Nanocomposites with polypropylene/clay/wood flour were prepared by melt blending and injection molding. Thermal, mechanical and morphological properties were characterized. The addition of ballmilled clay, compatibilizer and wood flour significantly improved the thermal stability of the hybrids. The tensile modulus and strength of most hybrids was highly increased with the increased loading of clay, maleated polypropylene (MAPP) and wood flour (WF), compared to the PP/WF hybrids. The tensile modulus and strength of most hybrids were highly increased with the increased loading of ballmilled clay, MAPP and wood flour, compared to the hybrids with PP/WF. The transmission electron microscopy (TEM) photomicrographs illustrated the intercalated and partially exfoliated structures of the hybrids with ballmilled clay, MAPP and wood flour.
The flame-retardant coatings were prepared by blending the synthesized triphosphorus modified polyester in the previous paper and hexamethylene diisocyanate-trimer and curing it at room temperature. The characterization of the films of the prepared coatings was performed. It was confirmed that no deterioration of physical properties of PU coatings was observed with the increasing phenylphosphonic acid (PPA) contents. Flame retardancy was tested by a 45˚ Meckel burner method and LOI method. With the 45˚ Meckel burner method, CATBTP-20C and CATBTP-30C that contain 20 wt% and 30 wt% of PPA, flame retarding component, respectively, showed the first grade flame retardancy with 2.8~3.9 cm of char length ; and, with LOI method, they exhibited a good flame retardancy as a range of 30~32% of combustion values.
The polyamide-amide-imide (PAAI) was synthesized by reacting 4,4'-diaminobenzanilide (DBA) with trimellitic anhydride chloride using a two-stage heating. The precursor of polyamide-acids was formed at first stage and followed by the formation of imide of PAAI. Two polyamide-imides (PAIs) were prepared from benzidine (BZ) or 4,4'-diaminodiphenylether (DPE) with trimellitic anhydride chloride. These three polymers had glass transition temperature in the temperature range of 240-250℃. X-ray data were obtained on thin film specimens cured at 250℃. There was a minimal kind of short-range order consisting of the most probable distances between neighboring chains. The average segmental spacing of short-range order decreased in the order of polymers obtained from 4,4'-diaminobenzanilide (DBA), polyamide-imide, and 4,4'-diaminodiphenylether (DPE). The imidization of three polyamide-imides was confirmed by 15N MAS NMR and FT-IR spectroscopy. 15N NMR spectrum of cured polyamide-imide showed imide 15N peak, thereby providing an evidence for the imidization of three polyamide-imides.
Chemicals for cosmetics, including skin, the skin absorbs some of the research in the field of science or pharmacy recently, about the environment and the health of the heightened interest in skin absorption, and many other human attributes and absorption evaluation studies are underway in various areas. In this study, The effects of commercial permanent wave products to skin which are composed with cysteine and bases using rat. Results are as follows; the content of penetration 4 hours later with steady state and no significant changeable after 20 hours later. In cysteine groups lag time and permeability coefficient of young skin is 3.32hr and 0.102μg/cm2·hr, lag time and permeability coefficient of old skin is 4.04hr and 0.106μg/cm2·hr. In conclusion of study lag time and permeability coefficient in old skin and wounded skin are faster than healthy skin. We notified that fine rinkle and rash of skin were changeable in the case of treating with permanent wave drugs than normal skin.
xTiO2-ySiO2 system photocatalysts were developed by sol-gel method based on the change of production parameters, and their structure of crystallization and the specific surface area were measured. Considering the efficiency of the ethanol and phenol degradation using the catalyst, the conclusions were obtained as follows: By means of X-ray analysis of xTiO2-ySiO2 powder that is obtained from Titanium and Silicon alkoxide by sol-gel process, it is shown that crystal structure of anatase type is a dominating structure and, on the other hand, the structure of rutile also partly exists. The increase of SiO2 contents causes the decrease of the degree of crystallization of the gel, whereas the specific surface area preferentially increases. It is shown that more than 90% of ethanol and phenol are degraded when reaction time is about three and an hours, and the maximum degradation rate of ethanol and phenol is shown in 60TiO2-40SiO2 catalyst.
