A biodegradable product obtained from compounds of thermoplastic polymers is described, comprising: a styrenic block copolymer, a plasticizer, and a biodegradation catalyst, in which the plasticizer is a natural oil and the biodegradation catalyst is a yeast. The method of preparation comprises atomizing a suspension comprising a polysaccharide and one or more nanoparticles into a solution comprising a cross linking agent. Accordingly, the motorgenerator does not have to cover an engine start torque when VSP\u2267VSP_s.