RT Journal Article
T1 Effect of different mechanical recycling processes on the hydrolytic degradation of poly(l-lactic acid)
A1 Beltrán González, Freddys
A1 Lorenzo Esteban, Vicente
A1 Orden Hernández, María Ulagares De La
A1 Martínez Urreaga, Joaquín
AB The growing production of poly(lactic acid) (PLA) has increased the interest for the mechanical recycling of this polymer. The main objective of this work is to study the effect of different mechanical recycling processes on the hydrolytic degradation of PLA. A commercial grade of PLA was subjected to two different recycling processes, one of them comprising an accelerated thermal and photochemical aging and a second melt compounding and compression molding step, and other including a demanding washing step after the accelerated aging process. The accelerated aging and, especially, the washing step had a significant effect on degradation during recycling. Samples of virgin and recycled plastic immersed in a phosphate buffered solution at 37 or 58 °C were removed at selected times and then characterized by gravimetric analysis, IR and UV spectroscopy, thermal analysis, x-ray diffraction and microhardness and viscosity measurements. The water absorption process, at both temperatures, can be modeled using a Fickian model only when the immersion times were short. The different recycling processes caused an increase of the diffusion coefficient of PLA at 37 °C, while at 58 °C the differences were smaller. DSC results pointed out that mechanical recycling promotes a slight crystallization of PLA at 37 °C that explains the increasing of the hardness during the hydrolysis.
PB Elsevier Ltd.
SN 0141-3910
YR 2016
FD 2016-11
LK https://hdl.handle.net/20.500.14352/17888
UL https://hdl.handle.net/20.500.14352/17888
LA eng
NO Received 28 June 2016, Revised 12 September 2016, Accepted 17 September 2016, Available online 19 September 2016.
NO Ministerio de Economía y Competitividad (MINECO)
NO Universidad Politécnica de Madrid
NO Ecoembes
DS Docta Complutense
RD 10 abr 2025