Interactions In Polymer Blends Research Articles

The Effect of Interactions in Polymer Blends Studied by Monte Carlo Simulations

The Effect of Interactions in Polymer Blends Studied by Monte Carlo Simulations

FTIR studies of polar interactions in polymer blends

AbstractSpecific interactions in binary blends of poly(vinyl chloride) (PVC) with ethylene–vinyl acetate copolymers (EVA) and ethylene‐methyl acrylate copolymers (EMA) were investigated by observation of band shifts of the carbonyl absorption using ATR‐FTIR spectroscopy at variable temperature. Blends of PVC with EVA and EMA could be prepared as heterogeneous, homogeneous or metastable homogeneous mixtures, depending on the copolymer composition. The miscible systems as well as the heterogeneous ones showed only very small or no band shifts. The metastable blends exhibited shifts of several wave numbers to lower values, which vanished at higher temperatures as the blends demixed. Strong interactions in the metastable blends could be related to good impact properties of the corresponding two‐phase systems.

Solid-state NMR study of charge-transfer interactions in polymer blends

Polymer blends containing electron donor (N-ethylcarbazol-3-yl)methyl methacrylate (NEC-MM) and electron acceptor 2-[(3,5-dinitrobenzoyl)oxy]ethyl methacrylate (DNBEM) moieties were studied. The number of inter- vs intramolecular charge-transfer (CT) interactions was varied by preparing blends of polydonor with polyacceptor, as well as blends containing a homopolymer and an acceptor-donor copolymer. The blends were one phase for NECMM contents greater than 35 mol%. At lower donor contents, two phases with different amounts of CT complexation were shown to exist. CT interactions result in restricted mobility and reduced free volume and interatomic distances in the bulk polymer blends

Scanning electron microscopy methods for studying interfacial interaction in polymer blends

The scanning electron microscopy method in combination with the selective etching technique for polymer blends have been used to evaluate interfacial interaction in natural rubber and low density polyethylene blends. The morphology of the polymer blends, studied under externally applied strain, has been investigated to understand the role of interface adhesion between natural rubber and polyethylene phases, for two separate crosslinking systems, i.e. sulphur and peroxide. Externally induced strain which facilitates phase separation in sulphur cured blends by initiating cracks at the interface; peroxide curing prevents separating out of the polyethylene phase from the natural rubber matrix. In the latter case, induced stress is distributed predominantly by developing fine flaw paths in the rubber matrix. The method which has been developed for natural rubber and polyethylene blend systems may be used to evaluate the degree of interfacial adhesion between the dispersed phase and the dispersion medium for other kinds of polymer-polymer, polymer-filler as well as polymer-fibre composites.

Poly(ethylene oxide)-poly(methyl methacrylate) interactions in polymer blends: an infra-red study

Following our previous work in this field it is shown that the vibrational infra-red spectrum indicates that polyoxyethylene, usually in the most stable helical structure (H), transforms into atrans planar structure (T) when in contact with syndiotactic poly(methyl methacrylate) (PMMA). The conversion of solid H to solid T decreases gradually from syndiotactic PMMA to atactic PMMA to isotactic PMMA. A comprehensive interpretation is proposed in order to reconcile the detailed spectroscopic data reported here and the overall morphological descriptions reported by other authors.

FTIR‐ATR study of interactions in polymer blends containing polyesterurethane

AbstractMolecular interactions such as especially hydrogen bondings are considered to play a key role in polymer compatibility. In this study binary blends produced by extrusion of a MDI based segmented polyesterurethane (TPU) together with styrene‐acrylonitrile and acrylonitrile‐butadiene‐styrene copolymers, respectively, could be investigated without additional sample preparation using the infrared spectroscopic sampling technique of attenuated total reflection (ATR). With increasing content of the nitrile group containing polymers in the blends urethane carbonyl groups completely hydrogen bonded in the pure TPU are liberated. “Free” NH groups, however, are not detectable in the NH stretching region of the ATR spectra of the blends. The interpretation of the obtained spectral effects occurring in the blends is supported by experiments with N‐butyl‐carbamideacid‐methylester as model compound with an urethane linkage. The presented results lead to the conclusion, that intermolecular hydrogen bonding involving urethane NH groups and nitrile groups of the other polymers in the blends has been arised. Quantitative differences of these interactions between the two kinds of blends investigated in this study are discussed.

Screening of interactions in polymer blends

Screening of interactions in polymer blends

Interaction in polymer blends via dilute solution light-scattering under optical θ-conditions

It is demonstrated that dilute solution light —scattering experiments under ‘optical θconditions’ offer rapid and reliable judgement of the interaction parameters in polymer blends. This has been verified with miscible blends of polystyrene with poly(vinylmethylether) and with the immiscible pair polystyrene —poly(vinylisobutylether). The capabilities of the optical θ-approach in order to derive the influence of polymerpolymer interaction on chain dimensions are discussed shortly.

FT‐IR study of intermolecular interactions in polymer blends

Application de cette technique d'un melange homogene chitosane-alcool polyvinylique afin d'elucider les mecanismes moleculaires impliques dans ses proprietes mecaniques