Electrically conductive PTT-block-PTMO/SWCNTs+Graphene Nanoplatelets hybrid nanocomposites prepared by in situ polymerization

Hybrid Materials 2015; Sitges, Barcelona, Spain, 9 - 13 March 2015The studies were financed by the National Science Centre within project PRELUDE no 2013/11/N/ST8/00404.Peer Reviewe

Broadband dielectric spectroscopy of nanocomposites based on PVDF and expended graphite

2nd International Conference on Structural Nano Composites (NANOSTRUC 2014); 6 pags.; 4 figs.; Open Access funded by Creative Commons Attribution 3.0 licence.Nanocomposites based on poly (vinylidene fluoride) (PVDF) and expanded graphite (EG) were prepared by non-solvent precipitation from solution with different EG concentrations. Films were obtained by compression molding and their structural and dielectric properties studied. From Wide Angle X-ray Scattering (WAXS) experiments, it can be assessed that for all EG concentrations the -crystalline phase of PVDF is the predominant crystalline form. However, for composites with high nanoadditive content, higher than 3 wt.%, the -crystalline phase is also detected. Dielectric spectroscopy results showed that the nanocomposites present both high dielectric constant and electrical conductivity at low percolation threshold. Published under licence by IOP Publishing LtdThe authors thank the financial support from the Spanish Ministry of Science and Innovation (MICINN), Grant MAT2012-33517 and from the Polish National Science Centre and the Slovak Academy of Sciences in the frame of ERA-NET project APGRAPHEL.Peer Reviewe

The influence of soft segment length on structure and properties of poly(trimethylene terephthalate)-block-poly(tetramethylene oxide) segmented random copolymers

Two series of multiblock poly(ether-ester)s based on poly(trimethylene terephthalate) (PTT) as the rigid segments and poly(tetramethylene oxide) (PTMO) as the flexible/soft segments were synthesized with the aim of developing of the new family polyester thermoplastic elastomers (TPEs) based on PTT as rigid segment. The content of PTMO segments in the polymer chains was varied from 20 to 80 wt%. The investigations were mainly focused on the influence of flexible segments length with starting PTMG molecular weight at 1000 and 2000 g/mol, respectively, on the phase structure, thermal and mechanical properties of resulting copolymers. The copolymers were characterized by Size Exclusion Chromatography (SEC), Differential Scanning Calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), Wide-angle X-ray scattering (WAXS), Small-angle X-ray scattering (SAXS), and other standard physical methods. Cyclic tensile properties of them were studied with the aim to evaluate the elastic properties. SEC results clearly demonstrated the formation of molecular weight segmented copolymers with microphase separated structure as denoted by DSC and DMTA. The enhanced phase separation was observed for copolymers containing longer flexible segments.According to the characterizations, copolymers containing 50-80 wt% of flexible segments showed elastic behavior. Comparison of the values of permanent set for copolymers with shorter and longer flexible segments has shown that copolymers containing 30 and 40 wt% of long PTMO flexible segments have the best elastic properties (low permanent set)

Morphology and mechanical properties of polyamide 12 (PA12)/poly(vinylidene fluoride) (PVDF) blends

The morphology, thermal and mechanical properties of polyamide 12 (PA12)/poly(vinylidene fluoride) (PVDF) blends were investigated. These polymers are engineering, semi-crystalline polymers which are reciprocally immiscible. Differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA) and scanning electron microscopy (SEM) were used to characterize the polymeric materials. Mechanical properties were examined by static tensile test. The investigations demonstrate that blends with higher amount of PVDF, with the morphology of two co-continuous semicristalline phases, exhibit better mechanical properties. The blends with small content of PVDF and prepared by extrusion show the morphology of small separated domains of PVDF and full continuous PA phase. The morphology of these blends is different than the blends prepared by internal mixer and have better mechanical properties too. Thus they can be used in particular applications without a compatibilizing agent

Morphology and mechanical properties of polyamide 12 (PA12)/poly(vinylidene fluoride) (PVDF) blends

The morphology, thermal and mechanical properties of polyamide 12 (PA12)/poly(vinylidene fluoride) (PVDF) blends were investigated. These polymers are engineering, semi-crystalline polymers which are reciprocally immiscible. Differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA) and scanning electron microscopy (SEM) were used to characterize the polymeric materials. Mechanical properties were examined by static tensile test. The investigations demonstrate that blends with higher amount of PVDF, with the morphology of two co-continuous semicristalline phases, exhibit better mechanical properties. The blends with small content of PVDF and prepared by extrusion show the morphology of small separated domains of PVDF and full continuous PA phase. The morphology of these blends is different than the blends prepared by internal mixer and have better mechanical properties too. Thus they can be used in particular applications without a compatibilizing agent

Formation of LIPSS in nanocomposites of poly(ethylene terephthalate)/expanded graphite by using UV nanosecond laser pulses

Frontiers in Optics: The 100th OSA Annual Meeting and Exhibit/Laser Science XXXII; Rochester, New York United States; 17 Oct 2016 - 21 Oct 2016; http://www.frontiersinoptics.orgPeer Reviewe

LIPSS formation by nanosecond laser irradiation of Poly(ethylene terephthalate) and Poly(trimethylene terephthalate) reinforced with carbon-based fillers

XII Jornadas de Procesado de Materiales con Láser AIMEN; O Porriño (Pontevedra); 29 y 30 de septiembre de 2016The formation of Laser Induced Periodic Surface Structures (LIPSS) is a process commonly used to nanostructure polymer surfaces. Forming of LIPSS is possible because of the irradiation of the polymer surface with polarized laser pulses at fluences below the ablation threshold. This leads to a modulation of the depth of the surface, resulting from an inhomogeneous intensity distribution, due to the interference between the incoming and the surface-scattered waves, reinforced with a positive feedback process. Such structures have a spatial period close to the laser wavelength, aligned parallel to the polarization of the laser beamPeer Reviewe