• Polymer(Korea)
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• v.24 no.6
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• pp.763-769
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• 2000

The multifunctional cation exchangers, sulfonated polypropylene-g-(acrylic acid/styrene) [PP-g-(AAc/Sty)] were synthesized by the irradiational grafting of AAc and Sty onto PP staple fabric with electron beam accelerator and its subsequent sulfonation. The highest degree of grafting obtained was 190% at a monomer mixture of 30 vol% AAc: 70 vol% Sty and a solvent mixture of 30 vol% water : 70 vol% methanol and the degree of grafting decreased with an increase of the AAc content in the monomer mixture at constant solvent content. Maximum ion exchange capacity of the copolymer was 4.6 meq/g. The Li$^{+}$ adsorption ability of the copolymer synthesized in the study was the best among PP-g- AAc, sulfonated PP-g-Sty, and sulfonated PP-g-(AAc/Sty).).

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.42-43
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• 2006

We have prepared random, block and graft copolymers with single or dual sensitivities to various stimuli. We have conjugated these polymers to proteins at random lysine sites or at specific sites designed into the protein by genetic engineering. We are also grafting the smart polymers to the surfaces of nanobeads. We are applying these smart conjugates and smart nanobeads in microfluidic devices for various applications, including diagnostics, affinity separations and enzyme bioprocesses. In this talk I will update our work with these interesting hybrid systems.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.26-26
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• 2012

The hydrophobic nature of the wool surface give rise to difficult penetration of dye molecules. Among all the methods of modification, graft polymerization is an attractive method to impart a variety of functional groups to a polymer. Grafting has been made by irradiating the light on the polymer in the presence of a solvent containing monomer. The energy source commonly used are high-energy electrons, X-rays, UV and visible light. UV irradiation is a relatively low-energy radiation in comparison with others since it has the least possibility to change bulk properties. In the present paper, a photo-reactive dye was synthesized from quinizarin by the reaction with methacryloyl chloride. The synthesized dye was continuously grafted onto wool fabric at room temperature by UV irradiation. Several key parameters including UV energy, dye concentration and pH have been examined to understand their influence on the photoreactive coloration.

• Polymer(Korea)
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• v.25 no.6
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• pp.848-854
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• 2001

The crystallization behavior of poly (ethylene terephthalate) (PET) /ethylene-methyl acrylate-glycidyl methacrylate copolymer (E-MeA-GMA) blend was studied. The extent of reaction and the reaction rate between PET and E-MeA-GMA were measured with torque rheometer, FT-IR and SEM. The effects of the grafting reaction on the crystallization behavior were investigated with DSC and time-resolved light scattering (TR-LS) techniques. The morphological change at the lamellar level was also examined by using a small angle X-ray scattering (SAXS) method.

• Polymer(Korea)
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• v.39 no.2
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• pp.268-274
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• 2015

In this paper, the isothermal crystallization kinetics of a functional PP (FPP) with different grafting yields (GY)-methacryloxyethyltrimethyl ammonium chloride (DMC) grafted PP were investigated by differential scanning calorimetry (DSC). The results showed that the crystallization rate of FPP (GY=4.83%) was the highest for all of the studied samples. Furthermore, for the FPP with different GY, the value of $t_{1/2}$ became longer with increasing the grafting yield (GY). The possible explanation was that the quaternary ammonium groups introduced affected the crystallization process of the FPP in two opposite directions, i.e. promoting the nucleation and hindering the transport of the chain molecules towards the growing nuclei. Polarized optical micrographs showed that the DMC chains acted as nucleating agents, which accelerated the nucleation. In addition, the results showed the FPP had lower nucleation free energy than the PP. This study would be useful for designing the processing parameters of the grafted samples.

