Amphiphilic Double-Brush Polymers Based on Itaconate Diesters

Itaconic anhydride, a biosourced molecule, was readily transformed to polymerizable nonionic amphiphiles of the type R-Ita-R'; these amphiphiles carry an exo-chain double bond, which upon polymerization yielded amphiphilic double-brush polymers, especially when R and R' are immiscible, and consequently exhibit a tendency to self-segregate. DSC, WAXS, SAXS, and variable temperature FT-IR studies of these amphiphilic double-brush polymers confirm the occurrence of self-segregation followed by crystallization of the cetyl segments; in most cases a lamellar morphology is seen wherein the two immiscible segments form the alternating lamellae and the polymer backbone presumably lie along their interface. C16-Ita-HEG, which carries a hydrophobic cetyl chain and a hydrophilic heptaethylene glycol monomethyl ether unit, forms a hydrogel upon polymerization at concentrations above 2.5 wt %; an interesting feature of this hydrogel is that it exhibits a reversible thermal and shear-induced transformation to a sol, a property that could be of interest for biomedical applications.