• Textile Coloration and Finishing
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• v.8 no.6
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• pp.33-39
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• 1996

The purpose of this study was to investigate the structural characteristics, mechanical properties, and stress-relaxation behavior of PET filament, which were prepared at various spinning speeds(1650, 3300, 4500, 5000, 5500, and 6000 m/min) and anneal(12$0^{\circ}C$, 20 min & 15$0^{\circ}C$, 40 min). In 4500 m/min of spinning speed the crystallinity, crystallite size, and degree of orientation of PET filament rapidly increased. By increasing spinning speed, the temperature dependence of stress-relaxation sharply decreased. Same results were obtained from heat-treated samples. As a result, activation energy for stress-relaxation increased with the crystallinity and spinning speed.

• Fashion & Textile Research Journal
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• v.3 no.4
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• pp.367-372
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• 2001

Five kinds of commercial ramie and hemp fabrics were treated with cellulase under different concentrations. Samples were mercerized before enzyme treatment to investigate the effect of mercerization on cellulase enzyme treatment. Physical characteristics(weight loss, tear strength retention, wrinkle recovery, drape stiffness, dyeability) of cellulase enzyme treated and untreated samples were measured and compared. X-ray diffractions were examined to verify if there were any changes in their crystallinity of enzyme treated fabrics. Weight loss, wrinkle recovery and degree of crystallinity increased as the concentration of cellulase enzyme increased. In the meanwhile, tear strength retention and drape stiffness and dyeability decreased. Enzyme activity was more effective on mercerized samples. Particularly, there was distinct tendency to increase weight loss and flexibility.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1158-1161
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• 2004

Shell shaped hollow carbon nanoparticles are synthesized in the oxygen-hydrogen diffusion flame with $C_{2}H_{2}$ as precursor when it is irradiated with $CO_{2}$ laser of certain power. Below this power of laser, we couldn't get any other but amorphous soot. This shell shaped hollow carbon nanoparticles shows outer wall of high degree of crystallinity with void space inside of itself. And size distribution of these nanoparticles is measured with TEM image analysis. Also the structural comparison between this carbon nanoparticle and soot is done by Raman and XRD measurement. These results show this carbon nanoparticles are of grapheme structure, which means it has good crystallinity when compared with soot.

• Textile Coloration and Finishing
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• v.15 no.2
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• pp.102-108
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• 2003

Before studying graft polymerization of PP(polypropylene) nonwoven fabrics by electron beam preirradiation method, mechanical properties, thermal properties and degree of crystallinity of original and electron beam irradiated PP nonwoven fabrics were investigated. Morphological surface changes of electron beam irradiated PP nonwoven fabrics were not observed. And the melting temperature and crystallinity of electron beam irradiated PP nonwoven fabrics also did not change as compared with untreated PP nonwoven fabrics. But the breaking strength of electron beam irradiated PP nonwoven fabrics decreased with increasing electron beam absorbed dose due to breakdown of some parts of polymer main chain.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.3
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• pp.59-68
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• 2013

The cotton contains various impurities such as protein, wax, pectins, coloring matter, even though cotton has been a major source of pure cellulose. The purification processes have been commonly applied to obtain the pure cellulose. However the excessive purification treatments could lead to the damage in the cellulose structure which could result in the degradation of cellulose and the limited application of cotton cellulose. In this study, the changes in cellulose structural properties such as crystallinity and DP(degree of polymerization) by the various conditions of the purification processes were investigated. The less toxic agents such as hydrogen peroxide and sodium silicate were applied for the purification treatment in this study. The increase in the process times, the temperature and the applied amount of chemical agents resulted in the more purified cellulose. The DP of cotton cellulose was increased at the first weak conditions by the reduction of small molecules such as pectin, wax, and so on. Especially the 2 % addition amount of $H_2O_2$ with $Na_2SiO_3$ resulted in the higher value in the DP and the brightness compared to the 1.5 % addition amount of $H_2O_2$. However, the 4 % addition amount of $H_2O_2$ with $Na_2SiO_3$ showed the decreased value because of excessive treatment. In case of the changes in the crystallinity (Gjk), the highest value of the crystallinity was obtained by the 2% addition amount of $H_2O_2$ on the cotton cellulose, which showed similar with the change in the DP.

• Fashion & Textile Research Journal
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• v.21 no.3
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• pp.356-362
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• 2019

This study investigated the substantivity of anionic dyes for cationic-modified new rayon (cocell) fabric treated with cationic agent (CA), 3-(Chloro-2-hydroxypropyl)-trimethylammonium chloride (CA). We also investigate the dyeability of cationic-modified new rayon fabric after dyeing with gallut. CA was converted in an aqueous solution of sodium hydroxide into epoxypropyl trimethylammonium chloride. Treating with this epoxy reagent modified the hydroxyl groups of the new rayon fabric into the trimethylammonium group through ether linkage. The introduction of new cationic sites into new rayon fabric by pretreating with cationic agent improved the substantivity of the Gallnut dye with the new rayon dyebath. The degree of the cationization of cationic-modified new rayon and cotton fabric was evaluated by nitrogen (N) content. This study extracted the colorant of gallnut with hot water at $90^{\circ}C$ and 120 min. Cationic-modified new rayon fabric dyed with extracted solution from gallnut according to concentration of gallnut, dyeing temperature, dyeing time and concentration of cationic agent. Dyeability (K/S) was obtained by CCM observation after dyeing with gallut solution. In addition, fastness to washing and light were also investigated. The degree of crystallinity of new rayon and cotton fabric were 42.15% and 54.94%, respectively. N (%) content of cationic-modified new rayon was higher than the cationic-modified cotton. Dyeability (K/S) increased significantly with the increasing concentration of CA and gallut.

