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Anuwat Saetung Adisai Rungvichaniwat Phathanyaphon Tsupphayakorn-ake Pornsuda Bannob Tulyapong Tulyapituk Nitinart Saetung 《Journal of Polymer Research》2016,23(12):264
A series of new waterborne polyurethanes (WPUs) was successfully prepared by the prepolymer process from the bio-renewable sources hydroxytelechelic natural rubber (HTNR with MW 3000 g mol?1) and hydroxylated rubber seed oil (HRSO), with DMPA fixed at 5.6 wt%. The effects of ratio of HTNR and HRSO (ranging from 1.00/0 to 0.10/0.90) and of hydroxyl value (OHV) of HRSO (200 or 270 mgKOH/g) on final properties were studied. It was found that the particle size of WPU increased significantly with both HRSO/HTNR ratio and OHV of HRSO. Chemical structure of the WPU films was confirmed by FT-IR. The water uptake, mechanical, dynamic mechanical properties and thermal stability of WPU film improved with both HRSO content and OHV of HRSO, while swelling in THF decreased. All these WPU films had similar Tg. This article reports novel green biobased WPU with promising applications as adhesive for shoe industries. 相似文献
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Pornsuda Bomlai Penprapa Sinsap Supasarute Muensit Steven J. Milne 《Journal of the American Ceramic Society》2008,91(2):624-627
Lead-free piezoelectric ceramics in the system 0.95Na0.5 K0.5 NbO3 –0.05LiTaO3 were modified with ≤1 mol% MnO. Maximum densities occurred at a sintering temperature of 1050°C. Characteristic changes in the relative intensity of X-ray diffraction peaks were consistent with Mn ions substituting on the perovskite lattice to produce a change from orthorhombic to a mixture of tetragonal and orthorhombic phases. Grain growth during secondary recrystallization was also affected, leading to increased grain sizes. The dielectric constant increased from ∼600 in unmodified ceramics to ∼1040 in ceramics prepared with 0.5 mol% MnO. 相似文献
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(1?x)Na0.47K0.47Li0.06NbO3 (NKLN)–xAgSbO3 lead-free piezoelectric ceramics were prepared using a reaction sintering method. The effects of AgSbO3 doping on the structural and electrical properties of NKLN ceramics sintered at 1000–1040 °C were studied. The dopant affected densification, phase content, sintering temperature, microstructure and electrical properties. Variations in the relative intensity of X-ray diffraction peaks were consistent with Ag+ and Sb5+ ions substituting on the perovskite lattice to produce a change in the proportions of co-existing tetragonal and orthorhombic phases. Grain growth during secondary re-crystallization was also affected. The temperature of the orthorhombic–tetragonal (O–T) phase transition and the Curie temperature (TC) decreased as a result of AgSbO3 modifications. The dielectric and piezoelectric properties are enhanced for the composition near the orthorhombic–tetragonal polymorphotropic phase boundary. The 0.92Na0.47K0.47Li0.06NbO3–0.08AgSbO3 ceramics exhibited optimum electrical properties (d33=252 pC/N, εr=1450, tan δ=0.02, and TC=280 °C). These results reveal that (1?x)Na0.47K0.47Li0.06NbO3–xAgSbO3 ceramics are promising materials for lead-free piezoelectric application. 相似文献
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Pornsuda Bomlai Sureewan Sukprasert Supasarote Muensit Steven J. Milne 《Journal of Materials Science》2008,43(18):6116-6121
Incorporation of LiSbO3 into the lead-free piezoceramic composition 0.95Na0.5K0.5NbO3–0.05LiTaO3 produced a change from an orthorhombic to tetragonal crystal system in samples produced by reaction-sintering. The inferred
limit of solid solution along the compositional join, (0.95 − x)Na0.5K0.5NbO3–0.05LiTaO3–xLiSbO3, occurred at x ~ 0.06. Differential scanning calorimetry indicated broad peaks at temperatures associated with ferroelectric–paraelectric
transitions. The transition temperatures decreased with increasing values of x, up to x = 0.06. Microstructures showed secondary grain growth; a slight decrease in grain-size with increasing LiSbO3 modification was identified. 相似文献
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P. Bomlai N. Sirikulrat A. Brown E. Condliffe S. J. Milne 《Journal of Materials Science》2007,42(6):2175-2180
The secondary phase compositions in Sb-doped (Ba, Sr)TiO3 ceramics containing SiO2 and excess TiO2 sintering additives have been examined by XRD, BEI and EPMA techniques. It is shown that alongside the primary (Ba0.797Sr0.2Sb0.003)TiO3 phase, (Ba1.95Sr0.05)2(Ti1.2Si1.8)O8 and Sb-doped (Ba0.99Sr0.01)6Ti17O40 phases form at the intergranular regions. Substitution of up to 0.04 mol% MnO2 enhances the PTCR effect, giving a ratio ρmax/ρmin ∼ 7 × 105 for the optimum 0.04% MnO2 composition. At this level Mn cannot be detected in the microstructure by EPMA, however in insulating samples containing
