Toughening of Cocontinuous Polylactide/Polyethylene Blends via an Interfacially Percolated Intermediate Phase

Abstract

It will be shown that an interfacially percolated rubbery phase in a cocontinuous polylactide (PLA)/linear low-density polyethylene (LLDPE) blend results in a significant increase in the impact strength. All blends possess a tricontinuous phase morphology in which poly­(ε-caprolactone) (PCL), poly­(ethylene–methyl acrylate) (EMA), and ethylene–methyl acrylate–glycidyl methacrylate (EMA-GMA) percolate at the interface of PLA/LLDPE but offer different toughening and compatibilization effects. Among these components, the addition of EMA-GMA to the binary PLA/LLDPE blend reduces the cocontinuous PLA/LLDPE phase thickness from about 25 to 5 μm and yields a very tough material with an impact strength of about 515 J/m, which is approximately 13 times greater than the original cocontinuous PLA/LLDPE blend and more than 32 times that of PLA. The ternary blends show significant improvements in the impact strength within the tricontinuous region; however, the principal differences in the toughening effects are attributed to interfacial interactions between the phases. The interconnected network of the rubbery phase is expected to percolate the stress field throughout the tricontinuous system and reduce the detrimental dilatational stress in the bulk blend.

Compatibilization and Characterization of Polylactide and Biopolyethylene Binary Blends by Non-Reactive and Reactive Compatibilization Approaches

“…Wang et al [ 30 ] and Anderson et al [ 31 ] synthesized PE-PLA di-block copolymers (PE -b- PLLA) as a compatibilizer. Other compatibilizers reported in the literature are maleic anhydride grafted PE (PE -g- MA) [ 23 , 25 , 32 ], ethylene-glycidyl methacrylate copolymer (EGMA) [ 33 , 34 ], and ethylene-methyl acrylate-glycidyl methacrylate (EMA-GMA) terpolymer [ 34 , 35 ]. The use of these compatibilizers plays a key role in reducing domain sizes and improving interfacial adhesion and, subsequently, mechanical properties.…”

Effect of nanoparticle localization on the rheology, morphology and toughness of nanocomposites based on poly(lactic acid)/natural rubber/nanosilica

“…In the past decades, the preparation of polymeric blends based on bio‐materials has attracted great attention due to the enormous interest in new compounds and eco‐friendly material development . Due to their biocompatibility and biodegradability, these blends present a high ability for replacing petroleum based polymers . Poly(lactic acid) (PLA), an aliphatic polyester, is one of the most biodegradable and commercially available bio‐based polymers .…”

“…[1][2][3][4] Due to their biocompatibility and biodegradability, these blends present a high ability for replacing petroleum based polymers. [5][6][7] Poly(lactic acid) (PLA), an aliphatic polyester, is one of the most biodegradable and commercially available bio-based polymers. 8,9 It is derived from renewable resources, is easily processed and exhibits great physical properties; it has a wide range of applications in food packaging, drug delivery systems and also in industrial use.…”

Interfacial stability of compatibilizers dictated by the thermodynamic interactions in an immiscible system and the effects of micelles on the crystallization of PLLA

“…Blending PLLA with nonbiodegradable polymers such as polyolefins, elastomers, and rubbers and biodegradable polymers such as poly( ε ‐caprolactone) ( ε ‐PCL), poly(butylene adipate‐ co ‐terephthalate) (PBAT), poly(butylene succinate) (PBS), poly(ethylene succinate) (PES), and poly([butylene succinate]‐ co ‐adipate) (PBSA) has been conducted to ameliorate the drawbacks of PLLA like brittleness and inferior thermal stability. Since the price of bio‐based polymers is still higher than most of the competitive petroleum‐based polymers, the PLLA/petroleum‐based polymer blends are considered to be more economic for commercial applications.…”