This article presents the preparation of polylactide (PLA)-derived bioplastics, where kraft lignin (L), sulfonated kraft lignin (L-SO3H) or sulfonated kraft lignin in combination with silica (L-SO3H+SiO2) were used as natural additives. The functional groups present in the obtained bioplastics was investigated using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and their thermal properties were investigated using Differential Scanning Calorimetry (DSC) as well as Thermogravimetric analysis (TG). The impact of different additive combinations as well as the aging process on the properties of bioplastics, including their flammability characteristics, were investigated in detail. Additionally, mechanisms have been proposed to explain the observed network fragmentation during burning.