• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1867-1870
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• 2013

• Macromolecular Research
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• v.10 no.5
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• pp.291-295
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• 2002

Atomic force microscopy(AFM) was used to study the polyethylene(PE) surfaces grafted and immobilized with acrylic acid by Ar plasma treatment. The topographical images and parameters including RMS roughness and Rp-v value provided an appropriate means to characterize the surfaces. The plasma grafting and immobilization method were a useful tool for the preparation of surfaces with carboxyl group. However, the plasma immobilization method turned out to have a limitation to use as a means of preparation of PE surface with specific functionalities, due to ablation effect during the Ar plasma treatment process.

• Elastomers and Composites
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• v.24 no.4
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• pp.265-275
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• 1989

The graft copolymerizations of acrylonitrile (AN) and methyl methacrylate (MMA) onto chloroprene rubber (CR) were carried out with benzoyl peroxide(BPO) as an initiator. The effect of solvent, mole ratio of AN to MMA, reaction time and temperature, and initiator concentration on graft copolymerization were examined. It was observed that the grafting efficiency increased as increasing mole ratio of AN to MMA. the graft copolymer, acrylonitrile- CR-methyl methacrylate (ACM), was identified by infrared spectroscopy and morphology. Thermal stability of ACM was found to be improved when compared with those of CR.

• Nuclear Engineering and Technology
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• v.6 no.3
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• pp.161-169
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• 1974

Radiation grafting of acrylic acid onto nylon fabric has been studied by "simultaneous irradiation" method to render its surface more hydrophilic. Nylon fabric immersed in monomer solution was irradiated in air or under vacuum with gamma-rays from Co-60. Most parts of polyacrylic acid formed on the surface of the fabric were extracted off from the fabric with 0.1% solution of sodium hydroxide at 10$0^{\circ}C$. The chemical components of the grafted product have been determined. By comparing graft polymer with ungrafted polyamide, the rate of water absorption and antistatic behavior are improved. improved.

• The Korean Journal of Ceramics
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• v.5 no.3
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• pp.265-269
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• 1999

Polyethylene was modified with silanol groups on its surface by photografting of vinyltrimethoxysilane in vapor phase by using benzophenon as a polymerization initiator and by hydrolyzing the methoxysilane groups into the silanol groups with HCI solution. The modified polyethylene formed a dense and homogeneous apatite layer on its surface in a solution with ion concentrations 1.5 times those of human blood plasma within 21 days. This kind of biomimetic process could provide techniques for fabricating apatite-polymer composites with three dimensional structure analogous to the natural bone.

• Polymer(Korea)
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• v.32 no.6
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• pp.537-543
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• 2008

Crosslinked agar-g-poly(acrylic acid) (x-agar-g-PAA) super absorbent with a water absorbency ($Q_{H2O}$) of approximately 660 g/g was synthesized by the copolymerization of agar with an acrylic acid monomer. KPS and MBA were used as the initiator and crosslinker, respectively. Grafting was performed in air. Infrared spectroscopy was used to identify the product of copolymerization. The optimum conditions to synthesize the x-agar-g-PAA superabsorbent were 0.1 g of agar, 0.1 g of the KPS initiator, for 15 min; 50% AA monomer, 0.005 g of the MBA crosslinker, for a propagation time of 5 min; and 1 M NaOH for 15 min to allow for saponification. The reaction temperature was $80{^\circ}C$.

• Polymer(Korea)
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• v.26 no.3
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• pp.307-315
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• 2002

Major factors affecting the impact resistance of high impact polystyrene (HIPS), the rubber-toughened grade of polystyrene, are rubber-phase particle size and size distribution, molecular weight, morphology, and degree of grafting. Accordingly, it is important to control or investigate these factors. In this study, the effect of solvent content was analyzed by the morphology and particle size distribution of rubber phase, and final properties in bulk-solution polymerization of HIPS. The prepolymerization time was, first, determined by measuring the evolution of particle size distribution of dispersed phase to explain the phase inversion with time. As the solvent content increased, the size of rubber particle increased and then gradually decreased. Rubber-phase morphology was likely to have higher degree of grafting as the solvent content increased. Rheological and mechanical properties decreased as the solvent content increased because of the decrease of matrix molecular weight due to the chain transfer reaction to solvent and the existence of residual solvent. Nevertheless, the impact resistance seemed to increase when the rubber particle size increased.

• Polymer(Korea)
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• v.31 no.1
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• pp.1-7
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• 2007

In this study, the sulfonated ion exchange fiber was synthesized by $Co^{60}\;{\gamma}-ray$ radiation-induced graft copolymerization. Degree of grafting (DG) increased with increasing the total dose and showed the highest value at 50 v/v% styrene monomer. And also, the degree of sulfonation (DS) increased with increasing the DG and reaction temperature. DS showed the maximum value at 20 min. Ion exchange capacity and swelling ratio of ion exchange fibers increased with increasing the DS and their maximum values were 4.76 meq/g and 23.5%, respectively. Ammonia adsorption increased as increasing the ammonia concentration and ion exchange capacity and remained constant over 10 cycles.

• Polymer(Korea)
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• v.25 no.1
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• pp.49-55
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• 2001

The bi-functional ion exchangers, SAPP-g-(AN/St) were synthesized with mixed vinyl monomers(acrylonitrile and styrene) onto PP fabric by the pre-irradiation grafting with E-beam and its subsequent amidoximination and sulfonation. The degree of grafting of PP-g-(AN/St) was increased with decreasing acrylonitrile composition in the mixed monomers. The water uptake of copolymers increased with decreasing in the amidoxime ratio in the copolymers and increased by sulfonation, but decreased by amidoximation. The $UO_2^{2+}$ adsorption capacity of SPP-g-St, APP-g-AN, and SAPP-g-(AN/St) were 12.4, 34.0, and 38.0 mg/g, respectively and the optimum adsorption time is about 50 hrs. As a result of uranium adsorption, the synthesized ion exchanger, which we obtained have also good affinity toward the adsorption or chelating with $UO_2^{2+}$ ions.

• Macromolecular Research
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• v.14 no.5
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• pp.552-558
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• 2006

Biodegradable nanofibrous poly(L-lactic acid) (PLLA) scaffold was prepared by an electrospinning process for use in tissue regeneration. The nanofiber scaffold was treated with oxygen plasma and then simultaneously in situ grafted with hydrophilic acrylic acid (AA) to obtain PLLA-g-PAA. The fiber diameter, pore size, and porosity of the electrospun nanofibrous PLLA scaffold were estimated as $250\sim750nm,\;\sim30{\mu}m$, and 95%, respectively. The ultimate tensile strength was 1.7 MPa and the percent elongation at break was 120%. Although the physical and mechanical properties of the PLLA-g-PAA scaffold were comparable to those of the PLLA control, a significantly lower contact angle and significantly higher ratio of oxygen to carbon were notable on the PLLA-g-PAA surface. After the fibroblasts were cultured for up to 6 days, cell adhesion and proliferation were much improved on the nanofibrous PLLA-g-PAA scaffold than on either PLLA film or unmodified nanofibrous PLLA scaffold. The present work demonstrated that the applications of plasma treatment and hydrophilic AA grafting were effective to modify the surface of electrospun nanofibrous polymer scaffolds and that the altered surface characteristics significantly improved cell adhesion and proliferation.