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101.
Seong Ik Yoo Tae Yeon Lee Jin‐San Yoon Ik‐Mo Lee Mal‐Nam Kim Han Sup Lee 《应用聚合物科学杂志》2002,83(4):767-776
The interfacial reaction of the polyethylene (PE)/starch blend system containing the reactive compatibilizer maleated polyethylene (m‐PE) was directly characterized by Fourier transform infrared (FTIR) spectroscopy. A significant amount of anhydride groups on m‐PE existed as hydrolyzed forms, resulting in a large amount of carboxyl groups. Using a vacuum‐heating‐cell designed in the laboratory, the carboxyl groups were successfully transformed into the dehydrolyzed state (i.e., anhydride group). This result enabled the direct spectroscopic observation of chemical reaction occurring at the interface. For the PE/starch blend system containing m‐PE, the chemical reaction at the interface was verified by the evolution of ester and carboxyl groups in the FTIR spectra. The effect of the reactive compatibilizer on the interfacial morphology was also examined by scanning electron micrography (SEM). Enhanced interfacial adhesion was clearly observed for the blend system containing reactive compatibilizer. Tensile strengths of blend systems containing m‐PE also increased noticeably compared with the corresponding system without compatibilizer. A similar observation was made for the breaking elongation data. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 767–776, 2002 相似文献
102.
Novel monomers 1a, 1b, in which a phosphonate function is incorporated in both aromatic rings, were synthesized from the addition reaction of tetraisopropyl [2,2′-disulfanyl-5,5′-thiodiphenyl]-1,1′-diphosphonate and diisopropyl (2-sulfanylphenyl)-1-phosphonate with the glycidylmethacrylate. Free radical homo- and copolymerizations of phosphonate monomers containing methacrylate groups were first carried out in bulk and in THF solution. They offered (co)polymers for potential use in dental resins, in high yields and moderate to high inherent viscosities. The components and structure of the (co)polymers were confirmed by FTIR, SEC, 1H, 31P NMR spectra.
Thermal analysis by using differential scanning calorimetry indicated an amorphous structure of the (co)polymers obtained by polymerization in solution. Upon UV-radiation the composite resins have been synthesized by cross-linking reaction. 相似文献
103.
扩展阴极法处理含铜废水的研究 总被引:1,自引:0,他引:1
采用扩展阴极法对酸性稀溶液中Cu2+的回收处理进行了研究。结果表明:扩展阴极法与常规的板式电解法相比,去除率提高了38%,能耗降低了20%,电解废水的pH值适用范围在1~4之间,且处理废水量大。 相似文献
104.
Jean-Pierre Montheard Bernard Boinon Ahmed Belfkira Abderahim Sadel Quang-Tho Pham 《Polymer Bulletin》1992,28(6):615-620
Summary Vinylidene cyanide has been copolymerized in solution by radical reaction with equal initial mole fraction of para substituted acetoxystyrenes. The copolymers have been characterized by means of DSC, TGA and GPC. These products are stable up to 220° and have no visible glass transition temperature. The microstructure of these new copolymers has been studied by 13CNMR; they have an alternating structure and monomers units are arranged in head-to-tail placements. 相似文献
105.
FA and tocopherol composition of Vietnamese oilseeds 总被引:1,自引:0,他引:1
Bertrand?MatthausEmail author Klaus?Vosmann Long?Quoc?Pham Kurt?Aitzetmüller 《Journal of the American Oil Chemists' Society》2003,80(10):1013-1020
Seeds of 40 oilseed species from 23 different plant families (Brassicaceae, Cucurbitaceae, Fabaceae, Sapindaceae, Malvaceae,
Gnetaceae, Clusiaceae, Bruseraceae, Ranunculaceae, Convolvulaceae, Amaranthaceae, Tiliaceae, Basellaceae, Solanaceae, Umbelliferae,
Labiatae, Compositae, Theaceae, Euphorbiaceae, Caesalpiniaceae, Sapotaceae, Anacardiaceae, and Connaraceae) grown in Vietnam
were analyzed for oilseed oil content, FA, and vitamin E. The seed oil content varied between 0.2 g/100 g for Mangifera indica and 75.7 g/100 g for Calophyllum inophyllum, whereas only nine seeds contained more than 40% oil. The tocopherol content ranged from 26 (Sapindus mukorossi) to 9361 mg/kg (Litchi chinensis). In nine seed oils unusual FA such as conjugated, cyclopropenoic, or epoxy FA were found. 相似文献
106.
