Confecção de filmes biodegradáveis por extrusão de blendas de amido termoplástico e polibutileno succinato co-adipato (PBSA)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Blending high cost biodegradable synthetic aliphatic polyesters with low cost agropolymers, such as starch, is one of the alternatives for the production of biodegradable films. The objective of this work was to develop and characterize a biodegradable film based on thermoplastic starch (TPS) and polybutylene succinate co-adipate (PBSA), by film blow extrusion. TPS consisted on three different formulations: manioc starch/glycerol, manioc starch/high amylose corn starch/glycerol and manioc starch/high amylose corn starch/hydroxypropylated corn starch/glycerol, which were blended with PBSA in the following proportions: TPS:PBSA (0:100), (30:70) and (70:30). The films were characterized by mechanical, barrier, thermal, optical and microstructural properties, crystallinity, FTIR spectroscopy and goniometry. TPS:PBSA films were opaque showing a cream coloration, whereas pure PBSA films were translucent. Films with 70% TPS showed low crystallinity and poor mechanical properties compared to pure PBSA films. Films containing 30% TPS with high amylose starch showed good mechanical (up to 330% elongation) and barrier (<3,40 x 10-6 g.m-1.day-1.Pa-1) properties. Thermal transitions and chemical bonds of TPS:PBSA films showed no considerable changes as indicated by FTIR and DSC analyses, due to low miscibility of the TPS and PBSA polymers. Nevertheless, even with low miscibility and high TPS concentrations (70%), it was possible to film blow TPS:PBSA blends, whereas this is not possible with plain TPS polymers, due to the high and specific processability characteristics necessary for using this technique.

ASSUNTO(S)

alimentos - embalagens biofilme filmes biodegradáveis - processo de extrusão biodegradable films - extrusion process food - packaging biofilms

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