bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilization of Glass Cutting Sludge and Sanitary Ware Sludge in Ceramic Pressed Bodies
Authors: Theerapapvisetpong Apirat , Nilpairach Siripan
Published: August 2015

Ceramic manufacturers are finding the way to decrease firing temperature and recover their wastes in order to keep production costs down. In this study earthenware ceramic bodies were prepared by adding a soda-lime glass grinding effluent powder (dried sludge) as a fluxing agent at 0–50 wt.% into either sanitary ware sludge powder (from a sanitary ware manufacturing process) or fresh pottery clay from Ang-thong, Thailand. The dried and pressed mixtures were fired at 1100, 1125 and 1150 °C and tested for the firing shrinkage, modulus of rupture, water absorption and bulk density. The formed product microstructure was observed by the scanning electron microscopy, and the phase composition was characterized by X-ray diffractometer. The results revealed that the best condition for adding the glass powder in Ang-thong pottery clay was the inclusion of 10 wt.% soda-lime glass effluent powder in the pottery clay. Its flexural strength increased from 51.25 MPa to 93.40 MPa after firing at 1125 °C with the water absorption of 0.42 wt.% and the firing shrinkage of 10.25 %. The optimum firing temperature and soda-lime glass content in sanitary ware sludge were 1150 °C and 20 wt.%, respectively. Its flexural strength increased from 103.16 MPa to 118.16 MPa with the water absorption of 0.52 wt.% and the firing shrinkage of 13.67 %. The results illustrated the potential to use soda-lime glass cutting sludge and sanitary ware sludge as raw materials for earthenware ceramic body.
Effect of Bi2O3 on Thermal Properties of Barium-Free Glass-Ceramic Sealants in the CaO-MgO-B2O3-Al2O3-SiO2 System
Authors: Lawita Pornchanok , Theerapapvisetpong Apirat , Jiemsirilers Sirithan
Published: August 2015

Barium-free glass-ceramic sealants for the planar solid oxide fuel cell (pSOFC) have attracted considerable attention to avoid the crystallization of the high coefficient of thermal expansion (CTE) BaCrO4; reaction product at the interface between barium-containing glass-ceramic sealants and Crofer22 APU interconnect, which decreases the long-term mechanical stability of the sealant. In this study, Barium-free glass-ceramic sealants in the CaO-MgO-B2O3-Al2O3-SiO2 system with varying amounts of Bi2O3 from 0 to 10 wt. % were prepared by conventional melting and their thermal properties were investigated. The glass transition temperature (Tg), dilatometric softening temperature, and coefficient of thermal expansion (CTE) were determined by a dilatometer. The Tg, onset of crystallization (Tx) and crystallization temperature (Tc) were obtained from DTA. Results of phase analysis by X–ray diffraction of glasses after thermal treatment at 900 oC for 2 h indicated that the major phase of all glasses was diopside (MgCaSi2O6) and minor phases were åkermanite (Ca2MgSi2O7) and forsterite (Mg2SiO4). The Tg of the fabricated glasses tended to decrease with increasing Bi2O3 content while the CTE of glasses increased after the thermal treatment and was in the range of requirement for SOFC sealant.
Figures of Merit of Low-Cost CuAl0.9Fe0.1O2 Thermoelectric Material Prepared at Different Solid State Reaction Sintering Temperatures
Authors: Sakulkalavek Aparporn , Thonglamul Rungnapa , Sakdanuphab Rachsak
Published: August 2015

In this study, we investigated a CuAl0.9Fe0.1O2 compound prepared at two different sintering temperatures in order to find out the effect of sintering temperature on the compound's figure of merit of thermoelectric properties. The thermoelectric CuAl0.9Fe0.1O2 compound was prepared from high purity grade Cu2O, Al2O3 and Fe2O3 powders. The mixture of these powders were ground and then pressed with uniaxial pressure into pellets. The pellets obtained were sintered in the air at 1423 K and 1473 K. X-ray diffraction (XRD) patterns showed a single phase of CuAl0.9Fe0.1O2 with rhombohedral structure, , along with a trace of CuO second phase. Moreover, the XRD peaks of the sample sintered at 1423 K indicated that more Fe3+ atoms replaced Al3+ atoms in this sample than they did in the sample sintered at 1473 K. The average grain size of the CuAl0.9Fe0.1O2 compound prepared increased with increasing sintering temperature, whereas its mean pore size and porosity decreased with increasing sintering temperature. The dispersed small pores markedly decreased the thermal conductivity of the compound, while the Fe3+ substitution of Al3+ increased its electrical conductivity. The highest figure of merit (ZT) found was 0.021 at 973 K in the CuAl0.9Fe0.1O2 sample sintered at 1423 K. Our findings show that this low-cost material with a reasonable figure of merit is a good candidate for thermoelectric applications at high-temperature.
Study of the Hydrolytic Resistance of Glass Bottles under a High Fluctuated Weather Condition
Authors: Naknikham Usuma , Thepbutdee Suwannee , Jitwatcharakomol Tepiwan , Tapasa Kanit
Published: August 2015

