• Current Research on Agriculture and Life Sciences
• /
• v.32 no.2
• /
• pp.85-89
• /
• 2014

This study uses turbidity and rheological measurements to examine the effects of the molecular weight (MW), substitution type and substitution degree of cellulose ether and water content on the cooking characteristics of rice noodles, the turbidity of the cooking solution, and the compression strength of the cooked noodles. When increasing the MW of cellulose ether and water content, the turbidity decreased, thereby improving the morphological stability of the rice noodles during cooking. Thus, when controlling the above factors effectively, the rice noodle cooking solution had a lower turbidity than with wheat noodles. Measuring the compression strength of the rice noodles using a rheometer was also effective for examining the pasting characteristics of the rice noodles and texture changes during cooking. As a result, the water content and MW of cellulose ether were found to affect the pasting characteristics and texture of the rice noodles more than the other factors examined.

• Current Research on Agriculture and Life Sciences
• /
• v.31 no.3
• /
• pp.177-181
• /
• 2013

This study examined the effect of the molecular weight, substitution degree, and substitution type of cellulose ether on the mechanical properties of dried rice noodles. When increasing the molecular weight of the hydroxypropyl methylcellulose (HPMC), the bending strength of the dried rice noodles also increased. However, the bending strength of the rice noodles with added HPMCs was still lower than that of the wheat noodles. Meanwhile, the bending elongation of the dried rice noodles was higher than that of the wheat noodles and was increased when decreasing the molecular weight of the HPMC. In conclusion, the bending strength and elongation of dried rice noodles is affected by the substitution degree and type of cellulose ether.

• Current Research on Agriculture and Life Sciences
• /
• v.32 no.1
• /
• pp.18-23
• /
• 2014

The present study examined the effect of cellulose ether on the compression and adhesion characteristics of rice dough using a rheometer. When increasing the amount of hydroxypropyl methylcellulose (HPMC), the adhesion strength consistently increased. However, the compression strength of the rice dough was the highest with 2% HPMC. When increasing the molecular weight and decreasing the water content, the compression and adhesion strength of the rice dough were both increased. Furthermore, the substitution type and degree of cellulose ether were also found to be key factors determining the compression and adhesion strength of the rice dough.

• Transactions of the Korean hydrogen and new energy society
• /
• v.27 no.5
• /
• pp.478-484
• /
• 2016

Polyether ether ketone (PEEK) composite membranes have been intensively investigated for polymer electrolyte membrane water electrolysis (PEMWE). Covalently linked (CL) sulfonated polyether ether ketone (SPEEK) and cellulose polymer composite membranes were prepared and characterized. Polyether ether ketone (PEEK) and cellulose were sulfonated and then were covalently linked by 1,4-diiodobutane to produce covalently linked SPEEK and cellulose polymer composite membranes. The composite membranes showed better thermostability and electrochemical properties than SPEEK. The membranes were prepared by sol-gel casting method. CL-SPEEK/Cellulose composite membrane featured 0.2453 S/cm of proton conductivity at $80^{\circ}C$ which was better than that of Nafion.

• Clean Technology
• /
• v.13 no.3
• /
• pp.201-207
• /
• 2007

Carboxymethylcellulose (CMC), which is water-soluble at room temperature, was synthesized from cellulose in this study. Experimental parameters included reaction temperature, time, concentration of NaOH, and monochloroacetic acid (MCA). In mercerization and etherification, solubility and degree of substitution (DS) increased when NaOH (or MCA) concentration increased and maximum solubility and DS were achieved when NaOH or MCA was 30%. The effect of MCA concentrations on the DS was larger than that of the NaOH concentration. Tensile strength of the CMC was decreased by the increases of reaction time, reagent concentration and reaction temperature. Tensile strength also decreased by NaOH and MCA. However, low decrease of tensile strength was observed in near neutral region.

• Clean Technology
• /
• v.11 no.4
• /
• pp.189-194
• /
• 2005

Carboxymethylcellulose(CMC) which is water-soluble fiber was manufactured by mercerization and etherification in the earlier study. Experimental parameters were conversion time for each step, concentration of reagent and temperature. To know the presence of functional group, CMC was analyzed by FT-IR(Fourier Transform Infrared) spectroscopy. Ethanol was recovered using evaporator and purity of ethanol analyzed by GC-MASS was 97% and 83% after mercerization and etherification respectively. For the pilot plant, if CMC is folded by 40 times it showed maximum efficiency. Maximum solubility was obtained when the ratio of NaOH and MCA is 3 : 4.5.

