Dielectric Properties of Hyperbranched Polyesteramide with Long Alkyl Chain End Groups

Abstract

Summary: Hyperbranched polyesteramides were prepared using phethalic anhydride (Ph An) or maleic anhydride (M An) as an A 2 monomer and diethanol amine (DEA) as B 0 B 2 monomer. Bulk condensation technique was used to synthesize polymers with both OH and modified polymers with long alkyl chain end groups. The prepared polymers were characterized using 1 H-NMR, FTIR and TGA. Solution viscosity for hyperbranched polyester amide with hydroxyl end groups was measured as well. Dielectric and electric properties of the modified samples were investigated over a range of frequency and temperatures. No relaxation peak is noticed in the dielectric spectrum e(n) at various temperatures. The illustration of the imaginary part of the electric modulus M 00 versus frequency shows a peak which is shifted towards higher frequency in increasing temperature.

Structure–Property Relationships of Hyperbranched Polymer/Kaolinite Nanocomposites

“…In difference to the HPAE/Ka-DEA (in situ) nanocomposites, for the ex situ materials the activation energy decreases in confinement from 30 kJ/mol to 25 kJ/mol. On a molecular level, this could be understood by assuming that the system of hydrogen bonding, due to the hydroxyl groups [30,33,172,173 ], is changed or partly disrupted for the HPAE/Ka-DCA samples due to the confinement and/or the presence of the nanoparticles. The differences in the structures of both kind of different materials observed by the structural data (SAXS, TEM) is also reflected in its molecular dynamics as revealed by both the  and the -relaxation (see Figures 5.6 and 5.9).…”

“…It is worth mentioning that the activation energies decrease with increasing the concentration of the nanofillers by trend. One explanation for this behavior might be that the system of hydrogen bonding, due to the hydroxyl groups [38,173,173], is changed or partly interrupted for nanocomposites. These distortions of the hydrogen bonding network might lower the energy barriers for proton conduction.…”

Antifouling and antimicrobial polyethersulfone/hyperbranched polyester-amide/Ag composite

“…PESAM/Ag nanohybrid showed a sharp crystalline diffraction peak at 38 corresponding to (111) plane of AgNPs. 21 A broad non-crystalline peak (18)(19)(20)(21)(22)(23)(24)(25) was also recognized implying the amorphous nature of the hyperbranched polymer (Fig. 4).…”

“…PESAM was synthesized using our previously described protocol with slight modication. 23 Briey, Ph-An (0.17 moles) was reacted with D1PA (0.23 moles) under inert atmosphere at 140 C for 3 h. Aer complete dissolution of Ph-An, vacuum was applied for further 2 h to remove water. The reaction was stopped when the color of mixture was turned into yellowish viscous liquid.…”