ผลงานตีพิมพ์ทั้งหมด

Electrospun Conditions of Poly(vinyl chloride) Nanofibrous Membrane Plasticized with Polyurethane

Kritsada Phatcharasit, Wirach Taweepreda, Kanoktip Boonkerd, Jin‐Kuk Kim

Jurnal Teknologi · 2014

Electrospun poly(vinyl chloride) (PVC) nanofibrous were prepared by electrospinning. Various concentration of polyurethane (PU) were added to PVC solution for plasticization of the electrospun nanofibrous. The pristine and plasticized nanofibrous were characterized by field emission scanning electron microscopy (FE-SEM), differencial thermal analysis (DTA), and thermogravimetry analysis (TGA), respectively. Thermal properties form DTA and TGA results indicated that the addition of PU decreased glass transition temperature (Tg) of PVC and increased heat resistance of PVC nanofiber. The dielectric constant of plasticized nanofibrous measured using precision LCR meter indicated that the membrane were dense.

Effects of precipitation temperature on the photochromic properties of h-MoO3

Phuriwat Jittiarporn, Lek Sikong, Kalayanee Kooptarnond, Wirach Taweepreda

Ceramics International · 2014

Influence of N-Doped TiO2 Nanocomposite Film on Hydrophilic Property of Rubber Dipping Former Surface

Mahamasuhaimi Masae, Lek Sikong, Kalayanee Kooptarnond, Wirach Taweepreda, Fumio Saito, Pichaya Pitsuwan

Key engineering materials · 2014

The objective of this study is to explore a method to improve hydrophilicity of the surface of formers that could be more easily dipped to produce high quality dipped rubber products. Photocatalytic TiO2 composite films were prepared by sol-gel method. Glass formers were coated with nitrogen doped TiO2 nanocomposite film by dipping method and annealed at 600°C for 1 h. Phase formation of TiO2 was characterized by XRD. Morphology of the TiO2 films was observed by using atomic force microscopy (AFM). Optical absorption of the films and degradation concentration of methylene blue had been measured employing UV-Vis spectrophotometer. The hydrophilicity of the thin films was determined in terms of the contact angles of water and NR rubber latex droplets on the coated TiO2 composite films under visible light irradiation. It was found from the experimental study that the TiO2 nano-composite film can improve wet-ability of the coated former surfaces.

Physicochemical and Drug Release Characterization of Lidocaine-Loaded Transdermal Patches Prepared from STR-5L Block Rubber

Wiwat Pichayakorn, Hasleena Boontawee, Wirach Taweepreda, Jirapornchai Suksaeree, Prapaporn Boonme

Industrial & Engineering Chemistry Research · 2014

The aims of this study were to formulate 5% lidocaine-loaded transdermal patches using STR-5L block rubber as a main component of the patch base and to investigate their physicochemical characteristics, in vitro drug release, and stability. The results suggested that STR-5L block rubber could be feasibly used as a main component of the base of pharmaceutical transdermal patches with acceptable physicochemical properties. STR-5L block rubber patches containing lidocaine exhibited lower moisture absorption when compared with the blank counterparts because the drug molecules inserted between the polymer chains. Lidocaine still showed its own crystallinity characteristics after crushing and mixing in STR-5L block rubber patches. Additionally, no chemical interaction between the drug and polymer base was found. The drug-loaded patches could provide drug release with the best fitted to Higuchi square root of time. They had good stability during the studied period of 3 months when kept at 4 °C.

Preparation of Peel-off Mask from Deproteinized Natural Rubber Latex

Wiwat Pichayakorn, Prapaporn Boonme, Wirach Taweepreda

Advanced materials research · 2013

The aim of this research was to develop the peel-off mask in paste form which can be applied to the face and then formed removable thin film. Deproteinized natural rubber latex (DNRL) from Hevea brasiliensis was used as the major film former. After deproteinization by alcalase enzyme treatment, the protein amount was 0.257% that reduced from the initial amount of 1.531%. The appropriate types and amounts of additives were studied by optimization design. The product compatibility and stability were evaluated. The addition of active ingredients for skin nourishing was also investigated. The suitable formulation composed of DNRL, polyvinyl alcohol (PVA) and methylcellulose (MC) as film formers, propylene glycol (PG) and glycerin as plasticizer, Tween 80 as stabilizer, Paraben concentrate as preservative, and other active ingredients including tocopheral acetate, aloe vera, jojoba oil, and tamarind extract. The product was white viscous paste with the pH of 5.69, viscosity of 28,100 cps as pseudoplastic flow behavior, and stable when kept in well-close container at room temperature for more than 1 month. The product in situ film was good elasticity indicated by initial modulus (0.96 MPa), tensile strength (0.208 MPa) and elongation at break (105.6%). Skin irritation in rabbit skin was very slightly which showed the small rash skin but could recover soon. The complacency test in 50 healthy volunteers showed the good results with no irritation effect. In conclusions, DNRL could be prepared peel-off mask product with good properties.

