Effects of 1-n-tetradecyl-3-methylimidazolium bromide on the properties of polypropylene

In this study, 1-n-tetradecyl-3-methylimidazolium bromide ([C₁₄mim]Br), one kind of imidazolium ionic liquids (imi-IL), was incorporated into polypropylene (PP) via melting blend. The structure and properties of PP/[C₁₄mim]Br blend were investigated by differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA), and thermogravimetric analysis (TGA). DSC results show that the [C₁₄mim]Br has effects on the melting and crystallization process so that PP and PP/[C₁₄mim]Br blends (weight ratio is 100/3) have different melting and crystallization temperature. Results of DMA show that the [C₁₄mim]Br has the effects on the plasticization and crystallization of PP, and the glass transition temperature (Tg) of PP decreases around 11°C when 3 weight shares of [C₁₄mim]Br were incorporated into 100 weight shares of PP. Moreover, both tensile strength and impact strength of PP have been improved reasonably in this situation. TGA also shows the thermal stability of PP is not affected by the [C₁₄mim]Br, which was incorporated into it though its molecule is small.