Title
Synthesis and interfacial behavior of polystyrene-polysaccharide diblock copolymers
Author
Bosker, W.T.E.
Ágoston, K.
Cohen Stuart, M.A.
Norde, W.
Timmermans, J.W.
Slaghek, T.M.
Publication year
2003
Abstract
Linear block copolymers of polystyrene and polysaccharide were synthesized using a block synthesis method with amino-terminated polystyrene and sodium cyanoborohydride as reducing agent. Different types of polysaccharides, dextrans, and maltodextrins with various molecular weights were used. IR spectroscopy indicated a successful coupling. Yields of reaction are 75-95 wt %. Attempts to couple long dextrans (Mw > 6000 Da) were not successful. Interfacial pressure measurements of monolayers of the copolymers on water showed interfacial behavior typical for amphiphilic compounds and different from the starting compounds, confirming the coupling reaction. Time-dependent hysteresis occurs between successive compression and expansion cycles. This is, to a large extent, due to the slow adsorption/desorption of the polysaccharide chains at the air-water interface and the formation of aggregates of copolymer at the interface. Aggregates are mainly formed by H-bonds between adjacent polysaccharide chains. The relaxation time for hysteresis, determined for polystyrene-dextran copolymer, was 85 min.
Subject
Nutrition
Food technology
Infrared spectroscopy
Interfaces (materials)
Molecular weight
Monolayers
Polysaccharides
Polystyrenes
Synthesis (chemical)
Interfacial pressure
Block copolymers
To reference this document use:
http://resolver.tudelft.nl/uuid:01b5b929-d82e-44c6-87f7-c4c7ff01114c
DOI
https://doi.org/10.1021/ma020925u
TNO identifier
237009
ISSN
0024-9297
Source
Macromolecules, 36 (6), 1982-1987
Document type
article