Theses and Dissertations
Issuing Body
Mississippi State University
Advisor
Walters, B. Keisha
Committee Member
Elmore, Bill
Committee Member
Toghiani, Hossein
Committee Member
Schneider, Judy
Committee Member
Schulz, H. Kirk
Other Advisors or Committee Members
Hill, J. Priscilla
Date of Degree
5-1-2010
Document Type
Dissertation - Open Access
Major
Chemical Engineering
Degree Name
Doctor of Philosophy (Ph.D)
College
James Worth Bagley College of Engineering
Department
Dave C. Swalm School of Chemical Engineering
Abstract
Renewable polymers (bioplastics) offer an alternative to petroleum-based polymers and reduced environmental impact through decreased petroleum dependence and a sustainable product lifecycle via renewable, biomass-derived monomers and completely degradable polymers. Applying green chemistry principles, melt polycondensations of 1,3-propanediol with malonic acid and 1,3-propanediol with itaconic acid were performed to produce poly(trimethylene malonte) (PTM) and poly(trimethylene itaconate) (PTI), respectively. Aluminum chloride was used as the catalyst and reaction temperatures from 125-175 °C and reaction times from 2-32 h were attempted in order to produce high yields and molecular weights (Mw). Gravimetric yields ranged from 20-95 wt.% for PTM and 20-85 wt.% for PTI. Both PTM and PTI contained ester and ether backbone bonds, as determined by Fourier transform infrared and nuclear magnetic resonance spectroscopy. Gel permeation chromatography showed both PTM and PTI to have a bi-modal Mw distributions centered at 1.4±0.1 kDa and 35±3 kDa for PTM and 1.0±0.1 kDa and 38±2 kDa for PTI. For PTM, a Tg of -64 °C and a Tm of 29 °C was identified using differential scanning calorimetry (DSC). A crystallization temperature for PTI was found at ~160 °C using DSC. A hydrolytic degradation study was performed at 25 °C on PTM and PTI in pH 5.4, 7, 9, and 11 aqueous solutions for up to 4 weeks. The introduction of K+ ions (in the KOH aq. solutions) interfered with the AAC2 and AAL1 ester hydrolysis mechanisms through acid-base interactions. PTM was found to be susceptible to hydrolytic degradation and lost ~37 wt.% through ester hydrolysis and showed a molecular weight reduction of ~0.8 kDa over 10,000 min for a pH range of 7 to 11. PTI was also found to be susceptible to hydrolytic degradation with ~22 wt.% decrease through ester hydrolysis and molecular weight reduction of ~0.25 kDa over 10,000 min for a pH range of 7 to 11. PTM is a low molecular weight, saturated, linear copolymer and PTI is a low molecular weight, unsaturated, branched copolymer. Both PTM and PTI are renewable copolymers produced using green chemistry and mild reactions conditions and were found to be susceptible to hydrolytic degradation.
URI
https://hdl.handle.net/11668/15113
Recommended Citation
Rowe, Mathew Dennis, "Development of renewable and hydrolytically degradable polymers from biomass-based monomers" (2010). Theses and Dissertations. 1473.
https://scholarsjunction.msstate.edu/td/1473