聚氨酯改性氯丁接枝低毒溶剂型鞋用胶粘剂的研制

研究了一种能粘多种材质的溶剂型鞋用大底胶。该胶为一种聚氨酯改性氯丁、SBS接枝胶,粘接范围广,对PU、TPR、SBS等材质粘接性能比氯丁接枝胶好,适合鞋厂流水生产线;所用溶剂毒性相当低,对人无害,有利于劳动保护和环境保护。     

Electrocatalytic properties of NDGA and NDGA/FAD hybrid film modified electrodes for NADH/NAD redox reaction

The fabrication of monolayers composed of nordihydroguaiaretic acid (NDGA), and hybrid films composed of NDGA-flavin adenine dinucleotide (FAD) adsorbed films was performed in neutral aqueous solutions to produce electrochemically active thin films exhibiting one and two redox couples, respectively. An electrochemical quartz crystal microbalance and cyclic voltammetry were used to study the in situ growth of the NDGA and hybrid NDGA/FAD film monolayers. The NDGA modified film electrocatalytically oxidized NADH, ascorbic acid, dopamine, and N₂H₄ in neutral aqueous solutions. Well-separated voltammetric peaks were observed for dopamine and uric acid mixtures, and also for ascorbic acid and uric acid mixtures using the NDGA/GC modified electrode. When transferred to various aqueous buffered solutions, the two redox couples of the NDGA/FAD hybrid film and their formal potentials were observed to be pH-dependent. The electrocatalytic oxidation and reduction of NADH and NAD⁺ by a NDGA/FAD hybrid film in neutral aqueous solutions was carried out, and the electrocatalytic oxidation of NADH was performed using a NDGA/FAD hybrid film.     

一种在扩散加权图像降噪中的算法

扩散加权图像中的噪声为莱斯噪声并且图像本身含有丰富的边界信息,因而要求对DWI图像有效降噪的同时,能够较好地保留图像的边界信息。由于BEMD算法可将图像分解为细节图像及余项图像,其所分解的细节图像包括DWI图像的边界信息以及主噪声,而余项图像则描述图像的趋势信息。因此,提出一种将二维经验模态分解算法与改进的维纳滤波器相结合的降噪算法,并将该算法应用于DWI图像的降噪中。通过实验,将所提出的算法与其他算法应用于DWI图像的降噪处理,并通过对结果的分析比较证明所提出的算法能够更有效地对DWI图像进行降噪处理。     

利用腈纶废丝合成絮凝剂PAN—DCD

本文以腈纶废丝为原料与双氰双胺在碱性溶液中反应，成功地制得含有多种活性基因的聚合物ＰＡＮ－ＤＣＤ，并用于染料废水脱色及炼油厂废水除油，除酚的处理研究，与常规使用的几种絮凝剂进行处理结果对照，实验结果表明：该产品单独使用处理效果明显优于其他絮凝剂，与聚铝复合使用处理效果更为理想。     

豆油脚脂肪酸制备松香改性醇酸树脂的配方研究

利用豆油脚脂肪酸-松香-甘油-苯酐，采用脂肪酸法制备松香改性醇酸树脂。通过实验得到较佳工艺条件，确定经济合理的配方和各种原料用量，制备出符合标准的醇酸树脂产品，为加工成各色醇酸调合磁漆和脂肪酸调合磁漆奠定基础。此方法有效利用了废弃的大豆下脚料以代替市场紧缺的天然桐油和亚麻油，为豆油脚在涂料工业上的开发和利用开辟了新途径。     

The synergistic effect of dicyandiamide and resorcinol in the curing of epoxy resins

The synergistic effect of dicyandiamide (Dicy) and phenolic substances was studied, with resorcinol as a model compound. It was found that when Dicy and resorcinol are used jointly, the curing temperature of epoxy resin can be significantly lowered. FTIR and DSC data were used to illustrate the mechanism of the synergism. The addition of the phenolic hydroxyl group to epoxide was facilitated by Dicy, which favors the formation of phenoxy anions. The reaction of Dicy with epoxide was facilitated by resorcinol, which can exert “electrophilic assistance” for the addition of the amino group to epoxide. The presence of resorcinol also favors the addition of the hydroxyl group to the cyano group. The thermal and mechanical properties of the epoxy resins cured with Dicy/resorcinol or Dicy/phloroglucinol were studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1869–1874, 2003     

