Designing molecular weight distributions of arbitrary shape with selectable average molecular weight and dispersity

Abstract

While methods to control dispersity of a molecular weight distribution are slowly emerging, the question remains how any arbitrary distribution, and more precisely distribution shape, can be created in a polymer sample. Ultimately, if the aim is to create any shape form, then this can only be achieved by blending individual polymers. In here, we describe an approach to first generate molecular weight distributions of any shape with selectable average molecular weight and dispersity. With such software tool at hand, we discuss the influences of shape and dispersity on the residual structure. Molecular weight distributions are often less intuitive than anticipated, and effects can be complex. In the next step we show how these generated distributions are automatically fitted to interpolated RAFT polymer distributions, providing a detailed instruction which polymers need to be blended in which quantity in order to obtain the desired additive distribution. The software tools required for this task are demonstrated and discussed, and are made available to the reader for download.