Sökning: "Material degradation"

Visar resultat 11 - 15 av 592 avhandlingar innehållade orden Material degradation.

  1. 11. Cycle paths’ degradation processes and surface condition assessment

    Författare :Martin Larsson; Sigurdur Erlingsson; Anna Niska; Inge Hoff; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; construction design; cycle paths; degradation; distress modes; maintenance; municipalities; survey; cycling comfort; road surface measurements; surface evenness; surface texture; Building Materials; Byggnadsmaterial;

    Sammanfattning : A shift in modal share from car driving to cycling has many benefits, both from individual- and societal perspectives, e.g., better health from an increase in physical activity, lower levels of pollution and congestion. However, there are also some potential problems with such a shift. LÄS MER

  3. 12. 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

  4. 13. Material recycling of post-consumer flexible polyethylene packaging waste

    Författare :Ezgi Ceren Boz Noyan; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; degradation; polyethylene; melt-compounding; washing; post-consumer flexible packaging waste; mechanical properties; plastics recycling;

    Sammanfattning : The mechanical and thermal properties of recycled post-consumer flexible polyethylene packaging waste was studied, using material collected and sorted on a large-scale from two sources. Unwashed, laboratory-scale washed, industrial-scale washed, and industrial-scale washed and melt-compounded (industrially recycled) materials were used. LÄS MER

  5. 14. Tuning the polylactide hydrolysis rate without introducing new migrants

    Författare :Sofia Regnell Andersson; Minna Hakkarainen; Karin Jacobson; Ulrika Edlund; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; polylactide; sterocomplex; plasticizer; degradation; degradation products; ESI-MS; Biochemistry; Biokemi; Polymer chemistry; Polymerkemi;

    Sammanfattning : The possibility to control and tune the hydrolytic degradation rate of polylactide without introducing any new degradation products was investigated by subjecting polylactide with cyclic or linear oligolactic acid additives, and a stereocomplex between the L- and D-enantiomers of polylactide to hydrolytic degradation at 37 and 60 °C for up to 39 weeks. The degradation was monitored by measuring mass loss, molar mass changes, water uptake, changes of surface structure, crystallinity and thermal properties. LÄS MER

  7. 15. Heterogeneous Degradation and Recyclability of PP Studied by Imaging Chemiluminescence

    Författare :Mikael Hamskog; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Teknik; Technological sciences; recyclability; mapping; surface; heterogeneity; heterogeneous; evaporation; ageing; hamamatsu; russel; ICL; CL; Irganox 1010; Irganox 1076; oxidation; hydroperoxide; radical; carbonyl; luminescence; chemiluminescence; imaging chemiluminescence; recycling; stabilization; polypropylene; degradation;

    Sammanfattning : Oxidative degradation is a serious threat to long-term use and recyclability of polymers. Successful recycling of polymeric quality products requires characterization of the polymer material after reprocessing and use. LÄS MER