Polymers and Green Chemistry

Abstract

The purpose of this lab is to introduce students to some basics of the chemistry of polymers. Polymer chemistry is often an afterthought in the General Chemistry curriculum, but polymers are very much present in students’ lives. The lab introduces the relationship between molecular structure (e.g., branched vs. linear, bulky vs small side groups) and bulk properties (e.g., flexibility). This lab is also “pre-stoichiometry” in the sense that precursor ideas to stoichiometry are introduced without formal stoichiometric terminology. In one activity, the ratio of reacting alginate to calcium ions is varied to find the maximum yield of alginate gel. The lab introduces atom economy using addition and condensation polymers without formal stoichiometry. Students are likely to be at least a little familiar with recycling polymers before they even step into the lab. Building on this, using polymers as a lab topic provides an opportunity to bring Green Chemistry and Sustainability concepts into the lab course. Working with biologically-sourced, water-soluble starch or alginate polymers should be greener than working with polystyrene or nylon polymers which do not dissolve in pure water. The aforementioned atom economy example is also related to Green Chemistry principles. This document features contributions from Bozana Lojpur at Bradley University and Saskia van Bergen at the Washington State Department of Ecology.