Hindered phenolic antioxidants as heat-oxygen stabilizers for HDPE

Abstract

The effects of four hindered phenolic antioxidants in the short-term heat-oxygen stability of High-Density Polyethylene (HDPE) was evaluated by the Melt Flow Rate (MFR) and Oxidation Induction Time (OIT) analyses. The results showed that Irganox 1330 and Irganox 1010 had more excellent processing property and oxidation resistance behavior in HDPE than Irganox 1024 and Irganox 3114. The OIT values of HDPE with Irganox 1330 and Irganox 1010 were up to 97.25 min and 89.73 min respectively. The long-term accelerated heat-oxygen stability tests of HDPE containing hindered phenolic antioxidants were carried out at 110°C in deionized water pressurized with pure oxygen at a pressure of 10 MPa. The characterization of the long-term heat-oxygen stability was performed by Fourier Transform Infrared (FTIR), Differential Scanning Calorimetry (DSC) and tensile testing. However, the results exhibited that the aging resistance of HDPE containing Irganox 1010 was inferior to that of HDPE containing Irganox 1024 and Irganox 3114, which is quite contrary to their short-term effect on HDPE stabilization. It may be speculated that the ester groups of Irganox 1010 undergo hydrolysis during the long-term heat-oxygen stability tests, leading to the formation of 3-(3,5-ditert-butyl-4-hydroxy-phenyl) propanoic acid and pentaerythritol.

Antioxidant-induced transformations of a metal-acid hydrocracking catalyst in the deconstruction of polyethylene waste

“…This difference was likely due to the central ester groups in I-1010. During BA site-catalyzed hydrolysis, 30 surface carboxylate groups were more likely to form than phenoxy groups, which led to more severely blocked BA sites via steric effects (Fig. S16c †).…”

Recycled Post-Consumer HDPE as a Matrix for Hemp Hurd Bio-Composites for Commercial Scale-Up Operations

“…The slight decrease was due to the alteration of the material's chain structure as a result of the material's service and process histories. Furthermore, the OIT is a measure of the time it takes for a material to oxidize and was used in this study to observe the thermal oxidative stability of the HDPE specimens [1,25]. The vHDPE was found to have an OIT of ~ 51 mins while the P.C.…”

“…The breadth of the P.C. HDPE's peak is due to the varying chain length along with weakened stabilizers due to its level of degradation while the virgin counterpart had a narrower and sharper peak [25].…”