Sökning: "Ring opening"

Visar resultat 21 - 25 av 110 avhandlingar innehållade orden Ring opening.

1. 21. Novel Possibilities for Advanced Molecular Structure Design for Polymers and Networks

   Författare :Anna Finne; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ring-opening polymerization; coordination-insertion; germanium; cyclic tin alkoxides; spirocyclic initiators; poly L-lactide ; poly 1; 5-dioxepan-2-one ; triblock; star-shaped; network; functionalization; morphology; AFM; Polymer chemistry; Polymerkemi;

   Sammanfattning : Synthetic and degradable polymers are an attractive choicein many areas, since it is possible to control the way in whichthey are manufactured; more specifically, pathways tomanipulate the architecture, the mechanical properties and thedegradation times have been identified. In this work,L-lactide, 1,5-dioxepan-2-one and ε-caprolactone were usedas monomers to synthesize polymers with different architecturesby ring-opening polymerization. LÄS MER

3. 22. Porous degradable polyester scaffolds

   Författare :Peter Plikk; Ann-Christine Albertsson; Johan Lind; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; aliphatic polyester; copolymer; porous scaffold; ring-opening polymerization; electron beam; gamma irradiation; Polymerteknologi; Chemistry; Kemi;

   Sammanfattning : Tissue engineering is a growing research field in which degradable porous scaffolds are used to regenerate tissue from the patients own cells. The problems due to donor shortage or the lack of full property restoration from prosthetic implants can thereby be overcome. LÄS MER

4. 23. Polymer Nanocomposites in Thin Film Applications

   Författare :Linda Fogelström; Anders Hult; José M. Kenny; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nanocomposites; hyperbranched polymers; montmorillonite; clay nanoparticles; exfoliated; coatings; crosslinking; TEM; XRD; mechanical properties; thermal properties; cellulose nanofibers; Atom Transfer Radical Polymerization; Ring-Opening Polymerization; poly ε-caprolactone ; surface modification; grafting; interfacial adhesion; Polymer chemistry; Polymerkemi;

   Sammanfattning : The introduction of a nanoscopic reinforcing phase to a polymer matrix offers great possibilities of obtaining improved properties, enabling applications outside the boundaries of traditional composites. The majority of the work in this thesis has been devoted to polymer/clay nanocomposites in coating applications, using the hydroxyl-functional hyperbranched polyester Boltorn® as matrix and montmorillonite clay as nanofiller. LÄS MER

5. 24. Design of polyester and porous scaffolds

   Författare :Karin Odelius; Ann-Christine Albertsson; Monica Ek; Torbjörn Mathisen; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ring-opening polymerization; porous scaffold; L-lactide; 5-dioxepane-2-one; ε-caprolactone; spirocyclic initiator; star-shaped polyester; Polymer chemistry; Polymerkemi;

   Sammanfattning : The use of synthetic materials for tissue and organ reconstruction, i. e. tissue engineering, has become a promising alternative to current surgical therapies and may overcome the shortcomings of the methods in use today. LÄS MER

7. 25. Novel methods to synthesize aliphatic polyesters of vivid architectures

   Författare :Rajiv Srivastava; Ann-Christine Albertsson; Ronnie Palmgren; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polyesters; 1; 5-dioxepan-2-one; Caprolactone; Sn Oct 2; Enzyme; Lipase-CA; Ring-Opening Polymerization; Architecture; Tissue Engineering; Polymer chemistry; Polymerkemi;

   Sammanfattning : Cross-linked films of ε-caprolactone (CL) and 1,5-dioxepan-2-one (DXO) having various mole fractions of monomers and different cross-link densities were prepared using 2,2’-bis-(-caprolactone-4-yl) propane (BCP) as cross-linking agent and Sn(Oct)2 as catalyst. Reaction parameters were examined to optimize the film-forming conditions. LÄS MER