生物法PDO合成PTT结构与性能的研究

采用生物法1,3-丙二醇(PDO)直接酯化缩聚合成聚对苯二甲酸丙二醇酯(PTT),通过IR、1H NMR、DSC 和TG方法对其进行了表征,并与化学法PDO合成的PTT进行比较。结果表明,生物法PDO合成的产物是PTT;生物法PDO合成的PTT比同一纯度的化学法PDO合成的PTT色泽好、粘度大、摩尔质量高,且随PDO纯度提高,PTT粘度、摩尔质量增大;生物法PDO合成的PTT熔点与化学法PDO合成的PTT相差不大,熔融峰比化学法PDO合成的PTT 尖锐,熔融热大,结晶度高;不同PDO合成的PTT树脂热失重相差不大,表明PDO不同对PTT热分解行为影响不大。     

直接酯化法合成PTT的工艺探讨

研究了采用直接酯化法合成聚对苯二甲酸丙二醇酯(PTT)的催化剂种类、催化剂浓度、反应物料的物质的量比以及升温速率对反应的影响。实验证明,以硫酸钛水解物为酯化催化剂,三氧化二锑作为缩聚催化剂合成PTT是可行的。     

成核剂对聚对苯二甲酸丙二醇酯结晶行为和形态的影响

用差示扫描量热分析仪、广角X射线衍射仪和偏光显微镜，研究了聚对苯二甲酸丙二醇酯（P1T）与成核剂YS-688共混物的熔融结晶行为和晶体形貌。结果表明，成核剂不仅能够提高PTT、在高温区的结晶速率，同时还可以提高PTT、在低温区的结晶速率，但同时降低了PTT、的结晶度；光透过率测试表明，随着成核剂含量的增加，PTT、透明性先增加后略有下降，最佳加入量为1％（质量分数，下同）；偏光显微镜分析表明，成核剂影响PTT、的晶体尺寸，晶体尺寸随着成核剂含量的增加而减小；广角X射线衍射分析表明，添加成核剂没有改变PTT的晶型。     

聚丙烯成核透明剂的合成

介绍了聚丙烯成核荆成核功能、分类。以山梨醇类成核剂为重点对国内外聚丙烯成核剂的合成研究开发情况进行了介绍，并对本公司聚丙烯成核剂的合成工艺进行了简述。     

国产生物法1,3-PDO合成PTT研究

以国产生物法1,3-PDO及PTA为原料,采用直接酯化法工艺路线合成了PTT,对缩聚工艺进行了研究,并以IR对PTT进行了表征,结果表明:可以用催化剂A以国产生物法1,3-PDO为原料制备得到PTT,较佳的缩聚工艺为温度:255℃,压力<50 Pa,时间:3.5~4 h。     

聚丙烯成核剂合成及应用的研究进展

具有高附加值的透明PP材料逐渐得到人们的认可和重视,因此PP透明成核剂的合成目前成为高分子合成研究中的热点之一.本文对山梨醇类、有机磷酸盐类、松香型成核剂的合成原理和合成方法做了介绍,并对这三种成核剂及β晶型成核剂在近几年的应用研究进行了综述.     

玻纤增强阻燃PTT工程塑料的研制及应用

研制了一种30%玻纤增强阻燃聚对苯二甲酸丙二酯(PTT)工程塑料,重点考察了增韧剂、结晶成核剂、其它聚酯及溴锑复合阻燃剂对PTT性能的影响。结果发现,在PTT中添加适当的结晶成核剂、增韧剂及其它聚酯,不但使PTT材料的加工流动性得到改善,综合性能大幅提高,还可以提高其结晶度,加快结晶速率,促进制品定型,缩短生产周期;添加12份溴(锑)复合阻燃剂可以使PTT的阻燃级别达到FV-0级。     

