Blending PLA with Polyesters Based on 2,5-Furan Dicarboxylic Acid: Evaluation of Physicochemical and Nanomechanical Properties

Abstract

Poly(lactic acid) (PLA) is a readily available, compostable biobased polyester with high strength and toughness, and it is excellent for 3D printing applications. Polymer blending is an economic and easy way to improve its properties, such as its slow degradation and crystallization rates and its small elongation, and thus, make it more versatile. In this work, the effects of different 2,5-furan dicarboxylic acid (FDCA)-based polyesters on the physicochemical and mechanical properties of PLA were studied. Poly(butylene furan 2,5-dicarboxylate) (PBF) and its copolymers with poly(butylene adipate) (PBAd) were synthesized in various comonomer ratios and were blended with 70 wt% PLA using melt compounding. The thermal, morphological and mechanical properties of the blends are investigated. All blends were immiscible, and the presence of the dispersed phases improved the crystallization ability of PLA. Mechanical testing revealed the plasticization of PLA after blending, and a small but measurable mass loss after burying in soil for 7 months. Reactive blending was evaluated as a compatibilizer-free method to improve miscibility, and it was found that when the thermal stability of the blend components allowed it, some transesterification reactions occurred between the PLA matrix and the FDCA-based dispersed phase after 20 min at 250 °C.

Toughening Effect of 2,5-Furandicaboxylate Polyesters on Polylactide-Based Renewable Fibers

“…For all three polymers, the T g in the second heating scan is approximately 10 • C lower than that measured in the first scan, because the first heating/cooling cycle erases the aging phenomena responsible for the T g increase observed on the as-received materials. The T g values measured on the three polyesters are in line with literature data [30,51,52], and in particular, it is interesting to note that, for the two furanoate polyesters, the slight lengthening of the alkyl subunit causes a remarkable decrease in T g for PBF compared to PPF (40.7 • C vs. 51.6 • C in H2) [53]. In both cases, though, the T g is lower than that of neat PLA (60.5 • C in H2).…”

“…For all three polymers, the Tg in the second heating scan is approximately 10 °C lower than that measured in the first scan, because the first heating/cooling cycle erases the aging phenomena responsible for the Tg increase observed on the as-received materials. The Tg values measured on the three polyesters are in line with literature data [30,51,52], and in particular, it is interesting to note that, for the two furano- The neat, as-received polymers present the traditional thermal profile of semicrystalline materials, with glass transition between 40 and 70 • C and melting/crystallization between 100 and 200 • C (Table 3). For all three polymers, the T g in the second heating scan is approximately 10 • C lower than that measured in the first scan, because the first heating/cooling cycle erases the aging phenomena responsible for the T g increase observed on the as-received materials.…”

“…The most widely investigated blend is PLA/poly(butylene 2,5-furandicarboxylate) (PBF), reported as immiscible but with promising mechanical properties if the weight fraction of PBF is kept low (under 5 wt%) [ 28 , 29 ]. More recently, Terzopoulou et al [ 30 ] synthesized a copolyester of PBF with poly(butylene adipate) (PBF-co-PBAd) and investigated its effectiveness as a compatibilizer for the PLA/PBF blends. A similar copolyester was instead used as the only additive by Wang et al [ 31 ], who reported an increase in the strain at break from 5.7% of neat PLA to 222% of the blend containing 30 wt% of PBF-co-PBAd.…”

Modifications of Poly(lactic Acid) with Blends and Plasticization for Tenacity and Toughness Improvement

“…Many studies have recently been done on PLA rubber/elastomer blends to change the characteristics of PLA for numerous technical applications that need demanding applications [9,15,27,[94][95][96][97][98][99]. As for FDM 3D printing, PLA and NR were mixed with increasing toughness and investigated by Fekete et al [100].…”

Toughness enhancement of polylactide with low amounts of poly (butylene adipate‐co‐terephthalate) through in situ reactive compatibilization

“…With improved compatibility, it is expected that the toughness of PLA can be significantly improved without sacrifices the high stiffness and strength of PLA. Therefore, different stratagems, such as addition of a third phase of copolymers 19 or poly (methyl methacrylate) (PMMA), 20 in situ reactive extrusion with small molecules, 21,22 chain‐end engineering, 23,24 core‐shell toughening, 25 and constructing an integrative physical network 26 have been adopted to fabricate PLA blends with balanced properties. For example, Wu et al used ethylene‐methyl acrylate‐glycidyl methacrylate copolymer (EMA‐GMA) improved the compatibility between PLA and PBAT, resulting in the improved IS of the blends 27 .…”