Morphology and damping properties of triblock copolymer physical gels

This study was conducted in order to develop damping materials for practical applications, such as insulators for compact disk players and hard drive disks. Three types of styrene-based triblock copolymers and various paraffinic oils were selected to produce physical gels with low modulus. These polymer gels can be shaped by injection moulding to reduce the total cost for mass production. The miscibility and the morphology of the systems were examined by modulated-temperature differential scanning calorimetry (M-TDSC), dynamic mechanical thermal analysis (DMTA), transmission electron microscopy (IEM) and small angle X-ray scattering (SAXS). The experimental results showed that the glass transition temperatures of the mid blocks of the block copolymers swollen with the high Mw paraffinic oils obeyed the Fox equation. This means that the added paraffinic oil is selectively miscible with the mid blocks. However, it was also found by TEM that the polystyrene domains were also swollen by the low Mw paraffinic oil. [Continues.]