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.

Effect of grafting density on conformation of poly(acrylic acid) in solution by dielectric spectroscopy

Soft Matter ◽  
2018 ◽  
Vol 14 (35) ◽  
pp. 7190-7203 ◽  
Author(s):  
Xinlu Zhou ◽  
Kongshuang Zhao
Keyword(s):  
Acrylic Acid ◽  
Ethylene Oxide ◽  
Dielectric Relaxation ◽  
Dielectric Spectroscopy ◽  
Dielectric Relaxation Spectroscopy ◽  
Frequency Range ◽  
Grafting Density ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Poly Acrylic Acid

The effect of grafting density of poly(ethylene oxide) and dodecyl groups on the conformation of poly(acrylic acid) in solution was clarified by dielectric relaxation spectroscopy over a frequency range from 40 Hz to 110 MHz.

The Structure of Radiation Cross-Linked Poly (ethylene oxide) Gels

1971 ◽  
Vol 29 ◽  
pp. 76-77
Author(s):  
C. E. Cluthe ◽  
G. G. Cocks
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
Parallel Plate ◽  
Average Molecular Weight ◽  
Radical Reaction ◽  
Free Radical Reaction ◽  
Nitrogen Gas ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Initial Viscosity

Aqueous solutions of a 1 weight-per cent poly (ethylene oxide) (PEO) were degassed under vacuum, transferred to a parallel plate viscometer under a nitrogen gas blanket, and exposed to Co60 gamma radiation. The Co60 source was rated at 4000 curies, and the dose ratewas 3.8x105 rads/hr. The poly (ethylene oxide) employed in the irradiations had an initial viscosity average molecular weight of 2.1 x 106.The solutions were gelled by a free radical reaction with dosages ranging from 5x104 rads to 4.8x106 rads.

scholarly journals Isothermal Crystallization Kinetics of Poly(ethylene oxide)/Poly(ethylene glycol)-g-silica Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 648
Author(s):  
Xiangning Wen ◽  
Yunlan Su ◽  
Shaofan Li ◽  
Weilong Ju ◽  
Dujin Wang
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Rate ◽  
Poly Ethylene Glycol ◽  
Isothermal Crystallization Kinetics ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Kinetics Of

In this work, the crystallization kinetics of poly(ethylene oxide) (PEO) matrix included with poly(ethylene glycol) (PEG) grafted silica (PEG-g-SiO2) nanoparticles and bare SiO2 were systematically investigated by differential scanning calorimetry (DSC) and polarized light optical microscopy (PLOM) method. PEG-g-SiO2 can significantly increase the crystallinity and crystallization temperature of PEO matrix under the non-isothermal crystallization process. Pronounced effects of PEG-g-SiO2 on the crystalline morphology and crystallization rate of PEO were further characterized by employing spherulitic morphological observation and isothermal crystallization kinetics analysis. In contrast to the bare SiO2, PEG-g-SiO2 can be well dispersed in PEO matrix at low P/N (P: Molecular weight of matrix chains, N: Molecular weight of grafted chains), which is a key factor to enhance the primary nucleation rate. In particular, we found that the addition of PEG-g-SiO2 slows the spherulitic growth fronts compared to the neat PEO. It is speculated that the interfacial structure of the grafted PEG plays a key role in the formation of nuclei sites, thus ultimately determines the crystallization behavior of PEO PNCs and enhances the overall crystallization rate of the PEO nanocomposites.

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