analisi dell'effetto di consolvenza su un polimero termoresponsivo

Thermoresponsive polymers became very attractive in the last decades because they change drastically their structure upon a change of temperature. This thesis investigates the phase and thermal behavior of a poly(methylmethacrylate)-b-poly(N-isopropylacryl- amide) diblock copolymer in aqueous solution and in mixtures of water and methanol using turbidimetry and differential scanning calorimetry. Futhermore, by means of dynamic light scattering, the self-assembled micelles are investigated in dependence on temperature and solvent composition. A decrease of cloud point temperature and enth- lapy of transition are observed when the fracion of methanol increases. The size of the micelles decreases when adding methanol and they form clusters 2-3°C below the cloud point. The results are compared with PNIPAM homopolymer and to PMMA21-b- PNIPAM283, a similar block copolymer with a shorter hydrophobic part.