The energetic valorization process of bio-based polymers is addressed in this study, taking polylactide (PLA) as model. The pyrolysis of virgin and multiple-injected PLA was simulated by means of multi-rate linear-non-isothermal thermogravimetric experiments. A complete methodology, involving control of gases, thermal stability and thermal decomposition kinetics was proposed. The release of gases was monitored by Evolved Gas Analysis of the fumes of pyrolysis, by in-line FT-IR, with the aid of 2D-correlation IR characterization. A novel model to establish the thermal stability of PLAs under any linear heating profile was proposed. A kinetic strategy was methodically applied to assess the thermal decomposition in terms of activation energy and kinetic model. It was found that the pyrolysis technologies for virgin PLA could be straightforwardly transferred for the valorization of its recyclates.
Bibliographical noteThe authors would like to acknowledge the Spanish Ministry of Science and Innovation for the financial support through the Research Projects ENE2007-67584-C03, UPOVCE-3E-013, ENE2011-28735-C02-01, IT-2009-0074, as well as for the pre-doctoral research position for L. Santonja-Blasco through the FPI program. The Spanish Ministry for Education is acknowledged for the concession of a pre-doctoral research position to J.D. Badia and A. Martinez-Felipe by means of the FPU program. The authors thank the financial support of the Generalitat Valenciana through the ACOMP/2011/189, the Grisolia research position for A. Martínez-Felipe, and for the Forteza technician position for J.D. Badia. Universitat Politècnica de València (UPV, Spain) is thanked for additional support through the PAID 05-09-4331 and PAID 06-11-2037 projects. AIMPLAS is acknowledged for providing and processing the material. This paper is warmly dedicated to Gael Badia-Ombuena, in commemoration of his birth.
- Polylactide (PLA)
- Thermal decomposition kinetics
- Evolved Gas Analysis (EGA)