The occurrence of corrosion on glass surfaces results from the reaction between sodium in glass surfaces and water in the atmosphere under a certain condition. This reaction is promoted at high difference of humidity and temperature between a daytime and a nighttime especially in a rainy season. Glass surface treatments, for example by solutions, can improve the hydrolytic resistance. In the previous study, it was found that using 5wt% of alum gave the best effect to increase this property. The aim of this study was to examine the effect of closed and unclosed glass bottles during storage in a warehouse to the hydrolytic resistance. After treatment by 5wt% of alum, the amount of Na leached from the inner surfaces of glass bottles under simulated condition was determined. The weathering chamber was used to simulate the condition of a rainy season in Thailand with conditions set up and run in cycle. At first, the condition under the relative humidity (RH) value of 60 at 32°C was run for 12 hours, and then followed by RH of 80 at 25°C for 12 hours. The cycle was continued in the period of 8, 14, 21, 28, 53 days. After that the quantity of leached Na which is the conversion of hydrolytic property was analyzed by Flame-Atomic Absorption Spectrometry (FAAS). The results showed that the amount of Na leached from the untreated bottles was higher than the treated bottles around 5 times. It was also found that the quantity of leached Na from the untreated and closed bottles was raised with increasing time after 30 days while the untreated and opened bottles gave a rather constant result.
Effect of Gallium Loading on Reducibility and Dispersion of Copper-Based Catalyst
Authors: Udomsap Parncheewa , Supasitmongkol Somsak
Published: August 2015

The effect of gallium-promoted copper-based catalysts has been investigated in connection with the characteristic of the active copper phase. CuO-ZnO-Ga2O3catalysts with different gallium loadings were prepared using oxalate co-precipitation method. The effects of gallium loading on the properties of catalysts were studied by means of X-ray diffraction (XRD), transmission electron microscopy (TEM) and temperature-programmed reduction (TPR). The dispersion and metal area of copper were also determined by dissociative nitrous (N2O) adsorption technique conducted on a metal dispersion analyzer (BELCAT). The TPR profiles showed that the presence of two different reduction regions in the CuO-ZnO catalysts can be attributed to the reduction of highly dispersed copper oxide species (reduced at 246 °C) and bulk-like CuO (reduced at above 390 °C). By contrast, the only low-temperature reduction peak was presented in the TPR profiles after the Ga2O3loading was higher than 4 wt%. With the same molar ratio (Cu/Zn = 2:1), the reducibility of CuO-ZnO-Ga2O3was found to be more facile than CuO-ZnO due to the lower copper oxide crystallite sizes of gallium-promoted catalysts. Higher Ga2O3loadings resulted in an increase in both copper dispersion and metal surface area of all the catalysts studied in good agreement with the reduction behaviors in the TPR profiles, although all the gallium-promoted catalysts were slightly different for the reducibility.
Natural Hydroxyapatite (NHAp) Derived from Pork Bone as a Renewable Catalyst for Biodiesel Production via Microwave Irradiation
Authors: Buasri Achanai , Inkaew Thaweethong , Kodephun Laorrut , Yenying Wipada , Loryuenyong Vorrada
Published: August 2015

The use of waste materials for producing biodiesel via transesterification has been of recent interest. In this study, the pork bone was used as the raw materials for natural hydroxyapatite (NHAp) catalyst. The calcination of animal bone was conducted at 900 °C for 2 h. The raw material and the resulting heterogeneous catalyst were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and the Brunauer-Emmett-Teller (BET) method. The effects of reaction time, microwave power, methanol/oil molar ratio, catalyst loading and reusability of catalyst were systematically investigated. The optimum conditions, which yielded a conversion of oil of nearly 94%, were reaction time 5 min and microwave power 800 W. The results indicated that the NHAp catalysts derived from pork bone showed good reusability and had high potential to be used as biodiesel production catalysts under microwave-assisted transesterification of Jatropha Curcas oil with methanol.
Physical Properties of Xyloglucan/Bacterial Cellulose Composite Film Plasticized with Glycerol
Authors: Oontawee Saranyou , Jittavisuttiwong Pattarapa , Phonprapai Chanan
Published: August 2015

Last few decades, tamarind seed that is the food industrial waste was extracted their kernel to obtain xyloglucan for food, cosmetic, and medical applications. This study aimed to practically prepare and physically characterize the films containing xyloglucan (XG), bacterial cellulose (BC) and glycerol (GLY) for cosmetic applications. In the experiment, the films were prepared by varying (XG:GLY)-%BC ratio and using solution casting method. Preliminary, the films were observed the morphology. Subsequently, it was performed the adhesive test by using Texture Analyzer. From the preparation, it was found that the addition of BC provided the non-wrinkled films unlike the films that were prepared without BC addition. However, low transparent films were obtained from the addition of BC. From the adhesive test, the stickiness (SN), the adhesiveness (AN), and the cohesiveness (CN) were obtained simultaneously. The results revealed that the increasing of GLY and BC trendily increased SN and CN of the films, which (10:90)-9% films provided the highest SN (57.64 g) and AN (1.01 g.sec). However, (10:90)-9% films and (20:80)-8% provided insignificant difference of SN and AN. Meanwhile, (30:70)-7% films provided the lowest SN (10.77 g) and AN (0.21 g.sec). Moreover, the influence of GLY and BC on decreasing of CN was significantly found on (30:70)-7% films only. As the results, it could be concluded as the addition of BC into the films provided the non-wrinkled films, and the increasing of GLY provided the high adhesive films that suitable to apply on the skin for used as the transdermal patch. In the future works, the films will be added by the herbal extracts to provide biological activities such as anti-oxidation, anti-microbial, and anti-melanogenesis to the films.
Total Energy Requirement for Hydrogen Production Reactor Using Various Porous Media Materials
Authors: Srilomsak Mek , Aungkharuengrattana Waroht , Sesuk Thanathon , Charoensuk Jarruwat , Charochrojkul Sumittra
Published: August 2015

