• Macromolecular Research
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• v.13 no.6
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• pp.483-490
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• 2005

A novel, polysaccharide-based, superabsorbent hydrogel was synthesized through crosslinking graft copolymerization of methacrylic acid (MAA) onto kappa-carrageenan ($_{k}C$), using ammonium persulfate (APS) as a free radical initiator in the presence of methylenebisacrylamide (MBA) as a crosslinker. A proposed mechanism for $_{k}C$­g-polymethacrylic acid ($_{k}C$-g-PMAA) formation was suggested and the hydrogel structure was confirmed using FTIR spectroscopy. The effect of grafting variables, including MBA, MAA, and APS concentration, was systematically optimized to achieve a hydrogel with the maximum possible swelling capacity. The swelling kinetics in distilled water and various salt solutions were preliminarily investigated. Absorbency in aqueous salt solutions of lithium chloride, sodium chloride, potassium chloride, calcium chloride, and aluminum chloride indicated that the swelling capacity decreased with increased ionic strength of the swelling medium. This behavior can be attributed to the charge screening effect for monovalent cations, as well as ionic crosslinking for multivalent cations. The swelling of super absorbing hydrogels was measured in solutions with pH ranging from 1 to 13. In addition, the pH reversibility and on-off switching behavior, at pH levels of 3.0 and 8.0, give the synthesized hydrogels great potential as an excellent candidate for the controlled delivery of bioactive agents.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3163-3172
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• 2010

In this work, a novel method to synthesis of an acrylic superabsorbent hydrogel was reported. In the two stage hydrogel synthesis, first copolymerization reaction of acrylonitrile (AN) and acrylamide (AM) monomers using ammonium persulfate (APS) as a free radical initiator was performed. In the second stage, the resulted copolymer was hydrolyzed to produce carboxamide and carboxylate groups followed by in situ crosslinking of the polyacrylonitrile chains. The results from FTIR spectroscopy and the dark red-yellow color change show that the copolymerization, alkaline hydrolysis and crosslinking reactions have been do take place. Scanning electron microscopy (SEM) verifies that the synthesized hydrogels have a porous structure. The results of Brunauer-Emmett-Teller (BET) analysis showed that the average pore diameter of the synthesized hydrogel was 13.9 nm. The synthetic parameters affecting on swelling capacity of the hydrogel, such as AM/AN weight ratio and hydrolysis time and temperature, were systematically optimized to achieve maximum swelling capacity (330 g/g). The swollen gel strength of the synthesized hydrogels was evaluated via viscoelastic measurements. The results indicated that superabsorbent polymers with high water absorbency were accompanied by low gel strength. The swelling of superabsorbent hydrogels was also measured in various solutions with pH values ranging from 1 to 13. Also, the pH reversibility and on-off switching behavior makes the hydrogel as a good candidate for controlled delivery of bioactive agents. Finally, the swelling of synthesized hydrogels with various particle sizes obey second order kinetics.

• Macromolecular Research
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• v.16 no.8
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• pp.734-740
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• 2008

A new crosslinked, poly(acrylic acid)-based, dehydrating agent was synthesized through solution polymerization. The Taguchi method, a robust experimental design, was adopted to optimize the synthetic conditions based on the moisture and water absorbing capacities of the dehydrating agent. The method applied for the experiment was a standard L27 ($3^8$) orthogonal array with eight parameters and three levels. By analyzing the variance of the test results, the most effective parameters to control the moisture absorbing capacity (MAC) and its rate were the kind of alkaline base (LiOH, NaOH, or KOH) used as a neutralizing agent of the acrylic acid monomer and the degree of neutralization: The maximum MAC of 40% was achieved at only 2 hat $32^{\circ}C$ and 50% RH when KOH was used as a base and the degree of neutralization was 90%, respectively. However, the water absorbing capacity (WAC) of the resulting dehydrating agent was very low at 158 g/g, indicating that WAC is unaffected by MAC and its rate in this system. The surface morphologies of the agents were examined using scanning electron microscopy (SEM).

