Synthesis and characterization of poly(urethane-sulfone)s

Eight poly(urethane-sulfone)s were synthesized from two sulfone-containing diols, 1,3-bis(3-hydroxypropylsulfonyl)propane (Diol-333) and 1,4-bis(3-hydroxypropylsulfonyl)butane (Diol-343), and three diisocyanates, 1,6-hexamethylene diisocyanate (HMDI), 4,4′-diphenylmethane diisocyanate (MDI), and tolylene diisocyanate (TDI, 2,4- 80%; 2,6-20%). As a comparison, eight polyurethanes were also synthesized from two alkanediols, 1,9-nonanediol and 1,10-decanediol, and three diisocyanates. Diol-333 and Diol-343 were prepared by the addition of 1,3-propanedithiol or 1,4-butanedithiol to allyl alcohol and subsequent oxidation of the resulting sulfide-containing diols. The homopoly(urethanesulfone)s from HMDI and MDI are semicrystalline, and are soluble in m-cresol and hot DMF, DMAC, and DMSO. The copoly(urethane-sulfone)s from a 1/1 molar ratio mixture of Diol-333 and Diol-343 with HMDI or MDI have lower crystallinity and better solubility than the corresponding homopoly(urethane-sulfone)s. The poly(urethane-sulfone)s from TDI are amorphous, and are readily soluble in m-cresol, DMF, DMAC, and DMSO at room temperature. Differential scanning calorimetry data showed that poly(urethane-sulfone)s have higher glass transition temperatures and melting points than the corresponding polyurethanes without sulfone groups. The rise in glass transition temperature is 20–25°C while the rise in melting temperature is 46–71°C. © 1994 John Wiley & Sons, Inc.     

吹扫捕集-气相色谱分析海水和沉积物中的苯、甲苯、乙苯及二甲苯

单环芳烃苯、甲苯、乙苯和二甲苯（简称BTEX）是石油的重要组分，也是环境中需要重点监测的致癌污染物。本实验建立了动态顶空（吹扫捕集）和光离子化检测器的气相色谱测量海水、沉积物中痕量BTEX的方法。在120—1200ng／L的浓度范围，苯、甲苯、乙苯、间对二甲苯及邻二甲苯标准溶液的检出限分别为6．4、35．2、15．8、12．3、10．7ng／L，相对标准偏差0．9％-6．1％。样品无需预处理，海水中BTEX回收率为93．50％-98．40％。7个渤海表层海水样品中BTEX的浓度均低于140ng／L；海底沉积物中苯、甲苯、乙苯、间对二甲苯及邻二甲苯浓度分别为169—1243、531—1732、1308—5624、237—1136、510—5194ng／L。测量方法和结果对评价环境污染具有重要意义。     

Ni对单Pd型挥发性有机废气净化催化剂的助催化作用

本文以蜂窝状堇青石陶瓷为催化剂载体，用分步浸渍法制备了挥发性有机废气(VOCs)净化用Pd-Ni/La-Ce-Zr-Al₂O₃ /堇青石催化剂，考察了Ni助催化剂对单钯型VOCs净化催化剂性能的影响，并用H2-TPR、比表面、XRD、SEM等手段对催化剂进行了表征。研究表明，Ni的加入明显提高了催化剂的低温活性和热稳定性，经过800 ℃焙烧的Pd-Ni/La-Ce-Zr-Al₂O₃ /堇青石(m_Pd∶m_Ni=3∶20)催化剂的催化性能明显优于Pd/La-Ce-Zr-Al2O₃ /堇青石催化剂，甲苯起燃温度下降约25 ℃，经1 000 ℃高温处理后，仍能保持优良的催化性能。Ni的加入使Pd催化剂性能提高的原因应归结于活性组分分散度的提高和钯、镍与载体之间存在的强相互作用。     

甲苯氧化制苯甲酸的新催化体系

以分子氧为氧化剂,探索了甲苯氧化制苯甲酸的新催化体系,第一次把N-羟基邻苯二甲酰亚胺(NHPI)与钴盐组成的催化剂用于甲苯氧化反应.实验揭示:以NHPI/Co(acac)2(乙酰丙酮酸钴)和NHPI/Co(OAc)2(醋酸钴)为催化剂时,苯甲酸的收率可分别为55.5%与41.2%,文中还对氧气压力、反应温度与时间等对反应的影响进行了讨论,同时提出了可能的反应机理.     

The interactions of metal extractant reagents: VI. Aggregation equilibria of Cyanex 302 and Span 80 in toluene solutions

The aggregation equilibria of the commercial extractant Cyanex 302 in toluene have been studied by vapor pressure osmometry (VPO) at different temperatures. The experimental data, treated both graphically and numerically by means of the CPMIN program, can be explained by assuming the formation of a dimer species of the active component bis(2,4,4-trimethylpentyl)thiophosphinic acid for which the aggregation constants have been determined at 28, 40 and 50°C. The influence of other components of the commercial reagent in the aggregation equilibria have also been considered. The interaction between Cyanex 302 and the non-ionic surfactant Span 80 in toluene has also been investigated by VPO and the experimental results interpreted by the formation of mixed species between both reagents.     

