Abstract
A series of MOPEO-b-PCL diblock copolymers (DBCs) with M nMOPEO = 2.5 · 103 and M nPCL = (0.28 ÷ 2.43) · 104 was synthesized using the anionic ring-opening block copolymerization. A bulk structure of the copolymers was studied with DSC. One glass transition and three melting peaks for MOPEO-b-PCL were found, thus implying the existence of separate crystalline domains of both blocks in a copolymer structure. The intense micellization of DBCs in dioxane/aqueous solutions was found with a spectrophotometry, a static light scattering, and photography. A reduction in CMC and an increase in −ΔG° values with growth of the PCL length and at the addition of prednisolon (PS) were established. The hydrogen bonding of PS with DBCs was confirmed with FTIR spectroscopy.
Notes
1The weight fraction of MOPEO in the diblock copolymer.
2The ratio between units in PCL and MOPEO blocks, base-molPCL/base-molMOPEO.
1The glass transition temperature.
2The temperature region for a certain thermal transition.
3The specific capacity jump.
4The melting temperature.
5The melting enthalpy.
6The crystallinity degree: for pure MOPEG , where
is the melting enthalpy for 100% crystalline PEO (196.8 J · g−1) [Citation14], but for MOPEO and PCL blocks in the copolymer
[Citation14], where w is the mass fraction of corresponding block in DBC; the value of
for 100% crystalline PCL was taken of the study [Citation12].
7The crystallinity degree, calculated under condition of a participation of only PCL blocks in this melting process.
1The molar ratio between PS and DBC ϕ = 0.25 molPS/base-molDBC was constant in all the blends.