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Strain-induced hardening behavior and flow birefringence were studied on copolymers of ethylene-tetracyclododecene (E-TD) and ethylene-norbornene (E-NB) of various compositions subjected to uniaxial elongation with constant Hencky strain rate between 0.01 and 1.0s -1 in the temperature range from +40 to +60 o C above their respective glass transition T g . When compared...
We have prepared the intercalated nanocomposites of polypropylene (PP)/clay (PPCNs) successfully using maleic anhydride modified PP (PP-MA) and organophilic clay via melt extrusion process. The hierarchical structure of the PPCNs from the structure of confined PP-MA chains, in the space a few nanometer width between silicate galleries to crystalline lamellae of 7-15nm thickness and spherulitic texture...
Via in situ intercalative free-radical polymerization, we prepared clay/poly(methyl methacrylate) (PMMA) and clay/polystyrene (PS) nanocomposites from lipophilized smectic clays. The intercalation spacing in the nanocomposites and the degree of dispersion of these composites were investigated with X-ray diffraction and transmission electron microscopy, respectively. Under some conditions, the intercalative...
Using polymerization solutions containing 0.1 M aniline and 1 M HCl or 1 M HC104, which happened to give the same pH (0.2), we investigated the effects of different counter-anions on the primary and higher order structures as well as on electrochemical responses of the obtained polyaniline (PAn) films. From time developments of polymerization current and u.v.-visible absorption spectra as well as...
Elongational flow-induced crystallization behaviour was investigated on supercooled liquids of two poly(ethylene terephthalate)s (PET) with different crystallization habit via elongational flow opto-rheometry (EFOR), temperature-modulated differential scanning calorimetry (TMd.s.c.) and Rayleigh scattering in the temperature range of 100-130°C usually employed for blow moulding operations. The samples...
Electrochemical polymerization of aniline was conducted in constant current mode at different pH ranging from 0.2 to 3.7 in an ITO glass electrode-quartz cell assembly for in situ monitoring of the changes in potential, amount of charge passed through, and u.v.-visible absorption (u.v.-Vis) spectra during polymerization. u.v.-Vis spectra of product polyaniline (PAn) films were determined in different...
Structure development in polyaniline (PAn) films was followed during the electrochemical polymerization in 1 M HCl solution via a constant potential mode at + 0.76 ± 0.03 V and pH = 0.2 by using several in situ and/or out of situ techniques including UV-visible spectrometry, chronoamperometry, cyclic voltammetry, Rayleigh scattering and atomic force- and optical microscopy. As the polymerization...
A new method, 'biased impedance analysis (BIA)', was proposed for in situ measurements of a.c. impedance of polyaniline (PAn) film during and after deposition on an interdigitated array (IDA) electrode under d.c. bias (polarization) potential. With this BIA we designed two types of experiments: one was BIA under cyclic voltammetric (CV) sweep in 1 M HCl on PAn films polymerized via a constant current...
Elongational flow-induced crystallization in supercooled liquid poly(ethylene terephthalate) (PET) was investigated via elongational flow opto-rheometry (e.f.o.r.) and temperature-modulated differential scanning calorimetry (t.m.d.s.c.) in the temperature range 100-130°C, in which the blow moulding operation on PET is usually conducted. Measurements of tensile stress σ(t) and birefringence Δn(t)...
Via elongational flow opto-rheometry (EFOR), simultaneous measurements of tensile stress σ(t) and birefringence Δn(t) were conducted on a low density polyethylene (LDPE) melt and its blends with an ultra-high molecular weight polyethylene (UHMWPE) at 140°C under transient elongational flow with constant tensile strain rate CHARACTER OMITTED. The transient elongational viscosity η E (t) =...
Rayleigh scattering studies were conducted in order to examine the elongational flow-induced crystallization behaviour of poly(ethylene terephthalate) (PET) in the supercooled liquid state (100–130°C). In the specimen elongated at 110°C where spherulite growth was negligible, initially nothing happened, but flow-induced crystallization then occurred rather suddenly at a critical tensile strain of...
Competitive domain-structure development and homogenization under annealing were investigated via time-resolved light scattering and 1 H n.m.r. in melt-quenched blends of partially miscible poly(ethylene naphthalene-2,6-dicarboxylate) (PEN) and poly(ethylene terephthalate) (PET) loaded with/without PEN-PET random copolymer as a compatibilizer. In the early stage the domain structure formation...
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