Biodegradable PLA based nanocomposites for packaging applications: The effects of organo-modified bentonite concentration |
| |
| Authors: | Edla Maria Bezerra Lima Antonieta Middea José Manoel Marconcini Ana Carolina Corrêa Jéssica Fernandes Pereira Alessandra Vieira Guimarães Josimar Firmino de Lima Marianna Ramos dos Anjos Izabela Miranda de Castro Renata Nunes Oliveira Carla Ramos Moreira Maurício Magalhães de Paiva Francisco Luiz Correa Rangel Reiner Neumann |
| |
| Affiliation: | 1. Post-Harvest Pilot Plant of Fruits and Vegetables, Embrapa Food Technology, Rio de Janeiro, Brazil;2. Technology Characterization Sector, Centre for Mineral Technology (CETEM), Rio de Janeiro, Brazil;3. Embrapa Instrumentation, Nanotechnology National Laboratory for Agriculture (LNNA), Nanotechnology Network for Research in Agriculture – Rede AgroNano, São Carlos, Brazil;4. Federal University of Sao Carlos (UFSCar), Graduate Program in Materials Science and Engineering, São Carlos, Brazil;5. Department of Metallurgical and Materials Engineering, Alberto Luiz Coimbra Institute for Graduate Studies and Engineering Research Federal University of Rio de Janeiro (COPPE-UFRJ), Rio de Janeiro, Brazil;6. Post Graduation Program of Chemical Engineering, Chemical Engineering Department, Federal Rural University of Rio de Janeiro—UFRRJ, Rio de Janeiro, Brazil;7. National Institute of Technology (INT), Characterization Center in Nanotechnology for Materials and Catalysis (CENANO), Rio de Janeiro, Brazil |
| |
| Abstract: | The effects of concentration and surface modification of two Brazilian bentonite clays on nanocomposites' properties based on polylactic acid – (PLA) were investigated. The samples were prepared by the extrusion/injection method to obtain biodegradable packaging plastics. The raw materials and their bionanocomposites were characterized by various techniques. Natural clay samples presented a size of around 2 μm while the modified ones' size was 5–6 μm, probably due to the presence of cetyltrimethylammonium bromide in the interlayer space. The particle size and the contact angle increased with the treatment and the clay's density decreased. The organoclays were homogeneously dispersed in PLA, which can be associated with the interactions between PLA chains' carbonyl groups and the organoclays. The bionanocomposites present modified clay particles axis aligned to the flow direction of the extruder/injector. Chocolate organoclay acts as a nucleating agent to PLA crystal growth, increasing the sample's crystallinity, while Bofe organoclay interferes with the amorphous chain's mobility and diminishes the sample's crystallization. The addition of both organoclays to PLA diminished the sample's elongation at break and strength, although the organoclays increased the sample's Young modulus, even though Bofe organoclay is more active in PLA amorphous phase and Chocolate organoclay on the crystalline one. |
| |
| Keywords: | biocompatibility biodegradable biomaterials packaging |
|
|
