Combined effect of UVA radiation and agrochemicals on the durability of agricultural multilayer films

New generation agricultural films combine multilayer technologies, with the latest developments in chemicals resistant UV stabilisers and possibly the incorporation of barrier layers against agrochemicals. The photo-degradation behaviour of a series of experimental multilayer (ML) films exposed to accelerated ageing in combination with agrochemicals, was analysed. It has been shown that the presence of a barrier layer (EVOH or PA) adversely affects the mechanical behaviour of ML films, because of the low ductility of these barrier layers, whose failure is propagating to the other layers leading to premature failure of ML film structures. ML films with barrier layer have shorter lifespan due to the rapid photo-degradation of the barrier layer. It was confirmed that these layers absorb the main part of the agrochemicals load, acting as effective barriers. Agrochemicals were shown to accelerate the detrimental effect of the UVA radiation on PA and EVOH layers causing premature failure of the barrier layers, compromising evenmore the mechanical strength and durability of the entire film. The presence of barrier layers such as PA (mainly) and EVOH in agricultural ML films is not recommended, as both their mechanical properties and photodegradation behaviour are adversely affected by the presence of low ductility barrier layers, deteriorated by the combination of UVA radiation and agrochemicals.