Influence of different antioxidants on cure kinetics and aging behaviours of ethylene propylene diene rubber/low density polyethylene blends

Abstract

The aim of this article is to study the effect of antioxidants on cure properties and aging behaviour of ethylene propylene diene rubber (EPDM) and EPDM/low density polyethylene (LDPE) blends. Dicumyl peroxide cured EPDM and EPDM/LDPE blends are prepared with three categories of antioxidants, including: amine, N-isopropyl-N9-phenyl-r-phenylenedia mine (antioxidant 4010NA) and 2,2,4-trimethyl-1,2-dihydroquinoline (antioxidant RD); phenol, n-Otadecyl-b-(4-hydroxy-3,5ditert-butyl-phenyl)-propionate (antioxidant 1076) and sulphur containing antioxidant, 2mercapto benzimidazole (antioxidant MB). The damp heat aging was carried out at a relative humidity of 93% and a temperature of 40uC. The thermal aging was performed at 120uC. The two types of aging have been taken for eight weeks respectively. The combined antioxidant RD/MB is a favourable additive. The cure characteristics of EPDM with antioxidant RD/MB are notable compared with those of EPDM without antioxidants. Additionally, antioxidant RD/MB has the sound aging performance for the EPDM and EPDM/LDPE blend. Antioxidant 4010NA performs poorer than others during aging, due to the remarkable retardation for the peroxide vulcanisation process.

Influence of thermooxidative aging on the static and dynamic mechanical properties of long‐glass‐fiber‐reinforced polyamide 6 composites

“…The secondary antioxidants convert hydroperoxide to some more stable products, and then, autocatalytic degradation reactions are prevented. 24 For example, the efficiency of phenolic antioxidants has been ascribed to hydrogen bonding between amide groups in polyamides and the hydroxyl groups of the phenolic antioxidants and to the kinetic chain length shown by polyamides. 25,26 In this study, dumbbell-shaped injected samples of PA6/long glass fiber (LGF) were used for the systematic study of thermooxidative aging behaviors; the samples were subjected to oven aging at different times under 160 C. The static and dynamic mechanical properties of the aged PA6/LGF composites were characterized by thermogravimetric analysis, differential scanning calorimetry (DSC), DMA, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM).…”

Thermal aging on ethylene–propylene–diene rubber composites reinforced by samarium oxide, samarium borate and Sb in Sb doped SnO2

“…[1][2][3][4][5] These properties have extended its application to thermoplastic vulcanisates, electrical insulation, waterproof rolls and so on.…”

Synergistic Effects of Amine‐Containing Antioxidants on the Aging Performances of Ethylene Propylene Diene Rubber

“…It was reported that the majority of antioxidants had the most effective inhibition of peroxide crosslinking reaction. The hardness of these aged EPDM samples containing MBZ/445 behaves similar to each other, because the antioxidant complex has little effect on the peroxide crosslinking reaction of the EPDM . Importantly, the addition of antioxidants improves the antioxidative behaviors of EPDM.…”

“…By capturing the free radical, antioxidants hindered the oxidation process during aging. However, it should be noted that free radicals released by peroxide could be consumed by antioxidants, which would affect the mechanical properties of EPDM . In order to investigate the effects of antioxidants on the EPDM gum stocks, the cure property was firstly measured.…”

“…Therefore, it is of great significance to add antioxidant into the EPDM matrix to improve its long‐term service ability. The commonly used antioxidant types are amine‐containing antioxidants, including 2‐sulfur‐benzimidazole (MB), N‐isopropyl‐N’‐phenyl‐ρ‐phenylenediamine (4010NA), N‐cyclohexyl‐benzothiazyl‐sulfenamide (CBS), poly‐2,2,4‐trimethyl‐1,2‐dihydroquinoline (RD) and 4,4′‐bis(α, α‐dimethylbenzyl) diphenylamine (445) . For polymers, the essence of antioxidants is to prevent the degradation by trapping free radicals formed during oxidation process and thus to stop the attack of free radicals on macromolecular chains .…”