高性能环氧树脂涂料的研制

以甲基丙烯酸、丙烯酸丁酯及苯乙烯的聚合为接枝体，在过氧化苯甲酰作用下对E-51环氧树脂进行接枝改性，同时对三乙烯四胺进行曼尼希改性，制得多种改性固化剂，并用其与改性的环氧树脂配制成涂料，实验结果表明，当苯酚、甲醛和三乙烯四胺的物质的量比为3：3：1时固化剂的固化性能最好。     

Study of stability of high‐temperature polyimides using TG/MS technique

The oxidative stability of the carbon fiber‐reinforced composite of polyimide was examined, in real time, using the evolved gas analysis techniques. Off‐gas degradation products suggested the onset temperature for chain scissions to be fairly low at about 190–220°C. Based on the off‐gas products present and the trend of their release, the composite degradation mechanism appeared to be similar between 190 and 371°C, thereby marking 371°C to be the highest accelerated aging temperature for its long‐term lifetime prediction. Beyond 371°C, different degradation mechanisms would apply. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1219–1227, 2002     

Elucidation of the miniemulsion stabilization mechanism and polymerization kinetics

Styrene/hexadecane miniemulsions were polymerized at 50°C using a redox initiator. The miniemulsions and their corresponding latexes were characterized in terms of size, polymerization rate, and surface properties. The resulting data were analyzed to elucidate the miniemulsion stabilization and polymerization mechanisms. It was found that the free surfactant concentration exceeded the critical micelle concentration when large amounts of surfactant (60 mM sodium lauryl sulfate) were used, resulting in simultaneous micellar and droplet nucleation. Most surfactant was on the surface of the droplets (85%) or particles (95%). The fractional surface coverage was proportional to the surfactant concentration to the 0.55 power. Using a particle diameter equation, the number of particles was calculated to be proportional to the surfactant concentration to the 1.35 power. Through direct particle size measurements, a power of 1.38 was confirmed. The rate of polymerization was determined by reaction calorimetry to be proportional to the number of particles to the 0.59 power, in contrast to classical Smith–Ewart kinetics for conventional emulsions (1.0 power). The average number of radicals per particle was estimated from the rate and number data, and varied with the particle diameter to the 0.97 power. The observed kinetic dependencies were validated through an extension of Smith–Ewart theory. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3987–3993, 2003     

Effect of solution properties on nanofibrous structure of electrospun poly(lactic‐co‐glycolic acid)

Electrospinning of poly(lactic‐co‐glycolic acid) (PLGA) in chloroform or 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP) was investigated, focusing on its solution parameters, to develop nonwoven biodegradable nanofibrous structures for tissue engineering. PLGA nanofibers were obtained by electrospinning of 15 wt % PLGA solution and the resulting average fiber diameters were varied with the range of 270–760 nm, depending on solution property. When small amounts of benzyl triethylammonium chloride (BTEAC) was added to the PLGA/chloroform solution, the average diameter was decreased from 760 to 450 nm and the fibers were densely amounted in a straight shape. In addition, the average fiber diameter (270 nm) of nanofibers electrospun from polar HFIP solvent was much smaller than that (760 nm) of nanofibers electrospun from nonpolar chloroform solvent. Therefore, it could be concluded that conductivity or dielectric constant of the PLGA solution was a major parameter affecting the morphology and diameter of the electrospun PLGA fibers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1214–1221, 2006     

铵盐体系香波泡沫性能的研究

研究了两种铵盐型阴离子表面活性剂与烷基单乙醇酰胺、烷基二乙醇酰胺等复配体系在不同水硬度条件下的泡沫性能 ;考察了乳化硅油、羊毛脂、十八醇、珠光剂、香精、阳离子表面活性剂及聚合阳离子化合物等添加剂在香波体系中不同水硬度条件下对发泡性能的影响。实验条件下所有体系的稳泡性均较好 ,LSA与AESA复配后泡沫力增大 ,其中AE SA含量需 <1 0 % ;含烷基单乙醇酰胺香波体系的泡沫性能优于含烷基二乙醇酰胺的 ;羊毛脂和乳化硅油对香波泡沫的影响较大 ,而其它添加剂对香波泡沫的影响不大。     

Surface modification of a biomedical poly(ester)urethane by several low‐powered gas plasmas

Several low‐powered gas plasmas were employed to treat a biomedical poly(ester)urethane using the treatment gases of CO₂, O₂, NH₃, and SO₂ with different treatment time (2, 5, 10, and 15 min). The changes of the physical and chemical characteristics of the biopolymer surface were studied. Surface morphology was evaluated by scanning probe microscopy, which showed increased roughness of the surface after plasma treatment. The wettability of the surface was examined by static water contact angle (SCA) measurements, which presented that there was a decrease of SCA in all plasma treatments compared with the untreated surface and that each gas plasma had an optimum treatment time accompanied by a minimum contact angle. X‐ray photoelectron spectroscopy indicated the changes of the surface functional groups. The data demonstrated that CO₂ and O₂ plasmas resulted in the incorporation of oxygen‐containing groups, while NH₃ plasma resulted in the combination of nitrogen‐containing groups, and SO₂ plasma resulted in the formation of sulfur‐containing groups. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1273–1282, 2006     

