Dynamic Mechanical Analysis and Thermal Expansion of Lignin-Based Biopolymers

Biodegradable materials investigation has become a necessity and a direction for many researchers worldwide. The main goal is to find sustainable alternatives which gradually replace plastics based on fossil resources from the market, because they are very harmful to the environment and to overall quality of life. In order to get to the stage of obtaining different functional parts from biodegradable materials, it is necessary to study their properties. Taking into account these shortcomings, this paper aims at the mechanical characterization (DMA-Dynamic Mechanical Analysis) and thermal degradation (thermogravimetric analysis (TGA)) of lignin-based biopolymers: Arboform LV3 Nature^®, Arboblend^® V2 Nature, and Arbofill^® Fichte Arboform^® LV3 Nature reinforced with aramid fibers. The tested samples were obtained by using the most common fabrication technique for polymers-injection molding. The obtained results for the DMA analysis showed separate polymeric-specific regions for each material and, based on the tanδ values between (0.37-0.54), a series of plastics could be proposed for replacement. The mechano-dynamic behavior could be correlated with the thermal expansion of biopolymers for temperatures higher than 50/55 °C, which are thermally stable up to temperatures of at least 250 °C.