溶液法改性高分子表面技术的研究 (Ⅰ)──改性高分子表面的结构和性质

医用高分子材料的生物相容性问题逐步引起人们的重视［１］．除合成相容性好的材料外,另一个途径是对现有高分子材料进行改性以提高其生物相容性,其中表面改性因其对材料本体的影响小,成为医用高分子材料研究的一个热点．Ｒｕｃｋｅｎｓｔｅｉｎ［２］最早利用溶液法改...     

医用高分子材料表面的润滑改性进展

综述了医用高分子材料表面的润滑改性方法,对影响表面润滑性的因素进行了讨论,简述了材料表面润滑性的测定方法,润滑机理及润滑表面的形态,概述了表面润滑的医用高分子材料在临床中的应用。     

低温等离子体对高分子材料表面的改性

低温等离子体是以低气压放电(辉光、电晕、高频、微波)产生的电离气体,其中蕴含着丰富的活性粒子,可以引起种种化学反应。处于非平衡态的低温等离子体,其电子温度 T_e>>离子温度 T_i 和气体温度 T_g。如辉光放电或射频放电产生的低温等离子体,其 T_e≈10~4K, T_g则略低二个数量级。在低温等离子体条件下进     

壳聚糖改性—两性离子高分子表面活性剂的制备

以壳聚糖(CTS)为原料,通过Schiff反应以及烷基化反应在壳聚糖的活性氨基上先后引入亲水和疏水基团,合成了一种易溶于水的两性离子表面活性剂(Rm,n-CTS-B).采用红外光谱(IR)、核磁共振(1H-NMR)等方法对壳聚糖及其衍生物的分子结构进行表征;通过元素分析(EA)测定其取代度,采用正交实验确定其最优反应条件.对Rm,n-CTS-B的水溶性、表面张力以及泡沫性能进行了研究,结果表明:合成的R8,2-CTS-B具有良好的表面性能,表面张力能达到31.13 m N/m.     

用低温等离子体处理方法改性高分子材料表面

综述了利用等离子体改性高分子材料表面的最新进展,其应用与机理。     

壳聚糖改性的高分子表面活性剂的合成与性能

以商品壳聚糖(CTS)为原料,通过对-NH_2的化学改性,合成制备了壳聚糖改性的水溶性两性离子表面活性剂.采用正交试验法对合成反应工艺作了优化;通过红外光谱(IR)、核磁共振(H-NMR)及元素分析(EA)等方法对烷基壳聚糖中间体(RCTS)与最终产物,即烷基壳聚糖磺酸季铵盐(SRCTS)的分子结构进行了表征,并对SRCTS的水溶性、表面张力以及泡沫性能作了初步的探索.结果表明:经改性的SRCTS具有良好的表面活性与泡沫稳定性,其最低表面张力值可降至29.1mN/m;泡沫半衰期可提高65%.     

两性离子在高分子膜表面功能化改性中的研究进展

两性离子的合成工艺简单,官能团适用性强,且在水溶液中具有较强的水合能力与抑制蛋白质吸附性,因此两性离子在高分子膜表面的功能化改性中显示出很大的优势。将两性离子接枝于高分子膜表面可得到抗污染性强,血液相容性好,环境刺激响应性迅速的功能化膜。两性离子功能化改性高分子膜不仅能广泛应用于水处理和医务治疗中的人工器官材料、血浆分离等领域,在生物医药工业中的蛋白质浓缩、净化与分离等方面同样显示出巨大的应用空间。     

阻燃高分子复合材料中氢氧化镁的制备及其表面改性

以氢氧化镁为代表的无卤阻燃剂,由于其具有良好的阻燃、抑烟性能及环保特点,已日益得到学术界和产业界的重视.在实际应用过程中,人们发现阻燃剂的形貌对其阻燃性能具有较大影响,因此本文重点综述了化学沉淀法制备不同形貌及尺寸的氢氧化镁和各影响因素对其制备的影响,以及当前氢氧化镁表面改性的一些新方法,如:大分子改性等,使得其在复合加工过程中,能与高分子材料具有良好的相容性.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

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。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

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.