Punica granatum peel extractive (PPE), a novel stabilizer of polyethylene, is investigated in this study. Oxidation onset temperature (OOT), carbonyl index (CI), melt flow rate (MFR), tensile strength, and elongation at break are used to characterize the effects of PPE, which are also compared with commercial antioxidant (Irganox 1010) with the presence of tetrakis (2,4-di-tert-butylphenol) [1,1-biphenyl]-4,4 0-diylbisphosphite (PEPQ). Long-term and short-term aging results show that samples modified by PPE or Irganox 1010 (PE-PPE 0.12%-P and PE-1010 0.12%-P samples) have comparable CI value and stability of OOT. However, compared with PE-PPE 0.12%-P sample, much higher CI and larger change of MFR is detected for PE-1010 0.12%-P after UV irradiation and five extrusions. It suggests that PPE is better protector for PE against UV light and mechanical shear force. All results indicate that the effect of PPE in protecting PE is comparable or much better than Irganox 1010 and it can be used as multiple stabilizers for PE. Moreover, the stabilities of PE modified with PPE alone (PE-PPE 2%) is also investigated. Results show that PE-PPE 2% sample has good thermo-oxidative, UV and processing stabilities. All results reveal that PPE is a good candidate of PE stabilizer and it could avoid the usage of PEPQ in protecting PE.

Puerarin, a natural compound, was used as multifunctional protector for polyethylene (PE) and polypropylene (PP). Firstly, puerarin and tetrakis(2,4‐di‐tert‐butylphenol)[1,1‐biphenyl]‐4,4′‐diylbisphosphite (PEPQ) could protect PE and PP against thermos‐oxidative degradation: after modification, the oxidation induction time (OIT) of increased ca. 4,160% (PE‐P1200‐P sample) and 130% (PP‐P1200‐P sample); the carbonyl index (CI) obtained through accelerated aging decreased ca. 58% (PE‐P1200‐P sample). Secondly, it is excited to find that puerarin and PEPQ could pretect PE agianst photooxidative degradation: CI value decreased ca. 35% after modification. Thridly, the coorperation of puerarin and PEPQ was also benefit for the processing stability: the change of melt flow rate (MFR) between first and fifth extrusions decreased ca. 83% (PE‐P1200‐P sample) and 99% (PP‐P1200‐P sample). Forthly, puerarin and PEPQ could still protect PE against degradation after five extrusions: the loss of tensile strength and elongation at break decreased ca. 96% and 95% after modification. Finally, the interaction of puerarin with PEPQ was discussed and the role of puerarin in protecting polyolefins was proposed.