Sökning: "degradation"

Visar resultat 1 - 5 av 1894 avhandlingar innehållade ordet degradation.

  1. 1. From Fast to Slow Degradation Different Strategies to Characterise Polymer Degradation by Chromatographic Techniques

    Detta är en avhandling från Institutionen för polymerteknologi

    Författare :Guillaume Gallet; KTH.; [2001]
    Nyckelord :poloxamer; polylactide; degradation; oxidation. Hydrolysis. Solid phase microextraction;

    Sammanfattning : .... LÄS MER

  2. 2. Degradation of polyethylene pipes distributing chlorinated water : depletion of stabilizers, release of degraded products and polymer degradation

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Wenbin Yu; KTH.; [2011]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; polyethylene pipes; chlorine dioxide; degradation; NATURAL SCIENCES Chemistry Organic chemistry Polymer chemistry; NATURVETENSKAP Kemi Organisk kemi Polymerkemi;

    Sammanfattning : This thesis presents the study of antioxidants depletions in chlorinated media (10 ppm Cl2 - and ClO2 - aqueous media), polyethylene pipes degradations scenarios and migration of the degraded species to aqueous phase. Pressure testing on pipes and squalane testing with controlled pH aqueous media (6.8 ± 0. LÄS MER

  3. 3. Controlling Polylactide Degradation through Stereocomplexation and Lactic Acid Based Additives

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Sofia Regnell Andersson; KTH.; [2013]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polylactide; stereocomplex; plasticizer; degradation; degradation products; ESI-MS;

    Sammanfattning : The successful use of degradable materials in new applications depends on our ability to control the degradation process. A number of aspects need to be evaluated including degradation rate, the onset of degradation and the nature, formation and release of degradation products. LÄS MER

  4. 4. Free radical mediated cellulose degradation

    Detta är en avhandling från Stockholm : Kemi

    Författare :Erik Johansson; KTH.; [2003]
    Nyckelord :free radicals; cellulose; polymer; average chain length; bleaching; TCF; ozone; degradation;

    Sammanfattning : This thesis addresses the mechanisms involved in cellulosedegradation in general and Totally Chlorine Free (TCF) bleachingof pulp in particular. The thesis shows that the cellulosedegradation during high consistency ozone bleaching is explainedby free radical chain reactions. LÄS MER

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

    Detta är en avhandling från Institutionen för polymerteknologi

    Författare :Farideh Khabbaz; KTH.; [2001]
    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