Natural multi-function additive for linear low-density polyethylene: Scutellarin baicalensis extractive

Scutellaria baicalensis (SBC) richly possess active ingredients to satisfy the conditions for functional applications. Herein, the active components of SBC are extracted and introduced into linear low-density polyethylene (LLDPE) to perform as functional additives. The thermal oxygen stability, processing stability, ultraviolet (UV) stability, flame retardancy and mechanical properties are comprehensively investigated. Compared with pure LLDPE, the oxidation induction time (OIT) of LLDPE incorporating SBC extractive (SBE) increased ca. 24 times. The combination of SBE and antioxidant 626 produce more superior antioxidant capacity (OIT of 99.7 min is achieved), revealing an outstanding synergistic effect. After UV irradiation, the carbonyl index variation of the LLDPE adding SBE is less than 50% of that of pure LLDPE. The TGA test showed that SBE was involved in the free radical elimination process. Moreover, the horizontal burning time increases by 37 s with the introduction of both SBE and antioxidant 626. Those results adequately manifest that SBE is a natural, high-performance multi-function additive for LLDPE. This study validly expands the multi-functional application of natural substances into polyolefins, which is a great benefit to the green development of polymer-based composites.