From clay- to organoclay-film modified electrodes: tuning charge selectivity in ion exchange voltammetry

The surface of two natural smectite-type clay samples was chemically modified by covalent grafting of amine groups, by reaction with γ-aminopropyltriethoxysilane, which were easily protonated in HCl medium. Multisweep cyclic voltammograms of clay-film modified glassy carbon electrodes made of either the raw clays or the propylammonium-functionalized samples exposed to Ru(NH₃)₆³⁺ or Fe(CN)₆³⁻ electroactive probes were obtained. The results indicated a permselective behavior of these clay and organoclay-films based on either favorable or unfavorable electrostatic interactions. The cation-exchanging raw clay film modified electrodes exhibited accumulation properties for Ru(NH₃)₆³⁺ species while rejecting Fe(CN)₆³⁻, whereas the anion-exchanging organoclay coatings acted as a barrier against Ru(NH₃)₆³⁺ while increasing dramatically the concentration of Fe(CN)₆³⁻ species at the electrode surface. Strong binding of the probe to the organoclays resulted in a potential shift of ca. 0.1 V of the voltammetric signals characteristic of the Fe(CN)₆^3−/4− couple in the anodic direction. Their good preconcentration efficiency at low analyte concentration highlighted their interest for electroanalytical applications.     

Effect of charge density,molecular weight,and hydrophobicity on polycations adsorption and flocculation of polystyrene latices and silica

Adsorption and flocculation behavior of two series of synthetic polycations was investigated in dispersions of silica and polystyrene latices with various particle size and surface charge densities. Polycations of the first series (polydiallyldimethyl ammonium chloride‐PDADMAC) varied in molecular weight only, while polycations of the second series (derivatives of polymethacrylic acid) varied in both molecular weight and hydrophobicity. We have found that maximum adsorbed amount of high molecular weight PDADMAC on latex particles was nearly independent of the surface charge density when the particle size was comparable to the polymer coil dimensions in solution. Both low and high molecular weight PDADMACs were efficient flocculants, although significantly lower amounts of high molecular weight polyelectrolyte were required for the phase separation in the dispersions due to particles aggregation through “charge patch” mechanism. The increase of polymer hydrophobicity leads to higher adsorbed amounts and broadening of flocculation window by polycations of the second series on both substrates. However, no strong enhancement of segment–surface interactions on hydrophobic substrates was observed. Since formation of multilayers upon adsorption was also excluded, the difference in adsorption and flocculation behavior was related to the more compact conformation of hydrophobically associating derivatives in solution and at the interface. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3422–3429, 2006     

CaSO_4晶须对聚氨酯胶粘剂性能影响的研究

用实验室自制的相对分子质量为2500的聚己二酸-1,4-丁二醇酯二醇和甲苯二异氰酸酯、混合扩链剂配制聚氨酯胶粘剂,并使用实验室自制的改性和未改性200nm硫酸钙晶须对聚氨酯胶粘剂进行改性,考察不同硫酸钙晶须及其加入量、加入方式对聚氨酯胶粘剂综合力学性能的影响。根据实验结果,200nm改性硫酸钙晶须当加入量为3％时,聚氨酯胶粘剂的拉伸强度、初粘性和最终剥离强度均有明显提高。     

氯霉素在聚茜素红薄膜修饰电极上的伏安行为及其测定

研究了聚茜素红薄膜修饰电极(PARE)对氯霉素(Chloramphenicol,CAP)的电催化作用,并应用于对微量CAP的定量检测。实验结果表明:在0.010mol/LHCl+1.0×10-4mol/LCu2++0.10mol/LNaCl测定体系中,CAP的浓度在1.0×10-9mol/L～1.0×10-8mol/L范围内与它的氧化峰电流呈良好的线性关系,线性方程和线性相关系数分别为:ip(μA)=-0.188×10-8CCAP(mol/L)-7.62,γ=0.9997,检出限可达5.0×10-10mol/L。CAP的标准回收率为95.9%~102.9%,八次平行样品测定结果的相对标准偏差3.2%。