Sökning: "ethylene oxide propylene oxide"

Visar resultat 1 - 5 av 23 avhandlingar innehållade orden ethylene oxide propylene oxide.

1. 1. Ternary Block Copolymer - Water - "Oil" Systems: Effects of "Oil" Type and Block Size on Phase Behaviour and Structure

   Författare :Peter Holmqvist; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; poly propylene oxide ; poly ethylene oxide ; poloxamer; micelles; lyotropic liquid crystals; SAXS; structure; phase behavior; self-assembly; block copolymers; amphiphiles; poly tetrahydrofurane ; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : It has recently been established in our group that amphiphilic block copolymers consisting of a hydrophilic and a hydrophobic part can self-assemble in the presence of selective solvents (“water” and “oil”) into a variety of different solution and lyotropic liquid crystalline microstructures. The effects of the “oil” type, hydrophilic block size and hydrophobic block type on the phase behavior and microstructure of ternary isothermal copolymer - oil - water systems have been addressed in this thesis. LÄS MER

3. 2. Ternary Block Copolymer Systems - Phase Behaviour and Phase Structure

   Författare :Birgitta Svensson; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical chemistry; lyotropic; thermotropic; SANS; SAXS; scattering; semicrystalline; reverse micelle; micellar solution; liquid crystalline; phase diagram; phase behaviour; block copolymer; pluronic; poly ethylene oxide ; poly propylene oxide ; quantum chemistry; Teoretisk kemi; kvantkemi;

   Sammanfattning : Ternary isothermal (25°C) polyoxyalkylene triblock block copolymer ((EO)x(PO)y(EO)x where x is the number of ethylene oxide, EO, segments and y is the number of propylene oxide, PO, segments) systems with water and p-xylene as selective solvents for the PEO and PPO blocks, respectively, were chosen as study systems in this thesis as these ternary systems are good model systems for the self-assembly of block copolymers. The phase behaviour has been studied at varied block copolymer molecular weight and relative PEO/PPO block ratio. LÄS MER

4. 3. Polymer Ionic Materials: A Study of new Materials for Solid Polymer Fuel Cells and Rechargeable Polymer Batteries

   Författare :Britta Mattsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PPO; polystyrene; neutron scattering; poly propylene oxide ; PEO; polymer electrolytes; poly vinylidene fluoride ; poly ethylene oxide ; luminescence; Raman spectroscopy; proton conducting polymer; poly styrene sulfonic acid ; PVDF;

   Sammanfattning : Ion-containing polymeric materials are interesting for use in a wide variety of applications, where the flexible, yet mechanically stable, polymer matrix is essential. Intensive research is presently going on worldwide for applications as electrolytes in solid polymer batteries and fuel cells, where the ion-conducting polymer also serves as an electrode separator. LÄS MER

5. 4. Lactic acid production: extractive fermentation in aqueous two-phase systems

   Författare :Jordi Planes; Teknisk mikrobiologi; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gel excludion chromatography; polyethylenimine; ethylene oxide propylene oxide; phase forming polymers; aqueous two-phase systems; extractive fermentation; Lactococcus; Lactobacillus; Mikrobiologi; bakteriologi; virologi; mykologi; bacteriology; virology; mycology; Microbiology;

   Sammanfattning : There is an increased interest in the microbial production of lactic acid as a raw material for the synthesis of lactic acid polymers as biodegradable plastics. However, two factors limit the economical competitiveness of lactic acid production by microorganisms: lactic acid inhibition, which decreases both fermentation rate and the maximum lactic acid concentration, and the efficiency in the recovery of lactic acid. LÄS MER

7. 5. Amphiphilic Polymers as Additives in Biomedical Polyurethanes. Surface Properties and Morphology

   Författare :Maria Kober; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; polymer micelles; phase separation; migration; poly ethylene oxide ; surface enrichment; morphology; polyurethane; additives; Surface modification; amphiphilic polymers; polymer blends; Polymer technology; biopolymers; Polymerteknik;

   Sammanfattning : The aim of this work was to achieve surface modification of two biomedical polyurethanes and one poly(urethane urea) through the addition of small amounts of amphiphilic copolymers in solution. The matrix polymers used were the poly(ether urethane)s Pellethane 2363-80AE (P80) and 2363-75D (P75) and a poly(ether urethane urea) similar to Biomer (PUUR). LÄS MER