Synthesis and polymerization of a new nitrogen‐containing bis‐ortho‐diynylarene monomer

This study focuses on the preparation, characterization, and optical properties of new bis(3,4‐diphenylethynylphenyl)phenylamine. This is the first nitrogen‐containing bis‐ortho‐diynylarene (BODA) monomer having a nitrogen atom as the spacer group. BODA monomers are usually prepared from common bisphenols, thereby providing great synthetic versatility and the opportunity to develop a wide array of novel polyarylene thermosets by varying the aromatic spacer group. The new bis(3,4‐bisphenylethynylphenyl)phenylamine was synthesized in five steps. This compound emits an intense blue color (λ = 438 nm) upon irradiation by UV light and may be suitable for use as an emitting layer in electroluminescent devices. Bis‐(3,4‐bisphenylethynylphenyl)phenylamine and its polymer have photoluminescence quantum yields 34 and 38%, respectively, and long excited‐state lifetimes of 3.2 and 3.6 ns, respectively. The structure of the monomer and its polymer were characterized using spectroscopic techniques including Ultraviolet–visible Spectrophotometer, Photoluminescence Spectrophotometer, Fourier Transform infrared spectroscopy, and Gel Permeation Chromatography. The polymerizations were studied by Differential Scanning Calorimeter. The amount of weight loss and the thermostability of the nitrogen‐containing polymer were determined from thermogravimetric analysis. The electrical conductivity of neat HCl‐doped BODA‐derived polymer film was measured according to the standard four‐point probe technique. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6988–6996, 2006     

Radiation induced synthesis and swelling characterization of thermo-responsive N-isopropylacrylamide-co-ionic hydrogels

Two-component thermo-responsive hydrogels poly(N-isopropylacrylamide)-co-vinylbenzyltrimethylammonium chloride (NIPA-co-VBT) and poly(N-isopropylacrylamide)-co-p-sodium styrene sulphonate (NIPA-co-SSS) were prepared by using high energy gamma radiation. The gels were characterized by Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and sol-gel analysis. The presence of ionic monomers in NIPA leads to lower gel content. Introduction of ionic components in the matrix enhanced swelling extent but caused slower volume transition. The swelling studies in alcohol indicated that swelling extent was function of polarity of the swelling medium and all gels followed the order water > methanol > ethanol > iso-propanol. In mixed co-solvents (water-alcohol), they exhibit complex reentrant behavior. The co-polymer gels containing VBT swelled faster and to higher extent than those containing SSS. The dynamic swelling studies indicated that diffusion of water in PNIPA gel shifts from Fickian for PNIPA to anomalous for NIPA-co-ionic gels also the mean swelling time (MST) decreases for gels containing ionic monomers.     

亚麻等麻类纤维与乙烯基类单体接枝共聚反应的研究进展

近年来,乙烯基类单体与亚麻、大麻、苧麻等麻类纤维的接枝共聚反应已得到关注。本文着重总结接枝的引发方法,包括:1.辐射引发接枝;2.光引发接枝;3.Ce(Ⅳ)离子引发接枝;4.锰盐引发接枝;5.V(Ⅴ)离子引发接枝;6.Fenton's 试剂(Fe~(2+)-H_2O_2)引发接枝;7.过硫酸盐氧化还原引发体系接枝。上述各类引发体系及接枝纤维的结构与性能表征均在本文中作了述评。     

多官能单体TMPTA在LDPE表面光接枝聚合研究

以二苯甲酮(BP)为光引发剂、丙酮和水的混合物为溶剂,研究了室温下多官能单体三羟甲基丙烷三丙烯酸酯(TMPTA)在低密度聚乙烯(LDPE)表面的光接枝聚合(λ>300nm).研究表明,多官能单体的接枝速率较快,接枝聚合易产生交联结构,聚合后仍残留双键;延长聚合反应时间、增加单体用量有利于单体接枝转化率的提高;随引发剂用量增加,单体接枝转化率出现一峰值;在研究范围内,混合溶剂中水含量增加可使单体接枝转化率明显提高.扫描电镜观察到接枝膜表面形成了许多小球,表面粗糙度增加,疏水性提高.     

三氯化钛存在下碘酸钾滴定法测定锡

提出了采用铝加铁混合还原剂还原,三氯化钛存在下碘酸钾滴定法测定锡的绝对测量方法,研究了三氯化钛抑制氧的作用效果及作用机理。应用于巴氏合金中锡含量的测定,方法简便、快速,结果准确可靠。     

RuO<Subscript>2</Subscript>–TiO<Subscript>2</Subscript> mixed oxide composite coating for improvement of Al-alloy sacrificial anodes

It has been recently proved that RuO₂ can act as an effective surface activator of aluminum alloy sacrificial anodes. TiO₂ has the property of stabilizing RuO₂ coating and resisting biofouling on metal surfaces. Hence, a mixed oxide catalytic coating of TiO₂ and RuO₂ can enhance the galvanic performance of aluminum alloy sacrificial anodes and resists biofouling on the anode surface. In the present work RuO₂–TiO₂ mixed oxide was coated on aluminum alloy sacrificial anodes. The large and uniform porous nature of the coating was found to facilitate efficient ion diffusion. The coating was found to persist on the anode even after 3 months of galvanic exposure. The anode having an optimum combination of the mixed oxide had 70% TiO₂ as the major component in the coating. The catalytic coating significantly improved the performance of the anodes to a large extent.     

碱改性γ－Al_2O_3催化剂表面碱强度分布与COS水解活性的研究

用非水滴定法和Ｈａｍｍｅｔｔ系列指示剂测定了ＣＯＳ水解碱改性γ－Ａｌ_２Ｏ_３催化剂的表面碱强度分布．发现表面碱强度分布不均匀与表面能量分布不均匀相呼应．采用零点酸碱强度（Ｈ_（０，ｍａｘ））及碱中心区域分析法，Ｂｒｏｎｓｔｅｄ催化定律，进一步证实ＣＯＳ水解反应具有明显碱催化特征，较高活性催化剂的Ｈ_（０，ｍａｘ）一般为１０左右，对ＣＯＳ水解反应起主要作用的碱性中心的碱强度（Ｈ_０）为４．８≤Ｈ_０≤９．８．对碱金属氧化物改性后的γ－Ａｌ_２Ｏ_３催化剂，Ｂｒｏｎｓｔｅｄ规律在每个碱强度分区域内是适用的．     

Radiation induced polymerization of vinyl monomers and their application for preparation of wood-polymer composites

Polymerizing effects of high energy radiation has been found suitable for preparation of wood-polymer composites. In the present work after evaluating polymer products that have been obtained by irradiation method, wood-polymer composites have been prepared by in situ polymerization of vinyl acetate, acrylic acid and acrylic acid/styrene mixture using two samples of Iranian hardwoods, Beech and Hornbeam. These woods and their composites have been tested for their physical and mechanical properties. The results have shown that chemical bonding between polymer and the cell wall component lead to better strength properties in the composites.     

光度法测定水样中铝

研究了铝与对乙酰基偶氮胂(ASApA)显色反应,在pH 4.7的HOAc-NaOAc缓冲溶液中,Al3+与ASApA显色形成1:2络合物,最大吸收波长位于612 nm,ε-8.19×103L·mol-1·cm-1,铝量在0～2.8μg·ml-1范围内遵守比耳定律,用于水样中铝的测定,结果满意。