• Journal of Microbiology and Biotechnology
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• v.21 no.1
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• pp.37-42
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• 2011

A new versatile acrylonitrile-bioconverting strain isolated from a petroleum-contaminated sludge sample and identified as Rhodococcus ruber AKSH-84 was used for optimization of medium and biotransformation conditions for nitrilase activity to produce acrylic acid. A simple and rapid HPLC protocol was optimized for quantification of acrylic acid, acrylamide, and acrylonitrile. The optimal medium conditions for nitrilase activity were pH of 7.0, temperature of $30^{\circ}C$, agitation of 150 rpm, and inoculum level of 2%. Glycerol as a carbon source and sodium nitrate as the nitrogen source provided good nutritional sources for achieving good biotransformation. Nitrilase activity was constitutive in nature and was in the exponential growth phase after 24 h of incubation under optimal conditions without addition of any inducer. The substrate preference was acrylonitrile and acetonitrile. The present work demonstrates the biotransformation of acrylonitrile to acrylic acid with the new strain, R. ruber AKSH-84, which can be used in green biosynthesis of acrylic acid for biotechnological processes. The nitrilase produced by the isolate was purified and characterized.

• Polymer(Korea)
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• v.38 no.5
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• pp.588-595
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• 2014

A semi-interpenetrating polymer network (semi-IPN) hydrogel composed of crosslinked chitosan and poly (acrylic acid-co-crotonic acid) was prepared in the presence of glutaraldehyde (GA) as a crosslinker. Fourier-transform infrared, thermogravimetric analysis and scanning electron microscopy were employed to confirm the structure of the semi-IPN hydrogel. The swelling capacity of hydrogel was shown to be affected by the monomers weight ratio, chitosan content, initiator and GA concentrations. The results also indicated that the semi-IPN hydrogel had different swelling capacity at various pHs. Additionally, the swelling behavior of the hydrogel was investigated in aqueous solutions of NaCl, $CaCl_2$, and $AlCl_3$.

• Journal of Energy Engineering
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• v.24 no.3
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• pp.20-26
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• 2015

For the reliability of the combustible properties of arylic acid, this study was investigated the explosion limits of acrylic acid in the reference data. The flash points and AITs(auto-ignition temperatures) by ignition delay time were experimented. The lower flash points of acrylic acid by using Setaflash and Pensky-Martens closed-cup testers were experimented in $48^{\circ}C$ and $51^{\circ}C$, respectively. The lower flash points of arylic acid by using Tag and Cleveland open cup testers were experimented in $56^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 tester for acrylic acid. The AIT of acrylic acid was experimented as $417^{\circ}C$. The lower explosion limit(LEL) and the upper explosion limit(UEL) by the measured the lower flash point and the upper flash point of acrylic acid were calculated as 2.2 Vol% and 7.9 Vol%, respectively.

• Nuclear Engineering and Technology
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• v.52 no.11
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• pp.2607-2612
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• 2020

The present work was aimed to show the possibility of using hydrogel (acrylic/boric acid) for evaluation of the neutron radiation shielding. The influence of acrylic acid concentration, different gamma doses and relative contents of boric acid were studied. The physical properties and the thermomechanical stability of the studied samples were investigated. The shielding property of the composite for neutron was tested by Pu-Be neutron source (5 Ci) under room temperature. The neutron fluence rates and gamma fluxes were measured using a stilbene organic scintillator. The macroscopic effective removal cross-section Σ_R (cm^-1) of fast neutrons and total attenuation coefficient μ (cm^-1) of gamma rays has been studied experimentally. The transmission parameters, the relaxation length (??) and the half-value layer (HVL) were obtained. The obtained results indicated that the addition of boric acid to acrylic acid tends to increase the macroscopic effective removal cross-section Σ_R (cm^-1) to 0.141 compared to 0.094 of ordinary concrete.

• Journal of Biomedical Engineering Research
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• v.20 no.6
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• pp.547-553
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• 1999

생체재료로 사용되는 polyurethane(PU) 표면에 항혈전성 lumbrokinase(LK)를 고정함으로써 생체적합성을 향상시키고자하였다. 먼저 LK를 PU 표면에 고정하기 위한 가교제로서 4-azidoaniline hydrochloride와 poly(acrylic acid)를 이용하여 4-azidophenyl 작용기가 amido 결합으로 치환된 수용성, 광반응성 poly(acrylic acid)(PPa-II)를 합성하였다. H-nuclear magnetic reasonance spectrum(500MHz H-NMR)의 6-7 peak와 infrared spectrum (FT-IR) 의 2125.48 cm peak으로부터 PPA-II의 합성을 지원하였다. EH한 4-azidophenyl 작용기가 poly(acrylid acid) 잔기에 치환된 정도는 UV/VIS adpectrophotometric spectrum을 확인한 결과 11~14%임을 알 수있었다. 0.5 1및 5% PPA-II를 각각 광반응하여 얻은 PU는 39.5, 161.8 및 181.5 nmole/$\textrm{cm}^2$의 농도로 표면에 carvoxyl 작용기가 유도되었음을 알 수있었다. 0.05M KH2PO4 (pH 4.5) 용액에서 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide(EDC)를 촉매로 사용하여 LK를 PU표면에 amido 공유결합으로 고정하였으며, 이것은 지속적인 fibrinolytic 활성도를 보였다. PPA-II를 이용한 표면 개질 방법은 수용성 반응조건에서 이루어진다는 점과 광반응을 이용함으로써 특정부위에서의 표면개질이 가능하다는 점에서 그 응용가치가 크며 아울러 PU의 생체적합성을 향상시킬 수 있는 방법으로서 판단된다.

