Sökning: "Minna Hakkarainen"

Visar resultat 21 - 25 av 32 avhandlingar innehållade orden Minna Hakkarainen.

  1. 21. 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

  3. 22. 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

  4. 23. Closed-loop strategy for recycling of starch and poly (lactic acid) into new materials

    Författare :Duo Wu; Minna Hakkarainen; Monica Ek; Martin Lawoko; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Biopolymers such as starch and poly lactic acid (PLA) can be derived from agriculture and are among the most promising biobased plastics for packaging and other short term application. Considering the growing pressure of environmental safety and limited resources on our planet, it would be beneficial to retain the value of waste products by material recycling. LÄS MER

  5. 24. Closed-loop strategy for valorization of starch : From starch to functionalized starch biomaterials and bioplastics

    Författare :Duo Wu; Minna Hakkarainen; Elisabetta Ranucci; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Starch; Nano-graphene oxide; Microwave; Valorization; Scaffold; Biomineralization; Bioplastics; Compatibilizer; Plasticizer; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Sammanfattning : The desire to utilize renewable resources and avoid wastes drives us to develop new concepts for material design. Non-edible starch feedstocks and starch bioplastic wastes were previously considered useless. LÄS MER

  7. 25. Graphene Oxide Technology to Advance the Performance of Poly(lactic acid) Materials

    Författare :Huan Xu; Minna Hakkarainen; Jean-Marie Raquez; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Poly lactic acid ; Graphene Oxide; Stereocomplex; Nucleation Mechanism; Crystalline Morphology; Filler Structure; Mechanical Properties; Gas Barrier; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : In the past two decades, a burgeoning biorefinery concept has grown in concert with the materials science, contributing to the rise of biobased materials that respect environment and are versatile for various applications. An excellent example is poly(lactic acid) (PLA) that exhibits high strength and desirable degradability. LÄS MER