• Polymer(Korea)
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• v.31 no.6
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• pp.512-517
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• 2007

The grafting of styrene, glycidylmethacrylate (GMA) or acrylic acid (AAc) onto kapok fiber were performed by $Co_{60}\;{\gamma}-ray$ radiation-induced graft copolymerization. Degree of grafting (DG) of copolymers were increased with increasing monomer concentration and radiation dose. In addition to we confirmed the introduced functional group and measured ion exchange capacity. Morphology of the ion exchange fibers and their structures were analyzed by SEM and FT-IR.

• 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).).

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.322-327
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• 2019

This study was conducted to improve the performance of automatic grafting robot using image recognition technique. The stem diameters of tomatoes and cucumber at the time of grafting were $2.5{\pm}0.3mm$ and $2.2{\pm}0.2mm$ for scions and $3.1{\pm}0.7mm$ and $3.6{\pm}0.3mm$ for rootstocks, respectively. The grafting failure was occurred when the different height between scions and rootstocks were over 4 mm and below 2 mm due to the small contact area of both cutting surface. Therefore, it was found that the height difference at the cutting surface of 3 mm is appropriate. This study also found that grafting failure was occurred when the stem diameters of both scions and rootstocks were thin. Therefore, it was suggested to use at least one stem with thicker than the average stem diameter. Field survey on the cutting angle of stems by hand were ranged from 13 to 55 degree for scions and 15 to 67 degree for rootstocks, respectively, which indicates that this could cause the grafting failure problem. However, the automatic grafting robot developed in this study rotates the seedlings 90 degree and then the stems are cut using a cutting blade. The control part of robot use all images taken from grafting process to determine the distance between a center of both ends of stem and a gripper center and then control the rotation angle of a gripper. Overall, this study found that The performance of automatic grafting robot using image recognition technique was superior with the grafting success rates of cucumber and tomato as $96{\pm}3.2%$ and $95{\pm}4%$, respectively.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.524-536
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• 1994

Chitosan is known to be a good biocompatible natural polymer. Polyethyleneglycol monomethacrylates(PEGM) were grafted onto chitosan and their reaction conditions and properties of the graft polymers obtained were estimated. Using ceric ammonium nitrate(CAN) as the initiator, the optimum condition for graft polymerization was determined amount of the initiator and monomer concentrations and reaction time. Grafting yields such as total conversion, the percentage of grafting and the efficiency of grafting were calculated and examined the optimum reaction condition for high grafting yields. The percentage of grafting and total conversion were maximum at condition that the concentration of initiator was $4{\sim}5{\times}10^{-3}M$, the concentration of monomer was 0.5~0.6M, the reaction time was 2~3 hours and the reaction temperature was about $40^{\circ}C$. Thermal characteristics, solubility for chitosan solvents and inherent viscosity of synthesized graft copolymers were investigated. In high initiator concentration, characteristics of chitosan were greatly diminshed. In case of inherent viscosities, chitosan-g-PE-90 was 2.81 dl/g, chitosan-g-PE-200, 3.01dl/g and chitosan-g-PE-350, 4.93dl/g. And a tendency of viscosity increase depending on the length of ethylene oxide residue was confirmed. Degree of swelling, tensile strength, elongation of membrane prepared from graft copolymers were determined. Properties of graft copolymers were affected by percentage of grafting and length of ethylene oxides residue in polyethylene glycol monomethacrylates. Tensile strength, elongation and degree of swelling of graft copolymers were remarkably improved than chitosan. As percentage of grafting increased, the amount of drug permeation was also increased.

• Macromolecular Research
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• v.11 no.6
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• pp.495-500
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• 2003

UV-induced graft polymerization of glycidyl methacrylate (GMA) to a polypropylene (PP) membrane was carried out in the vapor phase with benzophenone (BP) as a photoinitiator. Attenuated total reflection Fourier transform infrared spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM) were utilized to characterize the copolymer. The degree of grafting increased with increasing reaction time, increased UV irradiation source intensity, and increased immersion concentration of the BP solution. The optimum synthetic condition for the PP-g-GMA membrane was obtained with a reaction time of 2 hrs, a UV irradiation source intensity of 450 W, and an immersion concentration of the BP solution of 0.5 mol/L. The pure water flux decreased upon increasing the degree of grafting and increasing the amount of diethylamino functional group introduced. The analysis of AFM and SEM images shows that the graft chains and diethylamino groups of PP-g-GMA grew on the PP membrane surface, resulting in a change in surface morphology.

