓度为100～200 g/L,催化剂的添加量为原料的0.25%(质量分数),反应温度80℃,反应压力2.0 MPa,溶液初始pH值为8,反应时间3～4 h。在此条件下,2-氨基偶氮甲苯转化率接近100%,2,5-二氨基甲苯收率大于98%,催化剂可重复使用5次以上,具有工业化应用前景。     

Yb(OTF)3催化2,4-二氨基甲苯与碳酸二甲酯合成2,4-甲苯二氨基甲酸甲酯

研究了Yb(OTF)3催化剂对2,4-二氨基甲苯与碳酸二甲酯反应合成2,4-甲苯二氨基甲酸甲酯的催化活性,采用L16(44)正交实验方案对反应温度、反应时间、原料比、催化剂用量4个因素进行了考察,得到了最优反应条件.在此条件下,TDC收率可达25.3%.初步研究了Yb(OTF)3催化DMC和TDA合成TDC的反应机理.对Yb(OTF)3催化剂的寿命进行了考察,发现催化剂无明显失活,可重复使用.     

3-氨基-4-甲基苯氨基甲酸甲酯的合成、表征及定量分析

鉴于在尿素法合成甲苯-2,4-二氨基甲酸甲酯(TDC)反应中含有大量的中间产物3-氨基-4-甲基苯氨基甲酸甲酯(TMC),因此,建立TMC的分析方法有助于尿素法合成TDC反应研究。首先采用甲苯为溶剂、ZnCl2为催化剂,以2,4-二氨基甲苯和氯甲酸甲酯为原料合成了TMC;提纯后试样的熔程在1℃以内,表明其纯度较高;然后,采用FT-IR、1 H NMR、元素分析、气质联用分析等方法确定了所合成的TMC试样的结构;采用外标法建立了TMC的高效液相色谱定量分析方法,测得其质量浓度在(0.3¹.5)×10-4 g/mL范围内与峰面积呈现良好的线性关系。     

2-（4′-乙基苯甲酰基）苯甲酸催化脱水闭环反应中Hβ沸石催化剂失活和再生的研究

研究了柠檬酸改性的Hβ沸石催化剂在2-(4′-乙基苯甲酰基)苯甲酸(BEA)脱水闭环合成2-乙基蒽醌(2-EAQ)工艺中的失活及再生性能。结果表明,催化剂经过多次重复使用,催化活性下降。通过乙醇洗涤催化剂再焙烧的方法,可以恢复催化剂活性。再生后的催化剂重复使用4次后,BEA的转化率仍然高达99.5%,2-EAQ选择性也高达99.4%。采用TG-DTA对乙醇洗涤前后失活催化剂进行表征,并结合电喷雾质谱API-ES和1HNMR对催化剂上积炭物种的组成进行了定性分析。     

3-(N-乙基-N-甲氧基羰基甲基)氨基-4-甲氧基乙酰苯胺的合成工艺研究

以3-(N-乙基)氨基-4-甲氧基乙酰苯胺(Ⅰ)和氯乙酸甲酯为原料、无水碳酸钠为缚酸剂、甲苯为溶剂,合成3-(N-乙基-N-甲氧基羰基甲基)氨基-4-甲氧基乙酰苯胺。经正交实验法,考察了Ⅰ和氯乙酸甲酯的摩尔投料比、反应温度、甲苯及碳酸钠用量对收率的影响,其最佳工艺条件为:n(Ⅰ):n(氯乙酸酯)=1:1.1,反应温度为100℃,溶剂甲苯用量为10.4 mL,n(Ⅰ):n(碳酸钠)=1:0.56,收率96.8%。     

2-(4''''-乙基苯甲酰基)苯甲酸催化脱水闭环反应中Hβ沸石催化剂失活和再生的研究

研究了柠檬酸改性的Hβ沸石催化剂在2-(4'-乙基苯甲酰基)苯甲酸(BEA)脱水闭环合成2-乙基蒽醌(2-EAQ)工艺中的失活及再生性能.结果表明,催化剂经过多次重复使用,催化活性下降.通过乙醇洗涤催化剂再焙烧的方法,可以恢复催化剂活性.再生后的催化剂重复使用4次后,BEA的转化率仍然高达99.5%,2-EAQ选择性也高达99.4%.采用TG-DTA对乙醇洗涤前后失活催化剂进行表征,并结合电喷雾质谱API-ES和1H NMR对催化剂上积炭物种的组成进行了定性分析.     

