Effect of the acrylic acid content on miscibility and mechanical properties of mixtures of poly[ethylene-co-(acrylic acid)] and poly(2-ethyl-2-oxazoline)

The miscibility behavior of blends of poly(2-ethyl-2-oxazoline) (PEOX) and poly[ethylene-co-(acrylic acid)] was studies as a function of the acrylic acid content with the help of differential scanning calorimetry (DSC), modulated DSC and dynamic mechanical thermal analysis (DMTA). Miscibility, ascertained by the existence of a single glass transition in the mixtures, is achieved only between the PEOX and the copolymers with a high acrytic acid content (20%). The other two polymer pairs are immiscible at all compositions. FTIR spectroscopy demonstrates that miscibility is enhanced by hydrogen bonding interactions between the amide groups of the PEOX and the carboxylic groups of the acrylic acid units in the copolymer. Tensile stress and compressive creep tests reveal that the 20 and the 40 wt.-% PEOX blends exhibit synergistic mechanical properties, i.e., better ultimate properties, smaller Young's moduli and higher creep compliances. � Wiley-VCH Verlag GmbH, 2001

Specific interactions study in complexes of poly(mono-nalkyl itaconates) with tertiary polyamides

This paper reports an FT-IR study of blends of poly(mono-n-alkyl itaconates) with poly(N,N-dimethylacrylamide) (PDMA) and poly(ethyloxazoline) (PEOX). Strong hydrogen bonding has been found, and both polybases have shown similar acceptor strengths. Derivative techniques show asymmetric profiles for the free carbonyl band of the polybases, resulting in shifted band locations. The extent of the interassociation has been estimated by spectral curve fitting of the polybase carbonyl band. The results show that the interaction degree in blends with PEOX does not depend on the length of the poly(monoalkyl itaconate) side group, while an inter-associating ability loss is observed in blends with PDMA as the side-group size of the polyacid increases. This different behavior is attributed to the greater interspacing between vicinal carbonyl groups in PEOX. This band shows conformational sensitivity and reflects the conformational changes that occur as the steric hindrances present in the medium (due to the bulky side groups of the polyacids) increase

Effect of the acrylic acid content on miscibility and mechanical properties of mixtures of poly[ethylene-co-(acrylic acid)] and poly(2-ethyl-2-oxazoline)

The miscibility behavior of blends of poly(2-ethyl-2-oxazoline) (PEOX) and poly[ethylene-co-(acrylic acid)] was studies as a function of the acrylic acid content with the help of differential scanning calorimetry (DSC), modulated DSC and dynamic mechanical thermal analysis (DMTA). Miscibility, ascertained by the existence of a single glass transition in the mixtures, is achieved only between the PEOX and the copolymers with a high acrytic acid content (20%). The other two polymer pairs are immiscible at all compositions. FTIR spectroscopy demonstrates that miscibility is enhanced by hydrogen bonding interactions between the amide groups of the PEOX and the carboxylic groups of the acrylic acid units in the copolymer. Tensile stress and compressive creep tests reveal that the 20 and the 40 wt.-% PEOX blends exhibit synergistic mechanical properties, i.e., better ultimate properties, smaller Young's moduli and higher creep compliances. © Wiley-VCH Verlag GmbH, 2001

Miscible blends of poly(vinyl phenyl ketone) and poly(4-vinyl phenol)

An analysis by differential scanning calorimetry, modulated differential scanning calorimetry, and Fourier transform infrared spectroscopy (FTIR) indicates that blends of poly(vinyl phenyl ketone) (PVPhK) and poly(4-vinyl phenol) (P4VPh) are miscible at ambient temperature. Miscibility, ascertained, is supported by the existence of a single glass transition for each composition of the PVPhK/P4VPh blends. The FTIR spectroscopy analysis demonstrates the formation of hydrogen bonds between carbonyl groups of PVPhK and hydroxyl groups of P4VPh. This specific interaction has a crucial role on the miscibility behavior of PVPhK/P4VPh blends. The evolution of the glass transition of the PVPhK, P4VPh, and its blends as a function of mixture composition shows negative deviations with to respect to the ideal mixing rule, and both Fox and Gordon-Taylor equations predict this behavior successfully. © 2006 Wiley Periodicals, Inc

Smart copolymeric nanohydrogels: Synthesis, characterization and properties

Novel smart pH-sensitive copolymeric hydrogels have been synthesized by inverse microemulsion polymerization of p-nitro phenol acrylate (NPA) and N-isopropylacrylamide (NIPA) using Aerosol (AOT) as a surfactant and ethylene glycol dimethacrylate (EGDMA) as a crosslinking agent. The polymerization reaction was performed in presence of an oil-soluble salt to reduce the dimensions of the micellar diameter. The average particle diameter and the particle size distribution of the nanogels were measured in acetone at 25 °C by quasielastic light scattering (QLS) showing average diameter of 33 nm. The nanogels were characterized by FTIR-ATR, H1 NMR, UV-vis spectroscopy and DSC. These nanoparticles had shown a selective swelling-collapse response to external pH changes. © 2008

Miscible blends of poly(vinyl phenyl ketone hydrogenated) and poly(styrene-co-4-vinylpyridine)

Miscibility behavior over a wide composition range was detected for polymer blends of poly(vinyl phenyl ketone hydrogenated) (PVPhKH) with poly(styrene-co-4-vinylpyridine) (PS-co-4VPy). Differential scanning calorimetry (DSC) and thermo mechanical analysis (TMA) reveal that each composition has only one glass transition temperature. The variation of the glass transition temperature with composition for PVPhKH/PS-co-4VPy miscible blends follows the Gordon-Taylor equation. FTIR analysis of this binary system indicates the existence of hydrogen bonding between pyridine ring of PS-co-4VPy and hydroxyl groups insert into PVPhKH. This specific interaction has a decisive influence in the phase behavior of PVPhKH/PS-co-4VPy blends. � 2004 Elsevier Ltd. All rights reserved