The Efficiency of poly(lactic acid) Butanolysis
Category: Research Poster
Author(s): Lucas Toth
Presenter(s): Lucas Toth
Mentors(s): Claudia Boot, Nhat Minh Tu Nguyen
Butanolysis is a commonly used analytical technique designed to quantify the ester-containing polymers in a sample. The polymer undergoes acid-catalyzed butanolysis, breaking down into shorter chains and forming butyl esters. The resulting monomers are quantified using gas chromatography in line with mass spectrometry (GC-MS). In applying butanolysis for biologically produced esters in the polyhydroxyalkanoate class (PHA)s, there is uncertainty about the efficiency of the transformation and if final product is comparable to polymer concentrations in the biological matrix. This study serves to determine the efficiency of conversion of a type of PHA, polylactic acid (PLA), to butyl lactate using butanolysis-GC-MS with two forms of 4060D PLA. By doing so, the results obtained by the procedure can be referenced with increased accuracy in regard to the true PLA output from biological sources. The PLA is combined with n-butanol in an acidic environment with benzoic acid as an internal standard in an autoclave at elevated temperatures, esterifying the PLA to butyl lactate. Then, acid is removed from the butanol solution with a water wash before the sample of PLA is injected into the GC-MS for Skyline butyl lactate quantification. This process produces an average yield of 71.11% ± 6.52 of the samples from expected concentrations. These results indicate that the initial polymers don’t entirely break or that there may be monomer loss during esterification.