Making Polylactide Tougher: The Promise of Furan Polyesters

#Polylactide (PLA) has emerged as a promising #bioplastic derived from renewable resources like corn starch or sugar cane. PLA can be processed using conventional plastic equipment, is commercially produced at scale, and has found uses in 3D printing, food packaging, medical implants and more.

However, PLA's intrinsic brittleness and low toughness limit its potential in many applications. As polymer engineers focused on bio-based materials, our research group has been investigating methods to improve PLA's mechanical performance while retaining its #sustainability benefits.

Blending with Furan Polyesters - A Fully Renewable Approach

Blending PLA with other polymers is a common route to improve toughness. But many traditional polymers are petroleum-based, negating PLA's green advantages. Our recent research targeted a novel class of renewable polymers, i.e., the aliphatic furanoate polyesters, as PLA toughening agents.

Furan polyesters like poly(propylene 2,5-furandicarboxylate) (#PPF) and poly(butylene 2,5-furandicarboxylate) (#PBF) are derived from 2,5-furandicarboxylic acid, itself obtained from agricultural waste. PBF has similar properties to petroleum-based polyethylene terephthalate (PET), but is 100% bioderived. Early results blending PBF with PLA showed promise, but poor interfacial adhesion between the polymer phases limited improvements.

Optimizing Interface and Reaping Mechanical Benefits

In our recent work, we used a compatibilizing agent to enhance adhesion between PLA and PPF or PBF domains. Optimized blend compositions exhibited yield behavior and extensive plastic deformation resulting in >900% higher strain at break compared to neat PLA, while retaining stiffness. These remarkable enhancements were achieved using just 5-10% PBF by weight.

We also melt spun these blends into fibers. The additional processing step further improved blend homogeneity, interfacial adhesion, and mechanical performance. Certain blend compositions exhibited exceptional toughness, with 50 times higher strain at break than neat PLA fibers.

Pathway to Greener High-Performance Materials

This research demonstrates a pathway to significantly boost PLA's toughness for single-use textiles, composites, flexible packaging and other applications where high stiffness, strength and ductility are critical. The fully #bioderived blends ensure PLA retains its sustainability edge versus traditional oil-based polymers.

We are now investigating the biodegradability of the prepared blends, to ensure that the preparation of these blends do not diminish the compostability and biodegradability of PLA.

The full results of this research are published open access in an article co-authored by Edoardo Zonta , Alessandro Dussin , Dimitrios Bikiaris , George Papageorgiou , Luca Fambri , Andrea Dorigato and myself: https://doi.org/10.3390/molecules28124811

I invite materials scientists, polymer engineers and industry professionals interested in high-performance bioplastics to connect with me to learn more about this work and start fruitful collaborations!