REVISTA DYNA ENERGÍA

Key words:

poliácido láctico, almidón, polivinil alcohol, compatibilidad, biodegradabilidad, poly(lactic acid), starch, polyvinyl alcohol, compatibility, biodegradability

Article type:

ARTICULO DE INVESTIGACION / RESEARCH ARTICLE

Section:

RESEARCH ARTICLES

ABSTRACT:
The presence of compatibilizer is a critical parameter in the development of poly(lactic acid) (PLA)-starch blend. Likewise, the availability of information about its characterization constitutes a gravitating factor for its performance. Therefore, the current study focused on mechanical, thermal, and biodegradability analysis and testing of PLA-oca (Oxalis tuberosa) starch blends in the presence of polyvinyl alcohol (PVA) and glycerol as compatibilizer and plasticizer agents, respectively. Formulations were obtained from different PVA contents (3, 6 and 9 %), two starch:plastificant ratios (50:50 and 45:55), and a constant proportion of PLA (38 %). A qualitative evaluation of the homogeneity of processed blends was performed by optical microscopy. It allowed to choose three formulations with the highest miscibility grade. Tensile strength and elongation at break of blends showed a proportional increase based on PVA content. The DSC study evidenced a unique value of glass transition temperature (Tg) for each formulation. In addition, Tg values are directly proportional to compatibilizer content. Endothermic bands were mainly attributed to the phase change of plasticizer. The biodegradability of blends was independent of their composition. Furthermore, the tests carried out on the specimens showed the following order of biodegradation: anaerobic conditions> vermicomposting> aerobic conditions> natural soil. For instance, PLA- oca starch blends could be suitable for agro-industrial purposes such as grow bags and seed germination trays.

Keywords: poly(lactic acid), starch, polyvinyl alcohol, compatibility, biodegradability