Dynamics of a bioinert polymer in hydrated states by dielectric relaxation spectroscopy

2017 ◽  
Vol 19 (2) ◽  
pp. 1389-1394 ◽  
Author(s):  
Toyoaki Hirata ◽  
Hisao Matsuno ◽  
Daisuke Kawaguchi ◽  
Manabu Inutsuka ◽  
Tomoyasu Hirai ◽  
...  
Keyword(s):  
Dielectric Relaxation ◽  
Side Chain ◽  
Water Interface ◽  
Dielectric Relaxation Spectroscopy ◽  
Segmental Dynamics ◽  
Side Chain Motion

The segmental dynamics of poly(2-methoxyethyl acrylate) at the water interface is extremely faster and comparable to the side chain motion.

Study of the Molecular Mobility of Polysaccharide Solid Thin Layers by Dielectric Relaxation Spectroscopy

1997 ◽  
Vol 500 ◽  
Author(s):  
K. Liedermann ◽  
L. Lapčík ◽  
S. Desmedt
Keyword(s):  
Dielectric Relaxation ◽  
Low Frequency ◽  
Thin Layers ◽  
Side Chain ◽  
Relaxation Processes ◽  
Dielectric Relaxation Spectroscopy ◽  
Frequency Range ◽  
Polar Groups ◽  
Calculated Activation Energy ◽  
Β Relaxation

ABSTRACTTemperature dependence of measured dielectric relaxation spectra (DRS) in the frequency range 20 Hz - 1 MHz of hydroxyethylcellulose (HEC) are in the temperature range 100 – 350 K. of Arrhenius character with one relaxation process at 150 – 250 K. This process reflects most probably β-relaxation of the side chain groups. Calculated activation energy of this process was 5730 kJ/mole. Four types of polysaccharides were studied at 293 K temperature: hyaluronic acid (HA), chondroitin sulfate (CHS), HEC and carboxymethylcellulose (CMC), in the low-frequency range 10−5 - 100 Hz. Measured dielectric spectra were interpreted as sum of one A.C. conductivity process and of up to two relaxation processes. The relaxation processes were described by means of the Havriliak-Negami formula and their parameters were related to the molecular structure of the polymers. The low value of a in CHS is related to its strong coupling due to the presence of two polar groups in its monomeric unit, whereas low values of α × β are interpreted as being due to the strong steric hindrances caused by long pendants present in HEC.

scholarly journals Effect of soft segment molecular weight on the glass transition, crystallinity, molecular mobility and segmental dynamics of poly(ethylene oxide) based poly(urethane–urea) copolymers

RSC Advances ◽  
2017 ◽  
Vol 7 (65) ◽  
pp. 40745-40754 ◽  
Author(s):  
Oguzhan Oguz ◽  
Stefanos A. Koutsoumpis ◽  
Eren Simsek ◽  
Emel Yilgor ◽  
Iskender Yilgor ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Ethylene Oxide ◽  
Dielectric Relaxation ◽  
Molecular Mobility ◽  
Soft Segment ◽  
Dielectric Relaxation Spectroscopy ◽  
Segmental Dynamics ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

The effect of poly(ethylene oxide) (PEO) soft segment molecular weight (Mn= 2000, 4600, 8000 g mol−1) molecular mobility and segmental dynamics of a series of polyurethane–urea copolymers (PU) was investigated by dielectric relaxation spectroscopy.

Observation of the side-chain motion of polypeptides in solution by measurement of picosecond dielectric relaxation

1981 ◽  
Vol 14 (6) ◽  
pp. 1698-1700 ◽  
Author(s):  
Haruki Nakamura ◽  
Satoru Mashimo ◽  
Akiyoshi Wada
Keyword(s):  
Dielectric Relaxation ◽  
Side Chain ◽  
Side Chain Motion

Dielectric relaxation spectroscopy of amorphous and liquid-crystalline side-chain polycarbonates

1997 ◽  
Vol 18 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Michael Wübbenhorst ◽  
Ernout M. Van Koten ◽  
John C. Jansen ◽  
Wim Mijs ◽  
Jan van Turnhout
Keyword(s):  
Dielectric Relaxation ◽  
Liquid Crystalline ◽  
Side Chain ◽  
Dielectric Relaxation Spectroscopy
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