In the realm of polymeric materials, polylactic acid (PLA) is considered one of the most sustainable materials capable of replacing fossil-based polymers, as it is a degradable aliphatic polyester derived from renewable resources such as corn. [1,2] However, there are some drawbacks: first, commercial isotactic PLA may take decades to fully degrade on land, [3] and its unrestricted production from corn competes with essential food resources. As other thermoplastic polymers, PLA can undergo mechanical recycling by melting and reshaping. However, this process deteriorates its chemical and mechanical properties. To tackle these issues, researchers have started investigating chemical recycling methods for PLA. [4,5] On these premises, this work presents a novel method for PLA chemical recycling consisting in the degradation and functionalization of post-consumer PLA waste. Our goal is to produce PLA based oligomers containing unsaturations, which can serve as building blocks for the subsequent synthesis of crosslinked materials with potential applications in different fields. One-pot reactions involving PLA waste (company ARISTEA, with Mn: 51000 g/mol and Đ: 1.9), maleic anhydride (MA) and different diols (HO-R-OH: ethylene glycol or 1,4-benzenedimethanol) were conducted under neat conditions, at 170 °C and using titanium isopropoxide as catalyst. Gel Permeation Cromatography (GPC) measurements showed the reduction in molecular weight over time: by varying the amounts of the reactants, unsaturated oligomers, with molecular weights spanning from 700 to 4000 Da, were obtained. The structure of the obtained oligomers was confirmed using ¹H NMR and DOSY NMR spectroscopy. Subsequently, they were used for the preparation of polymeric networks through the use of suitable crosslinkers (e.g. divinylbenzene) and radical initiators, with the aim to obtain novel thermoset materials with specific porosity, which could have application in advanced fields, i.e. gas storage.
New strategy for the upcycling of polylactic acid waste to novel thermosets
Nancy Ferrentino;Federica Santulli;Marina Lamberti;Mina Mazzeo;
2025
Abstract
In the realm of polymeric materials, polylactic acid (PLA) is considered one of the most sustainable materials capable of replacing fossil-based polymers, as it is a degradable aliphatic polyester derived from renewable resources such as corn. [1,2] However, there are some drawbacks: first, commercial isotactic PLA may take decades to fully degrade on land, [3] and its unrestricted production from corn competes with essential food resources. As other thermoplastic polymers, PLA can undergo mechanical recycling by melting and reshaping. However, this process deteriorates its chemical and mechanical properties. To tackle these issues, researchers have started investigating chemical recycling methods for PLA. [4,5] On these premises, this work presents a novel method for PLA chemical recycling consisting in the degradation and functionalization of post-consumer PLA waste. Our goal is to produce PLA based oligomers containing unsaturations, which can serve as building blocks for the subsequent synthesis of crosslinked materials with potential applications in different fields. One-pot reactions involving PLA waste (company ARISTEA, with Mn: 51000 g/mol and Đ: 1.9), maleic anhydride (MA) and different diols (HO-R-OH: ethylene glycol or 1,4-benzenedimethanol) were conducted under neat conditions, at 170 °C and using titanium isopropoxide as catalyst. Gel Permeation Cromatography (GPC) measurements showed the reduction in molecular weight over time: by varying the amounts of the reactants, unsaturated oligomers, with molecular weights spanning from 700 to 4000 Da, were obtained. The structure of the obtained oligomers was confirmed using ¹H NMR and DOSY NMR spectroscopy. Subsequently, they were used for the preparation of polymeric networks through the use of suitable crosslinkers (e.g. divinylbenzene) and radical initiators, with the aim to obtain novel thermoset materials with specific porosity, which could have application in advanced fields, i.e. gas storage.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
