Revisiting a Green Polymerization of Aspartic Acid for a Second-Semester Introductory Organic Chemistry Laboratory

As polymeric materials continue to play a pivotal role in modern society, it is imperative that chemists entering the workforce are properly trained in the fundamentals of the science. Chemistry curricula across the country are rapidly changing to provide better polymer instruction to satisfy this demand for both industry and academia. To help facilitate this, new course work and labs need to be vetted and interwoven into the curriculum. Here is described the implementation of a two-step, green synthesis of sodium poly(aspartate) (PAA) into a second-year organic chemistry laboratory course that interweaves polymer chemistry concepts with traditional organic chemistry–carboxylic acid derivative reactivity, understanding acyl substitution reactions and mechanisms, interpreting IR and 1H NMR data, and calculating percent yield. These objectives also delve into the fundamental principles of Le Chatelier’s principle, stoichiometry and solubility. This experiment provides modifications to existing literature protocols to improve safety, learning outcomes, and product purity. The protocol has been performed successfully over several semesters in multiple sections of a second-semester organic chemistry laboratory.