Furfuryl Alcohol and Lactic Acid Blends: Homo- or Co-Polymerization?

Sommerauer Sommerauer,Grzybek Grzybek,Petutschnigg Petutschnigg,Dachs Dachs,Sepperer Sepperer,Hüsing Hüsing,Tondi Tondi,Benisek Benisek,Elsaesser Elsaesser

doi:10.3390/polym11101533

Sommerauer Sommerauer, Grzybek Grzybek + Show 7 more

Open Access

https://doi.org/10.3390/polym11101533

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Abstract

Furfuryl alcohol (FA) and lactic acid (LA) are two of the most interesting biomolecules, easily obtainable from sugars and hence extremely attractive for green chemistry solutions. These substances undergo homopolymerization and they have been rarely considered for copolymerization. Typically, FA homopolymerizes exothermically in an acid environment producing inhomogeneous porous materials, but recent studies have shown that this reaction can be controlled and therefore we have implemented this process to trigger the copolymerization with LA. The mechanical tests have shown that the blend containing small amount of FA were rigid and the fracture showed patterns more similar to the one of neat polyfurfuryl alcohol (PFA). This LA-rich blend exhibited higher chloroform and water resistances, while thermal analyses (TG and DSC) also indicated a higher furanic character than expected. These observations suggested an intimate interconnection between precursors which was highlighted by the presence of a small band in the ester region of the solid state 13C–NMR, even if the FT-IR did not evidence any new signal. These studies show that these bioplastics are basically constituted of PLA and PFA homopolymers with some small portion of covalent bonds between the two moieties.

Highlights

Carbohydrates are the most abundant class of molecules produced by living processes
Five samples series covering furfuryl alcohol to lactic acid (F/L) ratios from 100:0, 75:25, 50:50, 25:75 and 0:100 (Table 1) were prepared and their physical and chemical properties were investigated in detail
The curing process of the five evaluated formulations showed that samples containing more furfuryl alcohol hardened in shorter time: After 24 h at 100 ◦ C

Summary

Introduction

Carbohydrates are the most abundant class of molecules produced by living processes. They are obtained directly and indirectly through photosynthesis and they are the most attractive compounds for replacing oil-based precursors [1]. Two of the most interesting molecules derived from carbohydrates are furfuryl alcohol (FA) and lactic acid (LA) because they can generate macromolecules through homo-polymerization to polyfurfuryl alcohol (PFA) and polylactic acid (PLA), respectively [2,3]. It is possible to polymerize FA in acid environment to polyfurfuryl alcohol (PFA) which is a thermosetting. Polyfurfuryl alcohol is typically produced through a highly exothermic, acid catalyzed polymerization reaction of furfuryl alcohol which is difficult to control and produces high porous inhomogeneous random structures [20,21]. A three-steps method to produce this polymer in a controlled manner was developed [22] and this breakthrough allows to consider FA as comonomer for new bio-materials [23,24]

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