Poly‐Lactic Acid: Production, Applications, Nanocomposites, and Release Studies

Abstract

Environmental, economic, and safety challenges have provoked packaging scientists and producers to partially substitute petrochemical-based polymers with biodegradable ones. The general purpose of this review is to introduce poly-lactic acid (PLA), a compostable, biodegradable thermoplastic made from renewable sources. PLA properties and modifications via different methods, like using modifiers, blending, copolymerizing, and physical treatments, are mentioned; these are rarely discussed together in other reviews. Industrial processing methods for producing different PLA films, wrappings, laminates, containers (bottles and cups), are presented. The capabilities of PLA for being a strong active packaging material in different areas requiring antimicrobial and antioxidant characteristics are discussed. Consequently, applications of nanomaterials in combination with PLA structures for creating new PLA nanocomposites with greater abilities are also covered. These approaches may modify PLA weaknesses for some food packaging applications. Nanotechnology approaches are being broadened in food science, especially in packaging material science with high performances and low concentrations and prices, so this category of nano-research is estimated to be revolutionary in food packaging science in the near future. The linkage of a 100% bio-originated material and nanomaterials opens new windows for becoming independent, primarily, of petrochemical-based polymers and, secondarily, for answering environmental and health concerns will undoubtedly be growing with time.

PLLA/ZnO nanocomposites: Dynamic surfaces to harness cell differentiation

“…Viability tests were performed seeding C2C12 cells at a density of 5000 cells/cm 2 µM of calcein-AM for 30 min at 37 °C in darkness conditions. Finally, samples were mounted with mounting medium without DAPI (Vectashield) and different images were taken for quantification.…”

“…[2][3][4][5] Numerous authors have modified PLLA to improve its characteristics for scaffolding in tissue engineering; to this purpose, PLLA has been blended with other polymers or inorganic materials to create composites. Different inorganic materials have been used such as hydroxyapatite (HAp), [6,7] carbon nanotubes (CNTs), [8][9][10] bioactive glasses [11,12] or metallic nanoparticles (NPs) [13,14] .…”

Twin-screw extrusion impact on natural fibre morphology and material properties in poly(lactic acid) based biocomposites

“…Deformation of PLA injected objects could limit their usage in thermally processed packages for instance (Jamshidian et al, 2010). The non-normalized test proposed here is a comparative study of heat stabilities for PLA and PLA biocomposites.…”

“…Poly(lactic acid) (PLA) has been intensively investigated in past years. This biodegradable polyester, which can be used in many applications from packaging to biocompatible materials, has a thermoplastic behaviour combined with high mechanical performance, good appearance and low toxicity (Jamshidian et al, 2010).…”

Estudo de nanocompósitos formados por PLA e nanopartículas de celulose.

“…A forma α é a mais estável e é gerada na cristalização por aquecimento ou por resfriamento, a forma β é formada por estiramento mecânico e a forma γ é desenvolvida apenas por cristalização em presença de hexametilbenzeno e possui alta ordenação pois, duas cadeias antiparalelas são ordenadas em apenas uma célula cristalina. [35,41,42 Durante a extrusão do PLA, para garantir que toda a fase cristalina esteja fundida e com viscosidade ideal para o processamento, a temperatura de ajuste do sistema de aquecimento é definida, geralmente, entre 200 e 210°C, valores entre 40 e 50°C acima da temperatura de fusão (T m ). A injeção é uma das formas mais utilizadas para moldar polímeros, principalmente se a peça final tiver um formato complexo ou se requerer exatidão dimensional.…”