Papers by Keyword: Biodegradable Polymer Blend

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.

Abstract: PLA/PCL and PLA/PCL/LTI blends were developed to improve the fracture properties of biodegradable PLA. LTI was blended to improve the miscibility of PLA and PCL. It was shown that the fracture toughness values were dramatically increased due to LTI addition. SEM results also exhibited that PCL spherulites decreases due to LTI addition and therefore, void formation is reduced and local stress concentration is suppressed, resulting in the improvement of the toughness values. The improved miscibility is also closely related to the enhancement of ductile deformation; as a result, the fracture toughness is increased.

Abstract: Attempts have been made to improve the impact resistance
of biodegradable thermoplastic polymer, PLA. A ductile biodegradable polymer, PCL, has been used to improve such property of PLA by using blending technique. Details of the impact fracture properties and mechanisms of PLA/PCL blends, however, have not fully been understood yet. Recently, it was also found that LTI can improve the immiscibility between PLA and PCL. In this study, PLA/PCL and PLA/PCL/LTI blends were prepared, and their impact fracture toughness values were measured
to assess the effect of PCL content and LTI addition on the impact resistance. Fracture mechanisms of the polymer blends were also characterized by scanning electron microscopy.