辐射交联高聚物的溶涨与弹性性能的修正关系式

在辐射交联过程中,Charlesby假定交联度(及裂解度)与剂量成线性关系,导出了交联高聚物的溶涨与弹性性能关系式(1)及(2)。     

PEO/PVAc共混体系辐射交联反应中溶胶分数与辐照剂量间的关系

交联度对由聚合物共混物辐射交联而制备出的材料的性能影响很大,研究共混体系的辐射交联度和交联行为是十分重要的。通常,用溶胶分数与辐照剂量间的关系表征聚合物的交联度和交联行为。文献[2]发现线性聚合物的溶胶分数与辐照剂量间的关系与高分子链结构参数有关。本文试图考察共混体系的辐射交联行为是否也与高分子链结构有关,并将线性聚合物的关系式(1)推广应用到PEO/PVAc共混体系中。目前,有关这方面的研究工作还未曾见文献详细报道。     

偶氮特异丁烷引发交联OV-1701石英弹性毛细管色谱柱的研究

ATB(偶氮特异丁烷)是一类性能良好的自由基引发剂、用它引发交联OV-1701石英弹性毛细柱,交联度大于96％,柱子内壁惰性,柱效高,热稳定性好,交联前后柱极性无明显变化,文中还对交联条件和反应机理进行了研究和探讨。     

聚己内酯/聚酯丙烯酸酯共混物的辐射交联及其形状记忆行为

研究了聚酯丙烯酸酯 (PEA)类多官能团物质与聚己内酯 (PCL)共混物的辐射交联效应 .分别考察了多官能团PEA的用量、官能团数目、辐射交联剂量等因素对聚己内酯的辐射交联规律、动态力学性能、形状记忆行为等性能的影响 .结果表明 ,PCL PEA共混物的辐射交联规律不再遵从Charlesby Pinner关系式 ,而是符合陈欣方 刘克静 唐敖庆关系式 .多官能团PEA的加入可以显著提高PCL辐射交联的效率 ;相同剂量时 ,官能团数目越多、用量越大的样品 ,生成的凝胶含量越多 ,强化辐射交联效应越大 .DMA分析表明 ,PCL强化辐照交联后的弹性模量和耐热性能显著提高 .强化交联PCL在其熔点以上都呈现出高弹态平台 ,可以实现形状记忆 .且交联度较高 ,形状记忆恢复速率较快 .     

LDPE／1,2—PBD共混体系的辐射交联

聚合物共混物经辐射交联后,具有多种优良性能,这些性能都与交联度有关。溶胶分数与辐照剂量间的关系常常被用来表征聚合物的辐射交联程度和交联行为。本文试图将共混物的组成、组份的分子链结构与其溶胶分数与辐照剂量间的关系式联系起来,从而预期共混体系的辐射交联行为。     

辐照对聚己内酯结构和性能的影响

研究了γ 辐照对不同分子量的聚己内酯 (PCL)的力学性能、热性能、结晶行为的影响 ,在此基础上 ,研究了辐射交联后的PCL的形状记忆行为 .研究结果表明 ,PCL的分子量越大 ,辐射交联所需的凝胶化剂量越低 .溶胶分数S +S1 2 与 1 D的关系很好地符合Charlesby Pinner关系式 ,说明PCL的辐射交联属于无规交联 .剂量对PCL的力学性能影响显著 ,剂量越大 ,抗张强度和断裂伸长率下降越多 ,但分子量较高的PCL的抗张强度受剂量的影响较小 .DMA分析表明 ,聚己内酯辐照交联后的弹性模量和耐热性能显著提高 .交联度较高的PCL表现出高弹态 ,可以拉伸 ,并具有较好的形状记忆行为 .DSC分析表明 ,辐射交联使PCL的结晶度有所增加 ,但也使结晶熔点有所降低     

用大口径厚液膜DEGS交联玻璃毛细管柱分析植物油脂肪酸的组成

对植物油脂肪酸组成的分析,通常采用二乙二醇丁二酸聚酯(DEGS)固定液的填充柱。由于填充柱柱效不高,在制备柱子时掌握不好常使硬脂酸、油酸等组分不能很好分离。一般只分析到芥酸,分析时间长,这些都会影响分析结果。大口径厚液膜交联柱比填充柱柱效高很多,并有柱容量大、耐溶剂,柱寿命长等特点,1983年以来发展很快,受到广泛重视。国内对大口径甲基硅酮交联柱的研究和应用已有报道。我们首次研制了大口径厚液膜DEGS交联柱,并用于植物油脂肪酸组成的分析,在15分钟     

用辐射交联方法测定含氟聚合物分子量FEP分子量的测定

本文提出并研究了用辐射交联方法测定难溶高聚物的分子量问题。不同熔融指数FEP共聚物,辐射交联后,其凝胶化剂量随熔融指数增大而增高。由高温弹模测得FEP的交联G值为1.2。由交联G值和凝胶化剂量计算得FEP的,它与熔融指数的关系为log∞3.5log(1/Ml)·该结果与一般高聚物的本体粘度与分子量关系相一致。     

高分子辐射交联技术及研究进展

介绍了辐射交联反应的机理;讨论了影响辐射交联反应的因素及有关动力学问题;报道了辐射交联对高分子材料性能的影响及应用技术进展;比较了辐射交联与过氧化物交联的技术经济差异。     

后交联法制备大孔吸附树脂及其对灯盏乙素的分离研究

通过种球溶胀法合成的粒径为15μm,交联度为80%的聚(苯乙烯-二乙烯苯)微球(PS-DVB),以三氯化铁为催化剂,通过悬挂双键后交联反应,制备出具有较高比表面积的大孔吸附树脂色谱填料;利用上述色谱填料装填成规格为4.6mm×250mm的色谱柱,对灯盏乙素进行高效液相色谱分离,以分离度、选择因子、柱效和保留时间为考察指标,研究了流动相比例、流动相流速、柱温和进样浓度等对分离过程的影响。在流动相为乙腈:0.4%冰乙酸(27:73,v:v),流速为1.0mL/min,柱温为30℃,进样浓度为300μg/mL的条件下,灯盏乙素和灯盏甲素的分离度为2.20,两组分可完全分离,保留时间为7.1min,为灯盏乙素的大规模制备提供了可能。     

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.     

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.     

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^-。     

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.     

Thermodynamics of the formation of oxosulfides of rare-earth elements

The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.     

探究“铁的锈蚀条件”实验创新设计

设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。