Itaconate Based Novel Amphiphilic Polymer Architectures

Abstract

Amphiphiles are natural or synthetic molecules consisting of hydrophilic polar head group and hydrophobic non-polar hydrocarbon tail. Beyond a certain concentration, known as critical micellar concentration (CMC), amphiphilic molecules can self-assemble into a large variety of morphologies, such as spherical micelles, cylindrical micelles, reverse micelles, vesicles, lamellae etc.1 The idea of self-assembly is not limited to small molecule amphiphiles, but it can also be extended to the macromolecular amphiphiles often referred to as amphiphilic polymers, wherein both hydrophilic and hydrophobic segments are typically polymeric in nature. There is another type of amphiphile carrying a polymerizable unit at the junction of the immiscible segments, the polymerization of which results in the formation of amphiphilic brush type of polymers. In this context, I have utilized a biosourced starting material namely, itaconic acid to prepare several types of polymerizable amphiphiles, which upon polymerization leads to the formation of amphiphilic brush polymers with different architectures. In my presentation, I will discuss about few of those architecturally different amphiphilic brush polymers based on itaconate. First, I will talk about the crystallization induced gelation in amphiphilic double-brush polymers, where we show that the gel-sol transition temperature as well as mechanical properties can be easily tuned by varying the length of the hydrocarbon side chain from C12 to C18.2 Finally, as these gels are biocompatible, we have shown that insulin can be encapsulated within the hydrogel and can be released in sustained manner for diabatic treatment. In my second chapter, I will talk about core-shell type of amphiphilic brush polymers, wherein, I will discuss about the bulk properties of two types of core-shell type of polymers; in one case the hydrophilic segments at the core and hydrophilic segments at the shell, in another case the amphiphilicity is reversed. In chapter 3, I will present multiple attempts to generate 2 dimensionally crosslinked polymer nanosheet structures based on itaconate followed by investigation of their thermal as well as morphological properties. In the final chapter, I will talk about a different class of amphiphilic polymers with multiblock architecture carrying a diacetylene unit at the middle of the hydrophobic alkyl segment and explored the possibility of topochemical polymerization of the diacetylene within a single folded polymer chain with limited success.