In a hydrogen production reactor, combustion of LPG was used as a heat source for ethanol steam reforming. For such purpose, the operating temperature was required to be around 700-900°C along the entire height of the reactor. Various types of porous media materials were used as a heat transfer media, i.e. 25mm ceramic saddles, random size bio-filter media from MTEC, ceramic foam, and ceramic balls. The objective of this study was to obtain the practical amount of total energy input, and compare with theoretical calculation which can achieve the required temperature of ethanol steam reforming for the hydrogen production. From our experiments, 13.20 kW of energy was needed to fulfill the requirement of the reactor, while only 2.49 kW was expected from theoretical calculation. Most energy loss was due mainly to: 1) heat loss at the top of the reactor where the metal part was directly exposed to the environment, 2) a large amount of energy loss at the furnace stack and, 3) insufficient mixing at the early stage of combustion at the bottom of the furnace as noticed by high CO concentration in flue gas. The porous media material has a significant effect on temperature distribution and energy consumption. The results show that the use of ceramic saddles as porous media consume more energy than the ceramic foam and the bio-filter media mixed with ceramic saddles during the start-up period of the reactor.
The Effect of Ternary Catalyst Atomic Ratios (PtRuSn/C and PtRuNi/C) on Ethanol Electrooxidation for Direct Ethanol Fuel Cell
Authors: Sudachom Napha , Warakulwit Chompunuch , Prapainainar Paweena
Published: August 2015

The effect of the different metal atomic ratios deposited on Vulcan XC-72R on ethanol electrooxidation reaction were investigated by producing of the ternary catalysts (PtRuSn/C and PtRuNi/C) in various atomic ratios (75:20:5, 75:15:10, 75:10:15, 75:5:20). All catalysts were prepared via polyol process. The nominal atomic ratios of the metals on the support were confirmed by EDX-SEM. The cyclic voltammetry was used to investigate the electrocatalytic activity of the catalysts. It was found that PtRuSn/C (75:10:15) showed the highest maximum current density of 3.25 mA/cm2among all Sn containing catalysts. However, PtRuNi/C (75:5:20) also exhibited the high maximum current density of 2.66 mA/cm2which was the maximum current density for Ni containing catalysts. Moreover, PtRuNi/C (75:5:20) exhibited the best activity and stability for ethanol electrooxidation reaction as showed in chronoamperometry tests. The current density at 3000 s was 0.54 mA/cm2. The size of the catalysts was about 1.9-3 nm measured by TEM. The catalyst also presented smaller particle size and better catalyst dispersion among all ternary catalysts. The addition of Sn facilitated the C-C bond breaking in molecule of ethanol while the addition of Ni facilitated better stability.
High Density Polyethylene Catalyst Waste as a Filler in Papermaking
Authors: Buggakupta Wantanee , Chaiarrekij Somporn , Suvarnakich Kuntinee , Niravittanon Auchuta , Apisampinvong Thawanrat
Published: August 2015

The study observes the use of a waste derived from high density polyethylene (HDPE) catalyst production as fillers in papermaking. The replacement of the industrial waste to two common fillers; calcium carbonate and clay, are of interest. The waste is in the form of bright slurry containing very fine particulates with titanium dioxide, calcium oxide and alumina, along with a small amount of chlorides. As-received HDPE waste of 0-30 wt% was added into a mixture of pulp stock to make handsheets. Cationic polyacrylamide was employed as a retention aid. The obtained handsheet samples were then dried and their properties were characterized and also compared with the handsheets holding carbonate and clay. Such properties included both physical and mechanical ones, i.e. apparent density, air resistance, brightness, opacity, smoothness, tear and tensile strength. The experimental results showed that the as-received industrial waste gave comparable outcomes to carbonate and kaolin clay. Improvement of the handsheet properties with the HDPE catalyst waste was discussed.
Photocatalytic Degradation of Phenol by Impure BiFeO3 under Visible Light Irradiation
Authors: Wanchai Katnanipa
Published: August 2015

Impure BiFeO3 as a visible light photocatalyst for phenol degradation was synthezied via solid state method. The calcined temperatures of catalysts were studied. The characteristics of the catalysts were determined by XRD, SEM/EDS and BET. The catalysts were mainly composed of rhombohedral distorted perovskite-type BiFeO3 phase with impurity phases (B2Fe4O9, Bi25FeO40 and Bi2O3). Photocatalytic activity of phenol (5 mg/l) was studied in the impure BiFeO3 illuminated with 200 w fluorescence lamps. The catalyst amount and initial pH value of phenol solution on the photocatalytic effiency have been also investigated. In the present experiments, the catalyst calcined at 800°C shows the highest activity. The optimum loading of impure BiFeO3 and pH value were obtained to be 0.5 g/l and 6, respectively.
In Vitro Resorbability of Three Different Processed Hydroxyapatite
Authors: Thammarakcharoen Faungchat , Palanuruksa Phee , Suwanprateeb Jintamai
Published: August 2015

