Sökning: "polyethylene"

Visar resultat 1 - 5 av 284 avhandlingar innehållade ordet polyethylene.

  1. 1. Environmentally Degradable Polyethylene : Effects of Additives and Environment on the Degradation and Degradation products

    Författare :Farideh Khabbaz; KTH; []
    Nyckelord :LDPE; polyethylene; oxidative degradation; photo-oxidation; thermo-oxidation; degradation products; photosensitisers; pro-oxidant; starch; master-batch; gas chromatography mass-spectrometry; GC-MS; solid phase microextraction; SPME;

    Sammanfattning : This thesis summarises and compares the influences ofdifferent additives (photosensitisers, pro-oxidants, abiodegradable filler) on blown low-density polyethylene (LDPE)films during photo- and thermal degradation with respect tochemical changes in the polymer matrices and identifieddegradation products. Additives studied were irondimethyldithiocarbamate (FeDMC), nickel dibutyldithocarbamate(NiDBC), carbon black, starch, a pro-oxidant that consisted ofmanganese stearate together with styrene butadiene rubber (SBR)or natural rubber (NR) and a master batch containing linearLDPE, starch and pro-oxidant. LÄS MER

  2. 2. Simulations of water clustering in vapour, hydrocarbons and polymers

    Författare :Erik Johansson; Högskolan i Borås; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; cluster; gibbs ensemble; monte carlo; water; polyethylene; external field; ions; Energi och material; Water; Monte Carlo; Gibbs Ensemble; Ion; External field; Cluster; Polyethylene;

    Sammanfattning : It is commonly known that water plays a crucial role in many natural and industrial processes. One of these processes is the formation of water trees, and the subsequent breakdown of polyethylene used for high voltage cable insulation purposes. LÄS MER

  3. 3. Small Molecule Diffusion in Spherulitic Polyethylene : Experimental Results and Simulations

    Författare :Alessandro Mattozzi; Ulf W. Gedde; Alan H. Windle; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; diffusion; polyethylene; poly ethylene-co-octene ; free volume; morphology; intermediate phase; spherulite; Monte Carlo simulation; Polymer chemistry; Polymerkemi;

    Sammanfattning : The diffusion of small-molecule penetrants in polyethylene is hindered by impenetrable crystals and by the segmental constraints imposed by the crystals on the penetrable phase. Liquid and vapour n-hexane sorption/desorption measurements were performed on metallocene catalyzed homogenous poly(ethylene-co-octene)s. LÄS MER

  4. 4. ALTERNATIVE POLYETHYLENE CROSSLINKING CONCEPTS FOR POWER CABLE INSULATION

    Författare :Massimiliano Mauri; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; epoxy; crosslinking; HVDC; polymer blends; click-chemistry; polyethylene; Renewable Energy; High-voltage insulation;

    Sammanfattning : We currently witness an accelerating shift from fossil energy sources to renewables driven by the urgent need to reduce carbon emissions. Wind, solar and hydro power is most abundant in places far away from the end user, which necessitates the efficient transport of electricity over long distances. LÄS MER

  5. 5. Oxidative Degradation of Polyethylene - A Cause of Off-flavour

    Författare :Thorbjörn Andersson; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biopolymers; Polymerteknik; Polymer technology; off-flavour; degradation; polyethylene;

    Sammanfattning : Polyethylene is the most frequently used polymer material in food packaging today. The polymer is often processed by film extrusion and extrusion coating between 250°C and 325°C. LÄS MER