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101.
Poly(butylene naphthalate) (PBN), poly(diethylene naphthalate) (PDEN), and poly(thiodiethylene naphthalate) (PTDEN) were synthesized and characterized in terms of chemical structure and molecular weight. The polyesters were examined by TGA, DSC, and DMTA. All the polymers showed a good thermal stability, even though depending on chemical structure. At room temperature they appeared as semicrystalline materials; the effect of the introduction along the PBN polymer chain of ether oxygen atoms or sulfur ones was a lowering in the Tg value, a decrement of Tm, and a decrease of the crystallization rate. Changing in chemical structure also affects the main α absorption associated with the glass transition which moves to lower temperature and whose energetic requirements decrease. The results were explained as due to the presence of highly flexible C? S? C or C? O? C bonds in the polymeric chain. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1694–1703, 2007  相似文献   
102.
Poly(D ,L ‐lactide) and poly(D ,L ‐lactide‐co‐glycolide) with various composition and with one methacrylate and one carboxylate end group were synthesized and grafted onto poly(vinyl alcohol) (PVA) via the carboxylate group. The graft copolymers were crosslinked via the methacrylate groups using a free radical initiator. The polymer networks were characterized by means of NMR and studied qualitatively by means of IR spectroscopy. The influence of the glycolide content in the polyester grafts and of the number of ester units in the grafts on thermal properties and swellability were studied as well. The high swellability in water is characteristic of all hydrogels. Differential scanning calorimetry (DSC) showed a single glass transition temperature that occurs in the range between 51 and 69 °C. Thermogravimetric analysis (TGA) of the networks showed the main loss in weight in the temperature range between 290 and 370 °C. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4536–4544, 2007  相似文献   
103.
医疗和危险废物高温洁净热处理及环境力学   总被引:3,自引:0,他引:3  
结合2003年中国的突发危害公众健康的事件,分析了医疗、化学战剂及危险废物的分类、特性,比较了各种高温热处理技术的基本要求,方法分类和设备特点,包括:各类焚烧炉、热解炉和等离子体裂解装置.还对前处理工艺要求,尾气处理工艺等进行了分析讨论,讨论了防止二次污染的技术手段,特别介绍了二噁英等高危险性产物的特性.还介绍了发达国家的医疗废物和危险废物的管理、处置和二次污染防治等情况.  相似文献   
104.
A novel epoxy system was developed through the in situ curing of bisphenol A type epoxy and 4,4′‐diaminodiphenylmethane with the sol–gel reaction of a phosphorus‐containing trimethoxysilane (DOPO–GPTMS), which was prepared from the reaction of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) with 3‐glycidoxypropyltrimethoxysilane (GPTMS). The preparation of DOPO–GPTMS was confirmed with Fourier transform infrared, 1H and 31P NMR, and elemental analysis. The resulting organic–inorganic hybrid epoxy resins exhibited a high glass‐transition temperature (167 °C), good thermal stability over 320 °C, and a high limited oxygen index of 28.5. The synergism of phosphorus and silicon on flame retardance was observed. Moreover, the kinetics of the thermal oxidative degradation of the hybrid epoxy resins were studied. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2354–2367, 2003  相似文献   
105.
Using the thermodynamical approach and the method of York, the back-reaction of anti-de Sitter Schwarzschild black hole in thermal equilibrium with conformal spin-2 field is studied. It is found that both approaches give identical results.  相似文献   
106.
超分子有机薄膜   总被引:1,自引:0,他引:1  
李亚军 《发光学报》2003,24(1):I001-I002
利用超分子有机薄膜技术能制成新的传感分子电子器件、光学器件和生物分子器件等,受到跨学科高技术研究领域的重视。本文描述了超分子有机薄膜的制备方法以及在各应用领域的研究状况。重点介绍了我们研究组在近20年工作中,利用LB膜技术,在光电器件、气体传感技术和光学非线性,特别是在生物传感技术方面的研究成果。按照生物体系提供的信息,模拟合成功能分子,建造有组织的分子组装体,以便用来研究依赖于分子排列的生物物理化学效应。  相似文献   
107.
潜热型热功能流体强化换热分析   总被引:4,自引:0,他引:4  
本文建立了分析带有相变微胶囊的潜热型热功能流体的流动和换热过程数理模型,应用有限差分法和移动热源法进行联合求解。计算结果表明,相变微胶囊的加入:较好地提高了流体的换热性能。获得了相变颗粒大小和体积分数对强化换热影响等结果。计算结果对该类流体的设计和应用提供了理论依据。  相似文献   
108.
Cardanol-based novolac-type phenolic resins were synthesized with different mole ratios of cardanol-to-formaldehyde, viz., 1:0.6, 1:0.7, and 1:0.8. These novolac resins were epoxidized with molar excess of epichlorohydrin at 120 °C in basic medium. The epoxidized novolac resins were, separately, blended with different weight ratios of carboxyl-terminated polybutadiene liquid rubber ranging between 0-25 wt% with an interval of 5 wt%. All the blends were cured at 150 °C with 40 wt% polyamide. The formation of various products during the curing of blend samples has been studied by Fourier-transform infra-red spectroscopic analysis. The tensile strength and elongation-at-break of the cured samples increased up to 15 wt% in the blend and decreased thereafter. This blend sample was also found to be most thermally stable system. The blend morphology, studied by scanning electron microscopy analysis, was finally correlated with the structural and property changes in the blends.  相似文献   
109.
光电变色器件用纳米晶氧化钛薄膜的微结构与特性   总被引:2,自引:2,他引:0  
唐洁影  张旭苹  孟莉莉 《光学学报》2003,23(12):502-1506
纳米晶TiO2薄膜在光电变色器件中具有很重要的作用。它的微结构直接影响染料的吸附、光的散射以及电荷输运的特性。因此,探索TiO2薄膜的微结构(如粒径、表面形貌和厚度等)及光电性能是非常有意义的。采用电子束蒸发工艺制备了光电变色器件用纳晶TiO2薄膜,利用原子力显微镜、X射线衍射、俄歇电子能谱等手段对纳米晶TiO2薄膜的表面形貌、结晶状态及组分进行了分析。从理论上研究和讨论了纳米晶TiO2薄膜晶粒尺寸对光电性能的影响,并用量子限制效应解释了吸收光谱峰值波长随粒径减小而发生蓝移的现象。  相似文献   
110.
ABA block copolymers of methyl methacrylate and methylphenylsilane were synthesized with a methodology based on atom transfer radical polymerization (ATRP). The reaction of samples of α,ω‐dihalopoly(methylphenylsilane) with 2‐hydroxyethyl‐2‐methyl‐2‐bromoproprionate gave suitable macroinitiators for the ATRP of methyl methacrylate. The latter procedure was carried out at 95 °C in a xylene solution with CuBr and 2,2‐bipyridine as the initiating system. The rate of the polymerization was first‐order with respect to monomer conversion. The block copolymers were characterized with 1H NMR and 13C NMR spectroscopy and size exclusion chromatography, and differential scanning calorimetry was used to obtain preliminary evidence of phase separation in the copolymer products. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 30–40, 2003  相似文献   
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