India accumulates 5.6 million tonnes of plastic waste every year, out of which 66% is the mixed waste polybags and pouches used for food packaging. Especially, the single-use cups, made up of polystyrene, are not generally recycled as their process is expensive and tedious. On the other hand, biodegradable composite materials on biodegradation and composting act as fertilizers. The applicability of these biodegradable packaging materials is less in the industries as they lack mechanical barrier properties compared with plastic packaging materials. Ultrasonication is one such technology that can result in the successful enhancement of various properties. In ultrasonication, the amplitude was changed to 20%, 40%, and 60%, and time of ultrasonication was varied as 2, 4, 8, and 16 min. Mechanical properties such as tensile strength (31.38 N) and puncture strength (13.35 N) showed improvement. Other important properties such as density increased, whereas the water vapor transmission rate of biodegradable cup samples was decreased. Novelty impact statement The developed composite biodegradable cup with ultrasonication has good mechanical properties. The developed biodegradable cup can be used as a single-use food server, thus reducing the use of plastic cups in the food industry.