0.08 mol% of MnO2, it was detected in the (Ba0.99Sr0.01)6Ti17O40 intergranular phase. 相似文献
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Pornsuda Bomlai Pattraporn Wichianrat Supasarute Muensit Steven J. Milne 《Journal of the American Ceramic Society》2007,90(5):1650-1655
Sodium-potassium niobate [Na0.5 K0.5 NbO3 ] powders were prepared following the conventional mixed oxide method. An orthorhombic XRD pattern, consistent with single-phase Na0.5 K0.5 NbO3 , was obtained after calcination at 900°C for 6 h. Introducing 5 mol% excess Na2 CO3 and K2 CO3 into the starting mixture allowed milder calcination conditions to be used, for example 800°C for 2 h. Primary particles in 5 mol% excess samples were cuboid, with maximum sizes of ∼2.5 μm. Equiaxed 0.3–0.4-μm particles were formed for non-excess powders, and also for powders prepared with 1 and 3 mol% excess alkali carbonates. The results suggest liquid formation during calcination of the excess 5-mol% starting powders. 相似文献
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Napatporn Petnoi Pornsuda Bomlai Sukanda Jiansirisomboon Anucha Watcharapasorn 《Ceramics International》2013
Bismuth sodium titanate [(Bi0.5Na0.5)TiO3 or BNT] ceramics incorporated with 0, 1, 5, 10, 15 and 20 mol% niobium were prepared by conventional solid state reaction method. The green bodies were sintered at 1050 °C for 2 h to obtain dense ceramics. The effects of substitution of niobium ion for titanium ion in BNT ceramics on micro-structure and dielectric properties were investigated. X-ray diffraction analysis showed the presence of a secondary phase when more than 5 mol% niobium was added. Within the solubility limit, Nb doping caused the grain size of BNTNb to be smaller than the undoped sample. The investigation of the dielectric properties showed that the transition temperature (Tc) was found to shift towards lower temperature as the content of Nb increased. In this research, the donor-type behavior and induced charged defects had significant influence on the electrical properties of Nb-doped BNT ceramics. 相似文献
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Subhan Salaeh Nantakan Muensit Pornsuda Bomlai Charoen Nakason 《Journal of Materials Science》2011,46(6):1723-1731
Influence of different types of rubber and ceramic material on cure characteristics, mechanical, morphological, and dielectric
properties of natural rubber (NR) vulcanizate was studied. Two types of ferroelectric ceramic materials: barium titanate (BaTiO3) and lead titanate (PbTiO3) were prepared by solid-state reaction with calcinations at 1100 °C for 2 h. The ceramic powders were then characterized
by X-ray diffraction (XRD), particle size analyzer, and SEM techniques. Ceramic/rubber composites were then prepared by melt
mixing of rubber and ceramic powders. Two different types of NR (i.e., epoxidized NR [ENR] and unmodified NR) and two types
of ceramic powders (i.e., BaTiO3 and PbTiO3) were exploited. It was found that incorporation of ceramic powders in rubber matrix and the presence of epoxirane rings
in ENR molecules caused faster curing reaction, and higher delta torque but lower elongation at break. This is attributed
to lower mobility of molecular chains and higher interaction between ENR molecules. Furthermore, SEM results revealed that
the BaTiO3 composites showed finer and better distribution of the particles in the rubber matrix than that of the PbTiO3 composite. This caused superior mechanical properties of the BaTiO3 composites. Furthermore, higher dielectric constant and loss tangent was observed in the ENR/BaTiO3 composites. 相似文献
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Barium-strontium titanate (BST) ceramics, co-doped with Sb and Mn oxides, were sintered on different powder beds: Sb-doped
BST; Al2O3; or Sb,Mn-codoped BST powder. Phase formation, microstructure and the electrical properties of the samples were analysed.
The PTCR behavior depended significantly on the type of powder bed used. The BST ceramic pellet sintered on the Sb-BST powder
displayed the largest PTCR effect, with a ρmax/ρRT ratio of ∼106. This was an order of magnitude greater than for samples sintered on the other two powders. Complex impedance analysis confirmed
that this was due to a large increase in grain boundary resistance at 250 °C. 相似文献
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