Dresden 2003 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 20: POSTER A

CPP 20.15: Poster

Montag, 24. März 2003, 19:00–21:00, ZEU/250

Heat capacity spectroscopy of semi-crystalline PHB from glass transition to the melt — •Sergey Adamovsky — Universität Rostock

Dynamic heat capacity of semi-crystalline poly(3-hydroxybutyrate) (PHB) was investigated. Heat capacity values between glass transition temperature and 80 grad Celsius are below the expected value from a 2-phase model (crystalline-amorphous combination). From this one gets the rigid-amorphous fraction as a function of temperature. For PHB the rigid-amorphous fraction disappears at about 80 grad Celsius, the crystallization temperature. At higher temperatures in the melting region heat capacity becomes frequency dependent. The molecular processes related to the frequency dependence of heat capacity yield a characteristic time of about 20 s at 160 grad Celsius.

Results on PHB as well as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-co-PHV) are presented.