Chiravoot Pechyen

Preparation of Polydiacetylene Vesicle and Amphiphilic Polymer as Time-Temperature Indicator

Polydiacetylene (PDA) was used as a colorimetric indicator depended on temperature and time. This paper presents a new time-temperature indicator based on PDA vesicle and amphiphilic polymer. The 10,12-pentacosadiynoic acid (PCDA) was prepared with different concentration of Pluronic F127 which was varied from 0 to 4 % w/v, respectively. After that, there was obtained in different temperature (30-50°C) until clearly color change. This solution could gradually change from blue to red color which it could observe by UV-Vis spectrophotometer. The absorbance in each solution was reported at 640 and 540 nm, respectively, and then calculated by the color response (CR). In addition, the CR increased that directly related with temperature and time, when the concentration of F127 was constant. Also, the CR increased that directly related with temperature and concentration of F127, when time was constant. This method could have potential application as a new time-temperature indicator.

Lipase-Catalysed Polymerization of Lactic Acid and the Properties of the Polymer

Lipase-catalysed polymerization is an emerging green alternative method for the synthesis of polylactic acid (PLA) from lactic acid (LA) monomer. Use of the lipase catalyst avoids the need for potentially toxic chemical catalysts. The concentration of the lipase enzyme is one of several factors which influence the polymerization process. This paper reports on the effects of the lipase concentration on the characteristics of the low molecular weight polylactic acid (PLA) formed via lipase-catalyzed polymerization of lactic acid. The polylactic acid products made by this method are characterized by Fourier Transform Infrared Spectroscopy (FTIR). Low molecular weight polylactic acid could be successfully produced from commercial lactic acid by using the commercial lipase Lipozyme TL IM at 50 °C in a 5-hour reaction.

Synthesized Silica Powder from Rice Husk for Printing Raw Materials Application

Rice husk is a form of agricultural biomass that provides an abundant silicon dioxides source. This study use rice husk ash as a material to prepare silica. Silica powder has been synthesized by the refluxing of rice husk ash with HCl 1,2 and 3 M at different time (60 and 120 min.) and subsequently adjusting the pH using 1 M. NaOH. The silicon dioxide extraction yield reached 85% and was effect by concentration of HCl solution and reaction time. The structure of the obtained silica powder were characterized by X-Ray Fluorescence (XRF), X-Ray diffraction (XRD), CIE L*a*b* (Visible spectrophotometer) and Scanning Electron Microscope (SEM). The highest purity of silica sample were 98.7% SiO2, CIE L*a*b* = 94.79 +0.48 +1.24, ∆E ≈ 3.28 (white power) and 2Ɵ = 22o (silica). Particle had a uniform size less than 3 μm. The objective of the next study will applied synthesized silica that enhances the print quality of the printing substrates.

Characterization of Eugenol Extracted from Lemongrass (Cymbopogon citratus (DC.) Stapf) for Food Packaging Materials

The goal of this research was to study a prospect of applying Lemongrass (Cymbopogon citratus (DC.) Stapf) extracted having antioxidant property (i.e. eugenol) to replace commercial antioxidant agent such as butylated hydroxytoluene (BHT) in packaging raw materials. The extracted eugenol was characterized using Gas chromatography (GC). A free radical scavenging activities of eugenol and BHT were also investigated using 2, 2-dipheny l-1-picryhydrazyl (DPPH) assay. It reveals that a concentration of eugenol resulting in a 50% inhibition of the free radical, IC50, (0.11 mg/ml) is lower than the IC50 value of BHT (0.14 mg/ml) indicating better radical scavenging activity. In its radical form, DPPH shows an absorbance maximum at 515 nm which disappears upon reduction by an antiradical compound. BHT, a synthetic antioxidant, slowly reacts with DPPH reaching a steady state within 5 hr. The kinetic (R2) is estimated to be 0.9283 at 25 °C. Eugenol rapid reacts with DPPH reaching a steady state within 2 h. The kinetic (R2) is estimated to be 0.9946 at 25 °C, our results conrm that eugenol can we used instead of BHT.

Surface and Mechanical Properties of Cellulose Micro-Fiber Reinforced Recycle Polyethylene Film

This work involved a study of polymer-fiber composites as biodegradable packaging made from recycled polyethylene (r-PE) and chemical-treated cotton fabric waste micro fibers. A compatibilizer, polyethylene-graft-maleic anhydride (PE-g-MA), was used to improve properties of the composites. Factors affecting composite properties were investigated including % PE-g-MA loading, and % fiber loading. The fiber composites were prepared by melt-blending technique. The materials were first mixed by a twin-screw extruder and shaped into samples by an extrusion blow molding machine. The samples were then characterized for mechanical, and morphological properties. It was found that properties of the composites were improved by adding the compatibilizer. Optimum properties of the composites were found at 10% (wt%) PE-g-MA loading. It was also revealed that tensile strength and modulus was found to increase as the % fiber loading was increased. SEM micrographs confirmed that interfacial bonding between the cellulose fibers and the r-PE matrix was enhanced as fewer voids at the interfaces were revealed by adding the PE-g-MA compatibilizer to the composites. Film formation occurred on all composites even if the polymer itself was inert biodegradation. The microbial colonization affected mainly of surface properties r-PE composites while changes were monitored also in the bulk properties of cellulose microfiber.