• Polymer(Korea)
• /
• v.29 no.1
• /
• pp.25-31
• /
• 2005

Cellulose acetate derivatives containing 6-(p-hexyloxyphenyl)carbonyl spirobenzopyran (CA-COSP) were prepared from base-catalyzed etherification of cellulose acetate, and their physical and photochromic properties were characterized. The degree of substitution of COSP was calculated from the amount of residual hydroxyl groups in cellulose acetate measured by the $^1H$-NMR and UV spectrometric data. It was ranging from 0.87 to 45.5% depending on the reaction condition. UV/vis spectrometry of the resulting CA-COSP revealed that the polymer shows a reversible color change by changing its color from colorless to blue upon UV irradiation forming a merocyanine structure, and returning back again to colorless spiropyran structure by visible light or by heat. The rate of color change was faster in solution than in the film. In the more polar solvent, the more stable was the resulting merocyanine, and the slower was the rate of reverse reaction to spiropyran. Compared to COSP blended with cellulose acetate, in which a phase separation was observed for samples containing more than 0.9 wt% of COSP, up to 48 wt% of COSP could be blended in CA-COSP without phase separation.

• Polymer(Korea)
• /
• v.36 no.1
• /
• pp.76-87
• /
• 2012

Three kinds of hydroxypropyl cellulose (HPC) derivatives, [6-{4-(4-cyanophenylazo)phenoxy}]hexyloxypropyl celluloses (CAHPCs) with degree of etherification (DET) ranging from 0.4 to 3, fully substituted acrylic acid esters of HPC (HPCA) and CAHPCs (CAHPCAs) were synthesized. The crosslinked HPCA (HPCAG) and CAHPCAs (CAHPCAGs) were also prepared by exposing thermotropic mesophases of HPCA and CAHPCAs to UV light. Both CAHPCs and CAHPCAs with DET ${\leq}$ 1.2, as well as HPC and HPCA, formed enantiotropic cholesteric phases whose optical pitches(${\lambda}_m$'s) increase with temperature, wheras both CAHPCs and CAHPCAs with DET ${\geq}$ 1.4 showed monotropic nematic phases. CAHPCAGs with DET ${\leq}$ 1.2, as well as CAHPCAs with DET ${\leq}$ 1.2, exhibited reflection colors in a wide temperature range. On the other hand, CAHPCAGs with DET ${\geq}$ 1.4, as well as CAHPCAs with DET ${\geq}$ 1.4, showed Schileren textures typical of nematic phase, indicating that the liquid crystalline structure is virtually locked upon photocrosslinking. The isotropization temperatures($T_i$'s) of both CAHPCAs and CAHPCAGs decreased with increasing DET. The $T_i$ of CAHPCAG, however, was higher than that of CAHPCA at the same DET. Moreover, the temperature dependence of ${\lambda}_m$ of CAHPCAGs was much weaker than that of CAHPCAs.

• Transactions of the Korean hydrogen and new energy society
• /
• v.29 no.5
• /
• pp.411-418
• /
• 2018

The polymer electrolyte membranes, CL-SPEEK/Cellulose composite membrane I, II, III with the improved electrochemical and mechanical properties were prepared and characterized. The engineering plastic polyether ether ketone (PEEK) and cellulose were sulfonated and cross-linked. The membranes were prepared by sol-gel casting method with different amount of cross-linking reagent. In conclusion, the composite membranes I, II, III showed improved thermostability, tensile strength and oxidative durability. Proton conductivity of the membranes was also improved and the composite membrane I showed 0.1312 S/cm at $80^{\circ}C$ which was the best of those composite membranes.

• Applied Chemistry for Engineering
• /
• v.10 no.4
• /
• pp.581-585
• /
• 1999

The surface treated hydroxypropyl methylcellulose(HPMC) which could adjust the soluble time was synthesized when 40 wt % glyoxal solution and $KH_2PO_4$ were sprayed and reacted. And also, the solution dynamic at different ratios of two adding agents were identified If the surface of HPMC was treated with only glyoxal, the dispersion characteristics at different ratios of two adding agents were identified If the surface of HPMC was treated with only glyoxal, the dispersion was observed in the neutral solution and the viscosity was increased after directly dissolved as the solution become alkali condition. But the fine-powder type of HPMC which reacted with glyoxal and $KH_2PO_4$ was dispersed regardless of pH of solution and observed that it was dissolved and its viscosity increased after elapsing some time. With increasing amount of glyoxal and $KH_2PO_4$, the soluble time was delayed. The reaction condition was about 60 min at $75{\sim}85^{\circ}C$. Especially, the removal process of organic solvent after reaction was not required due to reaction under water solution without organic during glyoxal and $KH_2PO_4$ treatment. And also, the HPMC which could adjust the soluble rate in water or organic solvent by changing the degree of substitution of HPMC was synthesized.