Study of the hydrolytic degradation of poly-3-hydroxybutyrate in the development of blends and polymeric bionanocomposites

• Published in: Journal of thermoplastic composite materials 2021-07, Vol.34 (7), p.884-901
• Main Authors: Silva, Raquel do Nascimento, da Silva, Lucas Rafael Carneiro, de Morais, Ana Carolina Lemos, Alves, Tatianny Soares, Barbosa, Renata
• Format: Article
• Language: English
• ISSN: 0892-7057; 1530-7980
• DOI: 10.1177/0892705719856044

Bionanocomposites of poly-3-hydroxybutyrate (PHB), polyethylene glycol (PEG), and organophilic vermiculite (VMT) clay were prepared at 95/5/3% and 90/10/3%and blends at 95/5% and 90/10% PHB/PEG in the form of films obtained via solution intercalation. The films were submitted to hydrolytic degradation according to the ASTM F1635-11. X-ray diffraction (XRD) analysis, mass loss, visual inspection, and Fourier transform infrared (FTIR) spectroscopy evaluated the properties of films. XRD analysis showed that the polymer chains were intercalated into the organoclay layers, and some degree of exfoliation was observed from this analysis. FTIR was performed to calculate the carbonyl index and to quantify the causing group of the degradation process. The visual inspection results showed that the film surfaces were whitened and brittle. This characteristic was more evident for the 90/10% PHB/PEG blend and 90/10/3% PHB/PEG/VMT composite. The addition of the organophilic VMT clay at 95/5/3% (PHB/PEG/VMT) displayed a larger mass loss; FTIR showed that degradation of pure PHB occurred in the amorphous regions and that the presence of PEG and VMT increased the polymer degradation, decreasing crystallinity.