Synthetic TiO2 nanoparticle emission from exterior facades into the aquatic environment.

http://publicationslist.org/data/denise.mitrano/ref-15/Mitrano_ENP_Transformation_Review_2015.pdf

Review of nanomaterial aging and transformations through the life cycle of nano-enhanced products.

As the polymer industry evolved, considerable effort was made to understand the degradation processes of high polymers during weathering and ways were found to inhibit or at least retard their chemical modification and loss of their physical and mechanical properties. Weathering is particularly severe for polymers because it combines the photophysical and photochemical effects of ultraviolet radiation with oxidative and hydrolytic effects of the outdoor environment. This article discusses photo-oxidation degradation (the behavior of polymers as a result of outdoor factors) and mainly concentrates on the photo-oxidative degradation of polyolefins and poly(vinyl) chloride. Polymer photostabilization with ultraviolet screeners, quenchers, hydroperoxide decomposers, and radical scavengers is also described.

Polymer Weathering: Photo-Oxidation

Thermal analysis and degradation mechanism of polyacrylate/ZnO nanocomposites

The influence of stabilizing additives on the photooxidation of polypropylene/montmorillonite (PP/MMt) nanocomposites exposed to UV light was studied. Two different stabilizers were used, a phenolic antioxidant and a redox antioxidant. A significant reduction in the induction period of oxidation was observed in the presence of MMt. This is believed to arise from interactions between the additives and the nanoclay. The interactions could involve the adsorption of additives onto the clay, the degradation of the alkylammonium cations exchanged in MMt, and the catalytic effect of iron impurities of the organomontmorillonite. Iron could catalyze the decomposition of the primary hydroperoxides formed by photooxidation of PP, which would in turn accelerate the additive consumption and decrease the length of the period before the permanent regime of oxidation is reached.

https://hal.archives-ouvertes.fr/docs/00/05/15/78/PDF/ccsd-00015626.pdf

Aileen Childs

Papers

Ageing and stabilisation of filled polymers: an overview