• Polymer(Korea)
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• v.25 no.5
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• pp.657-664
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• 2001

In this study. the effects of ${\gamma}$-irradiation on the crosslinking of low density poly ethylene (LLDPE) and linear low density polyethylene (LLDPE) containing crosslinking agents were investigated to find the degree of crosslinking in the polymer. The LDPE and LLDPE specimens were prepared by blending crosslinking agents with each polymers, and by hot-press-molding into a sheet at 13$0^{\circ}C$. The ${\gamma}$-irradiation was conducted at 50 to 150 kGy in nitrogen. The crosslinking percentage in these specimens was measured in relation to the irradiation dose and the type of crosslinking agents. The mechanical properties, thermal properties and crystallinity of specimens were examined as a function of irradiation dose as well. It was found that the degree of crosslinking of the irradiated specimens was increased with increasing irradiation dose and by the addition of crosslinking agents. The mechanical properties and thermal properties of specimens were improved in proportion to an increase in the degree of crosslinking. The crystallinity of original resin was decreased with increasing crosslinking density.

• Korean Journal of Human Ecology
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• v.2 no.1
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• pp.142-148
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• 1999

Tencel fabrics were treated with cellulase after mechanical prefibrillation treatment. SEM analysis was carried out to study morphological change of the treated fabric. The cellulase-treated Tencel fabrics were evaluated for weight loss and tensile strength. X-ray diffraction method, moisture regain, and K/S value were used to elucidate crystalline structural changes occurred by cellulase treatment. Degree of polymerization and copper number of the cellulase-treated fabrics were also measured to estimate effect of hydrolysis. SEM analysis indicated that with treatment of prefibrillation and cellulase, fibrils were produced and damage occurred deep into the fiber. Increases in concentration and time of cellulase treatment increased weight loss and decreased tensile strength retention of the treated fabrics. As cellulase hydrolysis progressed, degree of crystallinity, moisture regain and K/S value were not much changed. (Korean J Human Ecology 2(1) : 142∼148, 1999)

• Journal of the Korean Wood Science and Technology
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• v.36 no.1
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• pp.12-20
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• 2008

Radial and vertical variations of relative crystallinity and crystallite width of cellulose within stems of three softwoods (Pinus densiflora S. et Z., P. koraiensis S. et Z, P. rigida Mill.) grown in Korea were examined by an X-ray diffraction method. The mean of relative crystallinity was 61.7% in P. koraiensis, 60.6% in P. densiflora and 49.4% in P. rigida. The degree of crystallinity in earlywood and latewood increased with the age from pith to about 10~15 years, and then remained almost constant value. The relative crystallinitiy of latewood was slightly higher than that of earlywood. The relative crystallinity in P. densiflora was a little lower at the base of stem, but no significant difference by height was shown in P. koraiensis and P. rigida. The crystallite widths in the stems were 2.8 to 3.0 nm, but were not significantly different in earlywood and latewood by height. In conclusion, the relative crystallinity appeared to be a useful index for separating juvenile wood from adult wood in the softwoods of P. densiflora, P. koraiensis, and P. rigida grown in Korea.

• Journal of Conservation Science
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• v.37 no.6
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• pp.648-658
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• 2021

In this study, we aimed to analyze the chemical changes that occur in Korean paper in an accelerated deterioration environment of 105℃. We selected the Korean paper produced with different types of cooking agents (plant lye, Na₂CO₃) and during different manufacturing seasons (winter, summer). The degree of deterioration of the Korean paper was confirmed by measuring the brightness, yellowness, and pH level, and the degree of change in each vibrational region of cellulose as deterioration progressed through infrared (FT-IR) spectroscopy. The FT-IR analysis showed that, as deterioration progressed, the absorbance of the amorphous region in cellulose decreased, whereas the absorbance of the crystalline region slightly increased. X-Ray diffraction (XRD) analysis and Raman spectroscopy were performed to verify the changes in the crystalline and amorphous regions in cellulose indicated by the FT-IR results. Furthermore, the crystallinity index (CI) was calculated; it showed a slight increase after deterioration; therefore, CI was confirmed to follow the same trend as that observed for absorbance in the FT-IR results. In addition, as a result of Raman spectroscopic analysis, the degree of decomposition of the amorphous region in the cellulose under the manufacturing conditions was confirmed by the fluorescence measured after the deterioration.