A dynamic and thermal investigation by means of broadband dielectric spectroscopy and temperature modulated differential scanning calorimetry on the PDMS behaviour in several highly segregated diblock copolymers with varying PDMS molecular weight and volume fraction is presented. The mesophase morphology of these diblock copolymers has been characterized by means of transmission electron microscopy and small angle X-ray scattering. It is found that whereas the lamellar morphology (1D confinement) does not affect significantly the PDMS properties, in the case of the cylindrical (2D confinement) and spherical (3D confinement) segregations of the PDMS component in the PS matrix noticeable effects are evident, such as a strong reduction of the PDMS glass-transition temperature and a strong decrease (even suppression) of PDMS crystallinity ratio.

The authors acknowledge the University of the Basque Country, the Basque Government (A9/ UPV 00206.215-13568/2001), and the Spanish Ministry of Education (MAT 2007- 63681) for support. L. del Valle-Carrandi acknowledges the grant of the Basque Government. The support of the European Community within the SoftComp Network of Excellence (NoE) program (Project No. NMP3-CT-2004-502235) is also acknowledged.

5 páginas, 2 figuras, 2 tablas.

Peer reviewed