甲基环戊二烯的合成研究

以环戊二烯(CPD)、金属钠和一氯甲烷为原料合成甲基环戊二烯,包括制备环戊二烯钠和环戊二烯钠甲基化两步反应。结果表明,反应温度及环戊二烯与钠的摩尔比对甲基环戊二烯的收率影响显著。双环戊二烯的最佳解聚温度为250℃,对于CPD与钠的反应,反应初期温度应控制在较低的温度,以减少CPD二聚反应;反应后期可将温度升高至28℃,以加快CPD与钠的反应速率。最佳的CPD与钠摩尔比为2.2,此时甲基环戊二烯的收率达86%。     

甲基环戊二烯的合成研究

以环戊二烯（CPD）、金属钠和一氯甲烷为原料合成甲基环戊二烯,包括制备环戊二烯钠和环戊二烯钠甲基化两步反应。结果表明,反应温度及环戊二烯与钠的摩尔比对甲基环戊二烯的收率影响显著。双环戊二烯的最佳解聚温度为250℃,对于CPD与钠的反应,反应初期温度应控制在较低的温度,以减少CPD二聚反应;反应后期可将温度升高至28℃,以加快CPD与钠的反应速率。最佳的CPD与钠摩尔比为2.2,此时甲基环戊二烯的收率达86%。     

环戊二烯合成甲基环戊二烯的放大试验技术研究

在有关资料的基础上,对以环戊二烯、金属钠和一氯甲烷为原料合成甲基环戊二烯放大试验过程进行了研究,包括环戊二烯钠的制备和环戊二烯甲基化两步反应。放大试验表明,反应温度、搅拌和甲基化试剂滴加方式等因素是影响甲基环戊二烯收率的主要条件。环戊二烯钠的制备初期应严格控制温度条件在0~5℃,缓解环戊二烯二聚体的生产;后期逐渐升温至40℃左右,以加快反应速率。结合放大试验中出现的问题,寻找到了较佳的搅拌、加料等其他条件。在此条件下,甲基环戊二烯的收率为85%,和文献资料基本一致;二甲基环戊二烯的收率仅为2.0%。     

甲基环戊二烯的合成实验研究

以环戊二烯(CPD)、氢氧化钠和一氯甲烷为原料,合成甲基环戊二烯,最佳反应温度为8℃,CPD与氢氧化钠摩尔比为4.2,CPD加入速度为6.0 m L/min。此时甲基环戊二烯的收率达85.2%。     

甲基环戊二烯的合成实验研究

以环戊二烯(CPD)、氢氧化钠和一氯甲烷为原料,合成甲基环戊二烯,最佳反应温度为8℃,CPD与氢氧化钠摩尔比为4.2,CPD加入速度为6.0 m L/min。此时甲基环戊二烯的收率达85.2%。     

甲基环戊二烯催化剂制备方法的研究

对于不同方法制备Ａｌ２Ｏ３－ＭｇＯ－Ｋ２ＣＯ３催化剂用于环戊二烯与甲醇催化基化,以甲基环戊二烯的产率来评价催化剂活性。结果表明：各种方法ＭｇＯ含量均对催化剂剂活性有明显影响;各种方法制备的催化剂在ＭｇＯ含量２０％－３０％时活性最高;     

甲基环戊二烯基三羰基锰的合成

甲基环戊二烯基三羰基锰(MMT)是一种有机锰油品抗爆添加剂,被认为是有机铅的最好替代物。国内对其研究较少,本文对MMT的合成工艺进行了详细研究。研究了反应温度、反应时间及原料摩尔比对反应收率的影响。用气相色谱分析了产物含量,用FT-IR表征了产物结构。实验结果表明:反应温度160~170℃,反应时间2小时,甲基环戊二烯钠摩尔数∶二氯化锰摩尔数=1∶0.55为适宜的反应条件。在此条件下,该反应收率接近80%,气相色谱法分析产物中对甲基环戊二烯基三羰基锰含量99%以上。     

四苯基苯、吡啶基三苯基苯环四硅氧烷的合成

将四苯基环戊二烯酮或吡啶基三苯基环戊二烯酮分别与七甲基乙烯基环四硅氧烷进行Diels-Alder反应,生成了七甲基四苯基苯环四硅氧烷和七甲基吡啶基三苯基苯环四硅氧烷,并用元素分析、IR、Raman和^1H NMR对产物进行了表征。     

四氢环戊二烯三聚体的合成

双环戊二烯与环戊二烯反应,经两步合成了标题化合物。考察了环戊二烯与双环戊二烯反应中温度、压力、反应时间及溶剂用量对转化率和环戊二烯三聚体收率的影响,最佳条件220℃,0.5 MPa,m(溶剂)∶m(原料)为50%,反应4 h,双环戊二烯转化率85.4%,环戊二烯三聚体收率76.5%。考察了环戊二烯三聚体加氢反应中催化剂用量、温度、氢气压对反应的影响,在m(Raney Ni)∶m(原料)为25%,90℃,4.0 MPa的最佳条件下反应540 min,收率99.6%。两步反应总收率76.2%,产物经质谱、红外光谱等进行了表征。     

