Comparative Study of Properties of Biopolymers from Corn Starch with Addition of Microalgae Spirulina platensis

Abstract

The discovery of the environmental impacts caused by petroleum-based polymers has led to the use of natural polymers gaining more and more space. Naturally occurring polymers, also known as biopolymers, are chemical compounds produced by living things or raw materials from renewable energy sources. Their main advantage is decomposition, while polymers from fossil and non-renewable energies can take hundreds of years to decompose, biopolymers have significantly shorter life cycles. In this study, a study of the application of the biomass of the microalgae Spirulina platensis in biodegradable films with corn starch was conducted, aiming for the development of a functional film with rapid degradability. Approximately 48 biofilms were produced in varying concentrations (w/v), where the visual characteristics of each were observed and the ones that presented the greatest resemblance to conventional plastics were selected, being Trial 4 (T4) and Trial 46 (T46), composed of 2 and 70% v/v of microalgae, respectively. The other tries were discarded due to cracking, high fragility, and very gelatinous or very rigid appearance. The morphological characteristics of T4 and T46 biofilms were analyzed by Scanning Electron Microscopy (SEM) and compared to those of a conventional plastic bag and a commercially available biodegradable plastic bag, where it was possible to prove that the biofilms produced presented good morphological structure. The Fourier Transform Infrared Spectroscopy (FTIR) analysis provided structural information, proving the presence of polyhydroxyalkanoate in the biofilms produced. Two degradability tests were performed with satisfactory results obtained, proving the rapid degradation of the biopolymers produced. It was possible to prove that the biofilms under study present great potential for replacing conventional polymers.