Sökning: "Polyethylene LDPE"

Visar resultat 1 - 5 av 34 avhandlingar innehållade orden Polyethylene LDPE.

  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

  3. 2. Structural Aspects of Peroxide Crosslinking of Polyethylene

    Författare :Annika Smedberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; poly ethylene-co-divinylsiloxane ; network; poly ethylene-co-1; peroxide; crosslinking; LDPE; topography; 9-decadiene ; entanglements;

    Sammanfattning : Despite major developments in the ways of polymerising ethylene (the processes as well as the catalysts) the use of polyethylene is still restricted in several applications due to its low melting point. This shortcoming can in some areas be overcome by the introduction of crosslinks between the polymer chains. LÄS MER

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

    Författare :Massimiliano Mauri; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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. 4. Polyethylene Blends, a Material Concept for Future HVDC-cable Insulation

    Författare :Mattias Andersson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polymer blends; nanocomposites; polyethylene; conductivity; thermomechanical properties; High-voltage insulation; tie-chain;

    Sammanfattning : High-voltage cables are a critical component of tomorrow’s power grids that seamlessly integrate hydro, wind and solar power. Further improvements in transmission capacity of both high-voltage alternating- and direct-current, HVAC and HVDC, cables are likely reached through improved insulation materials. LÄS MER

  7. 5. Polyethylene – metal oxide particle nanocomposites for future HVDC cable insulation : From interface tailoring to designed performance

    Författare :Dongming Liu; Ulf Gedde; Mikael Hedenqvist; Richard Olsson; Linda Schadler; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVDC; electrical insulation; core-shell nanoparticles; surface modification; silane chemistry; nanocomposites; polyethylene; adsorption; long-term stability; interface; particle dispersion; cavitation; conductivity; HVDC; elektrisk isolation; ytmodifiering; silankemi; nanokompositer; polyeten; adsorption; långtidsstabilitet; ytskikt; partikeldispergering; kavitation; ledningsförmåga; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Sammanfattning : Low-density polyethylene (LDPE) nanocomposites containing metal oxide nanoparticles are considered as promising candidates for insulating materials in future high-voltage direct-current (HVDC) cables. The significant improvement in dielectric properties compared with unfilled polymer is attributed to the large and active interface between the nanoparticles and the polymer. LÄS MER