等温熔体结晶尼龙1010的晶体结构

WAXD研究表明,在结晶温度T_c≤196℃时,尼龙1010等温熔体结晶样品的结晶度X_c和微晶尺寸L_(100)随T_c升高近乎线性增大,而氢键面上的相对衍射强度R却降低;T_c>196℃后三者与T_c关系发生相反变化。结晶速率快时有利于分子链在垂直于氢键平面方向上堆砌,反之有利于在平行于氢键平面方向上生长。     

固态缩聚尼龙1010的熔化行为

本工作借助示差扫描量热法和X-射线衍射分析法(WAXD)首次研究了固态缩聚反应所得初生态尼龙1010的结晶特征和熔化行为。实验结果表明:固态缩聚反应的温度和时间以及产物分子量对初生态尼龙1010的熔化行为有着明显的影响。初生态尼龙1010结晶熔融双峰的显隐与其X-射线衍射峰特征没有明显的依赖关系,但随着尼龙大分子结晶的完善化而出现表观体积收缩观象。     

可分散性纳米SiO2/尼龙1010复合材料的结晶行为

采用熔融共混法制备了可分散性纳米SiO2/尼龙1010复合材料.通过X射线衍射和差示扫描量热法对尼龙1010及其复合材料的结晶行为进行了研究.结果表明,SiO2的加入作为结晶的异相成核点,使复合材料的结晶温度升高,熔融温度降低,使其结晶度稍有降低;SiO2的加入并没有改变尼龙1010的结晶形态,只是使尼龙1010的晶格尺寸发生了一定程度的改变.     

偏氟乙烯/三氟氯乙烯无规共聚物的结晶

用示差扫描量热法(DSC)、广角X射线衍射(WAXD)和傅里叶红外光谱(FTIR)研究了偏氟乙烯/三氟氯乙烯单体摩尔比为1:4的无规共聚物的结晶与晶体结构.结果表明,该无规共聚物属于半结晶型聚合物.在333～353K温度范围内退火,片晶逐渐完善、增厚,熔点和结晶度均随着退火时间的延长而升高.于353K退火时,由DSC结果计算得到片晶厚度约4.68nm.在333K退火时得到共聚物的最大结晶度约为14%.WAXD测试结果表明,沿晶粒(101)晶面的面间距为0.55nm,垂直于(101)衍射晶面方向上的晶粒平均尺寸为5.86nm.     

X-射线衍射法测定尼龙1010结晶度

根据X-射线散射强度理论,使用图解多重峰方法对尼龙1010三个结晶峰及非晶峰的衍射强度进行校正,首次导出了尼龙1010结晶度计算公式,所得结果与密度及量热测定结果具有很好可比性。     

尼龙1010盐固态缩聚反应的研究

采用测定转化率和分子量、红外光谱、X-射线衍射分析、元素分析、偏光显微镜和扫描电镜等方法研究了结晶尼龙1010盐的特性、尼龙1010盐固态缩聚反应的动力学及其相应的晶体结构形态,用DSC法探讨了其反应机理。     

聚己内酯在聚己内酯/聚乙烯基甲基醚共混体系中的结晶研究

通过示差扫描量热(DSC)、广角X射线衍射(WAXD)、小角X射线散射(SAXS)研究了聚己内酯(PCL)/聚乙烯基甲基醚(PVME)共混体系中PCL的结晶行为.研究结果表明,共混聚合物中PCL的结晶度几乎不随体系的组成而发生变化.共混物中PVME的存在没有改变PCL的晶体结构,但是随着PVME含量的增加,片晶之间的距离则大,这主要是由于非晶层增厚引起的.     

脂肪族聚酰胺热膨胀行为的研究

通过热膨胀测试,示差扫描量热分析(DSC)、广角X射线衍射(WAXD)与傅里叶变换红外光谱(FTIR)等方法研究了4种脂肪族聚酰胺玻璃化转变温度(Tg)、结晶行为以及氢键强度对热膨胀行为的影响,探索了影响脂肪族聚酰胺热膨胀的本质.DSC和X射线衍射结果表明,聚酰胺中结晶部分的热膨胀系数要低于无定形部分,但聚酰胺的熔融温度和结晶度对热膨胀的影响不够明确.相比较其它脂肪族聚酰胺,聚酰胺56(PA56)具有较高的玻璃化转变温度和较低的亚甲基/酰胺基(CH2/CONH)比例,表现出较低的热膨胀系数.研究发现,在相同条件下制备的脂肪族聚酰胺体系中,CH2/CONH比例或Tg与热膨胀系数具有明显的线性关系,随着CH2/CONH比例的降低或Tg的升高,热膨胀系数显著减小.FTIR的结果表明,聚酰胺分子链间的氢键密度和氢键强度随温度升高衰减的程度是影响其热膨胀行为的关键因素.     

尼龙1010结构的研究

本工作通过X-光衍射、红外光谱、示差扫描量热、偏光显微镜、粘弹谱及密度观测,考察了尼龙1010样品,分别从玻璃态结晶与从熔融态结晶后的聚集态结构,发现它的结晶结构与尼龙66相似,但从熔融态结晶的晶格有很大畸变,对所涉及的问题进行了讨论,提出了氢键面畸变的模型。     

在高压CO_2中聚乙二醇-聚己内酯嵌段共聚物的结晶行为

通过广角X射线衍射(WAXD)和小角X射线散射(SAXS)方法研究了PEO-b-PCL在CO2中的结晶形貌和片晶厚度的变化,利用高压示差扫描量热仪(HP DSC)考察了压力对熔融和等温结晶过程的影响.结果表明,PEO-b-PCL的结晶度、片晶厚度、熔融温度均随压力的升高而减小,结晶结构变得不完善.在等温结晶过程中,结晶速率随压力的升高而下降,结晶过程处于成核控制区,Avrami指数n在3.7~4.7,表明晶体的生长方式为三维生长.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

解决能源问题的新途径——光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。