Structural Behavior of Amphiphilic Triblock Copolymer P104/Water System

A detailed study of the different structural transitions of the triblock copolymer PEO27-PPO61-PEO27 (P104) in water, in the dilute and semi-dilute regions, is addressed here as a function of temperature and P104 concentration (C-P104) by mean of complimentary methods: viscosimetry, densimetry, dynamic light scattering, turbidimetry, polarized microscopy, and rheometry. The hydration profile was calculated through density and sound velocity measurements. It was possible to identify the regions where monomers exist, spherical micelle formation, elongated cylindrical micelles formation, clouding points, and liquid crystalline behavior. We report a partial phase diagram including information for P104 concentrations from 1 x 10(-4) to 90 wt.% and temperatures from 20 to 75 degrees C that will be helpful for further interaction studies with hydrophobic molecules or active principles for drug delivery.

Automated summary

In this study, the different structural transitions of the triblock copolymer PEO27-PPO61-PEO17 in water were investigated as a function of temperature and P104 concentration using various techniques. The regions of monomer existence, spherical and elongated cylindrical micelle formation, clouding points, and liquid crystalline behavior were identified. A partial phase diagram was presented, providing useful information for further studies on the interaction of P104 with hydrophobic molecules or active principles for drug delivery.