The Role of Two-Step Blending in the Properties of Starch/Chitin/Polylactic Acid Biodegradable Composites for Biomedical Applications

• Published in: Polymers Vol. 12; no. 3; p. 592
• Main Authors: Olaiya, Niyi Gideon, Nuryawan, Arif, Oke, Peter Kayode, Khalil, H P S Abdul, Rizal, Samsul, Mogaji, P B, Sadiku, E R, Suprakas, S R, Farayibi, Peter Kayode, Ojijo, Vincent, Paridah, M T
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 05-03-2020; MDPI
• Subjects: Biocompatibility; Biodegradability; biodegradable; Biodegradable materials; biomedical; Biomedical materials; blend; Blending; characterization; Chitin; Composite materials; Dynamic mechanical analysis; Ethics; extrusion; Fractures; Glass transition temperature; Impact strength; Loss modulus; Mechanical properties; Miscibility; Modulus of elasticity; Morphology; Particle size; Plasticizers; Polylactic acid; Polymer matrix composites; Polymers; Polyvinyl alcohol; Pressure molding; Tensile strength; Toxicity testing; Transplants & implants; two-step mixing; Yield stress; United States > US; biodegradable; polylactic acid; two-step mixing; blend; extrusion; biomedical; characterization
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym12030592

The current research trend for excellent miscibility in polymer mixing is the use of plasticizers. The use of most plasticizers usually has some negative effects on the mechanical properties of the resulting composite and can sometimes make it toxic, which makes such polymers unsuitable for biomedical applications. This research focuses on the improvement of the miscibility of polymer composites using two-step mixing with a rheomixer and a mix extruder. Polylactic acid (PLA), chitin, and starch were produced after two-step mixing, using a compression molding method with decreasing composition variation (between 8% to 2%) of chitin and increasing starch content. A dynamic mechanical analysis (DMA) was used to study the mechanical behavior of the composite at various temperatures. The tensile strength, yield, elastic modulus, impact, morphology, and compatibility properties were also studied. The DMA results showed a glass transition temperature range of 50 °C to 100 °C for all samples, with a distinct peak value for the loss modulus and factor. The single distinct peak value meant the polymer blend was compatible. The storage and loss modulus increased with an increase in blending, while the loss factor decreased, indicating excellent compatibility and miscibility of the composite components. The mechanical properties of the samples improved compared to neat PLA. Small voids and immiscibility were noticed in the scanning electron microscopy images, and this was corroborated by X-ray diffraction graphs that showed an improvement in the crystalline nature of PLA with starch. Bioabsorption and toxicity tests showed compatibility with the rat system, which is similar to the human system.