Synthesis and Characterization of Novel Encapsulating Materials Based on Functionalized Amphiphilic Block Copolymers

The synthesis and characterization of eight novel PEG-based amphiphilic block copolymers is reported. The polymers have been synthesized by reacting poly(ethylene glycols) (PEGs) of different molecular weights viz. 600, 1000, 1500 and 2000 and dimethyl 5-hydroxyisophthalate in the presence of concentrated H2SO4 as catalyst and further alkylating the resulting polymers by attaching heptyl and tetradecyl chains to phenolic hydroxyl group. The resulting functionalized amphiphilic polymers have been characterized by H-1 and C-13-NMR spectroscopy. These polymers, when dissolved in water, aggregate to form micelles, giving size ranging from 26.50 to 85.10 nm as determined by Dynamic Light Scattering (DLS) instrument. The molecular weights have been also calculated from the DLS and are in the range 8.8 10(3) to 8.5 x 10(4) KDa (Kilo Daltons). Critical Micelle Concentrations (CMC) of the synthesized polymers was determined using electrical conductivity meter with values in the range 115 to 148 mgL(-1) (milligrams per litre).