Stable Co-Continuous PLA/PBAT Blends Compatibilized by Interfacial Stereocomplex Crystallites: Toward Full Biodegradable Polymer Blends with Simultaneously Enhanced Mechanical Properties and Crystallization Rates

Abstract

Constructing stable co-continuous morphology of commercial immiscible polymer blends remains an ongoing challenge in terms of complex presynthetic routes, multiple parameter dependency, and intrinsic instability of phase morphology. Herein, we demonstrate a full biodegradable polymer blend, poly­(lactic acid) (PLA) and poly­(butylene adipate-co-terephthalate), where hitherto inaccessible co-continuous with asymmetric compositions (70/30) can be obtained with the assistance of interfacial stereocomplex crystallites (i-SCs) through reactive blending. By taking full advantages of this unprecedented compatibilizer, nanostructured co-continuous blends with synergistically enhanced comprehensive performance are achieved. First, due to the “rigid” i-SC, co-continuous morphology is induced through a simple melt blending procedure; second, considerable augmentation of the crystallization rate of the PLA matrix is accomplished on account of the in situ formed nucleation agent (i.e., i-SC); third, a super toughened material with simultaneously enhanced tensile strength, ductility, and impact strength can be acquired, resulting from the i-SC-induced co-continuous morphology; and fourth, i-SC can function as a “rigid” supporting layer between phases even above 200 °C, resulting in significantly enhanced morphology stability in melt. The versatile, facile, and practical strategy offers an industrially relevant technique to fabricate super-robust and fully biobased polymer materials.

Peroxide-Induced Synthesis of Maleic Anhydride-Grafted Poly(butylene succinate) and Its Compatibilizing Effect on Poly(butylene succinate)/Pistachio Shell Flour Composites

“…Among the different compatibilizers, the use of graft copolymers containing reactive groups, such as maleic anhydride (MAH) or glycidyl methacrylate (GMA), represents an effective way to improve the interfacial interaction between the polymer and filler and immiscible biopolymer blends [ 42 ]. For instance, based on these reactive compatibilizers, a feasible and robust strategy has been recently developed to prepare stable co-continuous blends of PBAT and PLA [ 43 , 44 ].…”

Property improvement of processed PLA/PBAT using chain extenders

“…PLA generally contributes to the mechanical properties as modulus of elasticity and tensile strength of the polymer blends, but the elongation at break decreases with increasing PLA content. Chen et al [12] studied the influence of two types of PLA; semi crystalline PLA and amorphous PLA, on properties of PLA/PBAT polymer blends. Mechanical tensile tests revealed that only when semi-crystalline PLA was utilized as the matrix did the ductility and toughness increase considerably when IM was employed as the sole processing procedure.…”

Enhancement of strength and toughness of bio-nanocomposites with good transparency and heat resistance by reactive processing

“…To address the above critical problems, we developed an industrially relevant strategy to fabricate advanced polylactic acid nanocomposites integrating superior mechanical property, multiple functionalities ( Figure 1 ). Polylactic acid (PLLA) ( Hamad et al., 2018 ; Li et al., 2021 ) is utilized as a biodegradable matrix because it is predominantly utilized in the rational design of renewable nanocomposites with promising features such as facile processability ( Zhao et al., 2020 ), mechanical stiffness ( Jin et al., 2019 ; Wu et al., 2021 ), and biocompatibility ( Chen et al., 2021 ; Muller et al., 2017 ). Surface-modified boehmite nanorods (AlOOH-GPS termed as AG) containing reactive epoxide groups were pre-made according to our previous work ( Fu et al., 2019 ; Hu et al., 2021 ; Li et al., 2020 ; Rong et al., 2022 ) ( Figure 1 A).…”