Grafted Block Copolymers: The Continuum Between 3-Arm Star and A-B-C Linear Triblock Copolymers


Rohit Gupta


Prof. Bryan Coughlin

Author Affiliation: 

Department of Polymer Science and Engineering, University of Massachusetts-Amherst


Multiblock copolymers with complex architectures o_er opportunities to create a diversity of ordered phases due to their greatly enlarged parameter space [1]. The studies on multiblock copolymer architectures are primarily limited to theoretical investigations of 3-arm star and A-B-C linear triblock copolymers [2]. A versatile synthetic strategy has been designed to synthesize a series of graft copolymers which lie along the unexplored continuum between 3-arm star and A-B-C linear triblock copolymers. The synthetic methodology includes the synthesis of block copolymer using living polymerization, followed by a single molecule insertion (SMI) which specifically inserts only once onto the polymer chain and provides the adequate functionality for eventual grafting the third polymer chain [3]. The SMI is followed by chain extension and finally the third polymer chain is grafted to the polymer backbone [4,5]. We had been investigating different chemistries which could satisfy the criteria for SMI in different polymer chains and will help in exploring the overall ternary phase diagram for these continuum block copolymers. The synthesized graft copolymers have been characterized using SAXS and TEM to study the effect of the variations in molecular architecture on the macromolecular self-assembly. The spontaneous self-assembly graft copolymers can be further investigated to produce highly ordered morphologies that could be utilized in a variety of applications.