Vero细胞蛋白过敏原性研究

目的　研究Vero细胞蛋白的过敏原性。方法　取不同剂量Vero细胞宿主细胞蛋白和裂解蛋白致敏豚鼠 ,隔日 1次 ,共 3次 ,每组 3只 ,以牛血清及生理盐水分别为阳性及阴性对照 ,末次致敏后 2 1d攻击 ,并观察攻击后的反应。结果　攻击后 30min ,10 0ng 只以上剂量组均出现过敏反应 ,且反应强度与剂量呈正相关。 2 4h各剂量组过敏反应的恢复情况各不相同。结论　Vero细胞宿主细胞蛋白及裂解蛋白均可以引起过敏反应 ,裂解蛋白的反应强度高于宿主细胞蛋白。     

新型阻垢剂IA-SSS-MA聚合物的合成与表征

以衣康酸(IA)、苯乙烯磺酸钠(SSS)和马来酸酐(MA)为单体,以水为溶剂,过硫酸铵作引发剂,合成了衣康酸-苯乙烯磺酸钠-马来酸酐(IA-SSS-MA)三元聚合物阻垢剂,考察了单体配比、反应温度、引发剂量、滴加时间等对聚合物阻碳酸钙垢效果的影响,结果表明:当单体配比为IA∶SSS∶MA=5∶1∶0.25(摩尔比),反应温度100℃,引发剂量占单体总量13%,滴加时间为5 h,阻碳酸钙垢效果最好,阻垢率达到98.11%。     

重组人白细胞介素-10在大肠杆菌中的表达及生物学活性分析

目的在大肠杆菌中表达重组人白细胞介素-10(Interleukin-10,IL-10),并检测其生物学活性。方法将IL-10基因重组到质粒pET11c中,转化BL21(DE),提取质粒,经酶切鉴定和测序分析;在25℃用低浓度的IPTG诱导表达,对包涵体IL-10稀释复性;经ELISA检测其含量,MC/9细胞增殖法检测其生物学活性。结果工程菌IL-10/pET11c/BL21诱导表达的目的蛋白以可溶性和包涵体两种形式存在,Westernblot鉴定证实为IL-10蛋白,两种形式的IL-10均具有一定的生物学活性。结论已成功地在大肠杆菌中表达了IL-10,为进一步纯化和制备IL-10的基因工程药物打下了基础。     

Spectroscopic studies of copper, silver and gold-metallothioneins

Metallothionein is a ubiquitous protein with a wide range of proposed physiological roles, including the transport, storage and detoxification of essential and nonessential trace metals. The amino acid sequence of isoform 2a of rabbit liver metallothionein, the isoform used in our spectroscopic studies, includes 20 cysteinyl groups out of 62 amino acids. Metallothioneins in general represent an impressive chelating agent for a wide range of metals. Structural studies carried out by a number of research groups (using (1)H and (113)Cd NMR, X-ray crystallography, more recently EXAFS, as well as optical spectroscopy) have established that there are three structural motifs for metal binding to mammalian metallothioneins. These three structures are defined by metal to protein stoichiometric ratios, which we believe specifically determine the coordination geometry adopted by the metal in the metal binding site at that metal to protein molar ratio. Tetrahedral geometry is associated with the thiolate coordination of the metals in the M(7)-MT species, for M = Zn(II), Cd(II), and possibly also Hg(II), trigonal coordination is proposed in the M(11-12)-MT species, for M = Ag(I), Cu(I), and possibly also Hg(II), and digonal coordination is proposed for the metal in the M(17-18)-MT species for M = Hg(II), and Ag(I). The M(7)-MT species has been completely characterized for M = Cd(II) and Zn(II). (113)Cd NMR spectroscopic and x-ray crystallographic data show that mammalian Cd(7)-MT and Zn(7)-MT have a two domain structure, with metal-thiolate clusters of the form M(4)(S(cys))(11) (the alpha domain) and M(3)(S(cys))(9) (the beta domain). A similar two domain structure involving Cu(6)(S(cys))(11) (alpha) and Cu(6)(S(cys))(9) (beta) copper-thiolate clusters has been proposed for the Cu(12)-MT species. Copper-, silver- and gold-containing metallothioneins luminesce in the 500-600 nm region from excited triplet, metal-based states that are populated by absorption into the 260-300 nm region of the metal-thiolate charge transfer states. The luminescence spectrum provides a very sensitive probe of the metal-thiolate cluster structures that form when Ag(I), Au(I), and Cu(I) are added to metallothionein. CD spectroscopy has been used in our laboratory to probe the formation of species that exhibit well-defined three-dimensional structures. Saturation of the optical signals during titrations of MT with Cu(I) or Ag(I) clearly show formation of unique metal-thiolate structures at specific metal:protein ratios. However, we have proposed that these M=7, 12 and 18 structures form within a continuum of stoichiometries. Compounds prepared at these specific molar ratios have been examined by X-ray Absorption Spectroscopy (XAS) and bond lengths have been determined for the metal-thiolate clusters through the EXAFS technique. The stoichiometric ratio data from the optical experiments and the bond lengths from the XAS experiments are used to propose structures for the metal-thiolate binding site with reference to known inorganic metal-thiolate compounds.