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Abstract  

Blends of poly(ether-sulfone) (PES) and poly(phenylene sulfide) (PPS) with various compositions were prepared using an internal mixer at 290C and 50 rpm for 10 min. The thermal and dynamic mechanical properties of PES/PPS blends have been investigated by means of DSC and DMA. The blends showed two glass transition temperatures corresponding to PPS-rich and PES-rich phases. Both of them decreased obviously for the blends with PES matrix. On the other hand, Tg of PPS and PES phase decreased a little when PPS is the continuous phase. In the blends quenched from molten state the cold crystallization temperature of PPS was detected in the blends of PES/PPS with mass ratio 50/50 and 60/40. The melting point, crystallization temperature and the crystallinity of blended PPS were nearly unaffected when the mass ratio of PES was less than 60%, however, when the amount of PES is over 60% in the blends, the crystallization of PPS chains was hindered. The thermal and the dynamic mechanical properties of the PPS/PES blends were mainly controlled by the continued phase.

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Abstract  

Miscibility in blends of semicrystalline polymers (poly(ethylene) adipate and poly(tetrahydrofuran)) and liquid crystal cholesteryl palmitate was investigated by means of differential scanning calorimetry and polarizing optical microscopy. Some(concentration-dependent) miscibility was found. A more pronounced miscibility exhibits the polyester-based blends probably due to the similar chemical structure of the two components and stronger interactions between the two components.

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Summary The mixing state of amphiphilic di-block copolymers consisted of poly(ethylene oxide) and poly(methacrylate) having azobenzene moieties in the side chains p(EO)114pMA(Az)24 and poly(ethylene oxide) p(EO)114 was investigated from the viewpoints of isothermal crystallization and nano-scale ordered structure. The chemical potential, which required establishing the constant crystal growth rate, decreased with the p(EO) content up to 60%. The hexagonal packed cylinder structure was observed for the blends with the p(EO) content up to 60% and the lattice spacing of (100) and (110) planes increased with the p(EO) content up to 60%. The blends of amphiphilic p(EO)114pMA(Az)24 and p(EO)114 were miscible without in the p(EO) content below 60%.

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Abstract  

The miscibility of crystalline syndiotactic polystyrene (SPS)/non-crystalline atactic polystyrene (APS) blend was estimated by the crystallization dynamics method, which evaluated the nucleation rate, the crystal growth rate and the surface free energy parameter. The melting temperature depression suggested that SPS/APS blends were the miscible system but not in molecular level. The relationship between the blend content and the chemical potential difference evaluated at a constant crystal growth rate showed a good linear relationship. These facts suggested that SPS/APS blends contained the concentration fluctuation with the size between few nm to less than 80 nm.

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Abstract  

Polymer blends of poly(β-hydroxybutyrate-co-b-hydroxyvalerate) (Biopol) with polyamide 11, possessing copolyester continuous phase, were degraded during 25 weeks in compost. The biodegradation was followed by mass loss and melting enthalpy measurements. The degradability was primary dependent on the hydroxyvalerate content in the blend.

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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.

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Abstract  

The phase transition and nano-scale ordered structure of four types of blends prepared from four di-block copolymers, consisting of hydrophilic poly(ethylenoxide) and hydrophobic poly(methacrylate) derivative, PEOm-b-PMA(Az)n having different PEO molecular length and same degree of polymerization of PMA(Az) were investigated. All blend systems formed hexagonal packed PEO cylinder structure, which was same with the nano-scale structure of these parent block copolymers. The SAXS and AFM observation suggested that the size of hexagonal structure of blend was larger than the average size of parent block copolymers. The melting enthalpy of PEO in blends was larger than the average value of parent block copolymers. DSC, SAXS and AFM observations indicated the miscible blend systems.

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Abstract  

The simultaneous DSC-FTIR was used for the observation of crystallization and melting of poly(vinylidene fluoride) (PVDF) and its blends with poly(methyl methacrylate) (PMMA) and poly(ethyl methacrylate) (PEMA). The isothermal crystallization was carried out under the condition of both α-form and γ-form crystallized competitively. The crystal growth rate of α -form and γ -form were evaluated from the absorbance changes at 795 cm-1 (α -form, CH2 rocking) and 810 cm-1 (γ -form, CH2 rocking) obtained by the DSC-FTIR. The crystal growth rate of γ -form decreased at the same crystallization temperature in the order of PVDF/syn-PMMA, PVDF/PEMA and PVDF/at-PMMA, which was corresponding to the order of interaction parameter. The mechanism of α -g transition of PVDF in the miscible blends with at-PMMA, syn-PMMA and PEMA was evaluated from the relationship between the decrease of α -form and the increase of γ -form. The critical crystallization temperature, at which the transformation from α -form to γ -form proceeded only in the solid state, shifted to higher temperature side in the order of interaction parameter.

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Journal of Thermal Analysis and Calorimetry
Authors: Niko Van den Brande, Cor Koning, Paul Geerlings, Gregory Van Lier, Guy Van Assche, and Bruno Van Mele

energy, and high thermal stability, PDMS is a desirable blend component [ 13 , 14 ]. One blend system containing PDMS that received much attention in literature is with polystyrene (PS), often in combination with PS-b-PDMS block copolymers as

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Introduction Thermal degradation and dynamic mechanical behavior of polymers and polymer blends are very important to predicting their suitability in the specific field of applications. Knowledge of degradation and mode of

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