牛物法PDO合成PTT结构与性能的研究

采用生物法1，3-丙二醇（PDO）直接酯化缩聚合成聚对苯二甲酸丙二醇酯（PTT），通过IR、^1H NMR、DSC和TG方法对其进行了表征，并与化学法PDO合成的PTT进行比较。结果表明，生物法PDO合成的产物是PTT；生物法PDO合成的肿比同一纯度的化学法PDO合成的肿色泽好、粘度大、摩尔质量高，且随PDO纯度提高，肿粘度、摩尔质量增大；生物法PDO合成的肿熔点与化学法PDO合成的肿相差不大，熔融峰比化学法PDO合成的肿尖锐，熔融热大，结晶度高；不同PDO合成的肿树脂热失重相差不大，表明PDO不同对肿热分解行为影响不大。     

成核剂和结晶促进剂对PET/PTT共混聚酯结晶性能的影响

分别采用双螺杆挤出法和转矩流变仪密炼法制备了PET/PTT共混聚酯,通过拉伸试验、冲击试验和DSC分析,研究了PET/PTT共混聚酯共混配比与力学性能的关系以及不同成核剂和不同结晶促进剂对PET/PTT共混聚酯结晶性能的影响。结果表明,当PET/PTT共混配比为75/25(质量比)时,PET/PTT共混聚酯能同时提高刚性和韧性,纳米SiO2成核剂可明显提高PET/PTT共混聚酯的结晶能力,聚醚1000结晶促进剂可显著提高PET/PTT/纳米SiO2共混聚酯的结晶速率。     

PTT复合材料力学性能研究进展

介绍了聚对苯二甲酸丙二醇酯(PTT)的结构特征、生产研究现状、有关的性能优势及其发展前景.给出了成核剂、增容共混物对PTT结晶性能的影响,以及聚丙烯(PP)、玻璃纤维(GF)、聚萘二甲酸乙二醇酯(PEN)短纤维、丙烯腈-丁二烯-苯乙烯(ABS)分别与PTT增容共混后力学性能的变化.可以看出,GF对PTT力学性能的提高很显著,能同时增韧增强,加入成核剂、增韧剂和PBT后进一步提高其部分力学性能,且改善了加工性能.PTT/ABS-g-MAH力学性能增加幅度比GF/PTT还要大,加入玻纤后性能进一步增强.     

合成四氯苯酐最佳工艺条件的选择

通过正交试验及对正交试验结果进行统计分析,检验了因子的显著性,确定了由苯酐氯化合成四氯苯酐的最佳工艺条件为:反应时间12h,反应温度80～160℃,原料配比为n(苯酐):n(工业级溶剂):n(催化剂):n(氯气)=1:10:B:C2,在此条件下摩尔产率为98%.溶剂和催化剂可回收循环使用,溶剂回收率＞85%,催化剂回收率＞50%.此种方法合成四氯苯酐具有产品产率高、质量好、成本低且不产生大量废硫酸的优点.用工业级溶剂代替化学纯试剂,并将反应器放大5倍,可获得同样的结果.     

Direct synthesis of isoparaffin from synthesis gas under supercritical conditions

To produce isoparaffins from synthesis gas directly, modified Fischer–Tropsch (FT) synthesis was carried out under supercritical conditions using n-butane as a medium. One-step FT synthesis using a hybrid catalyst consisting of Co/SiO₂, HZSM-5 and Pd/SiO₂ was carried out. Introduction of supercritical-phase n-butane increased light isoparaffins significantly and suppressed the formation of the by-product, methane. Under supercritical-phase butane, hydrogenolysis and isomerization reactions were promoted. Due to the fact that the optimum temperatures for FT and HZSM-5 catalysts are different, 513 K and over 573 K, respectively, two-step FT synthesis was also carried out to optimize the reaction temperatures. The first-step reaction used Co/SiO₂ catalyst containing small amount of HZSM-5 for FT synthesis at 513 K, and the second-step reaction used a hybrid catalyst containing Pd/SiO₂ and zeolite for hydrogenolysis and isomerization of hydrocarbons at 573 K. Introduction of supercritical n-butane increased the isoparaffin selectivity, and decreased the methane selectivity significantly. The production of heavy hydrocarbons C₉+ was inhibited in both gas and supercritical phase. The isoparaffin selectivity in the gas phase decreased with time-on-stream, but very stable for the supercritical-phase reaction. Because water and heavy hydrocarbons were removed from active sites on zeolite and the zeolite acidity was promoted in the supercritical medium, the selectivity of isoparaffin was considered stable. Among zeolites added to the hybrid catalyst in the second-step reactor, HZSM-5 and H-beta zeolite were suitable for producing light isoparaffins. These results indicated that two-step FT synthesis under supercritical n-butane was superior for producing light isoparaffins from synthesis gas directly.     

