Aqueous Solution Properties of Polyglycidol-Based Analogues of Pluronic Copolymers. Influence of the Poly(propylene oxide) Block Molar Mass
AbstractWith the present contribution we complement the picture of the behavior in aqueous solution of the entire family of LGP copolymers. The latter are considered analogues of the Pluronic copolymers in which the flanking poly(ethylene oxide) (PEO) blocks are substituted by linear polyglycidol (PG). PG is structurally similar to PEO and differs in that each monomer unit bears a hydroxymethylene group. So far two series of LGP copolymers, that is LGP60 and LGP130, based on poly(propylene oxide) (PPO) of molar masses 2000 and 4000, respectively, and PG contents ranging from 10 to 84 wt % have been studied. In particular, in the present paper we report on the synthesis and aqueous solution properties of a novel series of LGP copolymers that are close in composition to the Pluronic copolymers of the lowest molar mass of the central block of PPO, L31−P38. Seven copolymers based on PPO of molar mass of 1000 and PG content ranging from 30 to 90 wt % were prepared by applying the same two-step procedure employed for the synthesis of the LGP60 and LGP130 copolymers. The copolymers were prepared by means of anionic polymerization of ethoxyethyl glycidyl ether (protected glycidol) followed by cleavage of the protective groups. The aqueous solution properties were thoroughly investigated by a variety of methods, e.g., dye solubilization for determination of the critical micellization concentrations, turbidimetry, light scattering, small-angle neutron scattering, and rheology. A number of parameters were extracted from the experimental data and compared to those of the related copolymers from the LGP60 and LGP130 series to assess the influence of the molar mass of the central block of PPO.