• Polymer(Korea)
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• v.38 no.3
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• pp.265-271
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• 2014

In order to investigate the characteristics of the gradient fluorinated polyacrylate and polyurethane latex blend films, the fluorinated polyacrylate emulsion and the polyurethane emulsion were synthesized, and then the both emulsions were blended at a series of ratios. The effects of content of the fluorinated polyacrylate on the gradient structure and surface property of the blended films were assessed by AFM, XPS, SEM-EDX and surface free energy measurements. It appeared that, while the content of the fluorinated polyacrylate latex was up to 30%, the fluorinated polyacrylate particles were selectively gathered on the film-air (F-A) and film-glass (F-G) interfaces at room temperature. When the content of the fluorinated polyacrylate was under 30%, the gradient structure of fluorinated component was not evident. The further increasing of fluorinated polyacrylate in the mixed system facilitated the formation and enlargement of gradient structure, but the adhesion of film decreased a little.

• KSBB Journal
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• v.30 no.3
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• pp.97-102
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• 2015

This study aimed to evaluate the potential plantgrowth promoting effects of potassium polyacrylate, a superabsorbent polymer, and Bacillus sp. SH1RP8, a family of plant-growth-promoting bacteria. Potassium polyacrylate was selected as the polymer for use due to its high molecular weight and its ability to retain and continuously supply moisture. Plant-growth-promoting rhizobacteria (PGPR) were isolated from the soil and applied to plants growing in dry environments, such as saline conditions. The moisture absorption and retention abilities of potassium polyacrylate were evaluated at a high temperature ($50^{\circ}C$) and in a dry condition, during which time the polymer showed a water retention potential of 19606.07% after 29 days. To overcome the reaming problem in the soil environment, natural polymers (such as cellulose) were mixed with the potassium acrylate. The shoot growths of Peucedanum japonicum Thunb and Arundo donax were significantly enhanced when treated with the mixture of the isolated rhizosphere bacterium SH1RP8 and potassium polyacrylate (63.5 and 124.3%, respectively).

• Elastomers and Composites
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• v.46 no.3
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• pp.231-236
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• 2011

The polyacrylate/multi-walled carbon nanotube (MWNT) composites were prepared and investigated for the application as a counter electrode in solar cell. The electrical conductivity of the composites was increased with increasing MWNT content and with the thickness of the sheet. The surface resistivity value of the composite at 50 wt% loading of MWNT was 0.36 ${\Omega}$/sq. The thermal decomposition temperature of the composites was also increased with the MWNT contents, and the increase of $15^{\circ}C$ was observed at the composite of polyacrylate/MWNT (50/50, w/w). The increase of storage modulus of the composites was observed, especially at the higher temperature compared to polyacrylate. The dimensional change of polyacrylate decreased over $20^{\circ}C$, but that of the composite increased linearly with the temperature. The morphology of the composites stands for the good dispersion of MWNT into the polyacrylate matrix.

• The tire
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• s.18
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• pp.23-26
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• 1968

• The tire
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• s.19
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• pp.18-22
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• 1969

• Journal of the Korean Ceramic Society
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• v.39 no.8
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• pp.775-782
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• 2002

The effects of solid and dispersant concentration was investigated by wet-sieving method for knowing the amount of coarse particle in fine powders. In the work alumina powders, sodium hexametaphosphate and sodium polyacrylate were used for preparing slurry. It was confirmed that the coarse particle mass increased by increasing alumina concentration and decreasing dispersant concentration. With systematic measurements we know that the alumina powder and dispersant of one weight percent(1.0wt%) were proper quantity for coarse particle mass measuring, respectively. Sodium polyacrylate as dispersant showed higher coarse particle mass than sodium hexametaphosphate. The sieve mass was decreased according to increase of experiment number. Based on experiments it was considered that wet-sieving method is good tool for measuring a coarse particle mass in fine powders.

