Tailoring polymer dispersity by mixing ATRP initiators

Herein we present a simple batch method to control polymer dispersity using a mixture of two ATRP initiators with different reactivities. A wide dispersity spectrum (Đ ∼ 1.1–1.7) is achieved by altering the ratio between the two ATRP initiators while sustaining fairly monomodal molecular weight distributions. Depending on the targeted dispersity, a distinct kinetic profile was observed and, in contrast to previous ATRP approaches, near-quantitative conversions were obtained even for the highest dispersities. High end-group fidelity was also maintained in all cases as exemplified by chain extensions. Significantly, this method can be applied to various ATRP protocols as well as to various monomer classes.