Gerhard Maier Vendula Knopfova Brigitte Voit Pham Huu Ly Bui Tien Dung Do Bich Thanh 《大分子材料与工程》2004,289(10):927-932
Summary: Segmented block copolymers, consisting of non‐polar soft segments from hydroxyl‐terminated liquid natural rubber (HTNR) and polar hard segments from α,ω‐diisocyanato telechelics obtained by “criss‐cross”‐cycloaddition, have been synthesized. The block copolymer formation took place under relatively mild reaction conditions at 80 °C in dichloroethane in the presence of dibutyltin dilaurate as a catalyst. The resulting block copolymers were characterized by spectroscopic techniques (1H NMR, FTIR, UV‐vis spectroscopy) as well as GPC for molar mass determination. The block copolymers were compression molded in a hot stage press, and the resulting samples were characterized by DSC and stress‐strain measurement. The solubility and phase morphology of the materials have also been studied.
107.
Chin‐San Wu 《应用聚合物科学杂志》2004,94(3):1000-1006
In the present study, the properties of polycaprolactone (PCL) and wood flour (WF) blends were examined by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), Instron mechanical tester, and scanning electron microscopy (SEM). As for results, the mechanical properties of PCL were lowered obviously, due to the poor compatibility between the two phases, when it was blended with wood flours. A fine dispersion and homogeneity of wood flour in the polymer matrix could be obtained when the acrylic acid grafted PCL (PCL‐g‐AA) was used to replace PCL for manufacture of blends. This better dispersion is due to the formation of branched and crosslinked macromolecules since the PCL‐g‐AA copolymer had carboxyl groups to react with the hydroxyls. This is reflected in the mechanical and thermal properties of the blends. In comparison with pure PCL/WF blend, the increase in tensile strength at break was remarkable for PCL‐g‐AA/WF blend. The PCL‐g‐AA/WF blends are more easily processed than the PCL/WF ones since the former had lower melt viscosity than the latter. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1000–1006, 2004 相似文献
108.
Laurie Pesant Joseph Matta Cuong Pham-Huu François Garin Pierre Bernhardt Charlotte Pham Marc-Jacques Ledoux 《Topics in Catalysis》2004,(1):281-286
Platinum catalyst supported on a medium surface area -SiC was successfully used for the catalytic combustion of model carbon particles and compared to a catalyst supported on a low surface area -SiC. The -SiC-based catalyst showed no deactivation as a function of cycling tests while a strong deactivation was observed on the -SiC-based catalyst. This deactivation was attributed to the progressive encapsulation of the platinum particles by a layer of silica which built up during the combustion cycle. These results render possible the use of Pt/-SiC catalyst as a diesel carbon particle catalytic filter with continuous regeneration. 相似文献
109.
Formation and Accumulation of Intragranular Pores in the Hydrothermally Synthesized Barium Titanate Nanoparticles 下载免费PDF全文
Changyeon Baek Ji Eun Wang San Moon Chang‐Hak Choi Do Kyung Kim 《Journal of the American Ceramic Society》2016,99(11):3802-3808
As highly integrated circuits are demanded for high‐performance electric devices, small sizes of barium titanate (BaTiO3) as a dielectric material are desirable for the application of multilayer ceramic capacitors. Since the small sizes of the particles degrade the dielectric property, especially below a certain critical size, understanding the probable cause is significant for the high‐performance capacitors. Here, we have demonstrated nanosized BaTiO3 with average size below 30 nm and a uniform size distribution. High‐resolution transmission electron microscopy (TEM) shows that the as‐synthesized BaTiO3 contains intragranular pores. We have analyzed the correlation between the intragranular pores inside nanoparticles and their phase ratio of cubic and tetragonal. We have found that the presence of the intragranular pores affects low tetragonality of BaTiO3 particles, and the intragranular pores are generated by the accumulation of hydroxyl groups during hydrothermal reaction. Formation and accumulation of intragranular pores have been investigated by ex‐situ synchrotron X‐ray diffraction and TEM analysis, suggesting the phase evolution model of nanosized BaTiO3. 相似文献
110.
晶体的颗粒尺寸分布和形状是结晶产品的两个关键质量指标,不仅影响结晶产品的性质,还影响下游的过滤、干燥及运输存储等过程。利用超声粒度分析仪、衰减全反射傅里叶红外光谱仪、浊度仪与二维成像系统等分析仪器在线测量了不同搅拌速率和不同降温速率下阿司匹林乙醇溶液结晶过程中温度、浓度、颗粒尺寸分布和形状的变化情况。实验结果表明:较低的降温速率或者较大的搅拌速率条件下得到含有大量细晶的阿司匹林结晶产品;较高的降温速率下得到长宽比较大的阿司匹林结晶产品。调节降温速率和搅拌速率是一种有效控制阿司匹林结晶产品尺寸分布与形状的方法。 相似文献