Transdermal therapeutic system(TTS) is often used as the method of drug dosage into the epidermic skin. Natural polymer were selected as ointment material of TTS. We investigated the permeation of natural polymer ointment containing drug in rat skin using horizontal membrane cell model. Permeation properties of materials were investigated for water-soluble drug such as Nicotinic acid N-oxide in vitro. These results showed that skin permeation rate of drug across the composite was mainly dependent on the property of ointment base and drug. Proper selection of the polymeric materials which resemble and enhance properties of the delivering drug was found to be important in controlling the skin permeation rate. This result suggests a possible use of natural polymer ointment base as TTS of antihyperlipoproteinemic agent.
The hydrosilylation is an addition reaction of Si-H bond to unsaturated double bonds, which provides a convenient mechanism to synthesize poly(dimethylsiloxane-co-methylsiloxane)copolymer having siloxy units in polymer backbone. In this study, Poly(dimethylsiloxane-co-methylsiloxane) copolymer was synthesized through the polymerization reaction of cyclopentasiloxane with poly(methyl-hydrogen) siloxane. Silicone-hydrogen functional group of the poly(dimethylsiloxane-co-methylsiloxane) copolymer was substituted to the alkyl groups by hydrosilylation. And their structure was analyzed with FT-IR, H-NMR and GPC instruments, respectively. Surface tension of the synthetic compounds is increased from 22dyne/cm to 25dyne/cm according to increase additional EO moles. The cmc which was evaluated by surface tension was ranged 10-5 to 10-4mol/L and it was decreased according to increase of dimethyl siloxyl content. HLB number of these surfactants was evaluated 9.5 to 11.5 range. These silicone surfactants is applied to self-emulsifier defoamer and personal care products as surface tension depressant, emulsifier, foam control agent.
In this article a reliable and rapid method based on specific turbidimetry is proposed for the determination of sizes of nanoparticles. Conventionally in specific turbidimetry specific turbidities for a colloidal dispersion are measured as a function of light wavelength, and compared to theoretical values calculated from Mie scattering theory for presumed particle sizes. In contrast specific turbidity at a fixed wavelength is measured in the proposed method, and particle sizes are determined from the prepared calibration curve. The calibration curve is a plot of specific turbidity vs particle size and in this case the specific turbidities are measured for a couple of samples of known sizes.
Development of white light emitting materials has been an interesting area for scientists and scientists have developed many organic, polymer and inorganic materials for white electroluminescent devices. Among them, single component small molecules gave best results in terms of efficiency, simplicity of device fabrication, and CIE values. Therefore, this review covers detailed discussion about syntheses of small compounds used in white organic light emitting devices until 2007.
The core-shell latex particles were prepared by sequential emulsion polymerization using alkyl methacrylate as a shell monomer and potassium persulfate (KPS) as an initiator. We study the effects of core-shell structure of calcium carbonate/alkyl methacrlyate in the presence of an anionic surfactant sodium lauryl sulfate (SLS) and polyoxyethylene alkyl ether sulfate (EU-S133D)). The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer and morphology of latex by transmission electron microscope (TEM).
This study was done to investigate the antidiabetic and antioxidant effects of Lycii fructus in Streptozotocin (STZ)-induced diabetic rats. Diabetes was induced by intravenous injection of STZ at a dose 45mg/kg.b.w. dissolved in citrate buffer(pH4.5). The ethanol extract of Lycii fructus was orally administrated once a day for 7 days. The contents of serum glucose, total cholesterol were significantly decreaed (p<0.05) in Lycii fructus treated group compared to the those of STZ-control group, also content of Triglyceride (TG), Altherogenic index (AI) were decreased, but not statistically significant. But high density lipoprotein (HDL)-cholesterol and HDL-cholesterol/total cholesterol ratio (HTR) were increased in Lycii fructus treated group compared to the those of STZ-control group. The content of hepatic glycogen and activities of glucose-6-phosphate dehydrogenase(G-6PDH), glutathione-s-transferase(GST), superoxide dismutase(SOD) were significantly increased(p<0.05), glucose-6-phos-phatase(G-6pase)was significantly decreased(p<0.05) and The glutathione(GSH), glucokinase(GK) were increased. But not statistically significant In Lycii fructus treated group compared to the those of STZ-control group These results indicated that ethanol extract of Lycii fructus would have antidiabetic and antioxidant effects in STZ-induced diabetic rats.
