Sökning: "additive degradation products"

Visar resultat 1 - 5 av 13 avhandlingar innehållade orden additive degradation products.

  1. 1. LDI-MS strategies for analysis of polymer degradation products, additives and drugs

    Författare :Nina Aminlashgari; Minna Hakkarainen; Peter J. Schoenmakers; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; laser desorption ionization-mass spectrometry LDI-MS ; surface; polymer degradation products; additive; drugs; nanoparticles; nanocomposites; Kemi; Chemistry;

    Sammanfattning : The advancement of mass spectrometry (MS) has been and continues to be a prominent analytical technique for highly accurate determination of analytes. The goal of this thesis was to develop new laser desorption ionization-mass spectrometric (LDI-MS) methods for analysis of polymer degradation products, additives and drugs. LÄS MER

  3. 2. Powder degradation during powder bed fusion processing

    Författare :Ahmad Raza; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser-based powder bed fusion; Alloy 718; Powder degradation; Oxidation; Electron beam powder bed fusion; Additive manufacturing; AlSi10Mg; Residual oxygen; Spatter particles; Sublimation.;

    Sammanfattning : Powder bed fusion (PBF) techniques, including laser-based powder bed fusion (LB-PBF) and electron beam powder bed fusion (EB-PBF), are two rapidly growing additive manufacturing (AM) processes due to their ability to produce complex geometries in near-net shapes. To attain reproducibility and repeatability in PBF processes, a consistent set of powder properties is vital. LÄS MER

  4. 3. 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

  5. 4. Powder degradation during powder bed fusion processing: impact of processing conditions and alloy composition

    Författare :Ahmad Raza; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; residual oxygen; powder bed fusion – electron beam; powder degradation; oxidation; Alloy 718; AlSi10Mg; powder bed fusion - laser beam; TiAl6V4; Hastelloy X.; sublimation; spatter particles; Keywords: additive manufacturing;

    Sammanfattning : In the recent decade, powder bed fusion (PBF) metal additive manufacturing (AM) has attracted huge attention both from the industry and the research community. This effort has helped mature PBF technology as a potential alternative to conventional manufacturing processes as casting, machining, forging, etc. LÄS MER

  7. 5. Consumption and loss of commercial stabilisers in polyethylene exposed to different natural environments

    Författare :Nadejzda Haider; KTH; []
    Nyckelord :LDPE; MDPE; ultrasonic extraction; polymer additives; stabilisers; antioxidants; HALS; Irganox 1010; Irgafos 168; migration; consumption; GC-MS; additive degradation products;

    Sammanfattning : A procedure for the extraction and analysis of commercialstabilisers in low density and medium density polyethylene(LDPE and MDPE) films was developed and used to study theconsumption of stabilisers in polymers exposed to differentnatural environments. An ultrasonic technique was applied toextract HALS-3 (Chimassorb 944) from LDPE film and antioxidants(Irganox 1010 and Irgafos 168) from MDPE film. LÄS MER