丙烯醇催化氨化合成3-甲基吡啶催化剂的制备及性能

采用浸渍法制备了一系列H-ZSM-5分子筛负载过渡金属锌催化剂,在固定床反应器上考察了这些催化剂对丙烯醇催化氨化合成3-甲基吡啶的催化性能。通过对H-ZSM-5的硅铝比、锌负载量对催化剂催化性能影响的考察,发现硅铝比为80、锌负载量为12%时得到的催化剂Zn12/H-ZSM-5(80)的催化性能最佳。在常压、反应温度420℃、氨醇摩尔比3:1、空速300 h?1条件下,丙烯醇在该催化剂上的转化率和3-甲基吡啶的选择性分别达到97.8%和37.9%。利用X射线衍射(XRD)、X射线光电子能谱(XPS)以及吡啶吸附红外对催化剂进行了表征,结果表明,Zn12/H-ZSM-5(80)上负载的Zn2+为L酸;在丙烯醇生成3-甲基吡啶的反应过程中催化剂的脱氢活性物种为氧化锌,而加成和环合反应则主要是由催化剂中的L酸催化实现的。     

Ferroelectric Ceramics in the PbMg1/3Nb2/3O3-PbCd1/3Nb2/3O3 System

Solid solutions (1-x)PbMg_1/3Nb_2/3O₃ + xPbCd_1/3Nb_2/3O₃ with x = 0-0.30 are investigated with purpose to work out a capacitor ceramics with good dielectric properties and low sintering temperature. It is found that the perovskite phase forms at sintering near to 980°C and begins to decompose at higher temperatures. When x grows from 0 to 0.30, the Curie temperature linearly grows from -10°C to +25°C, the dielectric permittivity ε_m in the Curie point T_C decreases from 18000 to 6800 and the phase transition becomes more diffused. The dielectric permittivity at room temperature is rather high and the temperature stability is improved. The system is of interest, because it can serve as a base for working out some ceramic materials for capacitors with low sintering temperature, which needs of no special atmosphere at burning.     

3-溴甲基-3-甲基氧杂环丁烷的合成

以2,2-二溴甲基丙醇（BBMP）为初始原料,通过与碱发生关环反应生成3-溴甲基-3-甲基氧杂环丁烷（BrMMO）。讨论了碱的种类和用量对BBMP关环产率的影响以及反应体系中碱的浓度、反应温度和反应时间对合成BrMMO产率的影响。通过实验确定的最佳工艺条件为：BBMP与NaOH摩尔比为1.0∶1.1,NaOH醇溶液的质量分数为12%,反应温度为78℃,反应时间为4h时,BrMMO产率为65%。最终产品经元素分析、IR和1HNMR检测确定为BrMMO。该试验工艺简单,原料易得,且溶剂便于回收、污染小。     

3-叠氮甲基-3-甲基氧丁环的合成

以三羟甲基乙烷与碳酸二乙酯为原料,经环化反应合成了3-羟甲基-3-甲基氧丁环(HMM O)。在低温下,HMM O与对甲苯磺酰氯反应生成3-磺酸酯甲基-3-甲基氧丁环(M TM O)。M TM O和叠氮化钠发生叠氮化反应形成叠氮单体3-叠氮甲基-3-甲基氧丁环(AMM O)。三步反应收率分别为76%,96%,85%。用核磁、红外、元素分析和DSC表征了化合物的结构与性能。结构鉴定表明为目标化合物AMM O。     

Tunable color emission in LaScO3:Bi3+,Tb3+,Eu3+ phosphor

LaScO₃:xBi³⁺,yTb³⁺,zEu³⁺ (x = 0 − 0.04, y = 0 − 0.05, z = 0 − 0.05) phosphors were prepared via high-temperature solid-state reaction. Phase identification and crystal structures of the LaScO₃:xBi³⁺,yTb³⁺,zEu³⁺ phosphors were investigated by X-ray diffraction (XRD). Crystal structure of phosphors was analyzed by Rietveld refinement and transmission electron microscopy (TEM). The luminescent performance of these trichromatic phosphors is investigated by diffuse reflection spectra and photoluminescence. The phenomenon of energy transfer from Bi³⁺ and Tb³⁺ to Eu³⁺ in LaScO₃:xBi³⁺,yTb³⁺,zEu³⁺ phosphors was investigated. By changing the ratio of x, y, and z, trichromatic can be obtained in the LaScO₃ host, including red, green, and blue emission with peak centered at 613, 544, and 428 nm, respectively. Therefore, two kinds of white light-emitting phosphors were obtained, LaScO₃:0.02Bi³⁺,0.05Tb³⁺,zEu³⁺ and LaScO₃:0.02Bi³⁺,0.03Eu³⁺,yTb³⁺. The energy transfer was characterized by decay times of the LaScO₃:xBi³⁺, yTb³⁺, zEu³⁺ phosphors. Moreover absolute internal QY and CIE chromatic coordinates are shown. The potential optical thermometry application of LaScO₃:Bi³⁺,Eu³⁺ was based on the temperature sensitivity of the fluorescence intensity ratio (FIR). The maximum S_a and S_r are 0.118 K⁻¹ (at 473.15 K) and 0.795% K⁻¹ (at 448.15 K), respectively. Hence, the LaScO₃:Bi³⁺,Eu³⁺ phosphor is a good material for optical temperature sensing.     