Hydroxyapatite has been used as bone substitutes in many applications due to its biocompatibility and osteoconductivity. Generally, it is considered to be biostable and shows limited resorption in the body. In some circumstances, resorption of bone substitutes is more desirable since it could accelerate the bone healing process. It is known that processing route is one of the crucial parameters that could affect the properties of materials. Three different processes were employed in this study to fabricate hydroxyapatite samples including low temperature transformation of three-dimensionally printed calcium sulfate (HA1), high temperature sintering of three-dimensionally printed hydroxyapatite (HA2) and high temperature sintering of mold pressed hydroxyapatite (HA3). HA1 was found to contain high porosity and low crystallinity whereas HA2 had high porosity and high crystallinity. HA3 had low porosity, but high crystallinity. In vitro resorbability of these samples was studied by submerging all the samples in simulated body fluid (SBF) for 1, 7, 14 and 28 days and determining their phase composition, density change, liquid absorption, ions release and microstructure. It was found that HA1 showed the greatest density loss and liquid absorption followed by HA2 and HA3 respectively. Calcium and phosphorus ions in SBF were observed to decrease with submerging times for HA1 and HA2, but remained constant for HA3. SEM studies showed that new calcium phosphate crystals were found to form on the surface of the HA1 and HA2 samples whereas none was found on HA3. These results suggested that HA1 had the greatest resorbability and calcium phosphate crystals forming ability on its surface followed by HA2 and HA3 respectively. Therefore, porosity and crystallinity of the samples resulting from different processing routes are important factors for in vitro resorbability of hydroxyapatite.
Forming of Zeolite/Carbon Composite Substrate Coated with Titania for Photocatalyst Decomposition of Organic Compound
Authors: Gomonsirisuk Khemmakorn , Wasanapiarnpong Thanakorn
Published: August 2015

Organic contaminated wastes water from petrochemical industries can be removed by adsorbent and photocatalyst. In this work, the degradation rate of phenol have been studied at different ratios of activated carbon/NaA zeolite composite materials coated with TiO2 photocatalyst which are easily to be fabricated into tubular shape by extrusion method. In addition, the foam-inserted composite can be floated on the surface of waste water for the higher phocatalyst activity. While the composite is the low cost adsorbent with high absorption and high ion exchange properties. In order to optimize the efficiency of material, the various ratios of activated carbon/NaA zeolite (3:1, 1:1 and 1:3) and amount of coated TiO2 on the specimen’s surface was studied by UV/Vis spectrophotometer which related to phenol concentration. Moreover the various amount of phenolic resins (10, 20, 30, 40 and 50 wt%) at different reduction firing temperatures (600 and 650 °C) with soaking time of 1, 2 and 3 hours affected to the compressive strength of samples. For the characterization, XRD is used to characterize the phase and SEM is used to provide the morphology of the prepared composite materials.
Organic Based Heat Stabilizers for PVC: A Safer and more Environmentally Friendly Alternatives
Authors: Asawakosinchai Aran , Jubsilp Chanchra , Rimdusit Sarawut
Published: August 2015

Organic based stabilizers have been considered as a new technology providing environmentally friendly heat stabilizer for PVC pipe production to substitute conventional lead stabilizer as well as calcium zinc stabilizer. In this research, PVC samples stabilized with 5 types of heat stabilizers i.e. 1) commercial lead stabilizer, 2) commercial calcium zinc stabilizer, 3) commercial organic based stabilizer (OBS), 4) 1,3-dimetyl-6-aminouracil (DAU) and 5) eugenol, were investigated. From dynamic mechanical analysis, storage modulus at room temperature of PVC stabilized with DAU was found to provide the highest value among those stabilizers. Glass transition temperature of the PVC stabilized with all types of heat stabilizers was determined to be approximately 99°C except the value of about 89°C in eugenol stabilized PVC. Furthermore, PVC stabilized with commercial lead, calcium zinc stabilizer and commercial OBS could be reprocessed up to at least 5 cycles. Whereas, PVC stabilized with DAU was found to be able to withstand the processing cycle up to 4 cycles. Additionally, PVC stabilized with DAU showed the most outstanding short term thermal stability and can maintain its original color for at least up to 4 processing cycles. Finally, repeated processing of PVC stabilized with each type of heat stabilizers showed negligible effect on mechanical properties for at least up to 3 processing cycles. From the above results, it is evident that DAU showed high potential use as a safe and effective organic based heat stabilizer for PVC to substitute traditional lead or calcium zinc compounds.
Application of Numerical Method and Statistical Analysis in the Integrated Intensity Calculation of the Peaks from the X-Ray Diffraction (XRD) Pattern of α-Iron
Authors: Chakartnarodom Parinya , Kongkajun Nuntaporn , Senthongkaew Payoon
Published: August 2015

The aim of this work is to analyze the error of the calculated integrated intensity of the x-ray peaks of a-iron (BCC-Fe) powder from x-ray diffraction (XRD) pattern by using the numerical method and the statistical analysis. The a-Fe powder was characterized by the x-ray diffractometer using step scan mode, step sizes 0.03o 2q and 0.05o 2q, and preset times from 0.1 to 3.5 s. The integrated intensity () of an x-ray peak and its error () were calculated using numerical method. The correlation between the relative error () and the preset time or step size were analyzed by the statistical analysis methods which are linear regression and statistical hypothesis testing. The results from the statistical analysis at significance level of 0.05 show that the relative error () correlate with x = preset time or integrated intensity by when a1 and a2 are the positive constants. From the mathematical model, for this work, the step size does not affect the relative error. However, the increasing of preset time reduces relative error on integrated intensity calculation. To minimize the error on XRD analysis, the preset time should be greater than one second. Moreover, on a XRD pattern, the lower integrated intensity peak has the higher relative error.
Biaxially-Stretched Poly(Lactic) Acid (PLA) and Rubber-Toughened PLA Films: Tensile and Physical Properties
Authors: Boonthamjinda Lalintip , Petchwatana Nawadon , Covavisaruch Sirijutaratana , Chinsirikul Wannee , Kerddonfag Noppadon
Published: August 2015

