Influence of aging on molecular motion in PBAT-thermoplastic starch blends studied using solid-state NMR

Abstract

The influence of seven-month aging on molecular motion in blends of biodegradable poly(butylene-adipate-co-terephthalate) (PBAT) and corn starch plasticized with water, urea (U) and/or glycerol (G) was studied using solid-state ¹H and ¹³C NMR spectroscopy. Changes in ¹H and ¹³C NMR spectra due to aging in G-containing blends are explained by starch retrogradation. The increasing number of urea-glycerol interactions in the aged UG-containing blend can be deduced from the ¹H NMR spectra. The formation of a crystalline phase was not observed in the U-containing blends. The ¹³C spin-lattice relaxation times and scanning electron microscopy support this interpretation of the NMR spectra.

Keywords:

• Polymer blend
• PBAT
• TPS
• molecular motion
• aging

Additional information

Funding

This research was supported by the Slovak Grant Agency (Agentúra Ministerstva školstva, vedy, výskumu a športu SR) through VEGA (project no. 1/0570/17).