高纯度番茄红素的制备

番茄酱需要经过预处理后才能用于制备高纯度的番茄红素。该文详细考察了预处理各因素对番茄红素提取率和纯度的影响,确定了制备高纯度番茄红素的最优工艺为:取100 g番茄酱,加入200 mLc(Na2CO3)=0.5mol/L的水溶液于40℃皂化30 m in,然后用稀硫酸将皂化液中和起泡至pH=4~5。离心分离,得到的固体部分用100 mLw(C2H5OH)=95%的乙醇处理10 m in后,用有机溶剂进行提取。提取液在低温下结晶,制得的番茄红素质量分数达到了95%,整个过程的提取率为79%。     

粘度法测定植物纤维素的聚合度

介绍了以饱和氢氧化铜的乙二胺溶液(CED)为溶剂,通过测定CED溶液和一定浓度的植物纤维素-CED溶液在粘度计毛细管中的流出时间,利用Martin公式计算出试样特性粘数后,由Mark方程计算植物纤维素的聚合度的方法。利用该方法测得的纤维素棉浆粕的平均聚合度为546-556;该法使用的仪器简单,且准确度较高,相对误差小于1．5％。     

Conductive coating films based on low density In2O3 powders and polymer latexes

Several kinds of conductive coating films were prepared from a low-density indium(III) oxide powder (which was employed because it provides a much higher volume for the same weight) and polymer latexes. The low-density In₂O₃, which is an electrically conductive pigment, was prepared by pyrolysis followed by the combustion of water-swellable polymer microspheres imbibed with In(NO₃)₃, the precursor of In₂O₃. Either acrylamide/N,N'-methylenebisacrylamide or poly(vinylalcohol)/glutaricdialdehyde was used to generate spherical hydrogel particles. The polymer latexes with which the In₂O₃ was mixed had a soft core and a hard shell structure to ensure that the coating film has suitable mechanical properties in addition to conductivity. Acrylonitrile/butadiene/styrene copolymer ABS or acrylonitrile/butylacrylate/styrene copolymer ABAS latexes were used as binders for the conductive pigment. The powder coating followed by hot pressing, the water-borne coating consisting of low-density In₂O₃ and polymer latexes followed by curing, or the colloidal dispersion coating was used to deposit flexible conductive coating films on polyester sheets. The conductive pigment density and the polymer latexes' size and flowability are the factors that affect the characteristics of the film. We found that the colloidal suspension coating procedure based on ABAS latexes achieves better electrical and mechanical properties for the coating films. © 1996 John Wiley & Sons, Inc.     

Comparative study by computed radiography,histology, and scanning electron microscopy of the articular cartilage of normal goats and in chronic infection with caprine arthritis‐encephalitis virus

In the northeast of Brazil, caprine arthritis‐encephalitis (CAE) is one of the key reasons for herd productivity decreasing that result in considerable economic losses. A comparative study was carried out using computed radiography (CR), histological analysis (HA), and scanning electronic microscopy (SEM) of the joints of CAE infected and normal goats. Humerus head surface of positive animals presented reduced joint space, increased bone density, and signs of degenerative joint disease (DJD). The carpal joint presented no morphological alterations in CR in any of the animals studied. Tarsus joint was the most affected, characterized by severe DJD, absence of joint space, increased periarticular soft tissue density, edema, and bone sclerosis. Histological analysis showed chronic tissue lesions, complete loss of the surface zone, absence of proteoglycans in the transition and radial zones and destruction of the cartilage surface in the CAE positive animals. Analysis by SEM showed ulcerated lesions with irregular and folded patterns on the joint surface that distinguished the limits between areas of normal and affected cartilage. The morphological study of the joints of normal and CAE positive goats deepened understanding of the alteration in the tissue bioarchitecture of the most affected joints. The SEM finding sustained previous histological reports, similar to those found for rheumatoid arthritis, suggesting that the goat infected with CAE can be considered as a potential model for research in this area. Microsc. Res. Tech. 77:11–16, 2014. © 2013 Wiley Periodicals, Inc.     

