蚕丝蛋白与硅溶胶复合材料的研究

采用动态力学测试手段(DMA)并结合扫描电镜和拉曼光谱等方法,考察了用桑蚕丝蛋白与二氧化硅水分散体系(硅溶胶)制备的复合材料的结构与性质.结果表明,在此共混体系中,直径约为100 nm的二氧化硅聚集体与丝蛋白连续相的界面相容性良好.动态力学测试发现,复合材料的动态力学性能在15℃到55℃范围相对于纯丝蛋白材料得到了改善,二氧化硅组分的加入对丝蛋白分子链段的运动性有所阻碍,从而导致了40℃模量损耗的消失.     

PMPS/PMAc相容性与同步互贯聚合物网络的阻尼性能研究

互贯聚合物网络是一种聚合物合金 ,其组分的热力学性质决定组分间的相容性和微相结构 ,从而影响材料的阻尼性能 .采用同步互贯聚合物网络 (SIN)技术制备了一种新型的聚苯基硅氧烷 (PMPS) 聚甲基丙烯酸酯 (PMAc)阻尼材料 ,用DMA和AFM等表征研究了其玻璃化温度转变行为与微观相态结构 .结果表明 ,由相容性好的组分制备的SIN材料阻尼值最高 ,tanδmax 可达 1 4,只有一个玻璃化温度转变峰 ,其微相结构为双相连续 ;组分介于相容与不相容之间时 ,所构成的SIN样品的tanδ≥ 0 3的温度区间最宽 ,可达 170℃ ,微相结构为单相连续 ;由相容性差的组分制得的SIN阻尼材料的内耗峰裂分为两个区间 .PMPS PMAcSIN材料的阻尼性能可以通过调节组分的相容性进行控制 .     

胶乳接枝插层法天然橡胶/蒙脱土/聚丙烯酸丁酯纳米复合材料结构与性能的研究

采用胶乳接枝插层法,引入单体,制备了天然橡胶蒙脱土聚丙烯酸丁酯纳米复合材料.X射线衍射(XRD)和透射电镜(TEM)结果表明,在单体丙烯酸丁酯(BA)的作用下,改性蒙脱土片层被进一步撑大,并在橡胶基体中以纳米级分散;动态粘弹谱(DMA)测定结果显示,该体系的玻璃化温度有所提高,且60℃时具有较低的tanδ值,说明具有较小的滚动阻力;物理机械性能测试表明该方法有效地实现了对天然橡胶的补强.     

聚丙烯／顺丁橡胶动态硫化增韧的研究

研究了在聚丙烯(pp)与顺丁橡胶(BR)共混过程中加入橡胶硫化剂使共混体系中橡胶相动态硫化交联。研究结果表明,采用动态硫化法可提高共混物的冲击强度和拉伸强度。借助于SEM和DMA,证实了动态硫化使PP/BR共混体系具有相界面粘结良好的多相结构,改善了两相相容性。探讨了动态硫化增韧的机理。     

填充丁腈共聚物的动态力学性质

本文研究了用石墨粉剂和二硫化钼粉剂填充的丁腈共聚物(含丙烯腈约40wt%)的动态力学性能,贮能模量E'_c、损耗模量E"_c损耗因子tanδ。讨论了填料的体积分数、高聚物和填料之间的相互作用对这些参数及松弛谱的影响。试用了一种模型计算这些复合材料中间相的E₁值。     

超支化聚氨酯阻尼涂层的制备及性能

以甲苯-2,4-二异氰酸酯(TDI)和二乙醇胺(DEOA)为原料, 采用一步法合成了超支化聚氨酯, 并对其改性制备了光固化超支化聚氨酯(UV-HPU)和超支化杂化聚氨酯(HHPU)两种树脂. 用傅里叶红外光谱(FTIR)和核磁共振氢谱(1H NMR)表征了预期产物. 以其为预聚物制备阻尼涂层, 动态力学分析(DMA)研究表明, 这两种涂层都具有高阻尼因子(tanδ≥1.0)、宽阻尼温度范围(tanδ≥0.5, 大于50 ℃)和宽阻尼频率范围(20～160 Hz); 通过基本性能测试和热重分析(TGA)发现杂化涂层聚氨酯较光固化聚氨酯具有更好的机械性能和热稳定性能; 杂化涂层聚氨酯的FTIR分析可知杂化涂层中硅氧烷水解缩合, 提高了交联密度; 杂化材料的断面扫描电镜(SEM)分析表明, 硅氧烷的水解缩合并未形成大颗粒纳米粒子而是形成均相体系.     

