Synthesis and adsorption of polymers: Control of polymer and surface structure

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:5154604

Stoichet, M S

A simple and versatile technique to introduce carboxylic acid functionality to the surfaces of three fluoropolymer film samples is described. The adsorption of neutral poly(L-lysine) (PLL) from solution to the water-fluoropolymer interface is described. The methods of surface modification are combined and the adsorption of charged PLL to carboxylic acid-functionalized fluoropolymer film surface is discussed. The hydrophobic interaction as a driving force for adsorption is further studied where the synthesis and adsorption of poly(ethylene oxide) (PEO) and its derivatives are discussed. The synthesis of carboxylic acid-functionalized fluoropolymer films rely upon a two step mechanism where unsaturation is oxidatively removed. Contact angles of the acid-functionalized fluoropolymer films decrease with increasing pH. The adsorption of poly(L-lysine) (PLL) to the water-FEP interface was controlled by pH of the aqueous solution and PLL solution conformation. Only neutral [alpha]-helical PLL adsorbed to FEP (FEP-PLL). The adsorption of PLL to FEP-CO[sub 2]H was controlled by an electrostatic interaction. Both FEP-PLL and FEP-CO[sub 2]H-PLL are more hydrophilic than FEP. FEP-PLL-[epsilon]-amine reacts with 3,5-dinitrobenzoyl chloride in 65% yield whereas FEP-CO[sub 2]H-PLL-[epsilon]-amine reacts in 100% yield. Adsorption of PLL to FEP and FEP-CO[sub 2]H improves the peel strength of adhesive joints prepared with these substrates and the adhesion and growth of biological cells on these film samples. PEO was synthesized by anionic ring opening polymerization of ethylene oxide and was end-capped (PEO-R) by reaction with a (perfluoro)alkyl acid chloride. A polar interaction between substrate and segment controlled adsorption at the fluoropolymer-water interface. PEO and PEO-R adsorbed to the polystyrene latex-water interface. PEO-R showed increase surface activity over PEO at the air-water interface; PEO-perfluorodecanoate decreased the surface tension of water to 35 dyn/cm.

• Research Organization: Massachusetts Inst. of Tech., Cambridge, MA (United States)
• OSTI ID: 5154604
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation & Manufacture
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ADSORPTION
ALCOHOLS
AMINO ACIDS
CARBOXYLIC ACIDS
CHEMICAL BONDS
CHEMICAL REACTIONS
GLYCOLS
HYDROXY COMPOUNDS
LYSINE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC POLYMERS
POLYETHYLENE GLYCOLS
POLYMERS
SORPTION
SURFACE FINISHING
SURFACE PROPERTIES