VISCOSITY BEHAVIOR OF PS/TOLUENE SOLUTION IN DILUTE AND EXTREMELY DILUTE CONCENTRATION REGION

1.INTRODUCTIONAsearlyas1950sitwasfoundthatsolutionviscosityofasinglepolymerinextremelydiluteconcentrationregionusuallyrevealssomeabnormalities,i.e.,thereducedviscosityconcentration(hsp/c~c)curvesdeviatefromlinearrelationshippredictedasHugginsequationandshoweitheranupwardoradownwardturnasconcentrationisverylow[1].Evenifforthe[()-0.2()]identicalPMMA/toluenesolution,therearetwocontraryresults:onereportedthecurvebendsupward[2],whiletheotherfounditdownward[3].Inordertointerpretthisabnormalphe…     

ZSM-5分子筛催化剂酸性对积炭的影响

研究了几种分子筛在乙基化反应中的积炭过程,并与分子筛的酸性、孔结构等参数关联,阐明了ZSM-5分子筛催化剂的酸中心对积炭起着主要作用。酸强度越高,越容易积炭,酸量越大积炭越多。积炭的形成部位与酸中心在晶内外的分布关系密切。分子筛外表面酸中心比晶内的更易生成积炭,体现了积炭的择形性。     

X型沸石催化剂的甲苯甲醇侧链烷基化反应和吸附量热研究

本文报道了以原粉NaX和成型NaX为前体分别通过离子交换法及浸渍法制得的几种碱金属阳离子X型沸石上甲苯甲醇侧链烷基化反应的活性和选择性。并以NH₃和CO₂的微分吸附量热表征了这些催化剂的酸碱性。结果表明，在所有催化剂中成型KX的侧链反应活性最高。该催化剂对NH₃的微分吸附热为45 kJ/mol左右，吸附覆盖度为3.3 μmol/m²；对CO₂的微分吸附热在128～60 kJ/mol之间，吸附覆盖度为0.16 μmol/m²。对比其他三种酸性相近的催化剂，碱性更强(如K/KX(p)和K/KX(c))或更弱(如KX(p))时，侧链反应活性都较差。看来，成型KX催化剂的表面酸碱性匹配对侧链烷基化反应比较有利。该结果进一步证明了在甲苯甲醇侧链烷基化反应中催化剂酸碱协同作用的重要性。     

The effect of pressure on order destruction and order creation in linear or branched alkane mixtures

The pressure dependence of the excess enthalpy H ^E , dH ^E /dP, has been calculated from experimental excess volumes V ^E and dV ^E /dT using dH ^E /dP=V ^E –TdV ^E /dT. dH ^E /dP at zero pressure are reported at 25°C and equimolar concentration for the mixtures: cyclohexane with the series of normal alkanes (n-C _n , where n=6,8,10,12,14 and 16) and with the series of highly branched alkanes (br-C _n , where n=6,8,12 and 16), benzene, toluene and p-xylene +n-C _n and 1-chloronaphthalene +n-C _n and br-C _n . Experimental and Flory theory dH ^E /dP values are in good agreement for the whole cyclohexane +br-C _n series. For the n-C _n series, dH ^E /dP becomes increasingly positive deviating from the Flory predictions. This discrepancy is due to the presence of short-range orientational order in the higher n-C _n pure liquids which makes dH/dP more negative and which, upon mixing, is destroyed producing a positive contribution to dH ^E /dP not accounted for by the theory. The discrepancy between theoretical and experimental dH ^E /dP is large for benzene, but progressively smaller for toluene, p-xylene and 1-chloronaphthalene. These results are consistent with creation of order between the aromatic plate-like molecule and the long n-C _n in solution. For 1-chloronaphthalene +n-C _n , this order creation process produces a negative contribution to dH ^E /dP which balances the positive order-destruction contribution originated by the rupture, upon mixing, of short-range orientational order in pure n-C _n .     

兖州煤与催化裂化油浆共处理及其重质产物组成性质的初步研究

采用石家庄催化裂化油浆和兖州煤共处理，考察了反应条件对兖州煤转化及产物分布的影响，并应用棒状薄层色谱分析了共处理重质产物族组成的变化规律。结果表明，催化裂化油浆与兖州煤共处理，可大大提高兖州煤的转化率，共处理既可得到部分轻质油品，又可得到相当量的重质产物。ＴＬＣ／ＦＩＤ分析表明，催化裂化油浆与兖州煤共处理的重质产物与商用高等级道路沥青族组成近似，重质产物可用于制备高等组道路沥青。