Deconstructing Oligomer Distributions: Discrete Species and Artificial Distributions

Abstract

The separation of an oligo(methyl acrylate) distribution, obtained from reversible addition-fragmentation chain transfer (RAFT) polymerization, in ad iscrete (dispersity = 1) oligomeric library (degree of polymerization between 1a nd 22) is presented. The properties of this library in terms of diffusivity,g lass transition temperature,a nd viscosity are determined, filling as ignificant knowledge gap associated with these materials.T he obtained oligomer library is used to construct artificial oligomer distributions on demand. These artificial oligomer distributions are used to highlight the potential to tailor physical properties of am aterial, while concomitantly demonstrating the limitations associated with size-exclusion chromatography analysis of molecular weight and dispersity in particular.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Effects of crystallinity and dispersity on the self-assembly behavior of block co-oligomers in water

“…[13][14][15][16][17][18] or by combining controlled polymerization techniques with flash chromatography. [19][20][21] In addition, discrete block co-oligomers (BCOs) have been prepared by these methods, affording systems that at low molecular weights form highly-ordered, phase-segregated structures in bulk. [22][23][24][25][26][27] The introduction of dispersity in these low molecular weight BCOs has a dramatic effect on the nanophase separation and long range ordering.…”

Precise modulation of molecular weight distribution for structural engineering

“…The second approach is to blend samples with different average molecular weights. [28][29][30] Although this method is relatively simple and straightforward, the resultant blends suffer from complex compositions such as multimodal distributions, due to the intrinsic chain length heterogeneity of the blending stocks.…”

Online tracing of molecular weight evolution during radical polymerization via high-resolution FlowNMR spectroscopy

“…3 the combined data in conjunction with literature data on discrete RAFT-made oligo (methyl acrylates) are shown. 36 Both datasets fit nicely demonstrating the high accuracy of the DOSY method again. Since the literature data represent discrete oligomers they are essentially error-free in molecular weight determination, and hence confirm the accuracy of the MALS measurements of our data.…”

“…Diffusion coefficients as a function of weight-average molecular weight as benchmarked by SEC-MALS for MA RAFT polymerizations with varying target degree of polymerization (left) and linearized data with best fit to the data in conjunction with data from discrete RAFT MA oligomers from De Neve et al36 …”