配合物Zn(Him)2(OAc)2的室温固相合成及表征

乙酸锌与咪唑 (Him)通过室温固相反应一步合成配合物Zn(Him) 2 (OAc) 2 ,反应不需溶剂 ,2 0min即可完成 ,产率达 96% ,并用元素分析、红外光谱、热重分析、X -射线粉末衍射和X -射线单晶衍射对产物进行了表征。     

浅析聚乙烯醇缩丁醛的低温流动性

瓷用花纸行业就PUB低温流动性提出更高要求。对此，就影响PUB低温流动性因素进行了分析探讨。     

百菌清及其三氟衍生物对番茄早疫病菌的室内抑菌活性比较

采用生长速率法测定了不同浓度的百菌清及其三氟衍生物对番茄早疫病菌Alternaria solani(Ell,et Mart.)Jones es Gmut的室内杀菌毒力。试验结果表明，百菌清及其三氟衍生物的ED50值分别为6089．89mg／L和156．43mg/L。，前者是后者的38．93倍。百菌清三氟衍生物的毒力明显高于百菌清。     

二氨基乙腈及三胺的合成及表征

利用加成反应合成了两种新化合物二 ( 2 -腈基乙基 )氨基乙腈及三 ( 2 -腈基乙基 )胺 ,用红外光谱、1 H -NMR核磁共振谱、元素分析、ES -MS质谱及热重分析对其结构和热性质进行了表征。结果证实所制备的两种化合物即为目标化合物 ,这两种化合物热性质相似 ,在 30 0℃以下具有较好的热稳定性。     

CO气氛中液相催化COS水解活性的研究

在鼓泡反应器中，采用液相催化剂，对高浓度CO气氛中高浓度COS的水解反应进行考察，研究催化剂浓度、气液体积比、温度的变化对COS水解转化率及催化体系稳定性的影响，得出最佳工艺条件，并对反应机理进行初步探讨。结果表明,COS水解转化率随气液体积比增大而降低，随催化剂浓度增大而升高；在常温、常压和气液体积比为150 h^－1的条件下，质量分数为10%的催化剂水溶液中COS的水解转化率可达100%，连续使用20 h转化率不变。     

Characterization of the thermal properties of PLA fibers by modulated differential scanning calorimetry

Polylactide (PLA) has been melt spun to produce multifilament continuous yarns. The thermal characteristics of PLA filaments have been investigated using modulated differential scanning calorimetry (MDSC). With MDSC, it is possible to separate the different thermal events and to analyze them more precisely. The influence of hot drawing on thermal properties of PLA filaments has been studied. Hot drawing promotes an increase of glass transition temperature (T_g) and a decrease of heat capacity. The cold crystallization spreads on a larger range of temperature and the peak occurs at a lower temperature. The initial degrees of cristallinity of PLA filaments have been calculated thanks to the reversing and non reversing curves of MDSC. Tensile properties of PLA filaments are also investigated.     

Studies on crystallization behaviors and crystal morphology of polyamide 66/clay nanocomposites

X‐ray diffraction methods, DSC thermal analysis, and polarized light microscopy (PLM) were used to investigate the structural changes of nylon 66/clay nanocomposites. PA 66/clay nanocomposites were prepared by the method of melt intercalation. The results indicate that the addition of the intercalated organo‐montmorillonite (OMMT) can induce generation of the β‐form crystal of PA 66 and substantially affect the arrangement of molecules in the α‐form crystal, although the crystallinity scarcely changes. Also, the DSC results indicate that the addition of OMMT in the PA 66 matrix leads to increases of crystallization temperatures and the full width at half maximum (FWHM) of the exothermic peaks. Moreover, the viscosity factor is the main influence on FWHM of the exothermic peaks of PA 66/clay nanocomposites. The results of nonisothermal crystallization kinetics show that OMMT has the effect of heterogeneous nucleation and leads to the decrease of the size of the spherocrystal. The heterogeneous nucleation effects of OMMTs influence the mechanism of crystallization and the growth mode of PA 66 crystals. PLM photographs verify that the size of spherocrystal is decreased and visually confirm the theory of crystallization kinetics. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 756–763, 2005     