Green Lightweight Concrete Made from Natural Para Rubber Product

Duangden Raksritong, Danupon Tonnayopas, Wirach Taweepreda, Manoon Masniyom

Key engineering materials · 2013

Para Rubber Seed Shell (PRSS) as a coarse aggregate and coated by vulcanization and mixing epoxy natural rubber (ENR) was investigated. Natural rubber latex (60% DRC) was applied in two stages. Firstly stage, synthetic natural latex (ENR-35) solution was coated on the first layer of PRSS. After that, PRSS was coated by vulcanization in second layer. Then, pre-wetting was performed before mixing or casting the concrete for 5 days. Finally, CPRSS (Coated Para Rubber Seed Shell) was produced. The CPRSS aggregate was cast as self consolidation concrete (SCC) with different ratios of ordinary Portland cement: sand: CPRSS for 0.8-1: 0.6-0.85: 0.04-0.12 by weight, respectively and constant water/binder ratio at 0.45 throughtout this study. The ENR-35 was also used about 5% of the water content. However, the concrete was wrapped with polyvinyl sheet to prevent moisture loss during setting and curing in ambient temperature (29°C, 84%RH) for 28 days. The fresh concrete to slump test, harden concrete with bulk density and compressive strength of whole formulations was carried out to determine. The test result A8 indicted that the most ingredient suitable mixture of SCC involed cement: sand: CPRSS of 1:0.94:0.046. The SCC contained the slump as 120 mm, bulk density about 1916 kg/m3 and compressive strength was 37 MPa. Its was met specification of structural lightweight concrete. This beneficiation of SCC is also product as the green innovation building in terms of construction materials and resources, leaving minimal environmental impact, and having energy saving and eco-friendly materials.

Electrospun Epoxidized Natural Rubber with Poly(vinyl chloride) (ENR-PVC) Nanofibrous for PEMFC Applications

Kritsada Phatcharasit, Wirach Taweepreda, Kanoktip Boonkerd, Jin Kuk Kim

Advanced materials research · 2013

Various electrospun epoxized natural rubber / poly (vinyl chloride) (ENR/PVC) blend nonwoven membranes were prepared by electrospinning technique. Various concentration of epoxidized natural rubber (ENR) solution in N,N-dimethylformamide (DMF) were directly added to PVC solution for plasticization of the electrospun nanofibrous. Differencial thermal analysis (DTA), thermogravimetry analysis (TGA), fourier transfrom infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) were used to characterize the pristine and plasticized nanofibrous. DTA results indicated that the addition of ENR resulted in the shifting of glass transition temperature (Tg) towards lower temperatures. The blending of PVC with ENR is thermodynamically incompatible.

Feasibility Studies of Magnesium (II) Removal from Fresh Field Natural Rubber Latex Using Macroporous Cationic Exchange Resin

Sineenart Puangmanee, Wirach Taweepreda

Advanced materials research · 2013

The presence of magnesium ions (Mg2+) in fresh field natural rubber latex (FF-NRL) is a major concern for concentrated production. In general, Mg2+ is reduced by adding diammonia hydrogen orthophosphate (DAP) to FF-NRL. The reaction rate between DAP and Mg2+ in NRL is very slow and is the cause of waste latex sludge, waste time for more than 12 hours, and chemicals loss. Moreover, the waste latex sludge is toxic and has to be treated. In this research, the possibility of using cationic exchange resin to remove Mg2+ from the FF-NRL was investigated. The experiment was carried out by comparison the efficiency of difference commercial exchange resin on Mg2+ reduction rate after immersing in FF-NRL. The results were found that macroporous cationic exchange resin adsorped Mg2+ with highest rate. The Mg2+ content of NRL reduced to 100 ppm after immersing macroporous cationic exchange resin in FF-NRL for 6 hours. The performance of cationic exchange resin was increased after regenerate process with acid and can be used for further to reduce Mg2+ in FF-NRL. The morphology of cationic exchange resin was investigated using scanning electron microscope (SEM).

Deproteinized Natural Rubber as Chewing Gum Base for Nicotine Delivery

Wiwat Pichayakorn, Prapaporn Boonme, Wirach Taweepreda

Advanced materials research · 2013

This study aimed to prepare the nicotine chewing gums for smoking cessation using deproteinized natural rubber latex (DNRL) as gum bases due to its highly flexible property. The formulations were produced by the conventional heat melting and kneading methods. The experimental design was used to obtain the optimum 3 gum base formulations. Each formulation composed of olive oil as a plasticizer; sodium carboxymethylcellulose as an adsorbent; xylitol, mannitol and saccharin sodium as sweeteners instead of sugar. Gum base 1 and gum base 2 had the same sweetener amount but gum base 2 had the lower plasticizer amount, while gum base 1 and gum base 3 had the same plasticizer amount but different sweetener amount. Nicotine was added into each 3 gum bases (NCT1-3). The results showed no significant difference of appearance and taste. Their physicochemical properties were as following: pH of 8.45, 8.46, 8.54, hardness of 39.80, 36.28, 33.14 Shore A, initial modulus of 0.090, 1.260, 0.065 MPa, %elongation of 286, 403, 489%, drug content of 63.62, 70.95, 72.70%, and drug release when 500 times for force clamping of 48.72, 45.72, 67.74%, respectively. After storage at room temperature for 1 month, NCT1 and NCT2 showed unchangeable appearance, but NCT3 showed the slightly liquefied film and much sticky due to hygroscopic property of its sweetener. However, all formulations showed the significant reduction of drug amount which should be further improved in their stability properties.

Fabrication and Characterization of Epoxidized Natural Rubber-Chitosan Membrane

Wirach Taweepreda, Anuchit Wichianchom

Advanced materials research · 2013

The membranes obtained from the mixtures of epoxidized natural rubber latex (ENR) and chitosan solution were prepared and characterized. The chemical structure of the membrane was confirmed by ATR-FT-IR spectroscopy and found the peak at 1315 and 1155 cm-1 indicated ether linkage was formed between epoxide group and chitosan corresponding with an enhancement of their mechanical properties which were observed using dynamic mechanical thermal analysis (DMTA). The dielectric properties and ionic conductivity of membrane were investigated using LCR meter and found that the ionic conductivity was increased with increasing the chitosan content.