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Preparation and Compatibilizing Properties of Poly(styrene-graft-ethylene oxide) in Polymer Blends

Jannasch, Patric LU (1996)
Abstract (Swedish)
Popular Abstract in Swedish

Utvecklandet av helt nya baspolymerer för tillverkning av massprodukter förväntas i framtiden vara begränsad p.g.a. för höga investeringskostnader. En av de mest tydliga trenderna inom polymerindustrin idag är istället den ökande betydelsen av polymerblandningar. Kombinationer av två eller flera polymerer som bildar fasseparerade strukturer i blandning ger ofta material med attraktiva egenskaper. En kommersiellt viktig metod att förbättra den typiskt dåliga mekaniska hållfastheten och dåliga strukturella stabiliteten hos dessa material är att blanda in ytaktiva, kompatibiliserande ympsampolymerer. Dessa ympsampolymerer anrikas i fasgränsytor, där de sänker mellanfasenergin och ökar hållfastheten.... (More)
Popular Abstract in Swedish

Utvecklandet av helt nya baspolymerer för tillverkning av massprodukter förväntas i framtiden vara begränsad p.g.a. för höga investeringskostnader. En av de mest tydliga trenderna inom polymerindustrin idag är istället den ökande betydelsen av polymerblandningar. Kombinationer av två eller flera polymerer som bildar fasseparerade strukturer i blandning ger ofta material med attraktiva egenskaper. En kommersiellt viktig metod att förbättra den typiskt dåliga mekaniska hållfastheten och dåliga strukturella stabiliteten hos dessa material är att blanda in ytaktiva, kompatibiliserande ympsampolymerer. Dessa ympsampolymerer anrikas i fasgränsytor, där de sänker mellanfasenergin och ökar hållfastheten. Resultatet blir en blandning med reducerad fasstorlek och förbättrade mekaniska egenskaper. I denna avhandling behandlas framställning och användning av ympsampolymerer bestående av polystyren (PS) som ympats med polyetenoxid (PEO).



Tillsatser av ympsampolymerer reducerade fasstorleken i t.ex. blandningar av PS och polyamid-6 (PA-6), samt PS och polyamid-12. Elektronmikroskopi utnyttjades för att studera ympsampolymerer i fasgränsytan mellan PS och PA-6. Vid koncentrationer över en viss mättnadskoncentration av ympsampolymer i blandningarna erhölls ingen ytterligare minskning av fasstorleken. Vid dessa koncentrationer fasseparerade ympsampolymererna och bildade s.k. makrodomäner. Tillsatser av ympsampolymerer ökade även hållfastheten i fasgränsytorna. En av slutsatserna från detta arbete är att det är viktigt att rätt mängd ympsampolymer blandas in i polymerblandningar. För stora tillsatser är ekonomiskt förkastliga, dessutom kan bildandet av makrodomäner ha ogynnsamma effekter på blandningarnas mekaniska egenskaper. (Less)
Abstract
One of the main trends in the polymer industry today is the increasing importance of polymer blends. Combining two or more immiscible polymers in a polymer blend often leads to multi-phase materials with desirable properties. The typical poor morphological stability and low interfacial adhesion in these blends can be eliminated by adding compatibilizing graft copolymers.



Well-defined graft copolymers, having polystyrene (PS) backbones and poly(ethylene oxide) (PEO) grafts, were prepared by anionic polymerization of EO from active sites on PS copolymers. The graft copolymers were added as compatibilizing agents to PS blends containing a dispersed phase of either poly(butyl acrylate) (PBA), poly(butyl acrylate-co-acrylic... (More)
One of the main trends in the polymer industry today is the increasing importance of polymer blends. Combining two or more immiscible polymers in a polymer blend often leads to multi-phase materials with desirable properties. The typical poor morphological stability and low interfacial adhesion in these blends can be eliminated by adding compatibilizing graft copolymers.



Well-defined graft copolymers, having polystyrene (PS) backbones and poly(ethylene oxide) (PEO) grafts, were prepared by anionic polymerization of EO from active sites on PS copolymers. The graft copolymers were added as compatibilizing agents to PS blends containing a dispersed phase of either poly(butyl acrylate) (PBA), poly(butyl acrylate-co-acrylic acid) (PBAAA), polyamide-6 (PA-6) or polyamide-12 (PA-12).



