Toward Greener Polymeric Blends: Study of PBAT/Thermoplastic Whey Protein Isolate/Beeswax Blends

Journal Article · Tue Oct 01 04:00:00 EDT 2019 · Journal of Polymers and the Environment

DOI:https://doi.org/10.1007/S10924-019-01502-2· OSTI ID:22977051

Strauss, Mathias ^[1]; Morales, Ana Rita ^[2]

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1. National Center for Research in Energy and Materials (CNPEM), Brazilian Nanotechnology National Laboratory (LNNano) (Brazil)
2. University of Campinas (UNICAMP), DEMBio, School of Chemical Engineering (Brazil)

This work evaluated the effects of partial substitution of PBAT by thermoplastic whey protein isolate (WPIT) with addition of beeswax through blends processing and their morphological, mechanical, structural, thermal and rheological properties. Whey protein isolate (WPI) was denatured at 90 °C, using glycerol as plasticizer, to be transformed in a thermoplastic material and subsequently blended with PBAT using a torque rheometer at 130 °C. Addition of 10 and 30% of WPIT in the PBAT matrix was investigated with and without beeswax. Blends were pressed as films with ~ 320 µm of thickness. Scanning electron microscopy (SEM) analysis of PBAT/WPIT blends films revealed the presence of domains. These domains are compounded of whey protein, while at the continuous phase a moderate degree of mixture between PBAT and WPIT was observed by Raman analyses. WPIT did not alter the degree of crystallinity and the glass-transition temperature (T{sub g}) of the PBAT in the blends. Thermogravimetric curves of the blends showed decomposition stages related to WPIT and PBAT phases. Thermal stability of blends decreased in comparison to WPIT, which was associated to the cleavage of disulfide bonds of WPIT during processing and causes other kind of interaction between components. Besides, blends containing WPIT remained non-rigid polymers with Young’s modulus below 70 MPa. The tensile strength and elongation at break decreased due the presence of WPIT. Beeswax did not influence the thermal and mechanical properties explored in this study.

• OSTI ID: 22977051
• Journal Information: Journal of Polymers and the Environment, Journal Name: Journal of Polymers and the Environment Journal Issue: 10 Vol. 27; ISSN 1566-2543
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DISULFIDES
GLYCEROL
PROTEINS
SCANNING ELECTRON MICROSCOPY
TENSILE PROPERTIES
THERMAL GRAVIMETRIC ANALYSIS
THERMOPLASTICS