Spectroscopic characterization of 1,5-diphenyl-3,7-dihydroxy-1,5-diazacyclooctane — (8C ring compound) formed in N,N-diglycidylanaline/aniline curing systems

Summary A NMR and infrared analysis of the cyclic product formed by the reaction of N,N-diglycidylaniline with aniline confirms the structure of an eight-membered ring (I). The conformational structure of this compound is discussed.     

The near-infrared optical properties of an Nd (III) complex and its potential application in electroluminescence

A trivalent neodymium ion (Nd³⁺) complex Nd(PM)₃(TP)₂ was synthesized, and its optical properties was studied by introducing Judd–Ofelt theory to calculate the radiative transition rate and the radiative decay time of the ⁴F_3/2 → ⁴I_J′ transitions in this Nd(III) complex. The strong emissions of this complex at near-infrared region were owing to the efficient energy transfer from ligands to center metal ion. The potential application of this complex in NIR electroluminescence was studied by fabricating several devices. The maximum NIR irradiance was obtained as 2.1 mW/m² at 16.5 V.     

PACT工艺研究进展及应用中应注意的问题

介绍了粉末活性炭－活性污泥的产生、工艺流程,特点、作用机理探讨,去除污水中有机优先污染物的动学模型以及应用ＰＡＣＴ工艺应注意的几个问题。     

三氢化铝在推进剂中的应用研究进展

介绍了AlH_3的水解稳定性、热稳定性、长期稳定性及摩擦感度等性质以及相应的稳定化处理方法。综述了当前AlH_3在推进剂领域中的应用情况,并指出了其未来的发展方向。     

Synthesis and properties of poly(amide-imide)s based on 1,5-bis(4-trimellitimido)naphthalene

1,5-Bis(4-trimellitimido)naphthalene (II) was prepared by the condensation reaction of 1,5-naphthalenediamine and trimellitic anhydride. A series of aromatic poly(amide-imide)s (IV _a–o) was synthesized by the direct polycondensation of the diimide-diacid (II) and various aromatic diamines (III _a–o). The reaction utilized triphenyl phosphite and pyridine as condensing agents in the presence of calcium chloride in N-methyl-2-pyrrolidone (NMP). The inherent viscosities of the resulting poly(amide-imide)s were in the range of 0.55∼1.39 dL/g. These polymers were generally soluble in polar solvents, such as N,N-dimethylacetamide (DMAc), NMP, N,N-dimethylformamide (DMF). Flexible and tough poly(amide-imide) films were obtained by casting from a DMAc solution and had tensile strengths of 90∼145 MPa, elongations to break of 5∼13 %, and initial moduli of 2.29∼3.73 GPa. The glass transition temperatures of some poly(amide-imide)s were recorded in the range of 206∼218 °C, and most of the polymers did not show discernible glass transition on their DSC traces. The 10% weight loss temperatures were above 522 °C in nitrogen and above 474 °C in air atmosphere.     

Flammability limits and ballistic properties of fuel-rich propellants

The flammability limits and ballistic properties of composite fuel-rich propellants were studied experimentally, using PBAN/AP propellant formulations. Higher pressure and AP contents as well as smaller AP particle size were found to promote sustained combustion and to increase burning rate. The addition of potassium perchlorate (KP) in place of AP increased the burning rate pressure exponent from about 0.3 to over 0.7 at optimum conditions. Ferric oxide and copper chromite catalysts caused an increase of the burning rate by a factor of 2, while the addition of aluminum powder at the expense of the fuel binder was found to have a remarkable effect on the burning rate with a maximum increase of as high as 5-fold.     

生物基聚己二酸戊二胺聚合物结构及高速纺长丝性能

生物基聚己二酸戊二胺(聚酰胺56)是由生物基戊二胺和石油基己二酸聚合而成,通过核磁共振、红外光谱、元素分析表征了生物基聚酰胺56的结构,通过差示扫描量热分析、热重分析研究了生物基聚酰胺56的热性能,采用高速纺丝、拉伸两步法进行纺丝试验,并测试了其物理性能。与现有石油基聚酰胺66、聚酰胺6的性能相比,生物基聚酰胺56可纺性良好,纤维的力学性能较好,亲水性能优于聚酰胺6和聚酰胺66,是一种具有广泛应用前景的生物质纤维材料。     