The ion exchangers supported on silica gel containing primary, secondary, or tertiary amine groups show a behaviour that is weakly acidic, while the quaternary salts are strongly acidic. These properties change according to the hydrophilicities of the modifier functional groups. Ammonium salt derivatives supported on silica gel were prepared from silica modified with 3-Aminopropyltriethoxysiliane and N-3-(Trimethoxysilyl)propylehtylene diamine. The preparation and the ion exchange properties of two systems were discussed. Two systems have different hydrophilicities and contain ammonium chloride derivatives of 3-amminopropyltriethoxysilane and N-3-(triehtoxysilyl)propyl ethylene diamine supported on silica gel, SA+/Cl- and SA+/Cl-, respectively. The high affinity to perchlorate ion presented by the SA+/Cl- through the equilibrium studies of ion exchange led us to its application as an ion selective electrode for the perchlorate ion. The determination of the perchlorate ion in the presence of other anions and in complexes is very difficult. Few analytical methods are available and most of them are indirect. Both materials showed potential use as an ion exchanger; they are thermically stable, achieve equilibrium rapidly in the presence of suitable exchanger ions, and are easily recovered.
Pretreatment of eliminating FFA is needed to make biodiesel from animal fat recovered from leather wastes because its acid value is high. This study was carried out to investigate the influence of 4 different pretreatment methods, which are heterogeneous catalyst method, ion exchange resin method, low pressure.high temperature method, and alkali method on the eliminating FFA and fatty acid composition. The results showed that the rate of eliminating FFA increased in the order of alkali method > catalyst method > low pressure high temperature method > ion exchange method. In the case of pretreatment of alkali method using NaOH, the rate of eliminating FFA appeared more than 86% regardless of acid value. Therefore, it was considered that alkali method using NaOH was the most effective in the view of economical and productive aspects, taking it into account that the acid value of animal fat recovered from fleshing scrap generated during leather making processes was 7 to 8.
In the present study, impedance characteristics for AgO-Zn cell at various State-of-Charge (SoC) has been studied. The impedance measurements of AgO-Zn cell at various SoC were made over the frequency range from 100kHz to 10mHz with an amplitude 5mV. The impedance parameters have been evaluated by the analysis of the data using an equivalent circuit and a Non-linear least squares (NLLS) fitting method. The total resistances reflects the SoC of the cell. This indicates that the total resistance is important parameter for predicting SoC of AgO-Zn cell.
Dipalmitoyl phosphatidyl choline and p-nitrophenyl palmitate were directly sonicated in acidic water for 6 minutes to give clear stock solutions. The catalytic hydrolysis of p-nitrophenyl palmitate was studied at 30-50℃ in the presence of unilamellar vesicle and mixture of unilamellar and multilamellar aggregates. The difference of reaction rate between unilamellar and multilamellar was observed. The rate of unilamellar reaction compared to the rate of mixture reaction showed more catalytic effect. The phase transition temperature of vesicle was measured at 37-44℃.
This study was conducted to made a grid alloy (Pb-Ca-Sn-Al) which has a temporary composition ratio in order to improve the efficiency of lead acid batteries. The positive activity material made a 3BS(tri-basic lead sulfate; 3PbO·PbSO4·H2O) by a low temperature curing and it evaluates the plate efficiency through the life cycle testing. The initial current capacity of low temperature curing plate was excellent but the life cycle was not good (S1). As for the S2 plate, however, the initial current capacity and the life cycle were superior.