• Textile Coloration and Finishing
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• v.10 no.3
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• pp.43-49
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• 1998

Polyvinyl chloride (PVC) sheets were treated with corona discharge to produce peroxy radicals on the surfaces. The peroxy radicals formed on the PVC surfaces were subsequently used as initiators for the graft polymerization of acrylic acid or acrylamide in an aqueous solution. Introduction of acrylic acid and acrylamide on the PVC sheet could be confirmed by the observation of carbonyl and primary amine absorptions based on carboxylic acid and amide, respectively. The water contact angle$(90^\circ)$ of PVC sheet was constant, irrespective of time, while corona-treated and functional monomer-grafted PVCs were slowly increased with time, showing the rearrangement of surface polar groups in air condition. The water contact angle of PVC sheet$(90^\circ)$ was decreased by corona treatment$(78^\circ)$, and further decreased by the grafting of acrylic acid$(55^\circ)$ and acrylamide$(56^\circ)$ , indicating increased hydrophilicity of the modified surfaces. The half-life periods of surface voltage on acrylic acid- (62 sec) and acrylamide-grafted PVC (147sec) were significantly decreased when compared to those on PVC (3,115 sec) and corona-treated PVC (463sec). These results mean that acrylic acid- and acrylamide-grafted PVCs could be used as the antistatic sheets.

• Journal of the Korean Applied Science and Technology
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• v.20 no.4
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• pp.372-376
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• 2003

Water-soluble cutting fluids are used for processing of aluminium materials. This short article describes properties of new additives of water-soluble cutting fluids for aluminium materials. Various Diels-Alder adducts of unsaturated fatty acids with acrylic acid of maleic anhydride were prepared by thermal reactions. Triethanolamine salts of Diels-Alder adducts of dehydrated castor oil fatty acids with acrylic acid or maleic anhydride showed excellent anti-corrosion property of aluminium materals. These thermal adducts showed anti-rust property for cast-iron chips, too.

• Journal of Adhesion and Interface
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• v.12 no.2
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• pp.67-72
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• 2011

Acrylic pressure-sensitive adhesives are used in many different parts in the world. But acrylic acid in PSAs may occur unexpected results such as corroding adherends or producing by-products when applied within electronic devices. This study employed acrylic PSAs based on 2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA) and butyl acrylate (BA) with different coating thickness. There are two types of curing agents. One is methylaziridine derivative (MAZ) and the other is aluminum acetylacetonate (AlACA). This study examined the adhesion performance and curing behaviors using peel strength, probe tack and gel fraction. Also, the viscoelastic properties of acrylic PSAs were investigated from Advanced rheometric expansion system (ARES).

• Korean Journal of Materials Research
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• v.1 no.3
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• pp.151-155
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• 1991

The kinetics of isothermal crystallization in blends of poly(ethylene oxide) (PEO) and poly(styrene-co-acrylic acid) (SAA) has been examined as a function of the blend ratio, the copolymer composition, and the crystallization temperature, based on the Avrami eauation. The Avrami exponents were mostly chose to 2, independent of the crystallization temperature. The crystallization rate of PEO in PEO/SAA blends decreased with the increase of SAA content. And also, the higher the acrylic acid content in the SAA copolymer, 7he slower the crystallization rate of PEO in the blends.

• Journal of Adhesion and Interface
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• v.10 no.4
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• pp.174-181
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• 2009

The viscosity for hi-solid pressure sensitive adhesive to improve water soluble low viscosity pressure sensitive adhesive polymerized using seeded polymerization. While seed binder polymerizing it produces an optimum polymerization condition, and acrylic acid and seed binder concentration changed were measurement of viscosity variation and adhesive power at the substrate (SUS420J) as flowing results. In adhesive polymerization, seed binder concentration 7 wt%/monomer was recovered 60% of solid content, 2,100 cps of low viscosity and clear adhesive film. When acrylic acid content was 4 wt%/monomer, it was turned excellent adhesive power and holding power.