2,2,3-三氯-3-苯基-3-(3-甲基苯甲酰基)丙腈的合成研究

以苯甲酰氯、四氯化碳、间甲基苯甲酰氰为原料,合成了标题化合物。重点考察了氰化过程中不同原料配比、反应温度、时间、溶剂和催化剂用量对收率的影响。实验结果表明,其最佳反应条件为:n(1,1,2-三氯-2-苯基乙烯)∶n(3-甲基苯甲酰氰)=1∶1.2,二氯甲烷为反应溶剂,3 mmol催化剂三乙胺,室温反应5 h,总收率达80.6%。     

3-溴甲基-3-甲基氧杂环丁烷的合成

以2,2-二溴甲基丙醇(BBMP)为初始原料,通过与碱发生关环反应生成3-溴甲基-3-甲基氧杂环丁烷(BrMMO).讨论了碱的种类和用量对BBMP关环产率的影响以及反应体系中碱的浓度、反应温度和反应时间对合成BrMMO产率的影响.通过实验确定的最佳工艺条件为:BBMP与NaOH摩尔比为1.0∶1.1,NaOH醇溶液的质量分数为12%,反应温度为78℃,反应时间为4 h时,BrMMO产率为65%.最终产品经元素分析、IR和1HNMR检测确定为BrMMO.该试验工艺简单,原料易得,且溶剂便于回收、污染小.     

Ba3Tb(BO3)3:Eu3+的制备与发光性质

采用高温固相法合成了Ba3Tb(BO3)3:Eu3+红色荧光粉,并研究了Ba3Tb(BO3)3:Eu3+的发光特性。Ba3Tb(BO3)3:Eu3+的激发光谱包含250nm～330nm和350nm～400nm的2个宽带,最大峰值位于383nm,可以被紫外-近紫外发光二极管(light-emitting diodes,LED)有效激发。Ba3Tb(BO3)3:Eu3+的发射谱显示出4组发射峰,其主发射峰位于620nm,对应Eu3+的5D0→7F2跃迁;Eu3+掺杂摩尔分数为2%时,Ba3Tb(BO3)3:Eu3+发光亮度最高。经分析发现Ba3Tb(BO3)3:Eu3+存在Tb3+→Eu3+的能量传递。     

The Preparation and Crystal Structure of TlMnCl3, TlFeCl3, TlCoCl3 and TlNiCl3

The compounds TlMnCl₃, TlFeCl₃, TlCoCl₃ and TlNiCl₃ were prepared by heating T1C1 with the corresponding transition metal dichloride in an evacuated ampoule. Atomic positions were determined from powder photographs. All four compounds were found to be related to the perovskite type structure. TlMnCl₃ has a cubic structure, space group Pm3m, with a_o = 5.025 Å. The other three compounds are hexagonal, probable space group P6₃mc, with cell dimensions (in Å) a₀ = 6.976 and c₀ = 6.008 for the Fe compound, a₀ = 6.907 and c₀ = 5.981 for the Co compound and a₀ = 6.863 and c₀ = 5.881 for the Ni compound. The three hexagonal compounds are isomorphous. A measureable concentration of basal plane stacking faults was found to occur in TlFeCl₃ and also, to a lesser degree, in TlCoCl_3.     

Thermal analyses of poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)

Thermal analyses of poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(HB–HV)], and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(HB–HHx)] were made with thermogravimetry and differential scanning calorimetry (DSC). In the thermal degradation of PHB, the onset of weight loss occurred at the temperature (°C) given by T_o = 0.75B + 311, where B represents the heating rate (°C/min). The temperature at which the weight-loss rate was at a maximum was T_p = 0.91B + 320, and the temperature at which degradation was completed was T_f = 1.00B + 325. In the thermal degradation of P(HB–HV) (70:30), T_o = 0.96B + 308, T_p = 0.99B + 320, and T_f = 1.09B + 325. In the thermal degradation of P(HB–HHx) (85:15), T_o = 1.11B + 305, T_p = 1.10B + 319, and T_f = 1.16B + 325. The derivative thermogravimetry curves of PHB, P(HB–HV), and P(HB–HHx) confirmed only one weight-loss step change. The incorporation of 30 mol % 3-hydroxyvalerate (HV) and 15 mol % 3-hydroxyhexanoate (HHx) components into the polyester increased the various thermal temperatures T_o, T_p, and T_f relative to those of PHB by 3–12°C (measured at B = 40°C/min). DSC measurements showed that the incorporation of HV and HHx decreased the melting temperature relative to that of PHB by 70°C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 90–98, 2001