The innovation engine for new materials

Nicholas Moreno

Nicholas Moreno

Major: 

Chemistry

University: 

Haverford College

Mentor(s): 

Frank Leibfarth

Faculty Sponsor(s): 

Professor Craig Hawker

Faculty Sponsor's Department(s): 

Materials

Project Title: 

ORGANOCATALYTIC RECYCLING OF POLYLACTIDE: DETERMINING THE KINETICS AND SCOPE OF DEPOLYMERIZATION

Project Description: 

As domestic demand for petroleum increases, shifting away from it as a source of fuel and raw chemicals is becoming a necessity. Recycling materials is important to alleviate our fossil fuel dependence and move towards a more sustainable economy. Our work describes a novel organocatalytic route to recycle commodity polyesters. Polyesters are depolymerized using the powerful transesterification catalyst 1,5,7-Triazabicyclo[4.4.0]dec-5-ene in the presence of various alcohols. Monitoring the depolymerization through time, and correlating reaction rate to the alcohol’s structure allows a comprehensive understanding of the scope and limitations of this chemistry. Initial results indicate that primary alcohols cause depolymeriaztion in under 2 minutes, secondary alcohols take more than 30 minutes, and tertiary alcohols exhibit no breakdown, suggesting that sterics play an important role in these kinetics. Additionally, secondary alcohols cause an exponential decay in polymer chain length with respect to time, allowing us to extrapolate our data and calculate the reaction constant, K. Following depolymerization, we hope to employ the resultant esters in the production of novel, useful materials. Recycling polyesters provides innumerable opportunities to reduce our reliance on fossil fuels as a chief source of energy and raw materials.