Photo-oxidation of EPDM/layered double hydroxides composites: Influence of layered hydroxides and stabilizers

Abstract

Abstract. The photo-oxidation of ethylene propylene diene monomer (EPDM)/ layered double hydroxide (LDH) composites as well as EPDM/LDH with stabilizers is studied under accelerated UV irradiation (λ ≥ 290 nm) at 60°C for different time intervals. The development of functional groups during oxidation was monitored by FT-IR spectroscopy. The photodegradation of the pristine polymer and composites take place and the increase in hydroxyl and carbonyl groups with irradiation times, was estimated. EPDM filled LDH showed higher degradation rate than pristine EPDM, while in acidic medium EPDM/LDH showed almost equal degradation as in isolated conditions. These results show the advantages of LDHs as a filler as well as an acid killer. The effect of stabilizers is very less because of their concentration in comparison of LDH.

Ionic elastomers based on carboxylated nitrile rubber (XNBR) and magnesium aluminum layered double hydroxide (hydrotalcite)

“…Ionic elastomers based on carboxylated nitrile rubber (XNBR) and magnesium aluminum layered double hydroxide (hydrotalcite) [5][6][7][8][9], acrylonitrile-butadiene rubber (NBR) [10], chloroprene rubber (CR) [11], silicone rubber (SR) [12,13], and polyurethane PU [14][15][16] and solution styrenebutadiene rubber (SSBR) [17]. However, in the literature, there is no information on the impact of high loadings of unmodified magnesium aluminum layered double hydroxide used as a filler and a curing agent on the crosslinking process in XNBR.…”

Mechanisms of Uv Stabilization

“…62 Pristine polymer was more stable but the presence of hydrotalcite was preferential if material was to operate exposed to UV radiation in an acidic environment. 62 Combination of phosphites and hydrotalcite gives better stability to poly(ethylene terephthalate).…”

“…62 Pristine polymer was more stable but the presence of hydrotalcite was preferential if material was to operate exposed to UV radiation in an acidic environment. 62 Combination of phosphites and hydrotalcite gives better stability to poly(ethylene terephthalate). 63 It should be noticed that phosphites are also acid scavengers, but they are not hydrolytically stable, and most likely hydrotalcite prevents their hydrolysis.…”

“…61 Hydrotalcite acid-scavenging mechanism is presented in Figure 3.17. 62 In addition to hydrotalcite, calcium and zinc stearates are known as popular acid scavengers.…”

Photodegradation Processes In Polymeric Materials

“…The photooxidation of EPDM/LDH composites as well as EPDM/LDH with stabilizers was studied under accelerated UV irradiation [116]. EPDM filled LDH showed higher degradation rate than pristine EPDM.…”