Showing papers in "Polymer in 2001"

TL;DR: In this paper, the effects of two of the most important processing parameters, spinning voltage and solution concentration, on the morphology of the fibers formed were evaluated systematically, and it was found that spinning voltage is strongly correlated with the formation of bead defects in the fibers, and that current measurements may be used to signal the onset of the processing voltage at which the bead defect density increases substantially.

TL;DR: In this paper, thermoplastic starch (TPS) and poly(lactic acid) (PLA) were combined with polyethylene glycol and oligomeric lactic acid (OLA) to obtain a significant decrease in glass transition temperature (Tg) shift and mechanical properties improvement.

TL;DR: The use of infrared spectroscopy for characterization of the composition of chitin and chitosan covering the entire range of degree of acetylation (DA) and a wide variety of raw materials is examined further in this article.

TL;DR: In this article, three different molecular weight grades of nylon 6 were prepared by melt processing using a twin screw extruder, and mechanical properties, transmission electron microscopy, wide-angle X-ray diffraction, and rheological measurements were used to characterize the three types of composites.

TL;DR: In this article, an experimental investigation of the electrically forced jet and its instabilities was conducted, and the results were interpreted within the framework of a recently developed theory for electrified fluid jets.

TL;DR: In this paper, the mechanical properties and morphology of these nanocomposites were determined and compared to similar materials made by an in situ polymerization process using a conventional twin screw extruder.

TL;DR: In this article, two different clay treatments were added to polyamide 6 using four different types of extruders with multiple screw designs, and the mixtures of organoclay and polyamide were characterized by X-ray diffraction, transmission electron microscopy, and mechanical property tests.

TL;DR: In this article, a composite material comprising calcium carbonate particles dispersed within a polypropylene matrix was proposed, where the particles have a size within the range of 1 to 100 nm and a filling ratio of less than about 30% by volume.

TL;DR: In this article, the authors demonstrate the feasibility of dampening this instability and controlling the deposition of sub-micron polymer fibers in the form of non-woven mats, which are of interest for a variety of applications including semi-permeable membranes, filters, composite reinforcement, and scaffolding.

TL;DR: In this paper, a combination of traditional kinetic formal treatments and computer simulation has been made to analyze polydimethylsiloxane (PDMS) thermal degradation, and it was shown that PDMS thermally decomposes to cyclic oligomers through Si-O bond scission in a chain-folded cyclic conformation energetically favored by overlapping of empty silicon d-orbitals with orbitals of oxygen and carbon atoms.

TL;DR: In this article, a polymerizable cationic surfactant, vinylbenzyldimethyldmodecylammonium chloride (VDAC), was synthesized for functionalization of montmorillonite (MMT) and preparation of exfoliated polystyrene-clay nanocomposites.

TL;DR: In this paper, the influence of the CEC of the clay on the synthesis and structure of epoxy-clay nanocomposites was investigated by X-ray diffraction and transmission electron microscopy (TEM).

TL;DR: In this article, an irradiation grafting method was applied for the modification of nanoparticles so that the latter can be added to polymeric materials for improving their mechanical performance, using existing compounding techniques.

TL;DR: In this article, a polypropylene (PP)/clay nanocomposites (PPCN) were prepared via grafting-melt compounding by using a new kind of co-intercalation organophilic clay which had a larger interlayer spacing than the ordinarily organophilous clay only modified by alkyl ammonium.

TL;DR: In this article, polyimide-clay hybrid was prepared by blending of polyamide acid and organically modified-montmorillonite (OMMT) as a type of layered clays.

TL;DR: In this paper, a group transfer polymerization of four tertiary amine methacrylates, 2-(dimethylamino)ethyl methacelate (DMA), 2-(diethylamino),ethyl methacricrylate (DEA), DPA, and 2-(N-morpholino) methyl methacylate (MEMA) produced a series of near-monodisperse homopolymers (Mw/Mn<1.15).

TL;DR: In this article, a series of sequenced sulfonated naphthalenic polyimides with improved solubility were prepared by polycondensation in m-cresol using aromatic diamines containing phenylether bonds and/or bulky groups.

TL;DR: In this article, a review of the literature on conducting electroactive polymers (CEP) is presented, covering a 5-year period, beginning from 1995. The topics covered include the deposition of CEP (i) by bulk oxidative chemical polymerization, (ii) by surface-located polymerization and (iii) by coating of micro- and nanoparticles.

TL;DR: In this article, the intercalated nanocomposites of polypropylene (PP)/clay (PPCNs) successfully using maleic anhydride modified PP (PP-MA) and organophilic clay via melt extrusion process.

TL;DR: In this article, the structure of water molecules sorbed in different hydrophilic polymers was studied by DSC and FTIR, and the obtained data showed that, first, the sorbed water molecules are directly bound to the hydrophobic site to form non-freezable water, and beyond a certain water content threshold, the water molecules become freezable, but with a melting point lower than 0°C, due to their location in the second hydration layer.

TL;DR: Extrusion molding of both polymer-layered silicate nanocomposites and micro-composites based on the copolymer poly (ethylene-co-vinylacetate) with either 12 wt.% (EVA 12) or 19 wt.%(EVA 19) vinyl acetate content is described in this paper.

TL;DR: In this article, the interfacial effect on properties of epoxy composites was investigated by using infrared and raman spectroscopy, differential scanning calorimetry (DSC), and particle size analyzer.

TL;DR: In this article, the exfoliation and intercalation behaviors depended on the hydrophilicity of polyethylene grafted with maleic anhydride and the chain length of organic modifier in the clay.

TL;DR: In this article, three different curing agents were used: an aliphatic diamine, two cycloalaphatic diamines and a cyclo-aliphatic cyclophilic diamine.

TL;DR: In this article, a morphological analysis of nanocomposites consisting of nanoscopic silica fillers embedded in polyamide 6 was carried out on various composite systems, with different elementary particle diameters and filler contents as variables.

TL;DR: In this paper, the thermal degradation of poly(vinyl alcohol), both in the solid and molten state, was investigated, and it was shown that the greater flexibility of the polymer chains in the melt facilitated fragmentation of the chain and elimination of chain segments.

TL;DR: In this paper, the degradation of monodisperse lactic acid oligomers was studied in vitro to gain insight into the degradation performance of oligolactic acid grafted to dextran, which we use for the preparation of hydrogels based on physical interactions.

TL;DR: In this paper, a double percolation of yielded zones is presented to explain the specific influence generated by the nano-SiO 2 particles at low-filler loading regime, and the role of the modified nanoparticles in improvement of tensile properties of the nanocomposites is discussed in terms of per-colation concept.

TL;DR: In this article, the interaction between leafwood cellulose fibres and a plasticized wheat starch matrix has been investigated and different plasticized starch-based composites have been elaborated.

TL;DR: In this paper, the hydrogen bonding in the hard segments of the synthesized montmorillonite/polyurethane nanocomposites of various hard segment ratios was found to decrease with the increasing amount of montminillonite regardless of the hard segment ratio.