含能黏合剂PAMMO的间接法合成

以3-溴甲基-3-甲基氧杂环丁烷(BrMMO)为单体,按阳离子开环聚合机理,先合成出3-溴甲基-3-甲基氧杂环丁烷均聚物(PBrMMO),接着在偶极非质子溶剂中对其进行叠氮化,最终合成出含能黏合剂3-叠氮甲基-3-甲基氧杂环丁烷均聚物(PAMMO)。着重研究了BrMMO聚合过程中催化剂用量和反应体系温度对聚合的影响,确定出BrMMO聚合的最佳条件为:n(BF3.OEt2):n(BDO)=0.50:1.00,0℃下加入单体,通过红外光谱确定出叠氮化反应的完成时间。用红外光谱(IR)、核磁共振(1H-NMR)、热重分析(TGA)和差示扫描量热法(DSC)对产品进行了表征。     

3-叠氮甲基-3-甲基氧杂环丁烷与四氢呋喃共聚醚的合成与表征

以1,4-丁二醇(BDO)为引发剂,三氟化硼·乙醚(BF3·Et2O)为催化剂,使3-叠氮甲基-3-甲基氧杂环丁烷(AMMO)与四氢呋喃进行本体法阳离子开环聚合,得到3-叠氮甲基-3-甲基氧杂环丁烷与四氢呋喃的共聚醚(PAT).通过红外光谱、核磁共振氢谱、碳谱和凝胶渗透色谱对共聚醚进行表征.结果表明,合成的共聚醚中两种不同结构单元的摩尔比与投料比基本吻合,共聚醚的相对分子质量可控、分布较窄.差热扫描量热法测得PAT的玻璃化转变温度为-59.2℃,分解峰温为264.1℃,表明其具有良好的低温性能和热稳定性.     

含能黏合剂PAMMO的问接法合成

以3-溴甲基-3-甲基氧杂环丁烷(BrMMO)为单体,按阳离子开环聚合机理,先合成出3-溴甲基-3-甲基氧杂环丁烷均聚物(PBrMMO),接着在偶极非质子溶剂中对其进行叠氮化,最终合成出含能黏合剂3-叠氮甲基-3-甲基氧杂环丁烷均聚物(PAMMO).着重研究了BrMMO聚合过程中催化剂用量和反应体系温度对聚合的影响,确定出BrMMO聚合的最佳条件为:n(BF3OEt2):n(BDO)=0.50:1.00.0℃下加入单体,通过红外光谱确定出叠氮化反应的完成时间.用红外光谱(IR)、核磁共振(1H-NMR)、热重分析(TGA)和差示扫描量热法(DSC)对产品进行了表征.     

3-叠氮甲基-3-乙基氧杂环丁烷及其均聚物的合成与性能

为开发新型含能黏合剂,以三羟甲基丙烷、碳酸二乙酯、对甲苯磺酰氯、叠氮化钠为原料,合成出一种新型叠氮类氧杂环单体3-叠氮甲基-3-乙基氧杂环丁烷（AMEO）。用核磁、红外、元素分析和DSC表征了AMEO的结构与性能。以1,4-丁二醇为起始剂,三氟化硼乙醚络合物为催化剂,二氯甲烷为溶剂,AMMO为单体,借助于阳离子开环聚合,合成出聚3-叠氮甲基-3-乙基氧杂环丁烷（PAMEO）。用红外光谱、核磁共振、元素分析、羟值、数均分子质量表征和测定了聚合物的结构和性能。     

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.     

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。     

双官能团氧杂环丁烷活性单体的合成及固化性能的研究

以3-乙基-3-羟甲基氧杂环丁烷为原料,分别与对二溴苄,联苯二氯苄和双[4-(2-羟基乙氧基)苯基]丙烷合成具有双氧杂环丁烷官能团的活性稀释剂OXT121,OXBP,OXBPA单体。在光源为高压汞灯,波长为365 nm,测试时间为180 s的条件下,用GR61硫鎓盐作光引发剂,对OXT121,OXBP,OXBPA三种单体进行了实时红外转化率测试;对E-51环氧树脂黏度稀释效应进行了测定。结果表明,OXT121,OXBP,OXBPA三种活性单体具有良好的转化率,且能有效降低E-51环氧树脂黏度,是一类优良的UV阳离子活性稀释剂。     

3-硝酸酯甲基-3-甲基氧杂环丁烷的合成及表征

为发展硝酸酯聚醚黏结剂,以3-羟甲基-3-甲基氧杂环丁烷（HMMO）为底物,N2O5为硝化剂,制备了一种含能单体3-硝酸酯甲基-3甲基氧杂环丁烷（NIMMO）。讨论了N2O5与HMMO的摩尔比及反应温度对选择性硝化的影响。确定了最佳反应条件：N2O5与HMMO的摩尔比为（1．0～1.1）：1．0,温度为-15～-10℃,滴加完毕后待温度下降时立即中和终止反应。通过红外、核磁及元素分析对产品进行结构表征,表明是目标化合物,差热分析表明NIMMO的热稳定性较好。     

含能黏合剂BAMO-THF-GAP无规共聚醚的合成与表征

以3,3-二溴氧杂环丁烷(BBMO)、四氢呋喃(THF)和环氧氯丙烷(ECH)为单体,1,4-丁二醇(BDO)为引发剂,三氟化硼乙醚(BF3·OEt2)为催化剂,采用阳离子开环聚合法制备BBMO-THF-ECH无规共聚醚;然后将其进行叠氮化反应,制成含能黏合剂BAMO-THF-GAP(3,3-双叠氮甲基氧杂环丁烷-四氢呋喃-叠氮缩水甘油醚)无规共聚醚。研究结果表明:采用单因素试验法优选出制备无规共聚醚的最佳反应条件是w(BDO)=5%(相对于总单体质量而言)、n(BF3·OEt2)∶n(BDO)=1∶2、聚合时间为24 h、叠氮化反应时间为16 h和叠氮化反应温度为110℃。     

反应温度对聚3-乙基-3-羟甲基环氧丁烷支化度的影响

以3-乙基-3-羟甲基环氧丁烷为单体,BF1·O（C2H5）2为引发剂,二氯甲烷为溶剂,在-50～30℃的不同温度下通过阳离子自缩合开环聚合,合成超支化聚3-乙基-3-羟甲基环氧丁烷,产物相对分子质量在5000左右。^13C NMR测定结果表明,聚3-乙基-3-羟甲基环氧丁烷的支化度随聚合温度的升高而增大,聚合温度在20℃以上时聚合物支化度随反应温度的变化趋势变小,趋向不变。     

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-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。     

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.     

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%。     

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