A novel dispersion method comprising a nucleating agent solubilized in a microemulsion, in polymeric matrix: I. Dispersion method and polymer characterization

This is the first of a two-part study focusing on a novel dispersion method which enables increasing the crystallization rate of polypropylene (PP) through the incorporation of nucleating agent HPN-68 into the molten polymer using a microemulsion as a nanovehicle. The cycle time for processing the PP is significantly reduced and thus the effectiveness of its production is increased. Our concept is based on creating an advantage in dispersion capability of the nucleator that is dissolved in a nanoreactor vehicle in comparison with its conventional introduction as a crystalline powder. The microemulsions were introduced to the target PP using a mixer. By the end of the mixing, when the water phase had evaporated, only the nucleator and the surfactant remained in the matrix. The microemulsion components that solubilized the HPN-68 were mineral oil, alcohol, surfactant, and water. DSC results showed a 24% improvement in nucleation efficiency of PP by this method. WAXS results showed that HPN-68 is a γ-nucleator. It causes polymorphism by significantly raising the γ-phase concentration in the PP. SEM results showed a four-fold decrease in the PP spherulite size due to the improved dispersion of HPN-68 within the matrix via microemulsion compared to conventional nucleator incorporation.

This paper is the first part of a two-part study that focuses on a novel dispersion method which enables increasing the crystallization rate of polypropylene (PP) through the introduction of nucleating agent HPN-68 by microemulsion technology.Figure optionsDownload as PowerPoint slide