Biodegradable blends of urea plasticized thermoplastic starch (UTPS) and poly(ε-caprolactone) (PCL): Morphological, rheological, thermal and mechanical properties

Ana Carolina Correa; Vitor Brait Carmona; José Alexandre Simão; Luiz Henrique Capparelli Mattoso; José Manoel Marconcini

doi:10.1016/j.carbpol.2017.03.051

Biodegradable blends of urea plasticized thermoplastic starch (UTPS) and poly(ε-caprolactone) (PCL): Morphological, rheological, thermal and mechanical properties

Carbohydr Polym. 2017 Jul 1:167:177-184. doi: 10.1016/j.carbpol.2017.03.051. Epub 2017 Mar 18.

Authors

Ana Carolina Correa¹, Vitor Brait Carmona², José Alexandre Simão², Luiz Henrique Capparelli Mattoso³, José Manoel Marconcini³

Affiliations

¹ National Nanotechnology Laboratory for Agribusiness (LNNA), Embrapa Instrumentation, São Carlos, SP 13561-206, Brazil. Electronic address: carol_correa@hotmail.com.
² National Nanotechnology Laboratory for Agribusiness (LNNA), Embrapa Instrumentation, São Carlos, SP 13561-206, Brazil; Graduate Program in Materials Science and Engineering (PPG-CEM), Federal University of São Carlos, São Carlos, SP 13565-905, Brazil.
³ National Nanotechnology Laboratory for Agribusiness (LNNA), Embrapa Instrumentation, São Carlos, SP 13561-206, Brazil.

PMID: 28433152
DOI: 10.1016/j.carbpol.2017.03.051

Abstract

Biodegradable blends of urea plasticized thermoplastic starch (UTPS) and poly(ε-caprolactone) (PCL) were prepared in a co-rotating twin screw extruder. The UTPS and PCL content varied in a range of 25wt%. The materials were characterized by capillary rheometry, scanning electron microscopy (SEM), termogravimetry (TGA), differential scanning calorimetry (DSC) and tensile tests. Capillary rheometry showed better interaction between UTPS and PCL at 110°C than at 130°C. SEM showed immiscibility of all blends and good dispersion of UTPS in PCL matrix up to 50wt%. However, a co-continuous morphology was found for UTPS/PCL 75/25. Thermal analysis showed that introducing PCL in UTPS, increased T_onset due to higher thermal stability of PCL, and blends presented an intermediate behavior of neat polymers. The presence of PCL in blends improved significantly the mechanical properties of neat UTPS. Because they are totally biodegradable, these blends can be vehicles for controlled or slow release of nutrients to the soil while degraded.

Keywords: Mechanical properties; Morphology; PCL; Polymer blends; Rheology; Thermal analysis; UTPS.