Improvements of heat resistance and adhesive property of condensed poly-nuclear aromatic resin via epoxy resin modification

A bisphenol epoxy resin was used as modifier to increase the heat resistance of condensed poly-nuclear aromatic （COPNA） resin. The basic properties of COPNA resin and modified resin were characterized by Fourier transform infrared spectroscopy （FT-IR）, nuclear magnetic resonance spectroscopy （1H-NMR）, vapor pressure osmometry （VPO） and elemental analysis （EA）. Average structural parameters of resins were calculated by the improved Brown-Ladner method, and heat resistance of resins was tested by thermogravimetric analysis （TGA）. The chemical structure, mechanical properties and heat resistivity of the resin/graphite composites prepared with different resins were compared. The results show that the adhesive property and heat resistance of COPNA resin can be remarkably improved by addition of 5 wt.% epoxy resin. The reason is that the reactions between epoxy groups of epoxy resin and hydroxyl groups of COPNA resin improve the heat resistance and adhesive property of COPNA resin. Electric motor brushes with good mechanical properties and low electrical resistivity were successfully prepared by using the modified resin as binder.     

有机硅增韧改性双酚A型环氧树脂

采用侧环氧化硅油、端环氧基硅油及其预反应物对双酚A型环氰树脂(E-51树脂)进行改性。考察了侧环氧化硅油、端环氧基硅油及其预反应物的用量对固化产物的拉伸强度、断裂伸长率和冲击强度的影响。采用SEM对固化产物的拉伸断裂面形态进行了表征。实验结果表明,侧环氧化硅油、端环氧基硅油胺预反应物对E-51树脂的增韧效果最好。100.0份(质量份数)E-51树脂经10.0份侧环氧化硅油和5.0份端环氧基硅油胺预反应物改性后,拉伸强度达到75.09 MPa,断裂伸长率达到19.73%,冲击强度达到21.33kJ/m~2;比100.0份E-51树脂经10.0份侧环氧化硅油改性的E-51树脂的拉伸强度、断裂仲长率和冲击强度分别提高了1.66 MPa,2.41%,7.73kJ/m~2。     

ASPHALTENIC CRUDE OIL CHARACTERIZATION: AN EXPERIMENTAL INVESTIGATION OF THE EFFECT OF RESINS ON THE STABILITY OF ASPHALTENES

High performance liquid chromatography (HPLC) and Thin Layer Chromatographic (TLC) latroscan were used to characterize an asphaltenic stock tank oil (STO) from the North Sea. The whole STO was separated into saturates, aromatics, polars 1 (resins 1), polars 2 (resins 2) and asphaltene fractions. The separated resins (1) and the more polar resins (2), also termed asphaltene peptizing agents, were further characterized by HPLC in terms of their neutral, basic, pyrrolic and acidic components. Resins (1) and resins (2) were mixed in different proportions with whole (original) STO; the resulting mixtures were tested for asphaltene onsets of precipitation due to n-C5 injection at 25° C and 690 kPa. Results of these tests are presented and the observed trends are explained in terms of resins characters and/ or major constituents.     

ASPHALTENIC CRUDE OIL CHARACTERIZATION: AN EXPERIMENTAL INVESTIGATION OF THE EFFECT OF RESINS ON THE STABILITY OF ASPHALTENES

ABSTRACT

High performance liquid chromatography (HPLC) and Thin Layer Chromatographic (TLC) latroscan were used to characterize an asphaltenic stock tank oil (STO) from the North Sea. The whole STO was separated into saturates, aromatics, polars 1 (resins 1), polars 2 (resins 2) and asphaltene fractions. The separated resins (1) and the more polar resins (2), also termed asphaltene peptizing agents, were further characterized by HPLC in terms of their neutral, basic, pyrrolic and acidic components. Resins (1) and resins (2) were mixed in different proportions with whole (original) STO; the resulting mixtures were tested for asphaltene onsets of precipitation due to n-C5 injection at 25° C and 690 kPa. Results of these tests are presented and the observed trends are explained in terms of resins characters and/ or major constituents.     

