• Journal of Sericultural and Entomological Science
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• v.34 no.2
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• pp.32-40
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• 1992

Many studies have been carried out on the graft finishing in order to improve the quality of silk fiber. Various vinyl monomers, for instance, styrene, methylmethacrylate, 2-hydroxyeth-ylmethacrylate and methacrylamide, have been used practically up to date. Among these monomers, methacrylamide has been applied as the most favourable monomer onto silk fibers in recent years. The polymerization mechanism about styrene- and methylmethacrylate-grafted silk fiber has been studied by many researchers. They proposed that free radicals were formed and vinyl monomers were polymerized in silk fibroin by graft polymerization mechanism, while active sites were varied by the types of monomer and initiator as well as by the reaction condition. In general. there is another Opinion that monomers are polymerized and impregnated in the internal side of the fiber by homopolymerization, which has not been proved experimentally yet More than 10 years have been passed since methacrylamide was applied on the silk fiber, and at the present time most finishings are being achieved by methacrylamide. However, no attention has been paid to the polymerization mechanism of the methacrylamide-treated silk fiber yeL In this paper, the treatments of methacrylamide on silk fibers were studied in aqueous solution using potassium persulfate as an initiator. The polymerization mechanism of the methacrylamide-treated silk fibers was investigated and analyzed on the basis of the results of infrared spectroscopy, amino acid analysis and scanning electron microscopy. From the results of these instrumental analyses, it can be suggested that polymerization mechanism about the methacrylamide-treated silk fibers is not performed by graft polymerization which has been accepted generally in styrene and methylmethacrylate-grafted silk fibers. The different mechanism is supposed to be due to the difference in monomer types, initiator types and treatment conditions.

• Journal of Sericultural and Entomological Science
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• v.34 no.1
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• pp.49-56
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• 1992

Treatment of vinyl monomers onto silk fiber modifies the properties of the original silk fiber considerably. This field has been the subject of investigation by many workers using chemical and radiation initiation. Many studies on the reaction conditions, polymerization mechanism, physical properties and practical performances of methacrylamide-treated silk fiber have been continued. However, the polymerization mechanism has not been clearly revealed yet and this remains ambiguously whether the grafting is formed on fiber or not. In general, it has been accepted that free radicals were formed and vinyl monomers were polymerized in silk fibroin by graft polymerization mechanism, while active sties were varied by the types of monomer and initiator as well as by the reaction conditions. On the other hand, there is another argument on polymerization mechanism, in which monomers are polymerized and impregnated in the internal side of the fiber by homopolymerization. Though a large number of analytical methods are used to examine the polymerization mechanism of methacrylamide-treated silk fiber, the results on the basis of thermal analysis are merely reported in this paper. In differential scanning calorimetry (DSC) analysis, the thermal decomposition behaviors of the methacrylamie-treated silk fibers were determined and compared to those of the controlled silk fibers. DSC curves obtained from the methacrylamide-treated silk fibers showed double peaks at around 290$^{\circ}C$ (A peak) and 320$^{\circ}C$ (B peak) which are attributed to the thermal decomposition of the methacrylamide polymer and silk fibroin fiber, respectively. The temperature of A and B peak shifted to higher value with the increase of add-on. Also, the moisture regain of the treated silk fibers increased with add-on.

• Journal of Sericultural and Entomological Science
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• v.33 no.2
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• pp.82-86
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• 1991

The treatments of methacrylamide on silk fibers were studied in aqueous solution using potassium persulfate as an initiator, and suitable conditions of reaction were determined for weighing of silk fibers. The results obtained were summarized as follows ; The weight of MAA-treated silk fibers increased with monomer concentration. The adequate concentration of potassium persulfate was found to be 1.7%. Maximum weight increase was shown at initial pH 3.8 of reaction liquor controlled by buffer solution.

• Journal of Sericultural and Entomological Science
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• v.37 no.1
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• pp.39-45
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• 1995

In this study the effects of methacrylamide-treatment on the physical properties and practical performances of silk were investigated for 38% MAA added silk fibers. The main results obtained were as follows; The values of tenacity, tearing strength, elongation, modulus and toughness decreased by the treatments of MAA on silk fibers. The moisture regain was increased by the MAA treatment, which improved the antistatic performance of silk fabrics. The stiffness values of MAA-treated silk fabrics increased and the performances of crease recovery were improved.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.3063-3070
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• 2014

