Mapping Composition Evolution through Synthesis, Purification, and Depolymerization of Random Heteropolymers.

Area of Science:

• Polymer Chemistry
• Materials Science
• Computational Chemistry

Background:

• Random heteropolymers (RHPs) with multiple comonomers are crucial for functional materials.
• Increasing monomer diversity expands sequence space, leading to heterogeneity.
• Current RHP design relies on composition and simulations, with limited understanding of sequence heterogeneity and experimental correlation.

Purpose of the Study:

• To quantitatively map monomer composition evolution in four-monomer RHPs through a full design-synthesis-purification-depolymerization cycle.
• To validate in silico analysis by comparing simulated RHP compositions with experimental results.
• To investigate RHP conformation distributions in various solvents using computational methods.

Main Methods:

• Quaternary methacrylate RAFT copolymerization experiments were conducted.
• The Jaacks method was employed to determine 12 reactivity ratios.
• High-throughput computation based on self-consistent field theory (SCFT) was used for conformation analysis.

Main Results:

• Reactivity ratios were determined, accounting for competitive monomer addition and reversible equilibria.
• In silico analysis showed quantitative agreement (<4% difference) with experimental RHP compositions.
• Conformation distributions were mapped as a function of monomer chemistry, composition, and solvent properties.

Conclusions:

• Accurate determination of reactivity ratios is essential for reliable RHP design.
• Monomer composition is a viable parameter for engineering functional RHPs.
• Ensuring the livingness of RHP synthesis is critical for successful material design.