Bridging Reaction Engineering and Polymers Design: Solvent Effects in Continuous Flow Copolymerization

Authors

• Leila Ba, University of Nebraska-LincolnFollow

First Advisor

Mona Bavarian

Committee Members

Siamak Nejati, Bill Velander, Yasar Demirel

Date of this Version

5-2026

Document Type

Thesis

Citation

A thesis presented by the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science

Major: Chemical Engineering

Under the supervision of Professor Mona Bavarian

Lincoln, Nebraska, May 2026

Comments

Copyright 2026, Leila Ba. Used by permission

Abstract

Poly(glycidyl methacrylate-co-methyl methacrylate) [poly(GMA-co-MMA)] is a promising functional copolymer for photoresist applications due to its reactive epoxy groups and tunable physicochemical properties. This thesis is focused on this polymer and integrates theoretical solubility prediction, thermodynamic modeling, and continuous-flow synthesis to establish quantitative structure–process–property relationships for their use in microelectronic-grade solvents.

Solubility behavior in dimethyl sulfoxide (DMSO), propylene glycol monomethyl ether (PGME), and propylene glycol monomethyl ether acetate (PGMEA) was investigated using the Hildebrand and Hansen models, Hoy group-contribution method, Polymer Genome machine-learning platform, and Flory–Huggins thermodynamic analysis of Gibbs free energy of mixing. Experimental saturation solubility measurements at 25 °C confirmed apparent saturation at ≈ 0.3 g cm^-3 in DMSO and PGMEA. Flory–Huggins [delta]G_m values aligned well with experiment for good solvents but highlighted the concentration dependence and specific interaction limitations of the models for PGME.

Copolymers were synthesized in a Vapourtec tubular microreactor via free-radical copolymerization, and through systematically varying temperature (75–120 °C), monomer feed ratio, and residence time (5–80 min) in DMSO and PGMEA. ¹H NMR provided composition and conversion; GPC yielded M_w, dispersity (PDI), and degree of polymerization (DP_n) The use of DMSO resulted in higher molecular weight polymers compared to PGMEA under identical conditions, consistent with solvent effects on radical polymerization kinetics and chain transfer behavior. Temperature and feed ratio enabled independent tuning of composition and chain length, with narrow dispersity (PDI = 1.2 - 2.3) across all condition, indicating improved control compared to conventional batch processing.

This work demonstrates that continuous-flow synthesis, combined with multi-model solubility prediction and experimental validation, enables reproducible control over key polymer quality attributes. The established solvent–process–property relationships provide practical guidelines for tailoring poly(GMA-co-MMA) molecular weight, composition, and rheological behavior, advancing the scalable production of high-performance materials for advanced microelectronics and lithographic applications.

Advisor: Mona Bavarian