Wyniki wyszukiwania - BazTech

1

Non-isothermal crystallization of poly(trimethylene terephthalate)/single-walled carbon nanotubes nanocomposites

Szymczyk A., Roslaniec Z.

Polimery

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2012

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T. 57, nr 3

221-227

EN

In this work, non-isothermal crystallization behavior of nanocomposites based on poly(trimethylene terephthalate) (PTT) and single-walled carbon nanotubes (SWCNTs) and neat PTT was studied in order to determine the effects of SWCNTs on its crystallization behavior. Nanocomposites with 0.3 and 0.5 wt. % of SWCNTs were studied. Using of SAXS and DSC methods, the nanostructure of PTT/SWCNTs nanocomposites and neat PTT was investigated in real time in the process of crystallization from the melt. The correlation function approach was used to analyze SAXS data. Changes in long period values, thickness of crystalline lamellae, thickness of amorphous layers, degree of crystallinity during cooling from the melt were discussed.

PL

W pracy omówiono wyniki badań struktury nadcząsteczkowej i właściwości termicznych nanokompozytów poli(tereftalanu trimetylenu) (PTT) z jednościennymi nanorurkami węglowymi (SWCNT). Badane nanokompozyty zawierały 0,3 lub 0,5 % mas. SWCNT. Do oceny dyspersji SWCNT w matrycy PTT użyto skaningowego mikroskopu elektronowego (SEM). Metodą małokątowego rozpraszania promieni rentgenowskich (SAXS) i metodą różnicowej kalorymetrii skaningowej (DSC) badano nanostrukturę kompozytów PTT/SWCNT i PTT w czasie rzeczywistym w trakcie krystalizacji ze stopu. Parametry struktury nadcząsteczkowej badanych materiałów wyznaczono na podstawie analizy jednowymiarowych funkcji korelacyjnych. Omówiono zachodzące podczas chłodzenia ze stopu zmiany wartości wielkiego okresu, grubości lamel krystalicznych, grubości obszarów amorficznych oraz stopnia krystaliczności.

2

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

Ratajska A. M., Kulak W. P., Poeppel A., Seyler A., Roslaniec Z.

Polish Journal of Chemical Technology

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2009

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Vol. 11, nr 3

27-34

EN

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.

3

Temperature dependence of the FMR spectra of Fe3O4 and Fe3C nanoparticle magnetic systems in copolymer matrices

Guskos N., Typek J., Roslaniec Z., Narkiewicz U., Kwiatkowska M., Maryniak M.

Materials Science Poland

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2005

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Vol. 23, No. 4

1055--1063

EN

A binary magnetic nanoparticle system, consisting of Fe3O4 (35 wt. %), Fe3C (29 wt. %), and C (36 wt. %) filling in a PTMO-block-PET polymer at low concentration (0.3 %), has been synthesized. X-ray and SEM analyses have been carried out. The temperature dependence of the FMR spectrum of this system has been investigated. At higher temperatures resonance from Fe3O4 nanoparticles dominates the FMR spectrum, while at lower temperatures a more intense line from Fe3C is recorded. The temperature dependence of the FMR spectrum confirms that the nanoparticles of Fe3O4 reach the ordered state faster than Fe3C nanoparticles. In both cases, the spin-glass state is observed below 50 K.

4

FMR study of gamma-Fe2O3 magnetic nanoparticles in a multiblock poly(ether-ester) copolymer matrix

Guskos N., Typek J., Maryniak M., Roslaniec Z., Petridis D., Kwiatkowska M.

Materials Science Poland

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2005

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Vol. 23, No. 4

971--976

EN

Four samples containing gamma-Fe2O3 magnetic nanoparticles dispersed at a concentration of 0.1 % (samples I and I') and 0.3 % (samples II and II') in a polymer matrix have been prepared. The polymer filler was in two forms: as solid-state grains (samples I and II) and as a liquid solution in trichloromethane (samples I' and II'). The typical size of the magnetic nanoparticles was 10 nm. The samples were characterized by XRD and TEM spectroscopy. Ferromagnetic resonance (FMR) measurements were carried out at room (RT) and liquid nitrogen (LNT) temperatures for all four samples. An intense resonance absorption line from gamma-Fe2O3 was recorded, with a slightly asymmetric line shape. The FMR spectra at RT and LNT are almost the same, as could be expected for the composite matrix. For samples II and II', the resonance lines are centred at Hr = 3039(10) Gs and Hr = 3197 (10) Gs, respectively, with linewidths of deltaH = 1289(5) Gs and deltaH = 1364(5) Gs, respectively. For samples I and I', the following values of resonance line parameters were obtained: Hr = 3172(10) Gs for sample I', and Hr = 2958(10) Gs for sample I, with linewidths of deltaH = 1279(5) Gs and deltaH = 1200(5) Gs, respectively. In both cases the resonance field for samples obtained from a solid state filler is shifted to lower magnetic fields as compared to samples made from a suspension filler, which suggests stronger ferromagnetic interactions in these materials.