• Journal of Food Hygiene and Safety
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• v.33 no.6
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• pp.466-473
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• 2018

An analytical method of sodium polyacrylate in processed food products was developed and monitored by using size-exclusion chromatography. GF-7M HQ column and UV/VIS detector were selected based on peak shape and linearity. Flow rate, column oven temperature, and mobile phase were selected as 0.6 mL/min, $45^{\circ}C$, and 50 mM sodium phosphate buffer of pH 9.0, respectively. Samples for analysis of sodium polyacrylate were extracted with 50 mM sodium phosphate buffer of pH 7.0 for 3 hr at $20^{\circ}C$ and 150 rpm. Analytical method validation revealed proper selectivity and calibration curve was selected in the range of 50-500 mg/L, and correlation coefficient of calibration curve was more than 0.9985. Limit of detection of sodium polyacrylate was 10.95 mg/kg and limit of quantification was 33.19 mg/kg. Accuracy and coefficient of variation for sodium polyacrylate analysis was 99.6-127.6%, 3.0-8.3% for intra-day and 94.3-121.9%, 1.3-2.6% for inter-day, respectively. Sodium polyacrylate was detected in 40 samples among monitored 125 processed food products. Detected contents were less than 0.2%, limited by the Food Additives Code. Results suggest the established size-exclusion chromatography method could be used to analyze sodium polyacrylate in processed food products.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.48.1-48.1
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• 2009

Performance of organic field-effect transistors (OFETs) with various temperature-cured polyacrylate(PA) copolymer as a gate insulator was studied. The PA thin film, which was cured at an optimized temperature, showed high dielectric strength (>7 MV/cm), low leakage current density ($5{\times}10^{-9}\;A/cm^2$ at 1 MV/cm) and enabled negligible hysteresis in MIS capacitor and OFET. A field-effect mobility of ${\sim}0.6\;cm^2/V\;s$, on/off current ratio (Ion/Ioff) of ${\sim}10^5$ and inverse subthreshold slope (SS) as low as 1.22 V/decwere achieved. The high dielectric strength made it possible to scale down the thickness of dielectric, and low-voltage operation of -5 V was successfully realized. The chemical changes were monitored by FT-IR. The morphology and microstructure of the pentacene layer grown on PA dielectrics were also investigated and correlated with OFET device performance.

• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.33-43
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• 1990

Reactions of polyacrylic acid with hydroxyapatite, enamel and dentin were examined using infrared spectroscopy for the detection of $COO^-$ ions bonded to substrates. And also atomic aboscorption spectrophotometry and visible spectrophotometry were used to analyze the concentrations of calcium and phosphorus in the filtered solutions. The results were as follows. 1. Chemical adhesion of poly acrylic acid to hydroxyapatite, enamel and dentin was observed by infrared spectroscopy. 2. More calcium and phosphorus were detected in the filtered solutions of sodium polyacrylate-reacted specimens than in the filtered solutions of deionized Water-reacted specimens. 3. Mechanism of adhesion of polyacrylate to substrates is postulated that the bond is ionic in nature by displacement of $Ca^{2-}$ and ${PO_4}^3$ ions from the surface of substrates.

• Polymer(Korea)
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• v.27 no.4
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• pp.364-369
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• 2003

The copolymerizations of 2-fluorohexylethyl acrylate (FA) with 2-(o-(1'-methylpropylidenamino)carboxyl amino)ethyl methacrylate(MEM) with different molar ratios of the two monomers were carried out in methyl ethyl ketone using ${\alpha}$,${\alpha}$'-azobisisobutyronitrile as an initiator to synthesize water repellent polyacrylate derivatives with protected isocyanate groups. The contents of FA and MEM in the copolymers were analyzed by NMR. The monomer reactivity ratios of MEM (1) and FA (2) were determined by Kelen-Tudos plot as follows : r$\_$1/＝1.59 and r$\_$2/＝0.50. The number-average molecular weights of the copolymers were in the range of 39400 to 72400 and the polydispersity indexes were about 1.5. The protected isocyanate groups in the copolymers were converted into isocyanate groups above 150$^{\circ}C$. The contact angle of the copolymer with 65 ㏖% of FA fur water was about 95$^{\circ}$.