Structural changes and mechanical performance of recycled poly(vinyl chloride) bottles exposed to ultraviolet light at 313 nm

The structural changes and mechanical performance of virgin poly(vinyl chloride) (PVC) bottle (VB) compounds blended with postconsumer PVC bottles collected from a specified factory (RB‐F) and houses (RB‐H), were examined before and after UV irradiation at 313‐nm UV wavelength for different periods of time up to 28 days. The results indicated that, when exposed to UV light, the RB‐F/VB blends containing greater conjugated double bonds with higher yellowness index appeared to exhibit better mechanical performance than that of the RB‐H/VB blends. It was found that the amount of conjugated double bonds was not a linear function of the discoloration level of PVC compounds. Tensile strength of the VB compounds was not affected when incorporated with RB‐F recyclate, but progressively decreased with increasing RB‐H recyclate. An optimum concentration for RB recyclates to be added into the virgin compound was recommended for obtaining a maximum impact strength. Both tensile and impact strengths decreased with increasing UV exposure time, a severe degradation being obvious after a UV exposure time of 21 days. Hardness was not affected significantly by the addition of PVC recyclate, but increased with increasing UV exposure time. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 84–94, 2004     

Embedding poly(styrene sulfonic acid) into PVDF matrix—a new type of proton electrolyte membrane

Hydrophilic polymer segments, consisting of styrene sulfonic acid (SSA) units, were uniformly embedded into hydrophobic poly(vinylidene fluoride) (PVDF) matrix through the mediation of poly(methyl methacrylate) (PMMA) segments, with which SSA segments form a copolymer. Discrete domains (∼100 nm) assembled by the SSA segments have been identified throughout the matrix of the membrane, which was prepared through blending of the copolymer P(MMA-SSA) and the PVDF. The thermal stability of the SSA was largely boosted in such hydrophobic environment. This unique matrix structure offers proton conductivity of as high as 10⁻³ S/cm at a low SSA equivalent (0.6 mmol -SO₃H/g of membrane), which is accompanied with a low level of water uptake (26%) at ambient temperature. Using this type of polymer membrane as electrolyte, the electrochemical cell possesses obvious capacitive resistance when the membrane is in the anhydride form according to the impedance analysis. However, the capacitive character vanishes when the membrane is hydrated; this response is attributed to the existence of highly dispersed SSA domains in the membrane. This work also analyzes the impedance spectra of the membranes at different hydrated states or with different SSA contents by using an equivalent electrical circuit.     

Chromatographic performance of monodisperse–macroporous particles produced by “modified seeded polymerization.” I: Effect of monomer/seed latex ratio

In this study, the monodisperse–macroporous particles produced by a relatively new polymerization protocol, the so‐called, “modified seeded polymerization,” were used as column‐packing material in the reversed phase chromatography (RPC) of proteins. The particles were synthesized in the form of styrene‐divinylbenzene copolymer approximately 7.5 μm in size. In the first stage of the synthesis, the monodisperse polystyrene particles 4.4 μm in size were obtained by dispersion polymerization and used as the “seed latex.” The seed particles were swollen by a low‐molecular‐weight organic agent and then by a monomer mixture. The monodisperse–macroporous particles were obtained by the polymerization of monomer mixture in the seed particles. In the proposed polymerization protocol, the number of successive swelling stages was reduced with respect to the present techniques by the use of sufficiently large particles with an appropriate average molecular weight as the seed latex. A series of particles with different porosity properties was obtained by varying the monomer/seed latex ratio. The separation behavior of HPLC columns including the produced particles as packing material was investigated in the RPC mode using a protein mixture including albumin, lysozyme, cytochrome c, and ribonuclease A. The chromatograms were obtained with different flow rates under an acetonitrile–water gradient. The theoretical plate number increased and chromatograms with higher resolutions were obtained with the particles produced by using a lower monomer/seed latex ratio. The separation ability of the column could be protected over a wide range of flow rates (i.e., 0.5–3 mL/min) with most of the materials tested. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 607–618, 2004