Search for dissertations about: "melt spinning"

Showing result 11 - 15 of 17 swedish dissertations containing the words melt spinning.

2. 11. Biobased carbon fibers from solution spun lignocellulosic precursors

   Author : Andreas Bengtsson; Monica Ek; Maria Sedin; Elisabet Brännvall; Elisabeth Sjöholm; Johannes Ganster; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Carbon fiber; Carbonization; Cellulose; Kraft pulp; Softwood kraft lignin; Solution spinning; Stabilization; Barrvedslignin; Cellulosa; Karbonisering; Kolfiber; Lösningsmedelsspinning; Stabilisering; Sulfatmassa; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Abstract : Carbon fibers (CFs) have excellent mechanical properties and a low density, making themattractive as a reinforcing fiber in composites. The use of CFs is limited to high-end applications,since they are produced from an expensive fossil-based precursor via an energy-intensivemanufacturing process, explaining the need for cheaper CFs from renewables. READ MORE

4. 12. Processing of continuous fibers based on nanocellulose: Influence of dispersion and orientation on mechanical properties

   Author : Saleh Hooshmand; Stephen Eichhorn; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Trä och bionanokompositer; Wood and Bionanocomposites;

   Abstract : The aim of the work was to prepare continuous bio-based fibers where nano-sized cellulose was used to improve the mechanical properties. Two different strategies were used to reach this aim, melt-spinning of thermoplastic fibers reinforced with nanocellulose and dry-spinning of cellulose nanofibers without solvent or chemicals. READ MORE

5. 13. Process and properties of continuous fibers based on cellulose nanocrystals and nanofibers

   Author : Saleh Hooshmand; Tekla Tammelin; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Trä och bionanokompositer; Wood and Bionanocomposites;

   Abstract : In recent years, composites made from natural fibers based on cellulose have received increasing attention since they have a low environmental impact and good mechanical properties. However, these fibers are short and discontinuous and the conventional spinning techniques used for these fibers results in continuous yarns with mechanical properties considerably lower than that of the single fibers. READ MORE

6. 14. Development of softwood kraft lignin based carbon fibers

   Author : Ylva Nordström; Mikael Skrifvars; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polymera konstruktionsmaterial; Polymeric Composite Materials;

   Abstract : The polymer composites designed for high-performance applications are mostly based on carbon fiber reinforcement. The two most common precursors used currently for carbon fiber production are poly(acrylonitrile) and pitch (petroleum- or coal- based). As of today, the most promising alternative to these fossil originated raw materials is lignin. READ MORE

7. 15. Composition-Structure Correlations of Bioactive Glasses Explored by Multinuclear Solid-state NMR Spectroscopy

   Author : Renny Mathew; Mattias Edén; Robert Hill; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; bioactive glasses; glass structure; orthophosphate distribution; solid-state NMR; dipolar interactions; dipolar recoupling; multiple-quantum spin counting; READOR; REAPDOR; fysikalisk kemi; Physical Chemistry;

   Abstract : This PhD thesis presents a study of structure-composition correlations of bioactive glasses (BGs) by employing solid-state Nuclear Magnetic Resonance (NMR) spectroscopy.Silicate-based Na2O−CaO−SiO2−P2O5 BGs are utilized clinically and are extensively investigated for bone regeneration purposes. READ MORE