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.307-311
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• 2004

In cosmetics industry, we notice that the research should be focused on developing well-being related products such as SPA, esthetique, mass-customization, organics, naturals besides inner beauty and body shaping products. These well-being related products should satisfy customers' expectation about not only concern about health but also safety, reliability, and ethos about products. In that context, the systematic way for well-being related research in cosmetics should be carried out concerning anti-aging with fat-decom-position, vitamin, polyphenol, and organics. At the same time, there are several important factors in this research like augmenting efficacy, controlling skin-absorbency, skin-adaptability, forming, stabilization of activated com-ponents, improving sustainability, and developing new materials based on dermatologic and emotional science. It should be also emphasized that recent technologies such as bio-technology, nano-technology, and natural-material-technology are the cornerstones of developing well-being products.

• Proceedings of the Korean Fiber Society Conference
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• 1990.06b
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• pp.8-8
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• 1990

A new method for the graft polymerization of acrylonitrile onto starch is presented. Graft polymerization of acrylonitrile onto starch and the subsequent hydrolysis in sodium hydroxide solution to prepare absorbents is well known. This process has been utilized to produce the commercial product, Super Slurper. In a typical batch process, ~5% starch in water mixture is gelatinized at $95^{\circ}C$ under stirring for 1 hour then cooled to room temperature. The graft polymerization itself is carried out for approximately 2 hours at $25~30^{\circ}C$ on the gelatinized starch by eerie ion initiation. In this study, graft polymerization of acrylonitrile onto starch via a reactive extrusion process which is a continuous, efficient process is described. Initial concentration of starch in water is 35% and the reaction temperatures are between $50~80^{\circ}C$. However, the most significant difference in the reactive extrusion process is the short time in which the graft polymerization takes place. Preliminary results on the properties of graft polymerization products obtained from the reactive extrusion process are compared to those obtained from the batch process as well as the absorbency of the hydrolyzed samples. Absorbent material has also been prepared by sequential grafting and saponification in the extruder followed by a 2 hour heat treatment of the extrudate in an air circulated oven at $100^{\circ}C$.

• Advances in materials Research
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• v.11 no.3
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• pp.191-209
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• 2022

Very slow degradation of synthetic based polymers has created a severe environmental issue that increased awareness towards research in polymers of biodegradable property. Soy protein isolate (SPI) is a natural biopolymer used as matrix in green composites but it has limitations of low mechanical properties and high water sensitivity. To enhance mechanical properties and reduce water sensitivity of Jute-SPI composites, SPI was modified with pine rosin which is also a natural cross-linking agent. 30% glycerol on the weight basis of a matrix was used as a plasticizer. The fibre volume fraction was kept constant at 0.2 whereas the pine rosin in SPI ranged from 5% to 30% of the matrix. The effects of pine rosin on mechanical, thermal, water sensitivity and surface morphology have been characterized using various techniques. The mechanical properties and water absorbency were found to be optimum for 15% pine rosin in Jute-SPI composite. Therefore, Jute-SPI composite without pine rosin and with 15% pine rosin were chosen for investigation through characterization by Fourier transforms infrared spectroscopy (FTIR), Thermo-gravimetric analysis (TGA), X-Ray diffraction (XRD) and Scanning electron microscope (SEM). The surface morphology of the composite was influenced by pine rosin which is shown in the SEM image. TGA measurement showed that the thermal properties improved due to the addition of pine rosin. Antimicrobial test showed antimicrobial property in the composite occurring 15% pine rosin. The research paper concludes that the modification of SPI resin with an optimum percentage of pine rosin enhanced mechanical, thermal as well as water-resistant properties of jute fibre reinforced composites.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.974-978
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• 1999

This study was concerned with the scouring effect of anionic surfactants, PAPE(sodium polyoxyethylene alkyl phosphoric ester) for cotton fibres. Sodium polyoxyethylene(7) nonylphenyl phosphoric ester(CPB-1) and the sodium polyoxyethylene(7) tridecyl phosphoric ester(CPB-2) were synthesized by the phosphoric esterification reaction from NP-7(polyoxyethylene(7) nonylphenyl ether) and TDA-7(polyoxyethylene(7) tridecyl ether) as scouring agents. Defoaming ability, fibre wetting time and absorbency rate of scouring agents were investigated. Being compared with the conventional scouring agent(Ultravon GP; Ciba-guyge Co.), CPB-1 and CPB-2 showed a higher defoaming ability in the cotton scouring process at room temperature. And CPB-1 has a higher wetting effect than the agents, CPB-2 or GP in distilled water bath but CPB-2 showed more scouring effect in 1.2 wt % NaOH solution bath.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.9_10 s.157
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• pp.1344-1353
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• 2006

