• Journal of the Korean Applied Science and Technology
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• v.20 no.1
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• pp.27-32
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• 2003

The core-shell latex particles were prepared by sequential emulsion polymerization of alkyl methacrylate and styrene(ST) by using an water-soluble initiator(APS) after preparing monomer pre-emulsion in the presence of an anionic surfactant(SDBS). In organic/organic core-shell polymerization, the pre-emulsion method, which minimized required quantity of sulfactant, has been used to increase the conversion rate and the stability of core-shell latex particles as well as to reduce the formation of secondary particle that cause problems of soap-free emulsion during shell polymerization. We used several methods to observe the core-shell structure. The core-shell structure was studied by measuring pH change during hydrolysis by NaOH, glass transition temperature($T_g$) by differential scanning calorimeter(DSC), morphology of latex by transmission electron microscope(TEM) and change of particle size and distribution by a particle analyzer.

• Journal of the Korean Applied Science and Technology
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• v.18 no.4
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• pp.316-324
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• 2001

To prepare an acrylic type pressure-sensitive adhesive, quarternary polymers were synthesized from butyl acrylate (BA), 2-ethyl hexyl acrylate (2-EHA), methyl methacrylate (MMA), and 2-hydroxy ethyl methacrylate (2-HEMA). The quarternary polymers were identified by FT-IR and Molecular weight was measured by Gel Pearmeation Chromatography. Also, viscosity, solid content and peel strength were examined. The peel strength was 160 $g_{f}/25$ mm when the volume ratio of feed monomer to solvent was 1.3:1, and the ratio was relevant to commercial usage. The pot life of adhesive was 30 sec at the 50 m/min of heat treatment rate at, and it indicated that the minimum drying time was 30 sec. In weathering resistance test, peel strength of $160{\sim}180$ $g_{f}/25$ mm after 1000 h, with no residual remains on the adhesive surface.

• Elastomers and Composites
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• v.57 no.2
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• pp.29-39
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• 2022

In this research, the relationships between the chemical structures of 10 different acrylate monomers with 3 different cross-linking monomers were evaluated. The thermal stabilities of the prepared copolymers were evaluated by their weight-loss percentage through thermogravimetric analysis, and their glass-transition temperatures were analyzed using differential scanning calorimetry. Based on the results, some relationships between the chemical structures of the monomers and their properties were derived and are discussed herein.

• Journal of the Korean Applied Science and Technology
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• v.21 no.3
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• pp.259-266
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• 2004

Film properties of monodispersed model composite latexes with particle size of 190 nm, which consist of n-butyl acrylate as a soft phase monomer and methyl methacrylate as a hard phase monomer with different morphology was examined. Five different types of model latexes were used in this study such as random copolymer particle, soft-core/hard-shell particle, hard-core/soft-shell particle, gradient type particle, and mixed type particle. Tensile strength and tensile elongation at break of final films were evaluated. Those properties can be interpreted in terms of PBA/PMMA phase ratio and their morphology. The interfacial adhesion strength was also evaluated using $180^{\circ}$ peel strength measurement and cross hatch cutting test.

• Journal of the Korean Chemical Society
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• v.64 no.6
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• pp.354-359
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• 2020

This research was conducted to analyze the compatibility of used monomers and produce the high functional contact lens material containing silicone monomers. Silicone monomer (Sil-OH), Trimethylsilylmethacrylate (TSMA) were used as additives for the basic combination of Polyhedral Oligomeric Silsesquioxane (POSS), methyl methacrylate (MMA) and methyl acrylate (MA). And also, the materials were copolymerized with ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent, AIBN (thermal polymerization initiator) as the initiator. It is judged that the fabricated lenses of all combinations are optically excellent and thus used monomers have good compatibility. Measurement of the optical and physical characteristics of the manufactured hydrophilic lens material were varied in each case. Especially TSMA with POSS increases the oxygen permeability and Sil-OH with POSS increases the wettability by the addition of Sil-OH. These materials were considered to have compatibility each other, so it can be used in functional contact lens material.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1444-1446
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• 2009

The atmospheric pressure plasma polymerization of acrylate monomers was carried out to have dielectrics with easy preparation and high performance. The effects of discharge power, monomer concentration and deposition time on film properties were investigated using various characterization tools. With proper conditions, smooth dielectric layer of 100nm thickness was obtained. Dielectric property as organic dielectric layer has been studied for future applications in organic thin film transistors(OTFT).