Poly(lactic) acid (PLA) is bioplastic produced from corn starch; its brittleness limits the use of PLA in many applications. Biaxial stretching is one approach adopted by film manufacturers to enhance the properties of plastics such as polypropylene (PP). This study aims to produce biaxially-oriented PLA films which had been toughened with 1-10% core-shell rubber (CSR). Differential scanning caloriemetry (DSC) results indicated that all biaxially-stretched neat PLA and the PLA/CSR films possessed nearly 20% greater crystallinity than the as-cast film.The yield stress of the biaxially-stretched films were higher than that of the unstretched films in both machine (MD) and transverse (TD) directions. After biaxial stretching, the elongation at break of the stretched films was still much higher than that of the unstretched ones. The tear resistance was highest in the film with 5 wt% CSR, it became higher after biaxial stretching. The water vapor permeation (WVP) was also minimum in the film with 5 wt% CSR. The biaxially-stretched films had lower WVP than the unstretched ones due to the enhanced crystallization and chain orientation in the stretched films.
Characterizations of Fluorine-Containing Polybenzoxazine Prepared by Solventless Procedure
Authors: Pattharasiriwong Patcharat , Rimdusit Sarawut
Published: August 2015

A fluorine-containing benzoxazine monomer (BAF-4fa) from 4-(trifluoromethyl) aniline, 4,4′-(Hexafluoroisopropylidene) diphenol or bisphenol-AF and paraformaldehyde was synthesized using solventless method at temperature of 110°C without any catalyst. Chemical structure and thermal properties of as-synthesized benzoxazine resin were investigated and compared with fluorine-containing benzoxazine resin as well as with traditional bisphenol-A aniline based benzoxazine (BA-a) system. From Fourier transform infrared spectrum of BAF-4fa monomer, absorption band at 1243 cm-1 which were assigned to C-O-C stretching mode of oxazine ring and band around 1505 cm-1 and 951 cm-1 which were attributed to tri-substitutued benzene ring from the oxazine ring moieties were observed. The result is in good agreement with the BA-a monomer, indicating successful preparation of BAF-4fa via solventless technology. The obtained BAF-4fa also exhibits thermal curing ability which is a signature of benzoxazine resin. The exothermic heat of reaction of BAF-4fa was found to be less than that of BA-a as observed by a differential scanning calorimeter. The BAF-4fa monomer was step-cured at 200°C for 2 hours, 250°C for 3 hours followed by 270°C for 2 hours to achieve its fully cured stage. Glass transition temperature of PBAF-4fa from tanδ of dynamic mechanical analysis was found to be much higher than that of PBA-a i.e. 288°C vs 189°C. From thermogravimetric analysis, thermal degradation at 10% weight loss of PBAF-4fa was found to be 453°C compared to the value of 341°C of PBA-a while the char yield was 53% vs 28% of the BA-a polymer. As a consequence, the incorporation of fluorine atoms into polybenzoxazine is able to improve various thermal stability of the polymer which allows such application as high temperature resistance materials including electronic packaging, thermal resistance coating.
Effect of Fiber Surface Modification on Properties of Artificial Leather from Leather Fiber Filled Natural Rubber Composites
Authors: Sakmat Jutaporn , Lopattananon Natinee , Kaesaman Azizon
Published: August 2015

Artificial leather based on natural rubber (NR) filled with leather fibers was prepared using a hot pressing process. The leather fiber was obtained by shredding chrome-tanned leather into fibers with the sizes of 20-mesh. Three different modifying agents (i.e., 1% aqueous solutions of sodium hydroxide, urea, and sodium bicarbonate) were used in the modification of leather fibers. Mechanical properties of NR composites filled with 100 phr of modified or unmodified leather fibers were then investigated. The results showed that cure characteristics, tensile properties, tear strength and abrasion resistance of the composite combined with the modified leather fibers were clearly improved, compared to those of the simple unmodified leather fiber composite. Furthermore, interfacial adhesion between the leather fiber and natural rubber was found to improve. From this study, the result suggested that the urea solution provided the best property improvement when the other modifying agents were compared with.
Effects of Particles Size of Nanosilica on Properties of Polybenzoxazine Nanocomposites
Authors: Liawthanyarat Nutthaphon , Rimdusit Sarawut
Published: August 2015

Polybenzoxazine nanocomposites filled with three different sizes of silica nanoparticles are investigated for their mechanical and thermal properties. In this research, silica nanoparticles with primary particle sizes of 7, 14 and 40 nm were incorporated in polybenzoxazine matrix at a fixed content of 3% by weight. From the experimental results, the storage modulus of the polybenzoxazine nanocomposite was found to systematically increase with decreasing the particle sizes of nanosilica suggesting better reinforcement of the smaller particles. Glass transition temperature was found to slightly increase with the addition of the silica nanoparticles. The uniformity of the composite samples were also evaluated by thermogravimetric analysis to show good dispersion of the silica nanoparticles in the composite samples as a result of high processability of the benzoxazine resin used i.e. low A-stage viscosity with good wetting behaviors. Degradation temperature at 5% weight loss (Td,5) of polybenzoxazine nanocomposites filled with different particle sizes of silica nanoparticles was found to increase from the value of 325 °C of the neat polybenzoxazine to the maximum value of about 340 °C with an addition of the nanosilica of the smallest particle size used. Finally, the smaller nanosilica particle size was also found to show more pronounced effect on Td,5enhancement of the composite samples as a result of greater barrier effect from larger surface area of the smaller particles.
Fabrication and Application of Nanostructures Using Gas-Assisted Hot Embossing and Self-Assembled Nanospheres
Authors: Hong Rong Hong , Cih Cheng , Shu To Chung , Yang Sen Yeu
Published: August 2015

