Sökning: "NATURVETENSKAP Kemi Organisk kemi Polymerkemi"

Visar resultat 6 - 10 av 32 avhandlingar innehållade orden NATURVETENSKAP Kemi Organisk kemi Polymerkemi.

1. 6. Palladium-catalyzed lignin valorization : Towards a lignin-based biorefinery

   Författare :Maxim Galkin; Joseph Samec; Rafael Luque; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Lignin; Heterogeneous Catalysis; Palladium; Biomass; Depolymerization; Reduction; Oxidation; Biorefinery; Transfer Hydrogenolysis; Organic Chemistry; Organisk kemi;

   Sammanfattning : The work described in this thesis focuses on the cleavage of the β-O-4′ bond, which is the most abundant interunit linkage in the lignin polymer.In the first part, three methods based on palladium catalysis have been developed and their applicability has been verified using lignin model compounds. LÄS MER

3. 7. Additive-Driven Improvements in Interfacial Properties and Processing of TMP-Polymer Composites

   Författare :Seyedehsan Hosseini; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; molybdenum disulfide; magnesium stearate; thermomechanical pulp; alkyl ketene dimer; friction; rheology;

   Sammanfattning : Efforts to address environmental concerns have resulted in new regulations designed to plan the reduction of plastic and synthetic polymer usage, necessitating the search for sustainable natural alternatives with comparable cost-effectiveness and mechanical performance. Thermomechanical pulp (TMP) fibres are one of the most affordable natural fibres that have no chemical refining in production, production have a high yield of 90-98% and TMP fibres have been demonstrated to improve the mechanical characteristics (strength, stiffness and toughness) of wood-polymer composites (WPCs) compared to the pure polymer. LÄS MER

4. 8. Synthesis of Conjugated Polymers and Small Molecules for Organic Light-Emitting Devices and Photodetectors

   Författare :Petri Henrik Murto; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; solution processing; conjugated polymers; fluorescence; near-infrared; light-emitting electrochemical cell; organic photodetector; organic light-emitting diode;

   Sammanfattning : Production cost and environmental impact are the two major concerns that are related to the conventional optoelectronic devices. It is desirable for the modern semiconductors that they are free of toxic/costly metals, they can be processed with low-cost solution-based methods, and their optical, electronic, and mechanical properties can be easily tuned depending on the target application. LÄS MER

5. 9. An Investigation of Mixed Cellulose Esters and Acyclic Polyacetates: Effects of Side-Chain Lengths and Degrees of Ring-Opening

   Författare :Robin Nilsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; water interactions; oxygen permeation; storage modulus; ring-opening; water sorption; cellulose esters; side-chains; acyclic cellulose acetate;

   Sammanfattning : Bio-based polymers produced from natural sources are gaining an increased interest as potential replacement for today’s conventional fossil-based plastic polymers. Their use is already wide in many large-scale industrial areas such as healthcare, personal care, and food. LÄS MER

7. 10. Dissolution of cellulose in aqueous hydroxide base solvents

   Författare :Beatrice Swensson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; aqueous; NaOH; quaternary ammonium hydroxide; solvent; cellulose; dissolution;

   Sammanfattning : As we move towards a circular bioeconomy, new and advanced materials based on cellulose are constantly developed. Unlike most plastics or metals, cellulose cannot be melted, and therefore dissolution is an important tool for processing of cellulose but also for analytical purposes. LÄS MER