Preparation and characterization of thermoplastic starch/zein blends

Materials Research

Elisângela Corradini²  Antonio José Felix De Carvalho¹  Antonio Aprigio Da Silva Curvelo¹  José Augusto Marcondes Agnelli²  Luiz Henrique Capparelli Mattoso¹ 

[1] ,Universidade Federal de São Carlos Departamento de Engenharia de Materiais São Carlos SP ,Brazil

关键词: biodegradable polymers;    thermoplastic starch;    zein;    polymer blends;    thermal properties;   

DOI  :  10.1590/S1516-14392007000300002

来源: SciELO

【 摘 要 】

Blends of starch and zein plasticized with glycerol were prepared by melting processing in an intensive batch mixer connected to a torque rheometer at 160 °C. The resulting mixtures were compression molded and then characterized by scanning electron microscopy, differential scanning calorimetry, wide-angle X ray diffraction and water-absorption experiments. The blends were immiscible, showing two distinct phases of starch and zein. The water uptake at equilibrium and its diffusion coefficient were determined. The water uptake at equilibrium decreased with increasing zein content. The diffusion coefficient fell sharply on addition of 20% zein and remained constant as zein content was increased. No appreciable effect of zein on starch crystallization was observed by X ray diffraction. The use of zein in thermoplastic starch compositions causes a decrease in the water sensitivity of these materials and lower its melt viscosity during processing making zein a suitable and very promising component in TPS compositions.

【 授权许可】

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