The influence of the combined impact of shear stress and cavitation on the structure and properties of starch-natural rubber composite.

In this article, we examined a high-performance, environmentally friendly method for producing composite films based on starch and natural rubber latex (NR). To increase the compatibility of the components, the casting dispersions were subjected to short-term (10 s) mechanical activation in a rotor-stator device. Using the rotational viscosimetry method, it was found that mechanical activation reduces the structuring degree and the effective viscosity of the casting dispersions. The composite films with the NR content of 0-30 % were characterized using optical and SEM microscopy, X-ray diffraction, tensile, and moisture resistance testing data. When the NR content increases from 0 to 30 %, the elongation at break increased by 570 % and 950 % for films obtained using mechanical activation and without it, respectively. The extremely high increase in film tensile strength (on average by 155 %) and the decrease in the NR extractability with toluene due to the use of mechanical activation indicate the possibility of mechanically induced formation of an in situ copolymer at the starch-NR interface. The developed method can be recommended for large-scale production of composite starch-based materials.