The main aim of this research is to investigate the effect of salt concentration on the dielectric properties （AC （CrAC）, permittivity （d）, dielectric loss （d＇）, and dielectric relaxation process） and melting...The main aim of this research is to investigate the effect of salt concentration on the dielectric properties （AC （CrAC）, permittivity （d）, dielectric loss （d＇）, and dielectric relaxation process） and melting behavior of polyethylene oxide （PEO）/CdC12 complexes. The dielectric study was carried out over a frequency range 10-335 kHz and a temperature range 25--45~C. The AC conductivity, permittivity and dielectric loss of the PEO/CdC12 complexes increase with increasing salt concentration and temperature. Also, it was found that the addition of CdC12 salt to PEO host reduced the melting temperature of PEO host. Dielectric results reveal that the relaxation process of these complexes is due to viscoelastic relaxation or non-Debye relaxation at room temperature. Additionally, it was found that relaxation behavior remained viscoelastic at different temperatures and salt concentrations.展开更多
This article deals with the study of the viscoelastic and thermal properties of polyurethane (PU) rigid foamsfrom biobased and recycled components. Rapeseed oil (RO) and recycled poly(ethylene terephthalate)(PET) were...This article deals with the study of the viscoelastic and thermal properties of polyurethane (PU) rigid foamsfrom biobased and recycled components. Rapeseed oil (RO) and recycled poly(ethylene terephthalate)(PET) were used to synthesize PU polyols. Addition of adipic acid (ADA) to polyol resulted in improvedthermal and viscoelastic properties of foam materials. ADA content was varied from 1 to 6 wt%. Results ofthe dynamic mechanical spectra indicate an increase of the storage modulus E′ and the loss modulus E″ inthe whole temperature range for specimens with higher loading of ADA. In addition, damping factor shiftedto higher temperatures, but damping intensity remained almost unaffected by the compositions. Scanningelectron microscopy of the foams’ cross sections testified that the average cells’ size of 110 mm was unaffectedby the ADA content in polyol.展开更多
文摘The main aim of this research is to investigate the effect of salt concentration on the dielectric properties （AC （CrAC）, permittivity （d）, dielectric loss （d＇）, and dielectric relaxation process） and melting behavior of polyethylene oxide （PEO）/CdC12 complexes. The dielectric study was carried out over a frequency range 10-335 kHz and a temperature range 25--45~C. The AC conductivity, permittivity and dielectric loss of the PEO/CdC12 complexes increase with increasing salt concentration and temperature. Also, it was found that the addition of CdC12 salt to PEO host reduced the melting temperature of PEO host. Dielectric results reveal that the relaxation process of these complexes is due to viscoelastic relaxation or non-Debye relaxation at room temperature. Additionally, it was found that relaxation behavior remained viscoelastic at different temperatures and salt concentrations.
文摘This article deals with the study of the viscoelastic and thermal properties of polyurethane (PU) rigid foamsfrom biobased and recycled components. Rapeseed oil (RO) and recycled poly(ethylene terephthalate)(PET) were used to synthesize PU polyols. Addition of adipic acid (ADA) to polyol resulted in improvedthermal and viscoelastic properties of foam materials. ADA content was varied from 1 to 6 wt%. Results ofthe dynamic mechanical spectra indicate an increase of the storage modulus E′ and the loss modulus E″ inthe whole temperature range for specimens with higher loading of ADA. In addition, damping factor shiftedto higher temperatures, but damping intensity remained almost unaffected by the compositions. Scanningelectron microscopy of the foams’ cross sections testified that the average cells’ size of 110 mm was unaffectedby the ADA content in polyol.