• Polymer(Korea)
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• v.36 no.3
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• pp.302-308
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• 2012

The objective of this study is to investigate optimum reaction conditions for the grafting of poly($N$-vinyl- 2-pyrrolidone) (PVP) onto the surface of plasma-treated polypropylene film. The plasma treatment conditions were fixed as 200 W rf power, 6 LPM Ar flow rate, 30 sec treatment time, and 5 min exposure time after treatment. For graft copolymerization, we investigated the change of grafting degree with respect to reaction time, reaction temperature and $N$-vinyl-2-pyrrolidone concentration. Maximum grafting degree was obtained at the conditions of 6 h reaction time, $90^{\circ}C$ reaction temperature, and 40% $N$-vinyl-2-pyrrolidone concentration. The introduction of PVP was confirmed by ATR-FTIR, XPS, and SEM analysis.

• Polymer(Korea)
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• v.35 no.5
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• pp.478-482
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• 2011

In this study, several poly(styrene-co-(trimethoxysilyl)propyl methacrylate)-grafted ETFE films were prepared by a simultaneous irradiation grafting method. After mixing of styrene/(trimethoxysilyl)propyl methacrylate(TMSPM) monomers with various solvents, the effects of various irradiation conditions such as total dose, dose rate and monomer concentration on the degree of grafting of the prepared membranes were investigated. Results indicated that the higher degree of grafting was obtained when acetone was used as a solvent. The formation of poly(styrene-co-TMSPM) grafts on the ETFE films was verified using FTIR spectrometry and the distribution of the poly(PTMSPM) graft polymer over the cross-section of the grafted film was confirmed using SEM-EDX instrument.

• Polymer(Korea)
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• v.36 no.2
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• pp.137-144
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• 2012

The surface of polyethylene (PE) was modified through Ar atmospheric pressure plasma treatment and subsequent grafting of glycidyl methacrylate (GMA). Optimum plasma treatment conditions were determined through analyzing the surface free energies calculated from the contact angles between PE samples and three probe liquids, which were RF-power of 200 W, plasma treatment time of 600 sec, Ar flow rate of 5 LPM, and sample-holder moving speed of 20 mm/sec. To introduce the maximum amount of GMA on PE surface treated under the conditions, graft copolymerization conditions such as GMA concentration, temperature, and time were carefully controlled. Grafting degree (GD) was obtained through weight difference analysis of PE film before and after graft copolymerization. A maximum GD was achieved at the GMA concentration of 20 vol%, the temperature of $80^{\circ}C$, and the treatment time of 4 hr.

• Journal of the Korean Chemical Society
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• v.6 no.1
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• pp.64-68
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• 1962

The graft polymerization of styrene to polyvinyl alcohol using a photosensitizer(benzophenone) and ultraviolet light was studied. Styrene was grafted onto polyvinyl alcohol up to when polyvinyl alcohol was pre-immersed in water and irradiated by ultraviolet light for 24 hours styrene solution of benzophenone(0.01 molarity). The highest percentage of graft obtained in the grafting which was proceeded in the presence of water added immediately before irradiation was 29%. The grafting was proportional to irradiation time within a certain limit of time, i.e., 24 hours, and presumably was initiated at the surface. After a certain degree of grafting a definite maximum was reached. Graft polymer prepared in this experiment showed high resistance to various solvents.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05a
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• pp.110-112
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• 2004

Poyethylene films can be modified by radiation grafting of N-vinyl pyrollidone using y-radiation. FTIR spectra were used to confirm the modification of PE films. The modified films were activated by two-step and one step methods for electroless Cu plating. Morphology of metallized films has been investigated. Electroless Cu plating onto the modified films depends mainly on the grafting degree and activation type. The conductivity of the metallized films has been investigated.