Influence of carbon structures on the properties and photodegradation of LDPE/LLDPE films

• Published in: Polymers for advanced technologies 2022-05, Vol.33 (5), p.1727-1741
• Main Authors: López‐Martínez, Erick Daniel, Martínez‐Colunga, Juan Guillermo, Ramírez‐Vargas, Eduardo, Sanchez‐Valdes, Saul, Ramos ‐de Valle, Luis Francisco, Benavides‐Cantu, Roberto, Rodríguez‐Gonzalez, Jose Alberto, Mata‐Padilla, Jose Manuel, Cruz‐Delgado, Victor Javier, Borjas‐Ramos, Jose Javier, Da Silva, Luciano
• Format: Article
• Language: English
• Subjects: Artificial weathering tests; Carbon; Carbon black; carbon nanostructure; Carbonyls; Crystal structure; Crystallinity; Density; Elongation; Fluorescent lamps; Graphene; Haze; LDPE; Light transmission; LLDPE; Low density polyethylenes; Low molecular weights; Mechanical properties; Modulus of elasticity; Multi wall carbon nanotubes; Nanoparticles; Optical microscopy; Photodegradation; Polyethylene; Polymer blends; properties; Tensile properties; Tensile strength; Thermal stability; Thermogravimetric analysis; Weathering
• ISSN: 1042-7147; 1099-1581
• DOI: 10.1002/pat.5635

The effect of different carbon structures on the properties of low density polyethylene film and linear low density polyethylene blends (LDPE/LLDPE) subjected to artificial weathering, was studied. The carbon structures used were carbon black (CB), multi wall carbon nanotubes (MWCNT) and Graphene nanoparticles (GNP), at various loadings: 0.05, 0.1, 0.3, 0.5, 1.0, and 2 wt%. The PE‐Carbon structure composite films were characterized by optical microscopy (MOP), Haze, visible light transmission, UV–visible, thermogravimetric analysis (TGA), melt flow determinations (MFI) and tensile properties. Weathering measurements were evaluated in a QUV panel chamber with UV fluorescent lamps. The films degradation was analyzed following the change in carbonyl index of FTIR spectra, mechanical properties, and molecular weight. A noticeable better dispersion of CB and CNT particles in polyethylene matrix was observed compared with GNP. MWCNTs and CB produced high Haze and low visible light transmission. Thermal stability measured by TGA increased with the presence of GNP and CB. The crystallinity, melting, and crystallinity temperature (Tm and Tc) of the polymers increased with MWCNT and GNP. All the films with carbon structures presented an increase in the modulus of elasticity, with CB giving the highest elastic modulus. Artificial weathering of films with carbon structures showed that CB particles and CNT provided the highest UV protection to polyethylene, with a noticeable increase in low molecular weights and a retention in tensile strength and elongation at break which was reflected in maintaining their flexibility. Films with CNT showed the least significant changes in their properties, being more resistant to photo‐degradation.