Characterisation of Blends Based on Hydroxyethylcellulose and Maleic Acid‐alt‐Methyl Vinyl Ether

Abstract

Summary: Hydrophilic polymeric films based on blends of hydroxyethylcellulose and maleic acid‐co‐methyl vinyl ether were produced by casting from aqueous solutions. The physicochemical properties of the blends have been assessed using Fourier transform infrared spectroscopy, thermal gravimetric analysis, differential scanning calorimetry, dielectric spectroscopy, etc. The pristine films exhibit complete miscibility due to the formation of intermacromolecular hydrogen bonding. The thermal treatment of the blend films leads to cross‐linking via intermacromolecular esterification and anhydride formation. The cross‐linked materials are able to swell in water and their swelling degree can be easily controlled by temperature and thermal treatment time. The formation of the crosslinks is apparent in the dynamic properties of the blends as observed through the mechanical relaxation and dielectric relaxation spectra. The dielectric characteristics of the material are influenced by the effects of change in the local structure of the blend on the ionic conduction processes and the rate of dipolar relaxation. Separation of these processes is attempted using the dielectric modulus method. Significant deviations from a simple additive rule of mixing on the activation energy are observed consistent with hydrogen bonding and crosslinking of the matrix. This paper indicates a method for the creation of films with good mechanical and physical characteristics by exposing the blends to a relatively mild thermal treatment.

Degradation kinetics and molecular structure development of hydroxyethyl cellulose under the solid state mechanochemical treatment

“…The FTIR spectra of HEC before and after milling are shown in Fig. 3, which is consistent with the data earlier reported by Khutoryanskaya and Khutoryanskiy (Khutoryanskaya, Khutoryanskiy, & Pethrick, 2005). The absorbance at 3411 cm −1 corresponds to the O-H stretching vibration and the absorbance at 1067 cm −1 corresponds to the -C-O-stretching vibration.…”

Polymeric Acid Doped Polyaniline Nanotubes for Oligonucleotide Sensors

“…In addition to these peaks from PANI, the peak at 1714 cm À1 , which belongs to the C ¼ O group of polymeric acid [45], is seen, confirming that the polymeric acid was incorporated into the PANI nanotube structure.…”

Conducting polyaniline nanorods doped with aromatic carboxyl chain end functionalized polystyrene

“…The absorption bands at 970 and 858 cm −1 are attributed to the aromatic C H in-plane and out-of-plane bending vibrations for the 1,4 disubstituted phenyl rings [42][43][44]79]. In addition to the characteristic PANI bands, the weak absorption band at 1610 cm −1 is attributed to the stretching vibration modes of the C O group of the carboxylate group of the polymeric dopant and indicates the incomplete doping or low degree of dopant in the final product and confirms that the aromatic carboxyl functionalized polystyrene is incorporated within the PANI nanorods [80]. The thermal stability of each polyaniline sample was determined by TGA analysis.…”