Correlating the mechanical and surface properties with the composition of triblock copoly(2-oxazoline)s

Kranenburg, Johannes M.; Thijs, Hanneke M. L.; Tweedie, Catherine A.; Höppener, Stephanie; Wiesbrock, Frank; Hoogenboom, Richard; Vliet, Krystyn J. Van; Schubert, Ulrich S.

Abstract:

The elastic moduli, surface energies, and phase morphologies of poly(2-oxazoline) triblock copolymers were investigated and compared to the corresponding homopolymers and diblock copolymers, at a constant degree of polymerization. The elastic moduli of ABA triblock copolymers were bound by those of the respective AB diblock copolymers and A homopolymers. These results show that the elastic moduli of these copolymers – obtained by instrumented indentation – depended on the interplay between phase-separation, crystallization and hygroscopicity, and can be adjusted by tailoring the composition. The surface energy strongly depended on the presence of a poly(2-nonyl-2-oxazoline) block. If such a block was present, the surface energy was reduced due to segregation of nonyl sidechains to the surface. This segregation was promoted by annealing. The crystallization of nonyl sidechains at the surface promoted the development of surface texture and an increase in surface roughness, as demonstrated by atomic force microscopy topographic imaging.

Year:

2009

Type of Publication:

Article

Journal:

Journal of Materials Chemistry

Volume:

19

Pages:

222-229