Nanocompósitios poliméricos biodegradáveis à base de poli(hidroxibutirato-co-hidroxivalerato)

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2012

RESUMO

In this work, poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) nanocomposites were prepared by melt intercalation process using 1, 3 and 5 wt% of different phyllosilicates ¿ montmorillonite (OMMT) and halloysite (HNT). The effect of the clay type and content, as well as the processing conditions and the modification with organosilanes on the morphology and thermal and mechanical properties of the nanocomposites were evaluated. The crystallization characteristics of the nanocomposites were dependent on the clay type: OMMT prevented the formation of the spherulites, while HNT promoted the formation of a regular and oriented structure with higher melting temperature. The nanocomposites prepared with high clay content and high shear intensity presented a better dispersion, which resulted in an improvement in the mechanical properties and barrier property. The modified nanoparticles presented different results, depending on its degree of interaction with the polymer matrix. For weak interactions, it was observed an increase in ductility and toughness of the nanocomposites. The degradation of the polymer matrix in the presence of aminosilanes or quaternary ammonium salts negatively influenced the thermal and mechanical performance of the nanocomposites. The set of results revealed the potential of halloysite in comparison to montmorillonite. The nanocomposites with unmodified HNT presented the best set of properties, with improved processing characteristics, strain at break and impact strength while maintaining a high stiffness, and a reduction of 93% in the oxygen permeability.

ASSUNTO(S)

nanocompósitos polímeros biodegradáveis

ACESSO AO ARTIGO

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