The graft copolymers had no compatibilizing effect in the PS/PBA blends. In contrast, the graft copolymer stabilized the morphology and significantly reduced the phase size in PS/PBAAA blends, where the PEO grafts were found to interact with the PBAAA phase via hydrogen bonds. The graft copolymers also reduced the phase size in PS/PA blends, and graft copolymer interphases between the PS and PA-6 phases were observed. Above a saturation concentration of graft copolymer, there were no further reductions of phase sizes in the blends. At these concentrations, excess graft copolymer phase separated into macrodomains. Additions of graft copolymer also increased the interfacial adhesion in the blends. One of the main conclusions gained from this work is the importance of adding appropriate amounts of compatibilizer to immiscible blends. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Prof. Tirrell, David A., University of Massachusetts, Amherst, USA
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Anionic Polymerization of Ethylene Oxide, Polystyrene, Polymer technology, biopolymers, Polymerteknik, Ethoxylation, Grafting, Poly(styrene-graft-ethylene oxide), Crystallization, Interphases, Macrophases, Poly(butyl acrylate), Compatibilization of Polymer Blends, Polyamide
pages
58 pages
publisher
Chemical Engineering 2, Lund University
defense location
Lecture Hall C, Chemical Center
defense date
1996-03-21 10:15
external identifiers
  • other:ISRN: LUTKDH/TKKT--96/1035--SE
ISBN
91-628-1948-8
language
English
LU publication?
yes
id
1a0afad5-4013-4b0a-a5e1-fefbac4fd230 (old id 28241)
date added to LUP
2007-06-11 14:51:53
date last changed
2016-09-19 08:45:04
@phdthesis{1a0afad5-4013-4b0a-a5e1-fefbac4fd230,
  abstract     = {One of the main trends in the polymer industry today is the increasing importance of polymer blends. Combining two or more immiscible polymers in a polymer blend often leads to multi-phase materials with desirable properties. The typical poor morphological stability and low interfacial adhesion in these blends can be eliminated by adding compatibilizing graft copolymers.<br/><br>
<br/><br>
Well-defined graft copolymers, having polystyrene (PS) backbones and poly(ethylene oxide) (PEO) grafts, were prepared by anionic polymerization of EO from active sites on PS copolymers. The graft copolymers were added as compatibilizing agents to PS blends containing a dispersed phase of either poly(butyl acrylate) (PBA), poly(butyl acrylate-co-acrylic acid) (PBAAA), polyamide-6 (PA-6) or polyamide-12 (PA-12).<br/><br>
<br/><br>
The graft copolymers had no compatibilizing effect in the PS/PBA blends. In contrast, the graft copolymer stabilized the morphology and significantly reduced the phase size in PS/PBAAA blends, where the PEO grafts were found to interact with the PBAAA phase via hydrogen bonds. The graft copolymers also reduced the phase size in PS/PA blends, and graft copolymer interphases between the PS and PA-6 phases were observed. Above a saturation concentration of graft copolymer, there were no further reductions of phase sizes in the blends. At these concentrations, excess graft copolymer phase separated into macrodomains. Additions of graft copolymer also increased the interfacial adhesion in the blends. One of the main conclusions gained from this work is the importance of adding appropriate amounts of compatibilizer to immiscible blends.},
  author       = {Jannasch, Patric},
  isbn         = {91-628-1948-8},
  keyword      = {Anionic Polymerization of Ethylene Oxide,Polystyrene,Polymer technology,biopolymers,Polymerteknik,Ethoxylation,Grafting,Poly(styrene-graft-ethylene oxide),Crystallization,Interphases,Macrophases,Poly(butyl acrylate),Compatibilization of Polymer Blends,Polyamide},
  language     = {eng},
  pages        = {58},
  publisher    = {Chemical Engineering 2, Lund University},
  school       = {Lund University},
  title        = {Preparation and Compatibilizing Properties of Poly(styrene-graft-ethylene oxide) in Polymer Blends},
  year         = {1996},
}