We develop a simple and competitive fabrication of antireflective (AR) films with high-ordered nanostructure arrays on polycarbonate (PC) substrate by using gas-assisted hot embossing and a self-assembled technique. In this method, a self-assembled monolayer of polystyrene (PS) nanospheres is well-patterned on glass substrates as the first template. Subsequently, we use the plasma sputtering to deposit a conductive layer onto the surface of nanosphere (NS) patterned substrates, and then, electroforming is applied to fabricate a nickel mold with an inverse shape of nanospheres. In the last step, a unique glass transition is utilized to duplicate nanostructures on PC films via gas-assisted hot embossing. Not only in visible light but in near infrared, the optical properties of this AR film are similar or better than for other methods. This fabrication process also has great potential in industry, with its simplicity, large-area but low-cost.
Fabrication of Novel Polyhydroxybutyrate-co-Hydroxyvalerate (PHBV) Mixed with Natural Rubber Latex
Authors: Kuntanoo Karndarthip , Promkotra Sarunya , Kaewkannetra Pakawadee
Published: August 2015

Polyhydroxybutyrate-co-hydroxyvalerate (PHBV) is mixed with natural rubber latex to make better mechanical properties of PHBV. The various ratios between PHBV and natural rubber latex are examined to improve their mechanical properties. The PHBV are solid, easily broken, while natural rubber is excessive elastic materials. Concentrations of the employed PHBV solution are 1, 2, and 3 (%w/v). The mixtures of this solution to natural rubber latex are fabricated the biofilms in three different ratios, 4:6, 5:5, and 6:4, respectively. The films are characterized by electron microscope, universal testing machine, and differential scanning calorimetry (DSC). The electron micrographs of the mixed films and unmixed PHBV yield the lowest void distributions in 3%w/v PHBV. For mechanical properties, the averaged elastic moduli of 1, 2, and 3 (%w/v PHBV) mixed films are 773, 955 and 1,008 kPa, respectively. Their tensile strengths increase with increasing the PHBV concentrations. A similar trend is also found in elastic modulus. The crystallization and melting behavior of pure PHBV and the mixed films are examined by DSC. Melting transition temperatures of pure PHBV exhibit two melting peaks at 154°C and 173°C. In addition, the melting peaks of the mixed films remain in the range of 152-156°C and 168-171°C, respectively. According to their morphology, void distributions reduce twice, compared to the unmixed PHBV. Mechanical properties and thermal analysis indicate that the mixed PHBV can be improved their properties with more resilient and wide range temperature than usual.
More Values of L-Quebrachitol from Skim Natural Rubber Latex
Authors: Wannuch Teerawan , Nimpaiboon Adun , Sakdapipanich Jitladda
Published: August 2015

Natural rubber (NR) latex collected from Hevea brasiliensis rubber tree exists as a colloidal suspension with 30% dry rubber content (DRC). For convenient use and transportation, the latex is concentrated by centrifugation process. Through this process, the 60% DRC concentrated NR latex and 5% DRC skim latex as a by-product were produced. After using acid coagulation of skim latex, the skim rubber is obtained to use as a low-grade application due to high amount of non-rubber components as impurities. The water portion remaining after the coagulation of skim rubber consists of various water-soluble materials such as sugars, lipids, proteins and minerals, which can cause the water pollution if serum is directly discharged into the environment without proper treatment. However, 1.5% of L-quebrachitol was found in skim latex. It can be used in many applications such as a starting material for the synthesis of bioactive materials and inositol pharmacy. Thus, this work is an attempt to investigate the most effective extraction method of L-quebrachitol from skim latex. It was found that the appropriate solvent for extraction L-quebrachitol at high temperature and for recrystallization at low temperature is ethanol. The yield of L-quebrachitol about 2-3% by weight of solid serum was obtained. Moreover, a sweetness and antibacterial activity were also studied for its further applications. It was found that the sweetness of L-quebrachitol was twice than that of sucrose. No antibacterial activity of L-quebrachitol against Staphylococcus aureus and Streptococcus mutans was found.
Preparation and Characterization of Natural Rubber/Chitosan Films
Authors: Paoribut Kansiree , Taweepreda Wirach , Boonkerd Kanoktip
Published: August 2015

