Sökning: "polymer degradation products"

Visar resultat 1 - 5 av 66 avhandlingar innehållade orden polymer degradation products.

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

    Författare :Wenbin Yu; Ulf Gedde; Mats Jonsson; Minna Hakkarainen; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; polyethylene pipes; chlorine dioxide; degradation; Polymer chemistry; 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

  2. 2. SALDI-MS Method Development for Analysis of Pharmaceuticals and Polymer Degradation Products

    Författare :Nina Aminlashgari; Minna Hakkarainen; Klas Engvall; Åsa Emmer; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Surface assisted laser desorption ionization-mass spectrometry SALDI-MS ; polyester degradation products; pharmaceutical compounds; nanoparticles; nanocomposites.;

    Sammanfattning : Surface assisted laser desorption ionization-mass spectrometry (SALDI-MS) was evaluated as a new tool for analysis of polymer degradation products. A SALDI method was developed enabling rapid analysis of low molecular mass polyesters and their degradation products. LÄS MER

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

    Författare :Sofia Regnell Andersson; Minna Hakkarainen; Ann-Christine Albertsson; Marek Kowalczuk; KTH; []
    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. 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

  5. 5. Antimicrobial Polymer Composites for Medical Applications

    Författare :Peter Kaali; Sigbritt Karlsson; Ferruccio Doghieri; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; medical polymers; antimicrobial; body fluids; degradation; Polymer chemistry; Polymerkemi;

    Sammanfattning : The current study and discuss the long-term properties of biomedical polymers in vitro and invivo and presents means to design and manufacture antimicrobial composites. Antimicrobialcomposites with reduced tendency for biofilm formation should lead to lower risk for medicaldevice associated infection. LÄS MER