The purpose of this research is to investigate the actual wearing conditions of working uniform and identify problems for the aircraft mechanic. For this study, questionnaire surveys were conducted dividing according to styles of clothing; one-piece and two-piece styles. Subjects were 343 men working in flight line. Questionnaire of 159 two-piece styles and 184 one-piece ones were used in analysis. The results of the study are as follows; The result about wearing each type of working uniform showed that the two-piece one is always as the air force uniform, whereas the one-piece one is worn only a few times. They felt inconvenience during all operations except in the sitting position, crawling position, and positions in which they were using tools. Accordingly, the result of the functionality reported dissatisfaction on all question items. Therefore, uniform of two-piece style achieved better results on all questions related to motional flexibility and functionality. Questions on changes to finishing methods showed that each airline employed different methods for both two-pieced and one-pieced uniforms. The answers about the unstitched or worn-out parts of the two-piece garments showed that pants were unstitched on the inner seam of the trouser leg and hip regions, but the upper one was not. In case of the one-pieced uniform, the parts of wearing out is the seam of hip and the unstitched parts are knee region and hem line of pants. Questions concerning their satisfaction with the material of uniforms indicated a high rate of dissatisfaction, particularly in its ventilation and absorbency. Questions concerning the preferred design of working uniform indicated a preference for two-piece uniform rather than one-piece ones.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.4
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• pp.553-562
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• 2010

This survey investigates the conditions of summer working uniforms for contracted foodservice workers. The data were obtained from 67 workers through in-depth interviews (July 2005~October 2005). The results of study are as follows: The working environment changed to menu and cooking method (air temperature $28\sim37^{\circ}C$, humidity 72~86 %RH, radiant temperature $27\sim37^{\circ}C$, air velocity 0.14~0.37m/sec). They answered that the working environment has high temperatures, humidity, excessive noise, and liability to slide. The typical accidents were burns, cuts, slide, and ligament injuries in the workplace. Work duties consisted of cooking, serving food, washing, and cleaning up leftover food. All the employees carried out multi tasks. The primary working postures and motions were standing, crouching, and lifting. The female workers usually wore underwear (panty and brassiere), upper and lower work wear, aprons, waterproof-aprons, cotton-gloves, rubber-gloves, socks, and rubber-boots. The satisfaction of the uniform was relatively low for trousers and waterproof-aprons. The answer about the fit was generally "comfortable." They answered "back," "chest," and "head" were wet with perspiration during work. The uncomfortable parts were the crotch and neck. Questions concerning their satisfaction with the material of uniforms indicated a high rate of dissatisfaction, particularly for ventilation and absorbency. In case of the colors of the working uniform, workers preferred white color for the upper part, and black color for the lower part.

• Journal of the Korea Fashion and Costume Design Association
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• v.7 no.2
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• pp.11-24
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• 2005

The purpose of this study was to obtain and offer useful information on innerwear industry through an analysis of consumer purchasing behavior and preference of their between the 20's and 60's. From 310 questionnaires that were distributed, 310 with usable data were coded for further statistical analysis including descriptive statistics(frequency and chi-square test), by using SPSSWIN 10.0. The results were as follows: The results show that since the surveyed women's purchasing patterns were varied according to their ages it is necessary to develop new items and designs tailored for particular needs and wants of each age group. For those in their 20's, it is suggested that the innerwear design may consider reflecting the trend of the young women nowadays as characterized by a major fashion-led group who regard fashion as a way of expressing themselves and are not hesitant to wear clothing designed to be exposed their body. The innerwear products for women in their 30's and 40's should emphasize on the aspects of customizing and satisfying these women's different lifestyles. The study also reveal that for age groups of the 50's and 60's women these products should be developed in a way to intensify functions of thermal property and absorbency coupled with a classic design rather than daring styles. In conjunction with material developments it is necessary to establish a sizing system for the knitted innerwear products which reflect the specific characteristics of women's body type in their middle-and later years.