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Artigo Produção Nacional Revisado por pares
BIBTEX RIS

Biodegradable PLA based nanocomposites for packaging applications: The effects of organo‐modified bentonite concentration

2021; Wiley; Volume: 138; Issue: 36 Linguagem: Inglês

10.1002/app.50907

ISSN

1097-4628

Autores

Edla Maria Bezerra Lima, Antonieta Middea, J. M. Marconcini, Ana Carolina Corrêa, Jéssica Fernandes Pereira, Alessandra Vieira Guimarães, Josimar Firmino de Lima, Marianna Ramos dos Anjos, I. M. de Castro, Renata Nunes Oliveira, Carla R. Moreira, Maurício M. Paiva, Francisco Luiz Correa Rangel, Reiner Neumann,

Tópico(s)

Clay minerals and soil interactions

Resumo

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.

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