Natural rubber/chitosan (NR/CS) films at various NR/CS ratios were prepared here from the mixture of natural rubber latex (NRL) and chitosan solution using a solution casting method. The NRLs with and without sulfur curing agents were used. The NR/CS films were obtained after heating at 50oC for 24 hours. The NR/CS films prepared from the NRL with curing agents were further heated at 120oC for 30 min to acquire the NR networks. From swelling testing, it was found that incorporation of CS into the NR matrix gave the films with higher solvent resistance. The swelling index reduced proportionally with the increased CS loadings. Additionally, the solvent resistance of the NR/CS films was improved more once the NR was cured. In general, for every NR/CS ratio, the tensile strengths of the cured NR/CS films were higher than those of the uncured NR/CS films. After thermal aging, it was found that the tensile strength of the uncured NR/CS films decreased while that of the cured ones increased. Two thermal decomposition peaks were observed. The onset decompostion temperatures at lower and higher temperature were corresponding to the degradation of chitosan and natural rubber, respectively. The initial thermal degradation temperature of CS and NR in the NR/CS films was shifted to the higher temperature than that of the pure CS and NR, respectively.
Properties of Thermoplastic Elastomer Composites Prepared from Para Rubber Wood Sawdust Filled-Polypropylene/Natural Rubber Blends
Authors: Phakdee Rattiya , Boochathuma Ploenpit
Published: August 2015

Thermoplastic elastomer composites (TEC) based on blending of polypropylene (PP) and natural rubber (STR5L) filled with Para rubber wood sawdust were prepared by melting polypropylene at 180 °C in the internal mixer followed by adding STR5L and subsequently Para rubber wood sawdust. The size of Para rubber wood sawdust used were less than 800 μm. Thermoplastic elastomer composite compounds were compression molded at 180 °C for 13 min. for specimen preparation. The effect of blend ratios and Para rubber wood sawdust loading on the mechanical and physical properties of TEC were investigated. It was found that tensile strength, Young’s modulus, hardness and flexural strength of TEC decreased with STR5L and Para rubber wood sawdust loading, whereas the impact strength increased with increasing STR5L. It was obvious that loading of Para rubber wood sawdust didn’t change impact resistance and hardness of TEC. Furthermore, it was clarified that TEC (PP:STR5L:Sawdust) with the weight ratios of 90:10:30, 90:10:50, 70:30:30 and 70:30:50 showed the best mechanical properties. Accordingly, they were selected for further measurements of the water absorption and flexural properties for application to flooring. The water absorption of TEC was determined by immersing the composite samples in distilled water for 24 h at room temperature. The results showed that water absorption of TEC with the ratios of 70:30:30 and 70:30:50 was 0.25% and 1.64%, respectively, compared to the standard value of ≤ 3% for low water absorption ceramic tiles, ≤10% for medium absorption ceramic tiles and ≥10% for high water absorption ceramic tiles regarding to Thai Industrial Standards. For flexural properties, all selected TEC showed flexural modulus higher than 700 MPa which was the minimum requirement of Thai Industrial Standard (≥ 700 MPa). However, only TEC with the weight ratio of 90:10:30 gave the modulus strength reach to Thai Industrial Standards value of ≥30 MPa. Morphology of the cracked surface from the notched impact specimens with the weight ratio of 90:10:50 and 70:30:50 was examined by using Scanning Electron Microscopy (SEM). It indicated that the interfacial bonding between Para rubber wood sawdust and the polymer matrix of TEC with 90:10:50 ratio was poorer in comparison with that of 70:30:50 due to the numerous pulled-out sawdust flakes of TEC with 90:10:50 ratio observed much more than TEC with 70:30:50 ratio. This result indicated that adhesion between filler and polymer matrix of TEC with 30% STR5L blending was obvious to be stronger than that with 10% STR5L blending. As a result, it was remarkable that thermoplastic elastomer composites prepared with three immiscible materials showed acceptable mechanical and physical properties for application to flooring product with the economical process.
Synthesis and Characterization of PolyHIPEs Composites with Silica and Iron Oxide Nanoparticles
Authors: Seeharaj Panpailin , Eamsa-Ard Tanthip , Thasirisap Eakkasit
Published: August 2015

This study investigated the synthesis and modification of the properties of polyHIPEs by incorporating co-additives into the polymer matrix i.e. silica (SiO2)nanoparticles (1 wt%) to improve physical and mechanical properties and iron oxide (Fe3O4) nanoparticles (5, 10 and 15 wt%) to induce magnetic and heavy ion adsorption properties. PolyHIPEs composites were prepared in water in oil (w/o) emulsion system using the ratio of organic phase to aqueous phase of 20 to 80 vol%. The physical and mechanical properties of the polyHIPEs composites were found to decrease with SiO2 and Fe3O4 addition while the magnetic and adsorption properties increased with increasing Fe3O4 contents. The composites with 1 wt% SiO2 and 15 wt% Fe3O4 exhibited the highest saturated magnetization at 12.9 emu/g and they could be used for adsorption of iron ions (Fe3+) in iron(III) sulfate solution with 98.3 % adsorption at equilibrium.
Polyurethane Synthesis from Sugarcane Bagasse Organosolv and Kraft Lignin
Authors: Sakdaronnarong Chularat , Srimarut Nattawee , Laosiripojana Navadol
Published: August 2015

Sugarcane bagasse (SCB) was subjected to a single-step fractionation and hydrolysis reaction in the presence of various organic solvents. The reaction was performed at 170 °C for 3 h when sodium hydroxide was used as catalyst. The results showed that suitable solvents significantly enhanced the yield of lignin fractionation and simultaneous hydrolysis reaction took place indicated by an increase of hydroxyl groups in lignin molecules. Lignin-based polyurethane (LPU) from SCB organosolv lignin polyols had relatively better mechanical and thermal resistant properties compared to LPU from liquefied Kraft lignin from pulp and paper industry.
Application of Statistical Analysis in the Powder Injection Molding (PIM) of Mullite
Authors: Chakartnarodom Parinya , Kongkajun Nuntaporn , Chuankrerkkul Nutthita
Published: August 2015

