Thermoplastic starch (TPS) compositions were studied using stearic, lactic, and succinic acids as structural functional additives, with glycerol acting as a plasticizer. The technological aspects of TPS production and their physical and mechanical characteristies were determined. The production of TPS compositions with polyethylene in an 80:20 ratio was investigated, and their degradability under UV irradiation was tested. Structural changes in film-forming compositions with added TPS were analyzed using IR-Fourier spectroscopy and mass spectrometry. Based on the IR spectra, the formation of ester groups in TPS was confirmed due to the addition of acid to starch and thermomechanical treatment. The effect of TPS on the degradability of TPS+PE compositions was assessed using mass spectrometry, focusing on the composition of ion fragments and their intensities.