POS1-0487
Separation and Quantification of Living Chains in Photoiniferter RAFT Block Copolymers via Solvent-Gradient HPLC
When and Where
Nov 30, -0001
12:00am - 12:00am
Presenter(s)
Sungmin Choi (Pusan National University)
Co-Author(s)
Abstract
Dead chains formed during chain extension impose an intrinsic ceiling on block copolymer purity; however, they are neither readily quantified nor removed. Poly(benzyl acrylate) and its one-pot block copolymer with tert-butyl acrylate were prepared via visible-light photoiniferter RAFT polymerization using an α,ω-dihydroxyl trithiocarbonate. The two hydroxyl termini render the living chains significantly more polar than the mono-hydroxyl dead chains generated through disproportionation. Solvent-gradient HPLC (SG-HPLC) on bare silica effectively resolves these two populations based solely on their polarity differences, without requiring any post-polymerization end-group modification. The living chains account for ~96% of the total population. MALDI-TOF MS analysis of the isolated living chain fractions reveals Poisson-type distributions (Đ = 1.029 for the block copolymer), consistent with the theoretical limit (Đ = 1 + 1/DP). SG-HPLC thus enables both quantification of the degree of livingness and isolation of living chains with near-ideal chain-end fidelity.