In this work, the statistical analysis methods, including least square method and statistical hypothesis testing, were used to study the flexural strength and density of the specimens formed from mullite powder by powder injection molding (PIM). The feedstock for PIM consist of mullite powder and the composite binder consisting of 78 wt% polyethylene glycol (PEG), 20 wt% polyvinyl butyral (PVB), and 2 wt% stearic acid (SA). The PIM machine used in this work was the lab-scale plunger type. The compositions of the feedstock that could be injection molded by this machine were 50, 52, and 54vol% mullite. After molding, PEG in the green specimens was removed prior to sintering by soaking the specimens in the water at 60 °C for 24 hours while PVB and SA were removed during sintering. The sintering temperatures were 1300 to 1450°C. At significance level of 0.05, the least square method and the statistical hypothesis test showed that both feedstock compositions and sintering temperatures used in this work affected the densities of sintered specimens. However, the increasing of the flexural strength of sintered specimens was mainly by the increasing of the sintering temperature.
The Effect of Rotational Speed on Steel Pipe Lined Fe-WB Based Composite Coating by Centrifugal-SHS Process
Authors: Singsarothai Saowanee , Rachphet Vishnu , Niyomwas Sutham
Published: August 2015

The Iron-Tungsten boride based composite was coated on the inner surface of steel pipes by centrifugal-self-propagating high-temperature synthesis (centrifugal-SHS) process. The precursors were prepared by a stoichiometric ratio of wolframite mineral (Fe (Mn)WO4), aluminum (Al) and boron oxide (B2O3). Phase composition and microstructure of composite coating were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). On this study, depending on the rotation speed, the highest rotation speed (2250 rpm) produced highest micro-hardness of the composite (1699 HV).
Confined Growth of WO3 for High-Performance Electrochromic Device
Authors: Adhikari Sangeeta , Sarkar Debasish
Published: August 2015

Nanoscale material world attracted researchers because of their outstanding properties and prospective novel applications. Tungsten trioxide semiconductor is one of the fundamental functional materials due to its versatile application as gas sensors, solar cells, and smart windows. Confined growth of the metal oxide nanostructures can tune the electrical and optical properties for modern device application. The management of morphology is a challenge to investigate the ultimate performance. In this paper, self-assembled growth of four different tungsten trioxide nanostructures were carried using a different structure directing agents through either co-precipitation or hydrothermal techniques. The monoclinic spherical and rod-like WO3 nanostructures were obtained by acid precipitation method. WO3 nanocuboids and nanofibers were synthesized hydrothermally using HBF4 and NaCl as structure directing reagents to attain monoclinic and hexagonal crystal phases, respectively. Analytical techniques like XRD, TEM, and FESEM imaging methods were used to confirm the phase and morphology. All the nanopowders were calculated to have similar band gap energy at visible wavelength. A simple dip coated WO3/ITO fabricated electrode was used as a reference electrode to carry out the electrochemical measurements for all nanopowders. The evaluated properties suggested the plausible use of WO3 nanofibers for high efficient electrochromic device.
Physical and Optical Properties of Indium Oxide: Tin Nanoparticles Synthesized by Co-Precipitation Method
Authors: Kanoksinwuttipong Jiruntanin , Pecharapa Wisanu , Noonuruk Russameeruk , Techitdheera Wicharn
Published: August 2015

Indium oxide:tin nanoparticles were synthesized by co-precipitation method using InCl3 and SnCl4·5H2O as starting precursor with different molar ratios of Sn:In. The crystalline structure, optical properties, chemical bonding and morphologies of all samples were characterized by X-ray diffraction (XRD), UV–vis spectrometer, Raman spectroscopy and field emission scanning electron microscope, respectively. The XRD results show that the crystallinity of as-synthesized powders was initially amorphous phase. After calcination at 400 °C for 2 h, a single phase ITO powder with 10% (mol%) SnO2 was obtained. The particle size of each sample is approximately 20-25 nm. The color of indium oxide:tin nanopowders after heat treatment changed from white to yellow due to the substitution of oxygen vacancies in the sample. After calcination, the intensity of Raman peak significantly decreased with increasing amount of Sn loading. This phenomenon indicates that ion substitution may occur during the synthesis process. Moreover, it is noticed that the optical absorbance of obviously changed with increasing Sn loading.
Surface Modification of Zinc Oxide Nanoparticles Using Polyethylene Glycol under Microwave Radiation
Authors: Sooksaen Pat , Keawpimol Anutra , Deeniam Piyavan , Boonkum Panumart
Published: August 2015

This study investigated the effect of polyethylene glycol (PEG), with high molecular weight of 1500 and 4000, on the formation of zinc oxide nanostructures synthesized by microwave radiation. Microwave heating was carried out at 2.45 GHz at 480 and 640 watts with 5s/15s on/off step time. The precursors used were Zn(NO3)2.6H2O, NaOH and PEG. Microwave radiation generates heat to activate the formation of ZnO nanoparticles where the morphology can be controlled by the addition of PEG, time and heating power. The formation of wurtzite structure of ZnO was confirmed by X-ray diffraction. Morphology was investigated by a scanning electron microscope. PEG acted as a structure-directing agent or chelating agent resulting in the formation of rod-like and plate-like crystals. The average size of ZnO nanocrystals increased with increasing microwave power.