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This work is the first part of a study devoted to the understanding and the determination of the molecular mechanisms that are at the origin of the specific properties shown by reinforced elastomers. Different model filled elastomers composed of cross-linked polyethylacrylate chains reinforced with grafted silica nanoparticles were prepared varying the reactivity of the coupling agent with the ethylacrylate...
A series of poly(mono n-alkyl itaconate)s, poly(methyl n-alkyl itaconate)s and poly(di n-alkyl itaconate)s with n=12, 14, 16, 18 and 22 have been prepared by radical polymerization. NMR studies point out that poly(methyl n-alkyl itaconate)s and poly(di n-alkyl itaconate)s are mainly syndiotactic polymers whereas poly(mono n-alkyl itaconate)s are obtained as almost atactic polymers. The characterization...
The deformation mechanisms of rubber toughened polyethylene terephthalate (PET) are studied with fractography of impact fractured samples and tensile dilatometry. The dispersed phase consists of a mixture of an ethylene-co-propylene rubber (EPR) and a compatibilising agent (E-GMA8: copolymer of ethylene and 8wt% of glycidyl methacrylate). It is found that the ductile fracture behaviour, above the...
The nanostructure of a perfluorinated membrane material (Nafion 117 by DuPont) is investigated as a function of strain and load by small-angle X-ray scattering (SAXS) at a synchrotron source. Two-dimensional SAXS patterns are evaluated utilizing the multi-dimensional chord distribution function (CDF). Anisotropy of the extruded material is considered. Both the ionomer domain and matrix polymer nanostructure...
Natural rubber (NR) based nanocomposites with 10wt% natural and synthetic layered silicates were produced via the latex compounding method. As layered silicates, sodium bentonite (natural) and sodium fluorohectorite (synthetic) were selected in addition to a non-layered inert filler (English India clay or commercial clay) as reference material. The nanocomposites were prepared by compounding the dispersions...
Development of morphological structures during phase separation induced by radical polymerization of 2-chlorostyrene in the presence of polystyrene was studied with an electron microscope. No stirring of the mixture was made. Domain structure changed significantly with initial monomer composition within a narrow range. Salami domains similar to those observed in high-impact polystyrene (HIPS) formed...
The presence of hydrogen bonds in the chemical structure of polymers promotes and stabilises the crystalline phase. For liquid crystalline (LC) polymers, the side insertion of aliphatic units to the mesogenic unit is a suitable artifice to decrease the crystalline stability, without significantly affecting the stability of the LC phases. Here, we report on the synthesis of a LC homo-polyurethane with...
Non-woven biodegradable membranes fabricated by electrospinning have recently attracted a great deal of attention for biomedical applications. In this study, microstructure, morphology and texture of electrospun poly(glycolide-co-lactide) (GA/LA: 90:10, PLA10GA90) non-woven membranes were investigated after post-draw and thermal treatments to tailor the degradation and mechanical properties. As-prepared...
We consider reasons why the crosslinking reaction rate in poly(dimethyl siloxane) (PDMS) network coatings might differ from the rate found in the bulk and specifically examine the influence of coating thickness. Infrared spectroscopic ellipsometry (IRSE) is employed as an in situ probe of the reactions between vinyl (–CHCH 2 ) end groups on PDMS and SiH groups in a crosslinker and between...
This study was aimed at using micro-Raman spectroscopy for the local characterisation of phase separated blends based on epoxy polymer and copolyethersulphone thermoplastic. The morphologies developed in the blends containing 25% by weight of thermoplastic were studied. The calibrations of the Raman data for the determination of the copolyethersulphone content and the epoxide conversion are presented...
In situ measurements of the ionic conductivity were performed on polyethers, poly(ethylene oxide) (PEO) and poly(oligo oxyethylene methacrylate) (PMEO), with lithium triflate (LiCF 3 SO 3 ) as crystalline and amorphous electrolytes, and at CO 2 pressures up to 20 MPa. Both PEO and PMEO systems in subcritical and supercritical CO 2 increased more than five fold in ionic...
The 129 Xe-NMR method was used for evaluation of the sizes of free volume elements in amorphous glassy materials—random copolymers of tetrafluoroethylene and perfluorodioxoles of different structures. 129 Xe chemical shifts were measured at different pressures up to 1060Torr. The zero pressure chemical shifts obtained by extrapolation were used for calculation of the diameters of microcavities...
Molecular imprinting has become an established technique. However, little was done on direct investigation of the sorbents produced. In the present work, en ESR method was used for the investigation of the complex formation processes within the sorbents imprinted with copper(II) and nickel(II). The sorbents were synthesized from a mixture of linear low molecular weight polyethyleneimine oligomers...
An exhaustive study of the co-catalytic activity of phosphates on titanium and titanium/hafnium based catalytic systems in poly(butylene terephthalate) synthesis was conducted in order to investigate any improvement in the process and/or in the properties of the final polymer with respect to the industrially used titanium based catalyst. Small scale polymerisation and subsequent scale up in higher...
Needle-like poly(azomethine) crystals were successfully prepared by the polycondensation of 1,4-phenylenediamine and 1,4-terephthalaldehyde in liquid paraffin at 180 °C. The favorable polymerization concentration for the preparation of the well-defined needle-like crystals was 2.0×10 −2 moll −1 . The average length and width of the needle-like crystals were 7.7 and 0.6 μm, respectively...
The reinforcement of nylon 6 by layered aluminosilicates (LAS) and glass fibers was examined using the composite theories of Halpin–Tsai and Mori–Tanaka. Theoretical comparisons show that exfoliated LAS offer superior reinforcement to glass fibers owing to the filler's high modulus, high aspect ratio, and its ability to reinforce in two directions. The effect of incomplete exfoliation of simple stacks...
Aqueous solutions of poly(vinyl pyrrolidone)–fullerene complexes (PVP–C 70 ) have been studied using static and dynamic light scattering methods. Two diffusive processes were detected. The slow diffusion was interpreted as dynamics of large intermolecular PVP–C 70 complexes while the fast diffusion was associated with the presence of individual PVP molecules in solution. It was also...
The thermally stimulated discharge (TSD) currents technique has been used to study different types of inter- and intra-molecular interactions between the components in poly(methyl methacrylate) (PMMA)-based systems. The TSD current signal of the side-chain dielectric β relaxation mode of PMMA has been comparatively studied in bulk PMMA, PMMA polymerized in-situ mesoporous silica-gel, and these matrices...
Ring opening metathesis polymerization (ROMP) with Grubbs's catalyst was used to synthesize narrow polydispersity (PDI)diblock copolymers of norbornene (NOR) and norbornenedicarboxylic acid (NORCOOH). Norbornene (NOR) and 5-norbornene-2,3,-dicarboxylic acid bis trimethylsilyl ester (NORCOOTMS) were used as precursor monomers for thepolymerization. [NORCOOTMS] m /[NOR] n was converted...
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