(708e) Rheological Properties of Biodegradable Polymer/Clay Nanocomposites Based On Poly(Butylene Adipate-co-Terephthalate) and Polylactide

Environmental concerns and impacts caused by disposed plastics, in particular the harms to soil and water resources have triggered major plastic consumers to demand and the plastic industries to invest in the development of biodegradable polymers. Blending functionally different polymers together as well as compounding the polymers with inorganic fine particles has been one of the popular traditional approaches to develop new polymeric systems with the targeted material properties instead of synthesizing or creating totally new polymeric resins. Among the biodegradable polymers developed in recent years, poly(butylene adipate-co-terephthalate) (PBAT), possesses highly desirable material properties such as high elasticity, wear and fracture resistance, and oil and water resistance in addition to being truly biodegradable under composting conditions. However, high cost, dependency on petroleum resources, and low modulus have limited the broad application of this polymer. To reduce the overall cost and dependency on non-renewable resources for the ultimate blend as well as to increase the modulus of this polymer, it was blended with Polylactide (PLA), a bio-based, biodegradable polymer with high modulus. Blends with different ratios of PBAT and PLA were compounded with 3% Cloisite 30B and the melt properties of the blends were studied in this paper. Addition of PLA increased the modulus of the blend and the addition of 3% organoclay significantly increased both the storage and loss moduli of the blend as well. The rheological properties of the blend composites indicated a solid-like behavior versus the liquid-like behavior of the neat blends. Finally, it was concluded that organoclay is mostly located in the PBAT phase based on the results obtained for the storage and loss modulus crossover frequency of the composites.