• Elastomers and Composites
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• v.57 no.4
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• pp.222-230
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• 2022

In this study, a low-heat additive with a crosslink structure was dispersed in asphalt to simultaneously lower the production temperature of, and to modify the asphalt binder. This low-heat additive was prepared by different feeding ratios of styrene-butadiene-styrene (SBS) and polyvinylchloride (PVC) as polymer modifiers, and ZnO as a crosslinking agent. In order to confirm the crosslinking density and compatibility of the crosslink structured low-heat additive with asphalt, surface free energy, swelling ratio, differential scanning calorimetry (DSC), and scanning electron microscope (SEM) parameters were carefully investigated to examine this relationship, and the role of the crosslink structured low-heat additive. In addition, by measuring the penetration and softening point of the asphalt binder, it was confirmed that it corresponds to PG 64-22. With increasing ZnO in the crosslink structured low-heat additive, the swelling ratio decreased, leading to an increase in crosslinking density. The crosslink structured low-heat additive and the asphalt binder were found to be compatible with each other by DSC and SEM analysis.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2007.11a
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• pp.145-146
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• 2007

• Journal of Pharmaceutical Investigation
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• v.26 no.2
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• pp.137-144
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• 1996

The study was carried out for the preparation and evaluation of a buoyant hydrogel matrix (BHM), which is buoyant in a neutral or in pH 2.0 buffer solution, by the aspects of buoyancy, swelling, and drug release. Physical mixtures of HPC and CP in various molar ratio were employed as a mucoadhesive polymer which swells and controls the rate of drug release. Anhydrous citric acid and sodium bicarbonate in the molar ratio of 1:3 were employed as effervescing agents which provide a buoyancy for the mucoadhesive polymeric matrix. The buoyancy in vitro was expressed as both floating time$(T_{fl})$ and surfing time$(T_{sf})$, which are the time required for floating from the bottom to the surface of the medium and the time to keep the floated state at the surface of medium during release studies, respectively. A close relationship was observed between the buoyancy and the amount of effervescing agent added. $T_{fl}$ of the buoyant hydrogel matrices were decreased to about 10 seconds linearly with increasing the amount of effervescing agent in the range of 5 to 15%. $T_{sf}$ of the buoyant hydrogel matrices were varied from 1 to 3 hr depending on the amount of effervescing agent. The swelling was observed by changes in diameter of the buoyant hydrogel matrices in distilled water or acidic buffer solution, resulted in dependences on pH and the amount of effervescing agents. The release of hydrochlorothiazide from the buoyant hydrogel matrices were followed by apparent zero-order kinetics, while the buoyant hydrogel matrices were floated at the surface and maintaining their swollen shapes.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.151-157
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• 1999

The study was investigated the improved printing effect of heat transfer ability for the cotton fabric treated with disperse dyes. Some important factors were studied to determine the most optimal conditions such as concentration of dye, treated time and temperature, after treatment and before treatment using swelling agent, and molecular weight of dye. The fastness to laundering and light for heat transfer printing was measured.The optimal conditions of heat transfer printing for cotton fabric treated with disperse dye were concentration of 5% owf, treated temperature of $200^{\circ}C$, treated time of 3 minute. The diffusion of disperse dyes inside cotton fabric was accelerated as a result of swelling agent such as glycerin, ethylene glycol, tetramethylene glycol, propylene glycol using in this study. The effects of heat transfer printing were increased that the increasement of before treatment time for swelling agent, decrease of molecular weight of dye.

• Macromolecular Research
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• v.17 no.4
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• pp.250-258
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• 2009

One-step seeded polymerization was used to prepare $7{\sim}10{\mu}m$ of crosslinked monodisperse spheres with four crosslinking agents using $4.68{\mu}m$ poly(methyl methacrylate)(PMMA) seed particles in aqueous-alcoholic media in the absence of the swelling process. The crosslinking agents used were ethylene glycol dimethacrylate(EGDMA), allyl methacrylate(AMA), 1,6-hexanediol diacrylate(HDDA) and trimethylolpropane trimethacrylate(TMPTMA). The effects of the type and concentration of the crosslinking agents on the swelling, pore size, thermal property of the networks and morphology of the particles were studied. The chemical structures and concentrations of the crosslinking agents affected both the swelling ratio and the porosity of the networks. In addition, the chemistry of the reactive vinyl group and chain length of the crosslinking agents affected the stability of the monodisperse particles of the ultimate morphology.

• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.132-136
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• 1995

This study was carried out to elucidate the effective of some swelling agents on the soaking treatment of raw silk. The swelling of raw silk is commonly practiced by soaking in warm water, However, it is not enough to weaving of raw silk. Therefore, the combination of some chemical agents were tested to improve the swelling ratio of raw silk. The pretreatment of raw silk in 0.4N sodium carbonate aqueous solution before soaking in the mixed solution of Emulon 1 g/l, Emanol 0.5 g/l and 0.04N sodium silicate increased the swelling ratio by 57%, compared to the nontreatment. In SEM observation, the surface of raw silk soaked in swelling agents was swollen and smoothed.

• Macromolecular Research
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• v.13 no.2
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• pp.135-140
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• 2005

Poly(vinyl alcohol) (PVA) membranes crosslinked with poly(acrylic acid-co-maleic acid) (PAM) were prepared to investigate the effect of aging on their morphology by swelling them for up to 7 days. PAM was used both as a crosslinking agent and as a donor of the hydrophilic-COOH group. A $30 wt\%$ weight loss of the dry membrane was observed in the swelling test after 6 days. The surface of the membrane was dramatically changed after the swelling test. The surface roughness of the PVA/PAM membrane was increased, as determined by atomic force microscopy (AFM). The swelling loosened the polymer structure, due to the release of the unreacted polymer and the decomposition of the ester bond, thereby resulting in an increase in the free volume capable of containing water molecules. The water molecules present in the form of free water were determined by differential scanning calorimetry (DSC). The fraction of free water increased with increasing swelling time. The swelling of the membrane may provide space for the transport of protons and increase the mobility of the protonic charge carriers. The proton conductivity of the membranes measured at T= 30 and $50^{\circ}C$ was in the range of $10^{-3} to 10^{-2} S/cm$, and slightly increased with increasing swelling time and temperature.

• Polymer(Korea)
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• v.28 no.1
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• pp.18-23
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• 2004

Superabsorbent poly(potassium acrylate-co-acrylamide)s were synthesized in particle form using inverse suspension polymerization technique. Mean diameter of the prepared polymer particles decreased from 300 to 50 $\mu\textrm{m}$ with increasing surfactant concentration. The dynamic and equilibrium swelling behaviors during water absorption and drying process were investigated by weight measurement. The swelling ratio of polymer particles in water changed according to not only polymer crosslinking density, but particle size, saline concentration of aqueous medium, and copolymer compositions. Water sorption amount was increased with decreasing particle size, crosslinking agent concentration, and ion concentration in bulk solution. Being different from the water sorption process, the drying process was not significantly affected by particle size, polymer composition, or crosslinking amount.

• Nuclear Engineering and Technology
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• v.10 no.4
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• pp.195-201
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• 1978

The radiation-induced graft polymerization of methacrlic acid and methyl methacrylate onto a polyester fabric was investigated with ${\gamma}$-ray as the radiation source, and the rate of grafting was examined. When acrylic acid, methacrylic acid, and methyl methacrylate were grafted onto a polyester fabric, grafting efficiency was depened upon the dielectric constant of the solvent in the monomer mixture. The yield of the graft polymerization was related to the total dose, the concentration of the monomer, and the concentration of the swelling agent. The melting point and the glass transition temperature of MA and MMA grafted copolymers were analysed by means of DTA. Physical properties, such as the moisture regain, the antistatic property, and the wicking time were measured.

• Journal of the Korean Chemical Society
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• v.58 no.1
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• pp.92-99
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• 2014

The pH sensitive hydrogels composed of N-isopropylacrylamide (NIPA) and acryloyl phenylalanine (APA) were prepared by redox polymerization using N,N'-methylenebisacrylamide (MBA) as a crosslinker. Anti-inflammatory and analgesic agent, Keterolac Tromethamine (KT), was loaded successfully into poly(NIPA-co-APA) copolymeric hydrogels by swelling equilibrium method. To understand the nature of drug in the polymeric matrix, the newly synthesized drug loaded poly(NIPA-co-APA) copolymeric hydrogels were characterized by using differential scanning calorimetry (DSC) and X-ray diffraction (XRD) techniques. The scanning electron microscopy (SEM) technique result indicates the spherical smooth surface of the hydrogels. The drug (KT) releasing nature of the poly(NIPA-co-APA) hydrogels was studied in pH 1.2 and 7.4. Effects of drug loading, crosslinking agent, pH and the ionic strength of the external medium on swelling of hydrogels were also investigated.