Stabilizer activity in Al2O3/ poly(ethylene-co-butylacrylate) nanocomposites
(English)In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321Article in journal (Other academic) Submitted
The stabilizer activity of polymer nanocomposites based on poly(ethylene-co-butylacrylate) and 0.5 - 3 vol. % of two different types of Al2O3 nanoparticles was investigated. The nanoparticles were either functionalized using octyl- or amino-terminated silanes, or used as received. The nanocomposites also contained 0.2 wt. % of Irganox 1010, a hindered phenolic stabilizer. The activity of the stabilizer in the samples was analyzed by Differential Scanning Calorimetry (assessment of Oxidation Induction Time (OIT)), and compared those obtained for the pristine polymers. The stabilizer was adsorbed to the untreated Al2O3 nanoparticles resulting in a significant reduction in OIT. The reduction increased with increasing total surface area of the particles. Surface silanization of the nanoparticles resulted in an increase in OIT, compared to the untreated particles. The activity of the stabilizer was evaluated by OIT after thermal ageing of the nanocomposites in hot-air oven at 90C up to 30 days. No surface oxidation was observed on any of the samples using reflection infrared spectroscopy. The ageing showed that the stabilizer was not irreversibly adsorbed to the particle surfaces, resulting in a gradual release with the ageing time. This resulted in a slower reduction in OIT as function of aging time for the nanocomposites, compared to the pristine polymer. In order for the nanocomposites to exhibit similar or higher OIT values after thermal ageing, compared to unfilled EBA, > 0.5 mg of stabilizer per m2 of octyl- or amine-coated Al2O3 nanoparticles was needed. The loss of stabilizer was controlled by the evaporation rate of the stabilizer from the surface of the samples to the surrounding air.
poly(ethylene-co-butylacrylate), aluminum oxide, polymer nanocomposite, irganox 1010, antioxidant, stabilizer, OIT
IdentifiersURN: urn:nbn:se:kth:diva-28782OAI: oai:DiVA.org:kth-28782DiVA: diva2:390206
QS 201203282011-01-212011-01-212012-03-28Bibliographically approved