Search Results

You are looking at 1 - 10 of 45 items for :

  • "polyamide-6" x
  • Refine by Access: All Content x
Clear All
Journal of Thermal Analysis and Calorimetry
Authors: M. Evora, L. Machado, V. Lourenço, O. Gonçalez, H. Wiebeck, and L. de Andrade e Silva

Abstract  

The aim of this work is to study the ionizing radiation effects on thermal properties of there cycled polyamide-6. This polymer was irradiated with an electron beam of 1.5 MeV with different doses. The thermal properties of the samples were determined by TG, DSC and DMA measurements. It was observed that the irradiated samples of recycled polyamide-6undergo a crosslinking process.

Restricted access

Abstract  

Polyamide-6-block-polybutadiene copolymers have been prepared by the anionic polymerization of ɛ-caprolactam in presence of α,ω-dihydroxy terminated polybutadiene. TG, Hi-Res™ TGA, DSC, TMDSC and DMA techniques have been applied. The suitability of the methods used to determine the content, thermal stabilities and glass transition temperatures of the components constituting the block copolymer is discussed.

Restricted access

Abstract  

Equilibrium melting temperatures and crystallization parameters of polyamide 6/polyurethane blends were investigated. Thermal properties of the crystalline phase of blends obtained from polyamide 6 and polyurethane containing 40 wt% of hard segments, are only limited influenced by the overall blend compositon. Because from separate measurements single glass transitions for all samples were estimated, so in the investigated case the blending process may occur mainly between amorphous fraction of polyamide 6 and the polyurethane or, what is more probable, the polyurethane phase is dispersed in the continuous polyamide matrix, although some interactions exist.

Restricted access

Abstract  

The temperature dependence investigated by means of DMTA of dynamic storage modulusE′, dynamic loss modulus E″ and loss tangent tgδ of blends obtained from polyamide 6 and poly(β-hydroxybutyrate-co-β-hydroxyvalerate) (Biopol D600G) indicated, that the dynamic mechanical properties of the blends containing up to 40% Biopol D600G are governed by the properties of polyamide 6. First at the 50% Biopol D600G content in the blend the transitions of the Biopol phase become visible and dominant. The shifts of the loss modulus maxima of the blends might indicate some interactions between the blend components in the amorphous phase.

Restricted access

Abstract  

Blends obtained from polyamide 6 and polyester or polyether polyurethanes were investigated by means of DMTA. The blends were prepared by compounding in a twin-screw Brabender —Plasticorder. Changes in composition did not influence the glass temperature of the amorphous fraction of the polyamide, but also no distinct transition for separated polyurethane soft segment was visible. Therefore the blends seem to be multiphase systems, where the elastomeric polyurethane phase is dispersed in a continuous polyamide phase. From changes in the β relaxation region of the polyamide better miscibility of polyester polyurethanes comparing to polyether polyurethanes was explained by hydrogen bonding in the common amorphous phase.

Restricted access

Abstract  

A series of polyamide 6 nanocomposites (NC) and PA6/TPU/clay nanocomposite blends (NCB) were prepared from commercial polyamide 6, synthesized thermoplastic polyurethanes and two types of organically modified montmorillonites - Cloisite® 10A and Cloisite® 20A. The thermal behavior was examined by non-isothermal thermogravimetry (TG, DTG), differential scanning calorimetry (DSC) and dynamic-mechanical thermal analysis (DMTA). It has been proved that the thermal stability and tensile properties of these new systems were greater when the organoclay was present within the polymer matrix. What more these properties depend on both the OMMT loading and the type of the gallery cations of organically modified montmorillonites.

Restricted access

Abstract  

The aim of this work was to obtain membranes from polyamide 6/montmorillonite clay nanocomposites through the phase inversion technique. The nanocomposites and membranes from polyamide 6/montmorillonite clay were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Thermogravimetry (TG) and Differential Scanning Calorimetry (DSC). Microporous and asymmetric membranes were successfully obtained from nanocomposites and the results showed that the salts were incorporated by intercalation between the organoclay layers and, apparently that the nanocomposites and membranes were thermally more stable than the pure polyamide.

Restricted access

Abstract  

Polyamide 6.6 multifilament yarns are converted to crimped fibres by texturing in order to simulate the properties of natural staple fibre yarns for textile applications. Texturing is carried out by mechanical stresses (turbulences or twisting) in different atmospheres which affect crystallinity and thermal stability of yarns. Two polyamide yarns with the same linear density but consisting of filaments of different fineness were textured by the air-jet and the false-twist procedures. The influence of texturing conditions and filament fineness on crystallinity and thermomechanical behaviour and dimensional stability were studied by TMA and DSC. The air-jet texturing procedure leads to a slight increase in crystallinity of yarns whereas the false-twist texturing procedure was more effective especially when thicker filaments were textured. The inflection point of the shrinkage curve before melting was a good estimator of the effective temperature of yarn texturing.

Restricted access