1,4-Dioxane is an EPA priority pollutant often found in contaminated ground waters and industrial effluents. Conventional water treatment techniques are limited to decompose this compound effectively. Therefore, an advanced oxidation process system (AOP) was used for the degradation of 1,4-dioxane. This research investigates the effect of adding oxidants, such as ozone, air, and H2O2 during the UV irradiation of 1,4-dioxane solution. In order to analyze 1,4-dioxane, a modified 8270 method, which is an improved method of U.S EPA 8720, was used. Degradation efficiencies of 1,4-dioxane by only UV irradiation at various temperatures were not significant. However, The addition of oxidants and air bubbling in the UV irradiation system for 1,4-dioxane decomposition showed the higher 1,4-dioxane degradation rate. And, during AOP treatment the tendency of TOC changes was similar to that of 1,4-dioxane decomposition rate.
In general, anionic and cationic surfactants are incompatible because their mixtures form insoluble complexes. There are, however, some complexes that are soluble and behave like regular surfactants, specifically like nonionic surfactants, thus named pseudo-nonionic surfactant complexes. Pseudo-nonionic complexes are more effective and efficient than their ionic surfactant components as shown by their equilibrium and dynamic surface tensions and interfacial tensions. They pack at the interface more than their ionic components. Since, pseudo-nonionic complexes show their own characteristics, they can be treated as separate classes of surfactants distinct from ionic and nonionic surfactants. Novel cationic surfactant was synthesized, having the polyhydroxyl group at the head group. We found that aqueous mixtures of our cationic surfactant and usual anionic surfactant(SDS) could form homogeneous solutions even at high concentration. The properties of mixed surfactant solutions were measured. Foam stability, CMC(critical micelle concentration), water hardness tolerance and thickening effect were tested. The foam stability of mixed surfactants was very good and various synergy effects were observed.
The effects of fillers on the mechanical and thermal properties of glass/novolac composites have been studied. The matrix polymer and reinforcement were novolac type phenolic resin and milled glass fiber, respectively. Three different fillers, such as calcium carbonate, aluminum oxide, and wood powder were used for glass fiber reinforced plastic(GFRP) manufacture. Gravity, moisture content, tensile and flexural strength were measured to analyze the mechanical properties of GFRP and the final composites was burned in the electronic furnace at 1000℃ to confirm thermal properties GFRP containing aluminium oxide shows the highest thermal stability with 32% of weight loss at 1000℃ for one hour. GFRP containing calcium carbonate shows the maximum flexural strength (146 MPa), but that containing wood powder dose the highest tensile strength (65 MPa). Conclusively, we found that the characteristics of final composites strongly depend on several factors, such as types of materials, contents and chemical affinity of fillers. Therefore, it is very important to set up the combination of fillers for GFRP manufacturing to improve both mechanical and thermal properties at the same time.
To prepare weather-resistant modified silane acrylic resin coatings for an architectural purpose, tetrapolymers were synthesized by radical polymerization. 3-Methacryloxypropyltrimethoxysilane (MPTS) as a silicone monomer and n-butyl acrylate, methyl methacrylate, and n-butyl methacrylate as acrylic monomers were used. The composition of monomers was adjusted to fix the glass transition temperature of acrylic polymer for 20℃. The composition of MPTS in the synthesized polymer were varied from 10 wt% to 30 wt%. On the basis of synthesized resin amber paints were prepared and their physical properties and effects on weatherability were examined. The presence of MPTS in modified silane acrylic resins generally resulted in low molecular weight and broad molecular weight distribution, and also lowered the viscosity of the copolymers. The coated films prepared from these resins showed good and balanced properties in general. Adhesion to the substrate was outstanding in particular. Weatherability tests were carried out in three different types such as outdoor exposure, QUV, and SWO. The test results showed that the modified silane acrylic resins containing 30 wt% of MPTS had superior weathering properties.