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Cast polyurethane thermosets have been modified with randomly oriented exfoliated and intercalated montmorillonite clay using hyperbranched polymers (HBP) as reactive additives to promote dispersion of the clay platelets. The influence of the clay content on the stiffness of the nanocomposites is discussed in terms of simplified classical micromechanical models that allow correlations to be established...
The hydrolytic condensation of organotrialkoxysilanes containing (β-hydroxy) tertiary amine groups generates a significant fraction of intramolecular cycles and leads to the formation of closed structures. The aim of this study was to investigate if their co-condensation with a tetraalkoxy silane would take place by predominant intramolecular cyclization steps, eventually leading to functionalized...
The bacterium Pseudomonas oleovorans was utilized to produce a novel natural-synthetic hybrid block copolymer. This hybrid biomaterial consists of the natural hydrophobic polymer polyhydroxyoctanoate (PHO) end-capped with hydrophilic synthetic diethylene glycol (DEG). The addition of the synthetic component, in the form of PEG106, to the bioprocessing stage significantly affected polymer yield and...
Simple blending and dynamic vulcanisation of EPDM/PE blends using the resol/SnCl 2 system was studied in an extruder using a series of sampling devices. The melting of the PE pellets occurs just in front of and in the first kneading zone. Upon complete melting of the PE phase, the EPDM/PE blends reach very quickly their final morphology. Crosslinking of the EPDM phase to high levels occurs...
We apply a new X-ray scattering approach to the study of melt-spun filaments of tri-block and random terpolymers prepared from lactide, caprolactone and glycolide. Both terpolymers contain random sequences, in both cases the overall fraction of lactide units is ∼0.7 and 13 C and 1 H NMR shows the lactide sequence length to be ∼9–10. A novel representation of the X-ray fibre pattern...
Computational methods are described and applied to study how to develop coarse-grained force fields for cis-poly(1,4-butadiene) from the atomistic simulation. We developed an iterative method for potential inversion from distribution functions for the polymer systems. Then, we analyzed the static character and dynamic character from atomistic simulation and coarse-grained (CG) simulation as a simple...
Polyamide 6/clay nanocomposites (PAn, where n is the mass fraction of clay) with various clay loading were prepared by melt compounding in a twin screw extruder. Exfoliation of clay in a PA matrix was confirmed by X-ray diffraction. Strain amplitude response of PAn in both melt and solution states has been investigated. In the melt state, critical strain amplitude of PAn is sensitive to strain amplitude...
Poly(ethylene terephthalate) ionomer (PETI)/organically-modified montmorillonite clay (OMC) nanocomposites were prepared via melt extrusion. Sulfonated PET containing various incorporations of ionic comonomer and clay modifications were investigated. The random incorporation of ionic functionalities along the PET backbone enhances interactions between the matrix polymer and montmorillonite clay resulting...
As mechanical properties of short fiber reinforced thermoplastic injected components depend on flow induced fiber orientation, there is considerable interest in validating and improving models which link the flow field and fiber orientations to mechanical properties. The present paper concerns firstly the observation and quantification of fiber orientation in a rectangular plaque with adjustable thickness...
Singlewall carbon nanotubes were covered with polypyrrole via in situ miniemulsion polymerization of pyrrole monomer. They had nanotube surfaces partially enveloped with polypyrrole: the surfaces attached with polypyrrole particles, the surfaces covered with thin polypyrrole film, and bare surfaces. The nanotubes covered with polypyrrole were doped with LiClO 4 and mixed with a binder, Kynar...
A novel coupling agent containing 2-oxazoline and 2-oxazinone as well as hydrosilane moieties has been prepared by hydrosilylation of the corresponding allyl ether containing precursor with a methylhydrosiloxane–dimethylsiloxane copolymer. This hydrosiloxane containing coupling agent, termed as SCA, was characterized by 1 H NMR and its crosslinkability was proven by DSC. SCA was used for the...
The thermal behavior of a solution-cast liquid–crystalline polymer (LCP) film was extensively studied by positron-annihilation lifetime spectroscopy (PALS). From the positronium (Ps) lifetimes of the first heating process from 40 to 250°C at a heating rate of 2.5°C/h, four characteristic temperatures (140, 170, 200, 235°C) were observed. From a combined investigation with conventional differential...
Solution 17 O NMR spectroscopy was used for structure elucidation of siloxane copolymers with the natural abundance of 17 O, i.e. without any enrichment prior to spectroscopy. Homo, co, and terpolymers, as well as linear chains, cyclic oligomers, and graft polymers were investigated. All relevant chemical shifts and corresponding linewidths were reported for siloxane polymers substituted...
In the case of the insulation polymeric materials, such as polyethylenes, it is of essential interest to understand correlations between structural changes and (di)electric properties. The dielectric behavior of different polyethylenes, low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and high density polyethylene (HDPE), irradiated to different absorbed doses of gamma radiation,...
In this paper it is shown that the resistance to slow crack propagation in polyethylene can be predicted from a simple tensile measurement performed at 80°C. It is shown that for different types of polyethylene homopolymers and copolymers the slope of a tensile curve above its natural draw ratio (i.e. strain hardening) correlates well with the measured stress crack resistance. The data presented in...
Blends of styrene–butadiene diblock copolymer (S–B, 52wt% styrene content) and styrene–butadiene random copolymer (SBR) of various styrene compositions were studied by small-angle X-ray scattering, light scattering, and transmission electron microscopy. The composition of random copolymer plays an important role in the solubilization of SBR in S–B. The order–disorder transition temperature, T ...
A new route is developed by combining solid-state modification (SSM) by grafting vinyl triethoxysilane (VTES) with a sol–gel method to prepare PP/silica nanocomposites with varying degree of adhesion between filler and matrix. VTES was grafted via SSM in porous PP particles. Bulk polymerization under similar experimental conditions as in SSM resulted in homopolymerization of VTES. However, SEC and...
The preparation and modification of ethylene glycol dimethacrylate/2-hydroxyethyl methacrylate copolymers [poly (EGDMA-co-HEMA)] were carried out to study their properties on Immobilized Metal Ion Affinity Chromatography (IMAC). For that purpose, the adsorption–desorption assays of a phosphoprotein, ovalbumin (OVA) on different ion-containing adsorbents were investigated. The metal ion-complexing...
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