• Nuclear Engineering and Technology
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• v.41 no.8
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• pp.1101-1108
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• 2009

The ocean contains around eighty elements of the periodic table and uranium is also one among them, with a uniform concentration of 3.3 ppb and a relative abundance factor of 23. With a large coastline, India has a large stake in exploiting the 4 billion tonnes of uranium locked in seawater. The development of radiation grafting techniques, which are useful in incorporating the required functional groups, has led to more efficient adsorbent preparations in various geometrical configurations. Separation based on a polymeric adsorbent is becoming an increasingly popular technique for the extraction of trace heavy metals from seawater. Radiation grafting has provided definite advantages over chemical grafting. Studies related to thermally bonded non woven porous polypropylene fiber sheet substrate characterization and parameters to incorporate specific groups such as acrylonitrile (AN) into polymer back bones have been investigated. The grafted polyacrylonitrile chains were chemically modified to convert acrylonitrile group into an amidoxime group, a chelating group responsible for heavy metal uptake from seawater/brine. The present work has been undertaken to concentrate heavy metal ions from lean solutions from constant potential sources only. A scheme was designed and developed for investigation of the recovery of heavy metal ions such as uranium and vanadium from seawater.

• Polymer(Korea)
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• v.34 no.5
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• pp.464-468
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• 2010

In this study, a vinylbenzyl chloride (VBC) monomer was successfully grafted onto the several fluoropolymer films including poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP), poly(tetrafluoroethylene-co-perfluoropropylvinyl ether) (PFA), and poly(ethylene-co-tetrafluoroethylene) (ETFE) films by using a simultaneous irradiation method. The results indicated that PVBC graft polymer can be easily grafted onto the ETFE film than other fluorinated films under the same irradiation condition. The grafted films were characterized by using FTIR, TGA, and SEM-EDS instruments. The elongation at the breaking of the grafted films was found to decrease with an increase of degree of grafting (DOG). The PVBC-grafted ETFE films were found to have better mechanical properties than other PVBC-grafted fluorinated films.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3653-3659
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• 2015

This paper describes the reactive compatibilization of blends of a wholly aromatic thermotropic copolyester liquid crystalline polymer (TLCP) with random copolymers of ethylene and acrylic acid (EAA) and their salts. Blends were prepared by melt mixing in an intensive batch mixer, and the formation of a graft copolymer due to acidolysis between the TLCP and the acrylic acid group of the ionomer was evaluated. Chemical reaction was assessed by torque measurement during melt mixing and by thermal analysis and morphological observation. The Na-salt of the EAA ionomers was especially effective at promoting a grafting reaction. The extent of reaction depended not only on the cation, but also composition of the ionomer and reaction time. The product of the grafting reaction between the TLCP and a sodium-neutralized ionomer proved to be an effective compatibilizer for TLCP and EAA ionomers.

• Polymer(Korea)
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• v.36 no.6
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• pp.816-821
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• 2012

In this study, silane-crosslinked proton exchange membranes were prepared by step-wise radiation grafting of styrene and 3-(trimethoxysilyl)propyl methacrylate (TMSPM) onto an poly(ethylene-co-tetrafluoroethylene) (ETFE) film and followed by sol-gel processing and sulfonation. The sequentially grafted films with styrene to provide the proton conductivity and TMSPM to form the crosslinked structure were prepared by different grafting order. The structural changes and thermal properties of the prepared films were investigated by FTIR and TGA, respectively. After the introduction of sulfonic acid functional groups, the distributions of sulfonic acid group and silicon atoms at the inside of the sulfonated membranes were analyzed by SEM-EDX.

• Polymer(Korea)
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• v.27 no.3
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• pp.242-248
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• 2003

PP-g-(AN/Sty) was synthesized by grafting with acrylonitrile (AN) and styrene (Sty) onto PP staple fiber using an electron beam accelerator and followed by amidoximination and phosphorylation. Mole fraction of AN in the graft chain increased with the increase of the AN content in the monomer mixture. The highest AN grafting yield of 45% was obtained at a monomer ratio of 40 vol% AN/60 vol% Sty. Mole fraction of AN in the graft chain decreased with the increase of methanol amount used its solvent. As reaction temperature increased, the grafting yield of copolymer increased and reached equilibrium at 50$^{\circ}C$. Amount of amidoxime group in fibrous ion exchanger was increased as increasing amount of hydroxylamine, and the maximum content of amidoxime group was observed at 5.8 mmol/g with the 9 wt% hydroxylamine concentration. Content of phosphorous group in fibrous ion exchanger increased up to 0.5 N phosphoric acid concentration, and then leveled off. The adsorption ability of the copolymer for uranyl ion by the chelating adsorbents was in the following order : bifunctional PP-g-(AN/sty) > amidoximated PP-g-(AN/Sty) > phosphorylated PP-g-(AN/Sty).