油井防砂用环氧改性酚醛树脂耐介质性能研究

重点研究了环氧改性酚醛树脂在油井防砂中的耐介质情况。对比了改性与未改性酚醛树脂在清水、酸、碱、盐和柴油介质中的化学稳定性，以及固化温度、固化时间对固结岩芯耐介质性能的影响。结果表明，环氧改性的酚醛树脂耐介质性能得到改善，固化温度的提高和固化时间的延长有利于酚醛树脂耐介质性能的提高。     

离子液体中甲苯羰基化反应的探索研究

研究了以新型催化材料氯铝酸型离子液体（IL）为催化剂,催化甲苯羰基化反应合成对甲基苯甲醛的工艺过程。合成、改性得到了多种类型的IL,考察了不同IL催化甲苯羰基化反应规律。氯铝酸离子液体中甲苯羰基化反应的催化活性物种为Al2Cl7－,B酸改性的IL-I/2.0的催化活性有所提高,其中HCl改性效果最好,相同条件下甲苯转化率由改性前的26.5%提高到41.7%。以叔胺盐为阳离子中间体合成的B-L复合酸离子液体的催化活性明显高于IL-I,其中IL-T的催化活性最高。在离子液体/甲苯摩尔比为2.8、CO分压 3.0 MPa、反应温度40 ℃、反应1 h时的条件下,甲苯转化率达到56.4%,对甲基苯甲醛选择性为88.0%,进一步延长反应时间,甲苯的转化率可达80%以上。B-L复合酸离子液体催化剂用于甲苯羰基化反应,可使反应在较温和的条件下进行,并达到了较理想的甲苯转化率和对甲基苯甲醛选择性。     

过氧化物改性对LLDPE流变特性的影响

研究了兰州石化公司石化厂生产的LLDPE（牌号LL103AA）及其过氧化物改性料的流变模型;分析了它们的流变特性,并对它们的加工性能进行了对比。结果表明改性后的LLDPE具有更好的加工性能。     

环氧丙烯酸酯粉末涂料的合成及固化研究

实验以环氧树脂和丙烯酸为基本原料,合成可紫外光固化的粉末涂料。讨论了催化剂的种类、反应温度、反应时间等对合成反应的影响及光引发剂的种类、光照时间等对固化产物的影响。其合适的反应条件为:环氧树脂与丙烯酸的反应条件为甲苯为溶剂、四丁基溴化铵为催化剂,在110℃反应180 min。固化条件为:以TPO为引发剂,120 W/cm的紫外灯光照15 s。     

磷氧化物改性HMCM-22催化剂的制备及其择形催化合成对二甲苯

以磷酸三乙酯为磷氧化物前驱物通过浸渍法制备了一系列磷改性HMCM-22催化剂,在固定床反应器上考察了甲苯与碳酸二甲酯烷基化合成对二甲苯的择形催化性能。通过N2吸附脱附、NH3-TPD和吡啶吸附红外光谱等手段对催化剂进行了表征,并考察了反应温度及空速对甲苯烷基化过程的影响。实验结果表明：以磷酸三乙酯为磷氧化物的前驱物制备的磷改性HMCM-22催化剂在甲苯烷基化合成对二甲苯过程中不仅表现出优异的择形性能,而且还保持了较高的催化活性。这主要是由于磷酸三乙酯有较大的分子尺寸,浸渍过程中不仅覆盖了分子筛外表面酸性位,而且还保证其孔内的酸性位不受影响。     

MOLECULAR MECHANICS OF AGGREGATES OF ASPHALTENES AND RESINS OF THE ATHABASCA OIL

An analysis of the effects of an almost continuous chemical distribution of asphaltenes and resins on the molecular recognition processes occurring in crude oil indicates that their aggregates will have a broad distribution both in the chemical composition and in the strength of the intermolecular interactions responsible for the aggregation. Then, crude oil cannot be described just as a sol formed by solid asphaltene particles dispersed by resins or as a simple micellar system of asphaltene and resin molecules. The molecular aggregates may vary from solid particles formed by asphaltenes and resins to loosely bound micelles with quite short lifetimes. These different aggregates may coexist within the crude oil and many will exchange components with others. The entropic contributions to the changes in free energy upon aggregation were also discussed. Molecular mechanics calculations showed that a model asphaltene aggregate from Athabasca exhibits stronger interactions with its resins than with solvents such as toluene and n-octane. The resins showed a considerable selectivity for the different adsorption sites of the asphaltene aggregate. This selectivity was stronger than that found for the solvent molecules, indicating that it is enthalpically more favorable for them to form aggregates with the asphaltenes. The selectivity may also help to explain the specificity of some resins that are able to disperse only the asphaltenes of certain types of crude oils while failing to do the same for others.