Optimising Ductility of Poly(Lactic Acid)/Poly(Butylene Adipate-co-Terephthalate) Blends Through Co-continuous Phase Morphology

Abstract

This paper examines the effect of the melt viscosities of the two component polymers on the morphology and mechanical properties of a series of biodegradable polymer blends. Melt blended compounds of poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) are prepared and their melt viscosities, thermal properties, crystallinity, mechanical properties and phase morphology are investigated. From the relative melt viscosities of PLA and PBAT in the processing regime used in the study, it is possible to calculate the volume fraction at which a co-continuous phase structure is formed. The predicted value is 19 wt% of PBAT and this value is verified by the results of mechanical properties, where results for elongation-to-break show a dramatic rise from around 10% up to 300% in the composition range between 10 and 20 wt% of PBAT. The co-continuous phase structure is also validated by scanning electron microscopy. Graphical AbstractKeywords Poly(lactic acid) · Poly(butylene adipate-co-terephthalate) · Co-continuous phase · Biodegradable · Blends

Preparation and Characterization of Bio-Based PLA/PBAT and Cinnamon Essential Oil Polymer Fibers and Life-Cycle Assessment from Hydrolytic Degradation

“…The increase of elongation at break with the incorporation of PBAT into PLA blends, had been reported by some authors [36,42]. They have found that upon the addition of 20% PBAT to PLA/PBAT blends, there was an increase in the percentage of elongation at break of 26.6% [39] and 257% [33].…”

“…Related to the percentage of crystallinity, in Table 5, this percentage is approximately the same for all samples. For the homopolymers, PLA100 and PBAT100 had a similar percentage of crystallinity as demonstrated by other authors [36,71]. Samples for DSC were taken from the compressed plaques, which were previously subjected to a thermal process.…”

“…Then, the dispersed phase, which is the minority phase (PBAT), is distributed homogeneously through the matrix (PLA), maintaining some interfacial tension [35]. After cryogenic fracture, the disperse phase (PBAT) was observed in the form of spherical particles that leave some pores in the PLA matrix because of incompatibility between the two phases, which has been demonstrated in related papers of compatibility/miscibility in PLA/PBAT polymer blends [36,37].…”

Effect of empty fruit bunches microcrystalline cellulose (MCC) on the thermal, mechanical and morphological properties of biodegradable poly (lactic acid) (PLA) and polybutylene adipate terephthalate (PBAT) composites

“…Figure 3 (b) and 3 (c) indicate that the distance between particles is closer, thus will likely form co-continuous phase. The sample at the composition of 20/80 PBAT/PLA has a fine structure with the PBAT well dispersed in the PLA as also displayed by (Deng et al 2018). They have predicted that a co-continuous phase structure should be formed at a PBAT concentration of 19 wt%.…”

“…Besides, the distance between the particles also essential. (Deng et al 2018) has reported that when PBAT content less than 20 wt%, the PBAT disperses in PLA as droplets as can be seen in figure 3(a). However, when the PBAT content more than 20 wt%, PBAT and PLA form a co-continuous phase.…”