Antioxidant intercalated hydrocalumite as multifunction nanofiller for Poly(propylene): Synthesis, thermal stability, light stability, and anti-migration property.
Résumé
One of the major issues for poly(propylene) PP concerns its protection towards oxidative phenomena resulting in polymer failure. Using known anti-oxidant (AO), Irganox 1425, an original approach is taking advantage of the counterion, cations Ca2+, in building hydrocalumite inorganic sheets, and concomitantly providing the AO anions to be immobilized within an inorganic host structure. Through the classical co-precipitation method, the hybrid assembly composed of AO molecules interleaved between hydrocalumite layered structure is successfully elaborated in one-step process free of contamination. Hydrocalumite (Ca2Al) belongs to the family of layered double hydroxides (LDH). The structure of the AO-LDH hybrid material is determined by means of XRD, FT-IR, while the radical-scavenging activity of AO-LDH is investigated using DPPH• (1,1-Diphenyl-2-picryl-hydrazyl) radical concentration variation. A series of AO-LDH/PP composites is then obtained by dispersing AO-LDH into PP at different loading ratios, and addressing the thermal stability, light stability and anti-migration of the resulting composites. The use of hydrocalumite vessel in confining AO molecules helps to increase the thermal stability and resistance against the photo oxidation while providing a barrier effect against organic species migration. An optimized of 4 wt% AO-LDH into PP results in the best radical-scavenging activity, 1 wt% is preferred to stabilize PP under light, the former formulation is the best compromise of all the series.