Thermogravimetric analysis of starch-based biodegradable blends

DANIEL VEGA; MARCELO VILLAR; MARCELO D. FAILLA; ENRIQUE M. VALLÉS

POLYMER BULLETIN

SPRINGER

Lugar: Berlin; Año: 1996 vol. 37 p. 229 - 235

0170-0839

Thermogravimetric analysis (TGA) has been shown to be a useful technique to determinethe content of starch and other components that are usually present in blends of starch withsynthetic polymers. However, some of these blends are composed of elements with animportant superposition in their temperature degradation range. In these casesinterpretation of the TGA results becomes quite difficult and usually important errors arecommitted in the determination of blend composition. We present here a method toimprove the accuracy of the interpretation of TGA data. The analysis was developed tostudy blends containing starch, an ethylene-vinyl alcohol copolymer, and water plusglycerin as plasticizers. Using this procedure it is possible to predict blend compositionwith an error less than 3 %, even when there is an appreciable superposition between thetemperature degradation range of starch and poly(ethylene-co-vinyl alcohol). As theproposed method of analysis is quite general it may be extended to be used with othertypes of blends that give thermograms with similar characteristics to those described in thispaper.