INFLUENCE OF FILLER ON LIGHT BARRIER PROPERTIES OF NANOCOMPOSITE MULTILAYER FILMS

R. A FUENTES; Y. ALONSO; L. CASTILLO; S. BARBOSA

Terni

Congreso; POLY-K 2023 Advances in polymer composites and nanocomposites A scientific congress to celebrate the career of Prof. José Kenny; 2023

The development of light barrier films for food packaging based on polymer nanocomposites has gained moreinterest since this material type should provide a light barrier to reduce spoilage and extend product shelf lifeof photosensitive products [1]. In this sense, the aim of this work is to analyze the influence of filler type, andconcentration on light barrier properties of nanocomposite multilayer films based on polypropylene andmineral particles. Polypropylene (PP) monolayer and trilayer films containing a nanocomposite layer with 1and 5 % wt. of talc (SJ) or kaolinite (L) were studied. The used nomenclature for formulations wasPP/PP(Particle) % wt./PP. The films were obtained by thermocompression having thicknesses around 150 µm.The presence of three layers in the multilayer films was corroborated by optical microscopy. Light barriercapacity for all formulations was determined from measurements of transmittance by UV-vis spectroscopy at300 and 600 nm [2]. Figure 1a shows an optical micrograph where a trilayer structure can be observed inPP/PPSJ 5/PP film. Regarding the UV-vis spectra, the multilayer configuration allowed a reduction intransmittance that became more evident with filler addition, mainly talc. Transmittance values at 300 and 600nm for all films are presented in Figure 1b. Films containing kaolinite and talc demonstrated to have a goodperformance as light barrier materials. Furthermore, a notable enhancement in light barrier capacity wasreached for the multilayer film containing 5% wt. talc.Regardless of the filler type, film light barrier capacity increases with their presence and concentration. Forthis reason, the development of multilayer flexible films formulated from the same polymer matrix anddifferent mineral particles is a promising alternative as packaging material to protect photosensitive products.