Synthesis of L-lactid dimer via reactive distillation and synthesis and Processing of Poly (L-lactic acid) (PLLA) proposal linked to the thematic project: 2015/20630-4

• Grant number: 21/05719-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Effective date (Start): July 01, 2021
• Effective date (End): March 31, 2023
• Field of knowledge: Engineering - Chemical Engineering - Chemical Technology
• Principal Investigator: Rubens Maciel Filho
• Grantee: Sara Crivellin
• Host Institution: Faculdade de Engenharia Química (FEQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 15/20630-4 - Biorefinery development integrated to a bioethanol sugar cane plant with zero CO2 emission: routes to convert renewable resources to bio-products and bio-electricity, AP.TEM

Abstract

This proposal aims the production of L-lactide dimers (LLT), derived from L-lactic acid (LLA), in a one-step process via reactive distillation for the synthesis of high molar mass Poly(L-lactic acid) (PLLA) by Ring-Opening Polymerization (ROP), and the processing of PLLA by electrospinning. Assessing the world scenario, it has been observed a large number of publications referring both to the production of lactic acid (LA) and its isomers, such as LLA, and the synthesis of poly(lactic acid) (PLA) and derivatives (PLLA, PDLA, PLDLA), and little has been demonstrated about the synthesis of the cyclic dimer, lactide (LT). In recent years the great potential that polymers synthesized under favorable conditions have in terms of biodegradability, biocompatibility, and, in some cases, reabsorption, has also been widely publicized. Among these, PLLA is known to be efficient and used in several areas, from packaging production to medical applications, and also in 3D printing (additive manufacturing). The absence of available materials on the synthesis of LT leaves a gap that allows the evaluation of different technologies to obtain this product. In this sense, the proposal of this project has as a starting point to develop a strategy to obtain LLT using reactive distillation, integrating the synthesis reaction of LLT and its separation in a one-step and continuous. To this end, the reaction kinetics, phase equilibrium, and the influence of thermodynamic properties will be evaluated to reach an adequate process design. The LLT obtained will be used for the polymerization of PLLA and further processing by electrospinning to produce polymeric membranes. The obtained materials will be characterized by Gas Chromatography coupled to Mass Spectrometry (GC-MS), Gel Permeation Chromatography (GPC), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Raman spectroscopy (FT-Raman) and Scanning Electron Microscopy (SEM). As a result, it is expected to present a viable route of production of LT in a one-step aiming to increase the productivity of the process, the selectivity for the product of interest, and the optimization of the synthesis process of this product, completing the route of polymerization and processing of PLLA to validate the quality of the product obtained. (AU)