Biodegradation in soil environment of PCL / Starch blends

MARÍA PAULA GUARÁS; LEANDRO N. LUDUEÑA; VERA ALVAREZ

Mar del Plata

Simposio; XVI Simposio Latinoamericano de Polímeros (SLAP 2018) y el XIV Congreso Iberoamericano de Polímeros (CIP 2018); 2018

Polymers are the major environmental pollutants in the environment, due to their accumulation as a consequence of been non-biodegradable materials. Bio-based polymers have attracted increasing attention. Biodegradation can be explained as a chemical process involving micro-organisms that present in the environment convert materials into natural substances such as carbon oxide, water and compost1.Polycaprolactone (PCL) is synthetic aliphatic polyester that can be completely biodegraded by enzymatic activity. Its main advantages are its good processability and high elongation at break, but it has low rigidity and its cost is too high to be used for packaging applications. A possible solution is to blend PCL with less-expensive biodegradable polymers such as starch.Among natural and biodegradable polymers, thermoplastic starch has been considered as one of the most promising candidates because of an attractive combination of availability, price, processability and performance2. The structure of native starch must be modified, since its thermal degradation starts at a temperature below than its melting process. This modification is performed by the breakdown of the starch granule when it is processed in the presence of a specific amount of plasticizer, at a given processing conditions. The obtained product is known as thermoplastic starch (TPS). TPS has been blended with PCL without much success because of poor interfacial compatibility. However, the addition of a compatibilizer, like maleic anhydride-grafted-polycaprolactone (PCL-gMA), enhances the compatibility, increasing mechanical properties and lowering the water permeability of the blends.The aim of this work is to analyse the degradation in soil environment of PCL/starch blends. The degradation process with spectroscopy techniques, differential scanning microscopy and thermogravimetric analysis was studied at different times of degradation.