Sökning: "fiber morphology"

Visar resultat 21 - 25 av 83 avhandlingar innehållade orden fiber morphology.

1. 21. Bioresorbable copolymers with tailored properies : innovative materials för soft tissuel engineering

   Författare :Natalia Andronova; Ann-Christine Albertsson; Pieter Dijkstra; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; poly 1; 5-dioxepan-2-one ; poly ε-caprolactone ; poly L-lactide ; poly trimethylene carbonate ; triblock; network; cyclic tin alkoxide; controlled coordination-insertion ring-opening polymerization; thermoplastic elastomers; Polymer chemistry; Polymerkemi;

   Sammanfattning : The emerging need for new synthetic materials for soft tissue engineering applications encourages the search for innovative polymers having interesting properties. Ring-opening polymerization of lactones and lactides initiated by tin alkoxides has received particular attention due to the versatility of the method for building up well-defined biodegradable structures. LÄS MER

3. 22. Crystallisation of star polyesters with poly (ε-caprolactone) arms : approaching the problem of early stages in polymer crystallisation

   Författare :Eugenia Núñez; KTH; []
   Nyckelord :Technology; TEKNIKVETENSKAP; TECHNOLOGY; TEKNIKVETENSKAP;

   Sammanfattning : The knowledge regarding early stages in polymer crystallisation remains inconclusive due to experimental limitations. The reason is that the initially formed polymer crystals rearrange rapidly at the crystallisation temperature. Faster experimental techniques or simulation would be suitable alternatives to approach the problem. LÄS MER

4. 23. Hydrothermal recycling of natural and synthetic polymers to functional carbon materials

   Författare :Karin Adolfsson; Minna Hakkarainen; Istvan Furo; Andrea Kruse; KTH; []
   Nyckelord :;

   Sammanfattning : Utilizing renewable recourses and waste recycling are necessary for reaching a circular resource society. The concept of this thesis was to set up a sustainable recycling route, suitable even for low quality biopolymer and plastic waste for production of functional carbon materials. LÄS MER

5. 24. Modelling the degradation processes in high-impact polystyrene during the first use and subsequent recycling

   Författare :Francisco Vilaplana; Sigbritt Karlsson; Monika Ek; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Recycling; high-impact polystyrene; degradation; quality analysis; thermal analysis; vibrational spectroscopy; chromatography techniques; thermo-oxidation; reprocessing; dynamic mechanical properties; polybutadiene microstructure.; Polymer chemistry; Polymerkemi;

   Sammanfattning : Polymers are subjected to physical and chemical changes during their processing, service life, and further recovery, and they may also interact with impurities that can alter their composition. These changes substantially modify the stabilisation mechanisms and mechanical properties of recycled polymers. LÄS MER

7. 25. Novel Technique to Improve High-Velocity Cold Compaction : Processing of Polymer Powders and Polymer-Based Nanocomposite High Performance Components

   Författare :Bruska Azhdar; Bengt Stenberg; Leif Kari; Mikael Rigdahl; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polymer powders; nanocomposites; high-velocity compaction; high-energy ball milling; Manufacturing engineering; Produktionsteknik;

   Sammanfattning : Compaction of polymer powders and polymer-based nanocomposites by uniaxial high-velocity cold compaction (HVC), by high-energy ball milling (HEBM) and using a novel technique, relaxation assists, was investigated with a focus on the process parameters, the compactibility characteristics, surface morphology and friction. The basic phenomena associated with HVC are explained and the general energy principle is introduced to explain the pull-out phenomenon, springback gradient, delay time, relative time of the pressure wave, and stick-slip phenomenon during the compaction process. LÄS MER