1,720,987 research outputs found
Functionalised Polypropylene/POSS Hybrids: Thermal Properties, Crystal Growth and Morphology
No full textCaratterizzazione di Materiali polimerici bioartificiali costituiti da collagene e alcool polivinilico
No full textSTRUCTURE PROPERTY RELATIONSHIPS OF POLYMER BLENDS BASED ON FUNCTIONALIZED POLYOLEFINS
No full textThe thermal behaviour, morphology, molecular interactions and phase structure of blends based on polyolefins functionalised with diethylmaleate and commercial polymers (poly(vinyl chloride), polystyrene, poly(vinyliden fluoride)) were analysed by means of DSC, FT-IR, optical and electron microscopy. It is shown that the occurrence of partial miscibility phenomena is favoured by specific molecular interactions between the polymer components and is affected by the structure of the functionalised polyolefins, degree of functionalisation and thermal history
Processing, compatibilization and properties of ternary composites of Mater-Bi with polyolefins and hemp fibres
No full textTernary composites of a biodegradable thermoplastic matrix, Mater-Bi (R) (MB), with various polyolefins (PP, HDPE and PS) and hemp fibres (H) were obtained by melt mixing and characterized by SEM, OM, DSC, TGA and tensile tests. The properties of composites were compared with those of MB/polyolefin and MB/H blends. Maleic anhydride functionalized polyolefins were employed as compatibilizers. Crystallization behaviour and morphology of the composites were found to be affected by the composition, phase dispersion and compatibilizer. Thermogravimetric analysis indicated that the thermal stability of the polyolefin phase and fibres was influenced by the composition and phase structure. A significant improvement of tensile modulus and strength was recorded for composites of MB with PE and PS as compared to MB/H composites. The results indicate that incorporation of polyolefins in the biodegradable matrix, compared to binary matrix/fibre system, may have significant advantages in terms of properties, processability and cost. (C) 2011 Elsevier Ltd. All rights reserved
Polycarbonate/Linear Low Density Polyethylene Blends: Thermal and Dynamic-Mechanical Properties
No full textCRYSTALLIZATION BEHAVIOR OF POLYPHENYLENE SULFIDE IN BLENDS WITH A LIQUID-CRYSTALLINE POLYMER
No full textBlends of polyphenylene sulfide (PPS) with a commercial, wholly aromatic, liquid crystal copolyesteramide (Vectra-B950) have been prepared by melt-blending. The crystallization behavior of neat and blended PPS has been studied by differential scanning calorimetry (DSC), under both non-isothermal and isothermal conditions. It has been found that blending PPS with Vectra-B leads to an increase of the temperature of non-isothermal crystallization and to a pronounced acceleration of the isothermal crystallization, without any reduction of the degree of crystallinity. All these effects have been found to occur independent of the Vectra-B concentration, within the investigated range (2 to 20%, w/w). The results have been interpreted in terms of an increased nucleation density of the blends, probably due to heterogeneous substances, initially present in the Vectra-B bulk, which dissolve to saturation in the PPS phase, during melt-blending
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Ethylene/Hexene Copolymers Obtained by Novel Ziegler/Natta Catalysts Based on Titanium (IV) Bis-Carbvoxylate Chelate Complexes and Organoaluminium Compounds
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