Effect of tetrasilanolphenyl silsesquioxane on properties of sorbitol derivative-nucleated polypropylene cast films

ABSTRACT Nucleating agents cause an increase in crystallization temperature, making the production of highly oriented films much more difficult. In this study, a nucleating system composed of 1,3:2,4-bis(3,4-dimethylbenzylidene) sorbitol (DMDBS) and tetrasilanolphenyl silsesquioxane (phPOSS) was used to modify isotactic polypropylene (iPP). Oriented films characterised by different draw drown ratios (4.8, 9.7, 14.5) were prepared and analysed. Their mechanical properties, coefficient of friction, thermal properties, and structure as well as optical properties such as gloss, haze, and transparency, were also determined. The macromolecular orientation of films was tested by polarised light Fourier transform infrared spectroscopy. The proposed nucleating system provides films with superior mechanical and optical properties, which are accompanied by high orientation ability. The application of DMDBS and phPOSS allowed a 26% increase in penetration load at break and Young modulus by 70% compared to iPP. It can be assumed that DMDBS/phPOSS system is an efficient modifier for polypropylene film production.