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Kasahara, Takamitsu*; Takigami, Machiko*; Nagasawa, Naotsugu; Takigami, Shoji*
Transactions of the Materials Research Society of Japan, 34(3), p.395 - 398, 2009/09
no abstracts in English
Takigami, Machiko*; Hiroki, Akihiro; Nagasawa, Naotsugu; Kasahara, Takamitsu*; Takigami, Shoji*; Tamada, Masao
Transactions of the Materials Research Society of Japan, 34(3), p.391 - 394, 2009/09
Carboxymethyl cellulose (CMC) with different molar mass was prepared by acid hydrolysis at 121
C. CMC thus prepared was mixed with citric acid aqueous solution to form CMC-acid gel. By replacing sodium existing as counter ion in carboxymethyl group with hydrogen, CMC molecules coagulate and hydrogen bonds are formed among CMC molecules. The CMC-acid gel prepared in that way was subjected to evaluation of gel fraction, water absorption and mechanical properties. Gel fraction was higher in CMC with higher molar mass than that in CMC with lower molar mass at short incubation time. However, there was no difference in gel fraction attributable to molar mass of CMC after long time incubation. CMC with higher molar mass crosslinked more easily than CMC with lower molar mass. The gel made of CMC with lower molar mass was softer and absorbed more amount of water than that with higher molar mass. All the results were elucidated by number of hydrogen bonds in CMC molecule. The gel made of higher molar mass CMC becomes stiff and brittle after long time incubation, however, the gel made of lower molar mass CMC keeps softness and strength longer.
Kasahara, Takamitsu*; Takigami, Machiko*; Nagasawa, Naotsugu; Prawitwong, P.*; Takigami, Shoji*
Transactions of the Materials Research Society of Japan, 33(4), p.927 - 930, 2008/12
Carboxymethyl cellulose (CMC) forms a gel when mixed with acid as a result of replacement of sodium in carboxymethyl group with hydrogen; hydrogen bonds are formed among CMC molecules. CMC gel gets new property by mixing with other materials. Konjac mannan (KM) is a water soluble glucomannan with high molar mass and has high viscosity in low concentration aqueous solution. CMC gel is expected to have more elasticity by mixing with KM. Novel CMC-KM mixture gel is made by two processes; (1) mixing CMC with KM solution, (2) immersion of CMC-KM mixture in hydrochloric acid aqueous solution. Interaction of CMC and KM was studied by using KM with different molar mass. Molar mass of KM easily decreases by 
-irradiation. The effect of KM molar mass on characteristics of CMC-KM mixture is examined using tensile test fixture.
Kasahara, Takamitsu*; Takigami, Machiko*; Nagasawa, Naotsugu; Prawitwong, P.*; Tamada, Masao; Takigami, Shoji*
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 45, 2008/11
Carboxymethyl cellulose (CMC) forms a gel when mixed with acid as a result of replacement of sodium in carboxymethyl group with hydrogen; hydrogen bonds are formed among CMC molecules. CMC gel gets new property by mixing with other materials. Konjac mannan (KM) is a water soluble glucomannan with high molar mass and has high viscosity in low concentration aqueous solution. CMC gel is expected to have more elasticity by mixing with KM. Novel CMC-KM mixture gel is made by two processes; (1) mixing CMC with KM solution, (2) immersion of CMC-KM mixture in hydrochloric acid aqueous solution. Interaction of CMC and KM was studied by using KM with different molar mass. Molar mass of KM easily decreases by -irradiation. The effect of KM molar mass on characteristics of CMC-KM mixture is examined using tensile test fixture.
Takigami, Machiko*; Amada, Haruyo*; Nagasawa, Naotsugu; Yagi, Toshiaki; Kasahara, Takamitsu*; Takigami, Shoji*; Tamada, Masao
Transactions of the Materials Research Society of Japan, 32(3), p.713 - 716, 2007/09
Carboxymethylcellulose (CMC) gel was formed by addition of acid to CMC (CMC-acid gel). Gel fraction (weight of insoluble part/initial CMC weight) was calculated after removing uncrosslinked CMC by immersing the CMC-acid gel in water. It increased with acid concentration. Mechanism of CMC-acid gel formation was elucidated by aggregation of CMC molecules as the result of replacement of sodium in carboxyl group with hydrogen. Gels could be prepared by three different procedures; (1) mixing CMC and acid, (2) immersion of CMC or -irradiated CMC pastes in acid, and (3) -irradiation of CMC-acid gel. Gels with different elasticity and hardness were prepared changing degree of substitution of CMC, molar mass of CMC, species of acid, concentrations of acid and CMC, and application of -irradiation.
Takigami, Machiko*; Hiroki, Akihiro; Nagasawa, Naotsugu; Kasahara, Takamitsu*; Takigami, Shoji*; Tamada, Masao
no journal, ,
no abstracts in English
Takigami, Machiko*; Hiroki, Akihiro; Nagasawa, Naotsugu; Kasahara, Takamitsu*; Takigami, Shoji*; Tamada, Masao
no journal, ,