Physicochemical Properties of Carbons Prepared from Physic Nut Waste by Phosphoric Acid and Potassium Hydroxide Activations

Char derived from pyrolysis of physic nut waste at 400-800°C was used for the preparation of activated carbon by chemical impregnation of phosphoric acid and potassium hydroxide. The original char exhibited the BET surface area in the range of 120-250 m2·g-1. The surface area increased to 480 and 532 m2·g-1 when activated with H3PO4 and KOH, respectively. Equilibrium adsorption data was found to be best represented by the Langmuir isotherm with maximum monolayer adsorption capacity of 560.13 mg·g-1 at 30°C. The adsorption capacity of the physic nut residue activated carbon was comparable to commercial activated carbon.

Comparison on Pore Development of Activated Carbon Produced from Scrap Tire by Potassium Hydroxide and Sodium Hydroxide for Active Packaging Materials

Activated carbons were prepared by chemical activation from scrap tire with two chemical reagents, NaOH and KOH. The activation consisted of different impregnation of a reagent followed by carbonization in nitrogen at 700°C. The resultant activated carbons were characterized in terms of BET surface area, methylene blue adsorption and iodine number. The influence of each parameter of the synthesis on the properties of the activated carbons was discussed, and the action of each hydroxide was methodically compared. It is the first time that preparation parameters and pore texture characteristics are simultaneously considered for two closely related activating agents of the same char precursor. Whatever the preparation conditions, it was shown that KOH led to the most microporous materials, having surface areas and adsorption properties (methylene blue adsorption and iodine number) higher than those obtained with NaOH, which was in agreement with some early works. However, the surface areas, methylene blue adsorption and iodine number obtained in the present study were much higher than in previous studies, up to 951 m2/g, 510 mg/g and 752 mg/g, respectively, using scrap tire waste char:KOH equal to 1:1. The thorough study of the way each preparation parameter influenced the properties of the final materials bought insight into the activation mechanisms. Each time it was possible; the results of scrap tire waste chemically activated with hydroxides were compared with those obtained with anthracites; explanations of similarities and differences were systematically looked for.

Effect of Nano-Silica Loading on Barrier and Mechanical Properties of Food Packaging Based LLDPE Film

In the present work, nano-silica was used in preparing LLDPE/nano-silica as an outer layer film for LLDPE reinforced nano-silica/LDPE/LLDPE multilayer film for microwavable packaging materials in future work. Thus, the objective of this work was studied the optimal of modified nano-silica loading into LLDPE film on barrier and mechanical properties. The experiments were divided into 2 main steps: surface treatment of nano-silica with vinyltriethoxysilane by ultrasonic agitation, and preparation of linear low density polyethylene film reinforced with untreated and treated nano-silica which different silica quantities are 1, 3, and 5 phr by blown film extruder. And then the surface morphology of films was examined by SEM. The properties of the film were analysis, oxygen transmission rate of film was characterized by OTR, water vapor transmission rate of film was characterized by WVTR, and tensile properties (tensile strength, % elongation and modulus) of films were examined by universal testing machine. Results indicated that the LLDPE loaded with 1 phr of nano-silica treated with vinyltriethoxysilane had better tensile strength and % elongation than at 3 and 5 phr of treated and untreated nano-silica.

Modification of mechanical properties by TiO2 nano-particle for biodegradable materials made from palm oil sludge and activated sludge cake

Abstract Titanium dioxide (TiO 2 ) nano-particle is widely used in composite materials to its improved mechanical properties. TiO 2 nano-particle was used in the composite material that consists of palm oil sludge from the palm oil production and activated sludge cake from a papermaking process. TiO 2 was synthesized by a hydrolysis of titanium isopropoxide. The parameter was investigated by the mole ratio of reactant to different solvents (isopropanol and isobutanol). The solution was prepared by adjusting pH to acid solution, resulting in different sizes and distributions of precipitate which was heated at different temperatures. The obtained samples were then morphologically and structurally characterized using X-ray diffraction (XRD) and particle size distribution (PSD). The experimental results show that the TiO 2 sample from isopropanol solvent with heated temperature of 600 °C exhibits the best results. Consequently, different mass fractions of TiO 2 (0, 0.5%, 1.0%, 2.0%, 4.0% and 8.0%) were used for specimens that were made from palm oil sludge mixed with activated sludge cake. All samples were later characterized by 3-point bending test and compression test. The results indicate that the adding 0.5% and 1.0% TiO 2 particles to the composite material outperforms the other fractions in terms of enhancing mechanical properties. Nonetheless, mechanical properties tends to decrease when adding 2.0% TiO 2 .

Surface Degradation and Mechanical Properties of PVC/Wood-Pallet Composite under UV-Weathering Environment

This research studied the effects of 4 types of additives, , wood powder, UV-absorber, impact modifier and pigment, on UV-stability of PVC/Wood-Pallet prepared by extrusion process. The amount of additive used was varied from 0 35 %w/w. The central composite design (CDD) was employed to experimentally design the formulation of PVC/Wood-Pallet, in order to practically reduce the total number of experiments from 625 pipes (Full factorial design for 4 factors and 5 levels) to 30 pipes without losing the credibility of the results achieved. The photodegradation of the PVC/Wood-Pallet was performed by an outdoor exposure test. The progress of photodegradation was followed by determining the changes in mechanical properties, physical properties and appearance, and thermal properties as a function of exposure time. The results showed that the PVC/Wood-Pallet No.30 had better mechanical properties than the others over period of exposure time. In addition, it was found that UV exposure could actually improve short-term mechanical properties due to postcuring phenomenon.