• Applied Chemistry for Engineering
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• v.24 no.2
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• pp.148-154
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• 2013

UV curable acryl resin, pressure-sensitive adhesives (PSAs), are used in many different parts in the world. In particular, PSAs has been used in the wafer manufacturing process of semiconductor industry. As wafers become much thinner, UV curable PSAs require more proper adhesion performance. In this study, acrylic PSAs containing hydroxyl groups were synthesized using monomers of 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, styrene monomer and 2-hydroxyethyl acrylate. Isocyanate modified UV curable PSAs were then prepared by the adduct reaction that facilitates the UV curing property via controlling the amount of methacryloyloxyehtyl isocyanate. The proper adhesion performance and UV curing behavior of UV curable PSAs with various hydroxyl values were studied, and experimental conditions were then optimized to raise the efficiency of wafer manufacturing process. It was found that in case of using the equivalent ratio of 1 : 1 isocyanate hardener used in the UV curable PSAs, the peel strength before the UV curing process decreased as the amount of hydroxyl groups increased in the PSAs. The peeling adhesive strength was also decreased with increasing UV dose due to high curing characteristics.

• Journal of the Korean Applied Science and Technology
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• v.25 no.4
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• pp.525-532
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• 2008

To prepare a solution type acrylic pressure-sensitive adhesive, quarter polymers were synthesized from butyl acrylate(BA), 2-ethylhexylacrylate(2-EHA) as a base monomer, methyl methacrylate(MMA) as a comonomer, each of methacrylic acid(MAA), acrylic acid(AA) as a functional monomer. Acrylic solution type pressure-sensitive adhesives(PSA's) of isocyanate derivative crosslinking PSA's were prepared by crosslinking of BEMM, BEMA with toluene-2,4-diisocyanate. The structure of adhesive was identified by FT-IR. The viscosity was measured by using Brookfield DV-III and molecular weight was measured by using gel permeation chromatography. The physical properties of polyethylene film coated with BEMMT, BEMAT were measured as a function of the concentration. As the result, BEMMT(0.6, 0.8), BEMAT(0.6) showed peel adhesion of $160{\sim}180\;g_f$/25 mm width and shear adhesion of more than 24 hours, and tackiness of $4/32{\sim}6/32$ which was relevant to commercial usage.

• Environmental Engineering Research
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• v.11 no.4
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• pp.208-216
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• 2006

In order to create a single flocculant/dual flocculation system, polyacrylamide-co-trimethyl ammonium ethyl acrylate chloride (TAEAC) polymers with varying molecular weights and structures were prepared for use of flocculants. The higher the cationic density of the polymer is higher, the higher was the conversion rate and the ratio of monomer. An acrylamide as nonionic monomer was less reactive than a TAEAC as cationic monomer. The branched polymer which was polymerized with a cross-linking agent, N, N-methylene bis-acrylamide had a higher stability and higher viscosity than a linear polymer but its dewatering efficiency was poor in a single flocculation system. In the case of single flocculant/dual flocculation, the branched polymer has better flocculation efficiency and the water content of the dewatered cakes was lower than the others, as the result of a re-flocculation effect. The optimum conditions for dual flocculation are a sequence in which the $1^{st}$ and $2^{nd}$ dosage are 75% and 25%/total dosage of a single flocculation system. The dewatering efficiency of a dual flocculation system is improved considerably from 10 to 25% under the experimental conditions used herein.

• Polymer(Korea)
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• v.34 no.6
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• pp.588-593
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• 2010

New seven acrylic monomers with covalently bonded silicon, germanium, and tin were prepared for high refractive index materials. The monomers were copolymerized with a cross-linkable comonomer (Trimer) to prepare UV-films for optical characterization. The refractive index of the copolymers increased in proportion to the monomer content and extrapolated to determine that of homopolymer. $Ph_3Si$, $Ph_3Ge$, and $Ph_3Sn$ groups contributed to increase the refractive index of acrylic polymer, in which $Ph_3Sn$ was more effective than $Ph_3Ge$. The index increment confidently occurred with $Bu_3Sn$ attachment in comparison with aliphatic acrylic polymers. $Ph_3SnS$-attached acrylate polymer showed a refractive index of 1.671 at 589 nm. The index change was similarly observed at various different wavelengths (656, 830, 1310, and 1550 nm).