Mechanical and burning properties of highly loaded composite propellants

An improvement in the performance of solid rocket motors was achieved by increasing the oxidizer content of HTPB-based solid propellants. To minimize the adverse changes in the mechanical and rheological properties due to the increased amount of hard solid particles in the soft polymeric binder matrix, the optimum combination of the particle sizes and volume fractions of the bimodal ammonium perchlorate and the aluminum powder in the solid load was obtained from the results of testing a series of propellant samples prepared by using ammonium perchlorate in four different average particle sizes, 9.22, 31.4, 171, and 323 μm. The maximum packing density of solids in the binder matrix was determined by changing the sizes and the volume fractions of fine and coarse ammonium perchlorate at constant solid loading. The average size (10.4 μm) and concentration of aluminum powder used as metallic fuel were maintained constant for ballistic requirements. Optimum sizes and fine-to-coarse ratio of ammonium perchlorate particles were determined to be at mean diameters of 31.4 and 323 μm and fine-to-coarse ratio of 35/65. Solid content of the propellant was then increased from 75 to 85.6% by volume by using the predetermined optimum sizes and fine to coarse ratio of ammonium perchlorate. Mechanical properties of the propellant samples were measured by using an Instron tester with a crosshead speed of 50 mm/min at 25°C. The effect of oxidizer content and fine-to-coarse ratio of oxidizer on the burning rate of the propellant was also investigated by using a strand burner at various pressures. From experiments in which the size and the fine-to-coarse ratio of ammonium perchlorate were changed at constant solid loading, a minimum value of initial modulus was obtained for each fine-to-coarse ratio, indicating that the solids packing fraction is maximum at this ratio. The tensile strength and the burning rate increase, while the elongation at maximum stress decreases with increasing fine-to-coarse ratio of ammonium perchlorate. Experiments in which the total solid loading was increased at constant fine-to-coarse ratio of ammonium perchlorate show that the modulus, the tensile strength and the burning rate increase, while the elongation at maximum stress decreases with increasing solid loading. Propellants having solid loading of up to 82% exhibit acceptable mechanical properties and improved burning properties suitable for rocket applications. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1457–1464, 1998     

Synthesis and properties of poly(aryl ether ketone) copolymers containing 1,5-naphthalene moieties

Poly(aryl ether ketone) copolymers possessing various compositions of 1,5-naphthalene and 1,4-phenylene moieties were prepared by the reaction of 4,4′-difluorobenzophenone with hydroquinone (HQ) and 1,5-dihydroxynaphthalene (DHN) in the presence of sodium carbonate and potassium carbonate in diphenyl sulfone. The synthesized copolymers were characterized by FT-IR spectra, differential scanning calorimetry, and thermogravimetric analysis. Thermal analyses of the copolymers showed that the glass transition temperature increased, while the melting temperature and 2.5% weight loss temperature decreased with increasing content of 1,5-naphthalene moieties. For the copolymers synthesized with the molar fraction of DHN in the dihydroxy monomers (DHN, HQ) being over 0.4, no cold crystallization temperature and melting temperature were detected, indicating that these copolymers are almost amorphous. The crystal structure of the copolymers with the molar fraction of DHN being not higher than 0.2 is rhombic, equal to poly(ether ether ketone).     

The influence of high storage humidity on some properties of solid propellants

The absorption of water vapor by propellants based on hydroxy-terminated polybutadiene and an isocyanate from atmospheres of increasing relative humidities, and the swelling index of the propellant which had absorbed various proportions of water, were measured in an attempt to establish the extent of hydrolytic damage. The method was found incapable of assessing such damage, but it was shown that there was no measurable absorption of vapor below 92 percent relative humidity (RH). The MEK/polymer and toluene/polymer interaction parameters were determined.     

1,5-二(3-羟丙氧基)蒽醌的合成及表征

以1,5-二氯蒽醌与1,3-丙二醇为原料,DMSO为溶剂,用KOH催化反应制得黄色可聚合染料单体1,5-二(3-羟丙氧基)蒽醌.采用正交实验,对物料摩尔比、反应温度和反应时间进行了考察.最佳条件为:n(1,5-二氯蒽醌):n(1,3-丙二醇)=1∶10,反应温度100℃,反应时间15小时;目标产物的质量分数71.0%....     

Theory of burning of powders and solid rocket propellants (review)

The basic principles of the burning of powders and solid rocket propellants are briefly reviewed. Attention is concentrated on the physical significance of the phenomena. The experimental data are considered only within the framework of a comparison between experiment and theory. The review is mainly confined to work published within the last 5 to 8 years with little emphasis on the history of the problem. Heterogeneous systems are examined more closely than homogeneous systems, since in recent years the theory of burning of heterogeneous systems has developed more rapidly.Fizika Goreniya i Vzryva, Vol. 2, No. 4, pp. 3–17, 1966     

Synthesis and properties of 1,5- and 1,8-dichloro-substituted poly(9,10-dihydroanthracene-9,10-diylidene)s

Two new dichloro-substituted poly(9,10-dihydroanthracene-9,10-diylidene)s were prepared by self-condensation of 1,5-dichloroanthrone and 1,8-dichloroanthrone. The bromination and thermal and semiconductive properties were investigated.     