1-戊基-3-甲基咪唑类离子液体的合成

以1-氯戊烷和N-甲基咪唑为原料合成了室温离子液体1-戊基-3-甲基咪唑四氟硼酸盐(PMIMBF4)和六氟磷酸盐(PMIMPF6),通过考察各种影响因素对中间产物氯代咪唑盐(PMIMCl)的影响得出合成1-戊基3-甲基咪唑离子液体的最佳条件为:原料N-甲基咪唑与1-氯戊烷的投料比为1.2∶1,反应温度为70-75℃,反应时间为24 h。最终产物的收率为92%-94%。产物结构用FT-IR和1HNMR光谱进行表征。     

The concentrated emulsion approach to toughened polymer composites: A review

A series of tough polymers were prepared by combining flexible with rigid chains, using the method of concentrated emulsion polymerization. The tough materials obtained can be classified into four types: [a] those prepared via the polymerization of a monomer containing a dissolved elastomer, starting from its concentrated emulsion in water; [b] those prepared via heterogeneous (interfacial) crosslinking of two partially polymerized concentrated emulsion in water containing incipient latexes; [c] those prepared as semi-interpenetrating or AB network latexes, starting from a concentrated emulsion in water and [d] those prepared by mixing two partially polymerized concentrated emulsions and completing the polymerization. A concentrated emulsion differs from the conventional emulsion in that the volume fraction of the dispersed phase is higher than that of the most compact arrangement of monosize spheres (0.74) and can be as high as 0.99. The cells of a highly concentrated emulsion are no longer spherical, but polyhedral in shape, compactly packed and separated by thin films of continuous phase. As a result of such structure, a high polymerization rate and a high molecular weight can be achieved, the size (in the colloidal range) of the flexible phase can be controlled and the latter phase can be uniformly dispersed in the rigid one. Consequently, the concentrated emulsion method constitutes a suitable pathway to toughened composites. Owing to the compact packing of cells, the concentrated emulsion polymerization method is particularly suitable for cases in which reactions occur at the cell interface. For the materials of type [d], these reactions generate quasi-block copolymers, which compatibilize (via “auto-compatibilization”) the components of blends.     

Polyethylene‐Palygorskite nanocomposite prepared via in situ coordinated polymerization

A polyethylene/palygorskite nano‐composite (IPC composite) was prepared via an in‐situ coordinated polymerization method, using TiCl₄ supported on palygorskite fibers as catalyst and alkyl aluminum as co‐catalyst. These composites were compared with those prepared by melt blending (MBC composites). It was found that in the IPC composites, nano‐size fibers of palygorskite were uniformly dispersed in the polyethylene matrix. In contrast, in the MBC composites, the palygorskite was dispersed as large clusters of fibers. Regarding the mechanical properties of the IPCs, the tensile modulus increased and the elongation at break decreased with increasing fiber content, while the tensile strength passed through a maximum. The tensile strength and elongation at break were much smaller for the MBC composites. The final degree of crystallinity of the IPC composites decreased with increasing palygorskite content. Regarding the kinetics of crystallization, the ratio between the degree of crystallinity at a given time and the final one was a universal function of time. It was found that large amouns of gel were present in the IPC composites and much smaller amountes in the MBC composites.     

Synthesis and characterisation of antioxidant‐modified esters of dipentaerythritol as lubricating base oil

In this paper, five antioxidant‐modified esters were synthesised through two steps of simple esterification. Antioxidant‐modified multi‐hydroxyl compound was synthesised at the first step, and antioxidant‐modified esters were synthesised at the second step. This kind of esters is useful in many fields, such as lubricating oil and cutting compound, because of two important functions (antioxidant and lubricant) in the same compound. The active antioxidant group attached to these esters was 3‐(3,5‐di‐tert‐butyl‐4‐hydroxy‐phenyl)‐propionic acid. The esters were characterised with Fourier transform infrared spectroscopy (FTIR) and thermogravimetric (TG) analysis. The analytical results of FTIR demonstrates the changes of alcoholic hydroxyl and carboxyl and suggests that this synthesis was feasible. The TG analysis and rotating pressure vessel method show that this kind of esters has excellent oxidative stability. The physical properties of lubricating base oil, such as viscosity, viscosity index, pour point and flash point, suggested that this kind of esters can be used as lubricating base oil. Copyright © 2012 John Wiley & Sons, Ltd.