Investigation of the effects of various slip additives on the physical properties of polypropylene film produced by blown film extrusion method

In this thesis, a comprehensive study was conducted on films with different compositions. These films were produced by the blown film method, with fatty acid amides of varying chemical structures added to the heterophasic polypropylene matrix at different ratios as slip additives. The effects on the coefficient of friction of films, a crucial parameter for polymer processing, and the mechanical and thermal behaviors of the film were thoroughly investigated. The structure and ratio of the used slip additive were carefully considered, ensuring a comprehensive understanding of their effects. As the polymer, heterophasic polypropylene copolymer was selected considering the final product application, and the slip additives were added to the polymer matrix by melt mixing method. Oleamide, erucamide and ceramide, the most commonly used fatty acid amides in the industry, were selected as slip additives. These additives were added to the polymer matrix at 1, 3, and 5 wt % ratios. The compounds were produced as films using the blown film technique. The films with 7 wt. % slip additive was not applicable due to the accumulation of the additives on the film surface and no further productions were conducted with this ratio. The effects of the slip additives on the thermal and mechanical properties of polypropylene-based packaging films were investigated and compared depending on the structure and applied ratio of the additives. On the thermal properties of heterophasic polypropylene matrix no remarkable effect was observed with the addition of slip additives. It was concluded that the slip additives facilitate sliding at the interface between crystalline and amorphous regions in the polymer matrix, which leads to a decrease in modulus values. It was found that the internal-metal and external-metal friction coefficient values, which are essential parameters for polymer processing, decreased by more than 50% with the addition of a 3 wt. % slip additive compared to the neat polymer film.