Effect of melting temperatures on the orientation and rheology of polyacrylate/silica (PAcr/SiO₂) composite microspheres in twin‐screw extruder

Abstract

The dispersion and orientation arrangement of functional polymers with fillers are critical to their performance. However, there are rare detailed researches on the visualization of the orientation process about functional fillers in composite melts and the mechanistic effects on performance. In this work, it explored the change process of the orientation morphology for polyacrylate/silica (PAcr/SiO2) composite microspheres in polymethyl methacrylate (PMMA) at different melting temperatures. Afterwards, the morphology and distribution of oriented microfibers in composite fibers melted at different temperatures were observed by transmission electron microscope (TEM). The results showed that composite microfibers could be formed in tight arrangement and obtained average orientation of 50.88 in the composite fibers at 250°C. Under this circumstance, the addition of nano SiO2 particles had no effect on the rheological type. Meanwhile, the shear stress was 99.29% higher than that of pure PMMA system under the same conditions. As for the elongation at break, it was found that the elongation at break of the composite fiber prepared at 250°C was 169.43% higher than that of pure PMMA. Therefore, it provided a new method to achieve well dispersion of functional fillers in molten systems. Furthermore, it was beneficial to enhance the elongation at break of functional composites.