In this study, poly(N-methylol methacrylamide) (NMMAAm) and poly(N-methylol methacrylamide/vinyl sulphonic acid) (NMMAAm-VSA) hydrogels were synthesized by $^{60}Co-{\gamma}$ ray irradiation at an ambient temperature. The graphs belonging to the gelation percent- percent-dose and swelling curves were drawn by using data which were obtained from water and different pH solutions. Characterization of hydrogels was performed by FTIR and DSC-TGA analysis. Heavy metal ion ($Ni^{2+}$, $Co^{2+}$) removal capacities of hydrogels were investigated in aqueous solutions, which had different concentrations (100-1500 mg/L). In metal ion removal studies, pH value of aqueous medium was kept constant at 5.0. Maximum metal ion removal values were obtained for NMMAAm-VSA (1:3 mole ratio) hydrogels. Metal ion removal capacities of NMMAAm-VSA (1:3 mole ratio) hydrogels were found as 82 mg/g and 98 mg/g for $Ni^{2+}$ and $Co^{2+}$ ions, respectively.

• Journal of the Korean Chemical Society
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• v.13 no.4
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• pp.365-371
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• 1969

Ceric salt 를 觸媒로 使用하여 여러 가지 反應條件 下에서 絹布上에 Methancrylamide를 grafting 시키고, Schweitzer 試藥에 依한 溶解性 및 赤外線吸收 스펙트럼을 比較檢討하여 그라프드重合物의 生成을 確認하였다. 그라프트率은 溫度, 反應時間 및 Monomer濃度가 增加함에 따라 增加하였으며 그라프트率은 極大化하는 最適의 pH 値가 있음을 알았다. 그라프트率에 관한 理論式을 誘導하고 그 結果를 檢討하였다.

• Textile Coloration and Finishing
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• v.2 no.1
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• pp.40-43
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• 1990

• KSBB Journal
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• v.14 no.1
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• pp.58-65
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• 1999

A hydrogel, poly(N-isopropylacrylamide-co-N,N'-dimethylaminopropyl methacrylamide), sensitive to both pH and temperature was synthesized and characterized for its welling behavior, lower critical solution temperature (LCST), and its appearance. The hydrogel with 5 mol% of N,N'-diemthylaminopropyl methacrylamide (DMAPMAAm) increased its volume phenomenonally in a lower pH range (ph 1~8) even at temperature ($37^{\circ}C$ and $40^{\circ}C$) higher than LCST. This behavior was unique compared to the temperature -sensitive hydrogel which did not exhibit any swelling in the same pH range. The hydrogel with 20 mol% of DMAPMAAm was swollen significantly at a higher pH of 12. With pH decrease from 12 to 2 water content in the gel increased from 38.8 wt% and 60.6 wt%, and 90.8 wt% for 5 mol% and 20 mol% gel, respectively. The transition pH that pH effect overwhelmed temperature effect occurred at a lower pH for a higher temperature ($40^{\circ}C$) and a lower mol% (5 mol%) of DMAPMAAm. Transparency and LCST of the gel increased with higher DMAPMAAm mol%.

• Polymer(Korea)
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• v.35 no.5
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• pp.409-418
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• 2011

A novel silicone (Si) containing vinylic monomer, N-(3-(triethoxysilyl)propyl) methacrylamide (TESPMA), based on 3-aminopropyltriethoxysilane (APTES) and methacryloyl chloride (MCl) has been synthesized for formulation of waterborne polyurethane (WPU). Two types of vinyl group containing Si, methacryloxypropyltriethoxysilane (MPTES) and triethoxyvinylsilane (TEVS), have been used as coupling reagents for comparison of the effects of Si kinds with TESPMA on the WPU. A series of new siliconized WPU, vinyl acetate/vinyl ester of versatic acid (VAc-Veova), TESPMA, MPTES and TEVS hybrid latexes have been successfully prepared by emulsion polymerization in the presence of WPU dispersion.

• Current Research on Agriculture and Life Sciences
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• v.12
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• pp.83-95
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• 1994

Fixation rate of reactive dyes on silk fibroin showed the same tendency to absorption rate. Fixation rate of Yellow 179 and Blue 71 was quite slow and Black 5, Blue 49, Blue 4, Blue 19 and Blue 21 was relatively fast. Weight increase by MAA graft polymerization onto filk fibroin was decreased, on the whole, according to the the increase of dye fixation, but weight increase of silk fibroin dyed with Blue 71 and Blue 21 was much higher than that of silk fibroin. And weight increase of silk fibroin dyed with Yellow 179 was similar to that of silk fibroin and in case of Blue 19, weight increase was about 12%, constantly. Weight increase of silk fibroin dyed with Blue 71 and Blue 21 was higher and the others were lower than of silk fibroin. And weight increase was diminished according as the dyeing temperature rises. The color was a little changed by MAA graft polymerization.