Search for dissertations about: "chain elongation"

Showing result 21 - 25 of 47 swedish dissertations containing the words chain elongation.

  2. 21. New biodegradable polymers from renewable resources

    Author : Yan Liu; KTH; []
    Keywords : ;

    Abstract : High molecular weight poly(ester-carbonate)s have beenprepared by a two-step chain-extension reaction performed onoligomeric αω-bishydroxyl-terminatedpoly(1,3-propylene succinate).αω-Bishydroxyl-terminated copolymeric oligomers of1,3-propylene succinate/1,4-cyclohexanedimethylene succinatewere obtained by thermal polycondensation of1,3-propanediol/1,4-cyclohexanedimethanol/succinic acidmixtures having different composition, and subsequently chainextended using phosgene as coupling agent, which leads toaliphatic/alicyclic copoly(ester-carbonate)s. READ MORE

  4. 22. Strategies for Utilizing Biobased and Recycled Resources for Polylactide Plasticization

    Author : Xi Yang; Minna Hakkarainen; Karin Odelius; Youssef Habibi; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polylactide; poly 3-hydroxybutyrate ; poly butylene succinate-co-adipate ; bio-based; microwave; reactive extrusion; recycling; plasticizing; migration resistance; crystallization; polylaktid; poly 3-hydroxibutyrat ; poly butylen succinat-sam-adipat ; biobaserade; mikrovågsugn; reaktiv extrudering; återvinning; mjukgörare; migrationsmotstånd; kristallisering; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Abstract : There are many aspects that should be considered to achieve truly "environmental friendly" and "sustainable" materials. These include the raw material resource, the energy consumption, the chemicals generated and used, the emissions during production, processing, transportation, disposal and so on. READ MORE

  5. 23. On the rotational deformity of the shoulder following an obstetric brachial plexus palsy

    Author : Tomas Hultgren; Karolinska Institutet; Karolinska Institutet; []
    Keywords : ;

    Abstract : An internal rotation deformity of the shoulder occurs very frequently in brachial plexus birth palsy. Even though surprisingly accurate descriptions of the deformity were already published at the beginning of the 1900s, the nature of the deformity is not well understood and there is no consensus regarding surgical treatment. READ MORE

  6. 24. Environmentally Friendly Plasticizers for PVC : Improved Material Properties and Long-term Performance Through Plasticizer Design

    Author : Annika Lindström; Minna Hakkaraninen; Anders Södergård; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; poly butylene adipate ; poly vinyl chloride ; plasticizers; miscibility; mechanical properties; surface segregation; migration; degradation products; Polymer chemistry; Polymerkemi;

    Abstract : Linear and branched poly(butylene adipate) polyesters with number-average molecular weights ranging from 700 to 10 000 g/mol, and degrees of branching ranging from very low to hyperbranched were solution cast with PVC to study the effects of chemical structure, molecular weight, end-group functionality, and chain architecture on plasticizing efficiency and durability. Miscibility was evaluated by the existence of a single glass transition temperature and a shift of the carbonyl group absorption band. READ MORE

  7. 25. Mechanical Properties of Liquid Crystal Polymer Fibres

    Author : Eivor Neikter; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; copolymer hydroxybenzoic acid; thermotropic liquid crystalline polymers; polyethylene terephthalate; mechanical properties; hydroxybenzoic acid;

    Abstract : Fibres of thermotropic liquid crystalline polymers (LCP) and its blends containing a random coil polymer LCP have been spun at low draw ratio at different temperatures and shear rates. Their mechanical properties have been studied in detail. READ MORE