Direct synthesis of middle iso-paraffins from synthesis gas on hybrid catalysts

This paper focuses on the synthesis of iso-paraffin-rich hydrocarbons by Fischer–Tropsch synthesis (FTS) over silica gel supported Co catalyst (Co/SiO₂). The basic concept is to isomerize and/or hydrocrack the primary FTS hydrocarbon products. A physical mixture consisting of a small amount of zeolite or Pd/zeolite mixed with Co/SiO₂ enhanced the formation of C₄–C₁₀ iso-paraffins while suppressing the formation of higher molecular hydrocarbons, probably because of the selective cracking of these hydrocarbons on them. In separate experiments, a two-reactor system was used. The first reactor contained a physical mixture of Co/SiO₂ and zeolite, and the second reactor contained zeolites or Pd-supported zeolites. The two-reactor system gave sharp C-number distribution within C₃–C₆ and iso-paraffins-rich products. The hydrocracking of n-octane and n-decane (model compound simulating products of the FTS reaction) over mixed catalysts composed of various compositions of Pd/SiO₂ and ZSM-5 in the presence of gaseous hydrogen showed high and stable activity, and produced primarily iso-paraffin-rich hydrocarbons. The isomerization was favored for mixtures rich in Pd/SiO₂. The role of Pd was thought to be the inlet of hydrogen spillover to the zeolite surface.     

Thermodynamic equilibrium in the synthesis of dimethyl ether from synthesis gas

Chemical equilibrium in dimethyl ether synthesis from synthesis gas was studied thermodynamically over wide ranges of gas compositions and process parameters.     

Production of synthesis gas

The state-of-the-art for the production of synthesis gas from the steam reforming of methane is reviewed and discussed. Particular attention is given to the design of the tubular reformer and carbon formation on the nickel catalyst. Improvements in syngas technology are discussed, including: CO₂ reforming, autothermal reforming and heat exchange reforming, and the energy efficiencies of direct and indirect methane conversion are compared and contrasted.     

环己烯的绿色合成研究

探索了FeCl·36H2O催化环己醇脱水制备环己烯的最佳实验条件。当催化剂用量为环己醇质量的13.7%,油浴温度180～190℃,反应时间1h,环己烯收率可达86.1%,纯度达98.6%。结果表明:此法催化剂价廉易得、催化活性强、选择性高,又可重复使用;同时操作简单,不污染环境,是一条简单易行的典型的绿色合成途径。     

Surface synthesis of thiophene

A cyclization reaction has been observed in which thiophene is produced from acetylene and sulfur co-adsorbed on the Pd(111) surface. As in the case of acetylene trimerization to benzene the reaction yielding thiophene can proceed via an intermediate species of stoichiometry C₄H₄. The ability of the reaction intermediate to extract sulfur from the surface varies between the two phases of adsorbed sulfur that can exist on the Pd(111) surface.     

微波辐射技术直接法合成水处理剂PASP

可生物降解型水处理剂聚天冬氨酸(PASP)的制备有2种技术路线,分别为天冬氨酸单体直接聚合法和以四碳原子有机酸为初始原料的间接聚合法.以微波为辐射热源,根据微波聚合技术理论,应用直接聚合法合成出PASP.通过IR等技术表征聚合物为目标产品.同时研究了PASP的分子质量等因素对工业循环冷却水中CaCO3盐垢晶体的阻垢分解能力.     

Chemical synthesis of sphingolipids

The chemical synthesis of sphingosine, derivatives of sphingosine, and sphingolipids are reviewed.