Biography
Biography: Adina Anghelescu-Hakala
Abstract
Statement of the Problem: Biodegradable polymers are potential solutions to the environmental problems generated by plastic
waste. Every year, 8 million tons of new plastics are dumped into oceans. With growing market volumes of innovative bio-based
and biodegradable plastics such as Poly(Lactic Acid (PLA), the recycling of these materials is becoming a more viable option.
PLA has attracted particular attention as a substitute for conventional petroleum-based plastics. To increase sustainability
and management of plastic waste, new methods to close the recycling loop of PLA are needed. Recycling approaches have
limitations in that materials can only undergo a fi nite number of processing cycles before their properties are deteriorated.
Production of PLA from recycled components allows substantial energy savings compared to using virgin raw materials.
Methodology: PLA depolymerization by hydrolysis leads to production of high quality LA which can be used to reproduce
PLA polymers. Th is avoids the expensive and complex process of glucose fermentation, which is used to obtain virgin Lactic
Acid (LA). In this work, combined chemical and biochemical methods for PLA depolymerization to high value and quality
components are developed. Th e hydrolyzed PLA products were characterized by: (1) GC/MS: Evaluation of monomeric and
oligomeric content; (2) Chiral GC: Evaluation of D and L-LA enantiomers content; and (3) SEC: Calculation of molecular
weight and molecular weights distribution.
Findings: Th e PLA hydrolysis proceeds with higher rates in alkaline conditions with formation of LA monomer without
changes in the original composition of D, L isomers. Acidic hydrolysis of PLA produces a mixture of monomeric and oligomeric
forms and their composition depends on the reaction conditions.
Conclusion: By alkaline hydrolysis of PLA, LA monomer can be produced and repolymerized aft er conversion in acid form.
By hydrolysis of PLA in acidic conditions, oligomeric precursors suitable for further biochemical/enzymatic depolymerization
can be produced.