Changes of mechanical properties of protective polyethylene films applied in transport bottles and containers for liquid media after exposure to selected liquid media

Abstract

Polymers have effectual applications in many industrial branches. Especially in the automotive and food industry polymers are frequently applied. Thermoplastics can be used also including the transport of specific liquids. This study deals with an investigation of the mechanical properties of polyethylene film made of low-density polyethylene (LD-PE), which has a low density and high degree of chain branching. LD-PE film was exposed to chemical influences of selected liquid media (Savo disinfection, Savo Saponate, and Coca-Cola) for three months. Those media have a different value of potencia hydrogeni (pH). Degradation of mechanical properties of LD-PE film by selected media was monitored. Using tensile test important parameters: σB, εB and E for polymers were evaluated. After exposure, those values of parameters increased in comparison with values of original LD-PE film in the longitudinal direction. The increase of tensile stress at break (σB) in comparison with original LD-PE film was as following: for Savo disinfection - increase of 83.43 %, Savo Saponate - increase of 68.60 %, and Coca-Cola - increase of 67.63 %. In the transversal direction, the exposure in media has a different impact on investigated parameters. The increase of tensile stress at break (σB) in comparison with the original LD-PE film was as following: for Savo disinfection - increase of 14.06 %, and Savo Saponate - increase of 33.02 %. For Coca-Cola was recorded a reduction of 36.90 % in comparison with original LD-PE film. Savo disinfection and Savo Saponate have the most suitable influences on the mechanical properties of LD-PE film for the transport of those liquids after three months.