Resumo

GUZMAN, Manuel  e  MURILLO, Edwin A.. Structural, thermal, rheological, morphological and mechanical properties of thermoplastic starch obtained by using hyperbranched polyester polyol as plasticizing agent. Dyna rev.fac.nac.minas [online]. 2018, vol.85, n.206, pp.178-186. ISSN 0012-7353.  https://doi.org/10.15446/dyna.v85n206.71819.

In this work, the effect of the proportion of a hyperbranched polyester polyol (HBP) of fourth generation on the structural, thermal, rheological, morphological and mechanical properties of tapioca starch/HBP blends (TPS) was evaluated. For this purpose, the ratios of starch:HBP employed to prepare the TPS were: 30:70 (TPS30), 40:60 (TPS40) and 50:50 (TPS50). Using infrared (IR) analysis, it was observed that the presence of HBP produced a displacement at the absorptions of the C-OH, C-O and C-O-C bonds of the TPS. The X-ray diffraction (DRX) analysis showed that the starch crystallinity is A and B type, which increased with the HBP amount. The glass transition temperature (Tg) of the TPS, increased with the HBP content, but the thermal stability and viscosity (at an angular frequency of 1 Hz) presented an opposite behavior. The scanning electronic microscopy analysis (SEM) revealed that the granular structure of the starch was not completely destructured.

Palavras-chave : starch; hyperbranched polyester polyol; TPS; plasticization; properties.

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