玻璃纤维对聚甲醛基导电复合材料性能的影响

采用在转矩流变仪中熔融混合的方法制备了聚甲醛(POM)/多壁碳纳米管(MWCNTs)/玻璃纤维(GF)和POM/炭黑(CB)/GF复合材料,研究了GF的加入对复合材料的导电性能、结晶行为和动态力学性能的影响.采用场发射扫描电镜(FESEM)观察了复合材料中导电填料的分散状态,发现GF的加入对MWCNTs和CB的分散状态没有明显影响.虽然GF为导电惰性填料,但因其加入起到了占位作用,明显提高了导电填料的有效浓度,从而使复合材料的体积电阻率明显降低.采用示差扫描量热仪(DSC)研究了复合材料中POM的结晶行为,发现GF的加入对POM的结晶温度、熔点和结晶度均无明显影响.采用动态机械分析仪(DMA)对复合材料的动态力学性能进行了研究,表明GF的加入能够明显地提高复合材料的储能模量.     

SIS/石油树脂共混体系的阻尼性质

通过动态力学性能分析研究了嵌段共聚物聚苯乙烯-异戊二烯-苯乙烯（SIS）／油树脂共混体系的阻尼性质。SIS的硬段聚苯乙烯含量越高，损耗因子（tanδ）峰值温度和粘流温度越高。含有脂肪族系（C5系）石油树脂共混体系的粘流温度比含有氢化芳香族系（C9系）的高。石油树脂的软化点提高，tanδ峰值温度上升。随着石油树脂的含量增大，tanδ峰值增大，并向高温移动，但储能模量（E＇）却先大幅度减小，而后缓慢增大。石油树脂和SIS的软段聚异戊二烯（PI）具有更好的相容性。SIS／N油树脂共混体系的阻尼性能优异，如SIS-A／E120（100／125）在-11～115℃范围内tanδ〉0．3。     

聚氨酯弹性体/蒙脱土纳米复合材料的合成与性能

采用聚氨酯本体预聚法 ,利用原位插层聚合合成了聚氨酯 蒙脱土纳米复合材料 .通过X 射线衍射(XRD)和Molau实验研究了蒙脱土在复合材料中的分散情况 .红外分析 (IR)表明随着蒙脱土含量的增加 ,复合材料羰基氢键减少 .动态力学分析 (DMA)以及差热分析 (DSC)结果说明随着蒙脱土含量的增加 ,材料的玻璃化温度降低 .聚氨酯纳米复合材料的拉伸强度和断裂伸长率同时提高 ,表现出较好的力学性能 .     

蓖麻油型聚氨酯IPN的结构与性能研究

本文用蓖麻油,甲苯二异氰酸酯和甲基丙烯酸β-羟乙酯组成的加聚型网络(Ⅰ)和蓖麻油,甲苯二异氰酸酯和聚丙二醇组成的缩聚型聚氨酯(Ⅱ),以同步法形成了一组新型的IPN。用动态力学法和固体核磁共振法研究了它们的结构和性能,形成IPN后,力学数据显示出机械强度的提高,动态力学损耗谱上表现出,tanδ的增宽,固体核磁共振谱计算的结果是界面层的比例增高,但界面层比例并不随配比的改变而变化,它揭示出此IPN可能具有壳核结构。     

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.     

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.     

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。     

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.     

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.

     

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。     

Investigation of Kinetics of Solid-Phase Synthesis of Lithium Orthosilicate

The kinetics of the interaction between lithium carbonate and silica with various degrees of dispersion was investigated by TG and DTA methods. It was found that the utilization of pyrogenic silica with a specific surface area of about 300 m²g^-1 instead of aerosil with one of 175 m²g^-1 leads to an increase of the reaction rate between lithium carbonate and silica, which depends on the formation and growth of lithium orthosilicate crystals in the first stage, and is conditioned by the diffusion of lithium and oxygen ions through the lithium orthosilicate layer formed at temperatures above 800 K. This supposition is supported by the kinetic analysis results obtained with the use of the different models. The optimal regime of heating is recommended. This revised version was published online in July 2006 with corrections to the Cover Date.     

小环化合物中饱和碳质子化学位移的计算

小环化合物由于其张力、构型、构象和各向异性效应等原因,环碳上质子化学位移缺乏规律性,难以预测,对此作者曾提出一种近似算法。本文根据303种小环化合物中饱和碳质子的化学位移实验数据,将适于计算这类质子化学位移的公式表述为:     

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。