Synthesis, Characterization, and Processing of an Acrylic Thermoplastic

A multi-faceted polymer chemistry learning experience is highlighted in this laboratory experiment, where students work in pairs to synthesize, purify, characterize, and process a polyacrylate. This synthesis is accomplished through a radical polymerization without the need for Schlenk flasks or other rigorous air-sensitive techniques. The target polymer in this lab, poly(butyl methacrylate), allows for the analysis of diverse proton NMR spectra. In addition, the long alkyl chain decreases the glass transition temperature of the resulting polymer, allowing for student exposure to polymer processing via an in-lab molding step. This experiment is designed for second-year undergraduate students, and critical concepts learned in organic chemistry, such as radical initiation, propagation, and termination, are reinforced. In addition, spectroscopic analyses such as 1H NMR splitting patterns, 1H NMR chemical shifts, and bond identification via IR are included. Furthermore, students are exposed to concepts that may not be covered in organic chemistry, such as polymer purification, characterization, and processing.