ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Preparation, characterization, and application of soy protein isolate/Mg–Al layered double hydroxide-based bionanocomposite films

Shreya Sharma, Niranjan Das, and Bonamali Pal

School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala, India

E-mail: bpal@thapar.edu

Received: 3 October 2022  Accepted: 25 January 2023

Abstract:

Soy protein isolate has received much attention in recent decades due to its abundance, eco-friendliness, low cost, film-forming capacity, and processability. In this study, novel soy protein isolate (SPI)-based bionanocomposite films were prepared by integrating Mg–Allayered double hydroxide (LDH) at different loadings (0%, 2%, 5%, and 9% w/w) using a simple solution casting process. The Mg–Al LDH was synthesized in a 2:1 molar ratio via a co-precipitation method. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field-emission scanning electron microscopy, and thermogravimetric analysis (TGA) revealed intercalation/exfoliation of Mg–Al LDH sheets in the SPI matrix of bionanocomposite films. Agglomeration of Mg–Al LDH was distinctly noticed as its concentration increased from 0 to 9% (w/w). The bionanocomposite films showed considerable thermal stability. Mechanical and biodegradation qualities were also investigated. The tensile strength values of the prepared films with 0%, 2%, 5%, and 9% w/w LDH loadings were found to be 2.12 ± 0.25, 1.60 ± 0.15, 1.64 ± 0.08 and 1.58 ± 0.06 KNm/g, respectively. The SPI-Mg/Al LDH 5% film showed a substantial increase in tensile strength and efficiently degraded in non-sterile soil.

Keywords: Soy protein isolate; Layered double hydroxide; Bionanocomposite films; Thermal stability; Biodegradability; Mg–Al

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-02702-w

Chemical Papers 77 (6) 3265–3275 (2023)