Biodegradable polymer characterization laboratory unit

A current research area of significant environmental, economic, and scientific importance is biodegradable polymers. ^1-4 Biodegradable polymers is also an area that has great promise for being used to integrate life science into the chemical engineering curriculum. To this point, however, high quality laboratory manuals on biodegradable polymers have not been developed. Therefore, a laboratory unit titled "Biodegradable Polymer Characterization" has been developed. The laboratory unit provides a hands-on educational experience to students by exposing a variety of polymer samples (polyvinyl alcohols, polycaprolactones, polylactic acid) to simulated biomass environments and characterizing the samples against the exposure time. Independent variables that students can explore include biodegradation medium (slurry or soil), microorganism species and concentration, moisture content (for soil), temperature, pH, nutrient species and concentrations, polymer surface roughness, and polymer concentration. Analytical methods available include respirometry, melt index, gel-permeation chromatography, tensile strength, and thermogravimetric analysis. Students are able to study the relationship between polymer structure and biodegradation properties. They are challenged to use statistical methods to determine which polymer physical and chemical property measurements best correlate with biodegradability. Through this process, the students develop a vivid understanding of fundamental principles of polymer science, as well as the importance of societal and environmental issues with polymer materials design, manufacturing, and applications. Pedagogy that. has been demonstrated to be effective in improving student learning, e.g., cooperative learning, formative assessment and feedback, and reflective writing, is incorporated into the laboratory materials.