Synthesis of Biodegradable Cellulose-Chitin Polymer Blend from <i>Portunus pelagicus</i>

Abstract

Disposal of petroleum-based plastics has become a major concern due to its resistance to chemical, physical and biological degradation. As such, the production of an alternative biodegradable material from renewable sources is beneficial. This study aims to produce a polymer blend film, of enhanced formability and durability, from cellulose and chitin, the two most abundant naturally-occurring biodegradable polymers in the environment. Chitin was initially extracted from Portunus pelagicus shells through demineralization and deproteinization. The crude chitin is of comparable crystallinity with the commercially-available. However, other proteins were speculated to be present as indicated by the extra peaks in the XRD profile. This was then followed by the dissolution of the polymer powders in LiCl/DMAc, blending, casting, forming, cold-pressing and drying. The independent variables considered were cellulose-chitin ratio and the forming time. From the results, samples formed after 24 hours are relatively thinner, softer and more flexible. In addition, the best sample with UTS at 27.36 MPa was that of 80:20 cellulose-chitin, while the worst at 14.79 MPa was that of 20:80 cellulose-chitin both formed after 24 hours. ANOVA revealed that neither the main factors nor the interaction significantly affected the measured values. Lastly, thermal and biological degradation tests showed that the film started to degrade at 308°C and supported 4.9 x 103 and 3.8 x 104 CFU of mold and bacteria, respectively.