Controlling Microstructure in Thermoplastic Polyurethane/Graphene Oxide Nanocomposites via Rigid Segment Length

Thermoplastic Polyurethane (TPU) is a commercially and academically interesting polymer with a wide range of applications. Engineering the micro-structure of the block-copolymers is of crucial importance for achieving desired mechanical properties. Incorporation of nanofillers such as graphene and graphene oxide platelets provides a means to control the phase separation for this material. Dissipative Particle Dynamics (DPD) are preformed to study the phase separation of systems with these nanofillers and determine how much difference functionality makes in a variety of TPUs with hard segments of different lengths. Platelet nanofillers act as a nucleating agent in TPUs with shorter hard segments, inducing local order; as the hard segment length becomes longer, the ordered local structures formed by hard segments break down. Functionalized nanofillers do not aid or hinder the nucleation in TPUs with short hard segments, but may enhance order in TPUs with moderately longer segment length, particularly with a hard segment to nanofiller length that is 1/3 the length of the nanofiller size.