This thesis has two main objectives (1) synthesizing block copolymers containing specifically functionalized segments in well-defined locations and densities and (2) studying the interfacial activity of these copolymers as a function of composition. Interfacial activity is assessed through adsorption at the solution/solid interface and the polymer/air interfaces. The approach for preparing these functionalized diblock copolymers involved anionically copolymerizing an unfunctionalized monomer with a functionalized monomer. The functionalized copolymer, poly (styrene-co-(p-hydroxystyrene)), because of the acidity of the phenolic group protective group chemistry was required. Therefore the protected monomer, 4-(tert-butyldimethylsilyl)oxystyrene, was synthesized. Poly (styrene-co-(p-hydroxystyrene)) of known composition and structure was synthesized through the copolymerization of styrene and 4-TBDMSoxystyrene. Subsequent desilylation of the tert-butyldimethylsilyl ether generated the phenol functionality. This deprotection was quantitative, generating poly (styrene-co-(p-hydroxystyrene)). The protected and the deprotected copolymers were used to characterize the copolymer's composition. The adsorption behavior of poly (styrene-co-(p-hydroxystyrene)) was studied at the solution/solid interface. The amount of polymer adsorbed was studied as a function of copolymer composition. Using UV depletion, adsorption was studied from THF to alumina generating for each polymer studied adsorption isotherms. At each molecular weight, polystyrene served as a control and the amount of copolymer adsorbed was found to be a function of composition. The adsorption results agreed qualitatively with theoretically predicted behavior. The reactivity of the phenol functionality was used as a reactive handle to incorporate surface-active groups (perfluoroalkyl groups) at defined locations and densities along the copolymer chain, generating a surface-active polymer (SAP) of known composition. The adsorption behavior of these SAPs was studied from a 10K polystyrene matrix. Adsorption was studied as a function of SAP concentration and composition. Heat treated 10K polystyrene films served as a control. At all SAP compositions studied there was an enrichment of the surface region with SAP. The perfluoroalkyl groups preferentially adsorbed at the polymer/air interface as indicated by XPS and contact angle data. The amount of SAP adsorbed was found to be a function of composition. This adsorption data provides experimental evidence that copolymer composition influences adsorption behavior and ultimately surface composition.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-8926 |
| Date | 01 January 1994 |
| Creators | Viviano, Katrina Rose |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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