Using the potential of Canadian goldenrod (Solidago canadensis) as a functional filler with antioxidant activity of low-density polyethylene composites as an example of sustainable development of an invasive plant

Novel bio-based low-density polyethylene (LDPE) composites have been manufactured using different Canadian goldenrod (CG) invasive plant parts. Fragmented and ground blossoms (CGB) and mixed leaves and stems (CGSL) were used as fillers introduced by melt mixing into an LDPE matrix at various concentrations (2, 5, 10, 20, 40 wt%). Moreover, the influence of a series of modified fillers based on stems and leaves saturated with an extract made of blossoms (CGSL+E) on LDPE has been verified. The oxidation resistance of composites was enhanced based on the oxidation induction time (OIT) assessment, which increased from 0.5 min for LDPE to 178 min (CGB), 231 min (CGSL), and 140 min (CGSL+E). All composite series formed by compression molding were exposed to UV-light radiation using Xenon lamps and subjected to spectroscopic (FTIR) analysis, color assessment, and mechanical testing. LDPE/CGSL+E composites demonstrated the most favorable mechanical properties after UV-light exposure. In their case, an increase in Young modulus of 360 MPa was observed for the 40 wt% sample (PE ∼ 180 MPa) and an acceptable decrease in tensile strength of 6.5 MPa compared to the reference LDPE of 9.8 MPa. The study consists of a screening for future research on the use and simultaneous valorization of the invasive plant into functional composite fillers with increased oxidation resistance. • Canadian goldenrod (CG) invasive plants were valorized as functional fillers. • All CG parts (blossoms, stems, and leaves) exhibit strong antioxidant activity. • Polyethylene-CG composites show improved OIT and UV-light aging resistance.