超支化聚酰胺胺(PAMAM)的阳离子改性及絮凝性能

采用3种阳离子单体,通过Michael加成反应,分别对超支化聚酰胺胺(PAMAM)进行了端基阳离子改性,改性产物作为絮凝剂用于处理油田污水.使用模拟三元复合驱油田污水,研究了PAM-AM改性反应条件对产物絮凝性能的影响,并对改性产物结构进行了红外表征.实验表明,优选阳离子单体甲基丙烯酰氧乙基三甲基氯化铵(DMC),反应...     

Synthesis and polymerization of 1,5-bis( N -carbazolyl)pentane with its structural and behavioral highlights

Carbazole, the well-known electron donor and hole-transporting organic light-emitting molecule was modified into 1,5-bis[N-carbazolyl]pentane (1,5-BNCP) by introducing the saturated pentane spacer. Such insertion fixed the certain space between growing polymer chains and demonstrated π–π stacking effect over its morphology and structure. Its contribution in improving the thermal stability and photosensitization was also investigated. The FT-IR and 1H NMR was used to characterize monomer. Morphology of subsequently polymerized material was seen under SEM. The position of polymerization and structural change were studied by FT-IR and XRD, respectively. Thermal study with reference to glass transition temperature and stability was analyzed by DSC and TGA. Optical properties of monomer and polymer were investigated by UV–visible and photoluminescent spectrophotometer. The material was found crystalline, thermally stable, highly photosensitized and white light emitter.     

1,7(1,5)-二芳基庚(戊)二烯类姜黄素衍生物、类似物结构与活性的关系研究

大量研究结果证明,姜黄素具有抗肿瘤,抗氧化,消炎的作用与它们的结构有密切关系,且大部分姜黄素衍生物与类似物的药理活性较姜黄素本身有所提高.这为进一步开发新的姜黄素衍生物与类似物药理功效奠定了理论基础.本文就近年来对1,7(1,5)-二芳基庚(戊)二烯类姜黄素衍生物与类似物结构的改造、修饰与其活性之间关系的研究进行探讨.     

HTPB-based polyurethanes for inhibition of composite-modified double-base (CMDB) propellants

Polyurethanes were synthesized by the reaction of hydroxy-terminated poly-butadiene (HTPB) and diisocyanates such as toluene diisocyanate (TDI), diphenyl-methane diisocyanate (MDI), hexamethylene diisocyanate (HMDI), and isophorone diisocyanate (IPDI). Carbon black and antimonytrioxide (Sb₂O₃) were incorporated into these formulations as fillers. Dioctyladipate (DOA) and trimethyllolpropane (TMP) were also added as a plasticizer and crosslinker, respectively. These polyurethanes were investigated as inhibitors for composite-modified double-base (CMDB) propellants. Due to superior mechanical properties, thermal properties, and low nitroglycerine absorption, HTPB–MDI–TMP-derived filled polyurethane was selected and evaluated as an inhibitor for a CMDB propellant. © 1997 John Wiley & Sons, Inc. J Appl Polm Sci 65:355–363, 1997     

丁基橡胶的阻尼性能及其应用

丁基橡胶阻尼材料的研究包括：低温性能的改进和高温功能区的拓展。与其他弹性体并用共硫化,可改善其低温性能;与树脂共混,可使阻尼功能区向高温拓展,提高其高温阻尼性能。丁基橡胶共混改性的方法通常有2种：(1)采用动态硫化,将树脂混入丁基橡胶中;(2)加入丁基橡胶与第二组分的接枝或嵌段共聚物作增容剂进行共混。     

水滑石的结构特性及作为塑料助剂的应用

水滑石是一种阴离子层柱化合物,基于其独特的结构和物理化学特性,已在许多工业领域显示广阔的应用前景。作者简要介绍了水滑石的结构、性质和合成方法,在此基础上,着重综述了其作为塑料助剂的应用。     

The crystallinity of poly(phenylene sulfide) and its effect on polymer properties

The crystallinity and crystallizability of poly(phenylene sulfide) have been examined by a number of common techniques. Several provided qualitative information, but only one, x-ray diffraction, was considered sufficiently reliable and reproducible to allow quantitative comparisons. Based on x-ray measurements, an approximate degree of crystallinity, termed crystallinity index (C_i), could be readily assigned. According to this method, virgin polymer possesses significant crystallinity (C_i ≈ 65%). Curing (crosslinking) the resin below its melting point did not change the crystallinity but did affect the crystallizability. Lightly cured resin suitable for molding and film extrusion was easily quenched from the melt to give amorphous polymer. The amorphous samples crystallized rapidly when heated to temperatures > 121°C (250°F). At mold temperatures below 93°C (200°F), moldings with very low surface crystallinity were produced. Annealing (204°C, 400°F) caused rapid crystallization of such moldings, and changes in crystallinity were correlated with observed changes in physical properties. The resin crystallizes so rapidly that these quenched moldings possessed a crystallinity gradient, the internal crystallinity being substantially greater. At high mold temperatures (121–204°C, 250–400°F), moldings very similar to fully annealed specimens were obtained.