Thermal, Mechanical and Micromechanical Analysis of PLA/PBAT/POE-g-GMA Extruded Ternary Blends

Abstract

In order to toughen Poly(lactic) acid and binary blends with low PBAT content while maintaining a high biodegradability of the final material, poly(lactic) acid (PLA)/poly(butylene-adipate-co-terephthalate) (PBAT)/ polyolefin elastomer grafted with glycidyl methacrylate (POE-g-GMA) extruded ternary blends have been investigated in this work from a thermal, mechanical, and rheological point of view. The two elastomers have been added in different amounts as dispersed phases into the PLA matrix, paying attention to the final objective: the design of a 90% biodegradable formulation according to EN 13432. These ternary blends exhibited improved impact properties but still low elongation at break. Consequently, to the ternary composition with the best compromise of PLA quantity, biodegradability and thermo-mechanical properties (81 wt.% PLA, 9 wt.% PBAT, and 10 wt.% POE-g-GMA) a small quantity (10 wt.%) of a biobased plasticizer was added in order to further increase the impact properties in parallel with the tensile flexibility. Two types of plasticizers were investigated, one not reactive [Acetyl Tributyl Citrate (ATBC)], and one reactive [Glycidyl ether (EJ-400)]. A micromechanical study, in order to investigate the toughening mechanism of these systems, was carried out on the final formulations. They were also examined by dilatometric tests and elastoplastic fracture mechanics correlating the data obtained to the morphology and to the rheological properties. In conclusion, the best compromise between impact, tensile properties and biodegradability content was achieved using the reactive plasticizer (EJ-400) whose interaction with the matrix is confirmed by the FT-IR analysis.

Poly(lactic acid) (PLA)/Poly(butylene succinate-co-adipate) (PBSA) Compatibilized Binary Biobased Blends: Melt Fluidity, Morphological, Thermo-Mechanical and Micromechanical Analysis

“…The volume strain was calculated, assuming equal the two lateral strain components, according to the following Equation [ 60 , 61 , 62 ]: where the volume variation is Δ V , the starting volume is V 0 , ε 1 is the axial (or longitudinal) strain and ε 2 is the lateral strain.…”

Sustainable Micro and Nano Additives for Controlling the Migration of a Biobased Plasticizer from PLA-Based Flexible Films

“…The crystallinity percentage (Xcc) of PLA in the blends was calculated as [ 50 ] where Δ H m,PLA and Δ H c,PLA are the melting enthalpy and the enthalpy of cold crystallization of PLA, X PLA is the weight fraction of PLA in the sample and Δ H° m,PLA is the melting enthalpy of the 100% crystalline PLA, equal to 93 J/g [ 51 ].…”

Fracture behavior and mechanical, thermal, and rheological properties of biodegradable films extruded by flat die and calender

“…For example, acetyltri‐n‐butylcitrate (ATBC) was used to increase the strain at break, 22 epoxy‐based Joncryl to improve the MS and strain‐hardening, 23 and 2,5‐dimethyl 2,5‐di(tert‐butylperoxy) hexane 24 to improve impact strength. Ternary blends containing POE‐g‐GMA 25 or (EMA‐GMA) 26 along with PLA‐PBAT were studied to improve the high‐speed resistance properties.…”