Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Starch and cellulose-based polyurethane biocomposites which have provided a detailed comparison from synthesis to characterization. A practical approach from structural analysis to biocompatibility.

ABSTRACT
The use of fossil fuels for synthesis, and hazardous environmental impacts, are forcing researchers to produce green polymers by incorporating bio-based raw materials as reinforcement for biomedical and packaging applications. Novelty of current work is the extraction of reinforcing material from bio-based resources i-e rice husk and potato. For the synthesis of polyurethane (PU) biocomposites, Hydroxyl-terminated polybutadiene (Mn = 4069gmol−1) was reacted with 1,6-Hexane diisocyanate to form prepolymer. 1,4-butane diol was used as a chain extender. Two series of biocomposites were prepared using starch nanocrystals (SNCs) and cellulose crystals (CNCs). Fourier transform infrared (FTIR) analysis depicted the successful development of linkages. Thermal gravimetric analysis (TGA) exhibited that the thermal stability of prepared composites was enhanced by increasing the concentration of reinforcement up to 407°C. Dynamic mechanical analysis demonstrated the values of storage modulus (E′) and loss modulus (E″) up to 7.104 and 10.744 MPa for SNCs-based and CNCs-based biocomposites, respectively. All the prepared biocomposites exhibited significant inhibition of biofilm against E. coli (64.5%) and S. aureus (49.7%) and good biocompatibility with hemolysis values of 2.45% and 9.11% for PUS and PUC series, respectively. Additionally, the PUS series of biocomposites showed greater swelling behavior (66.84%) as compared to PUC series with swelling of 42.78%.