Effect of diatomaceous earth filler and reversible crosslinking reaction Agent (RXR) on high-Density polyethylene (HDPE) and isotactic polybutene (PB-1)

Abstract

This study explores the influence of a novel reversible crosslinking reaction agent (RXR) and Diatomaceous earth on the properties of two distinct polymers: high-density polyethylene (HDPE) and isotactic polybutene-1 (PB-1). Reactive extrusion with a the unique RXR agent was used to create microcomposites with both unmodified and modified DE. A comprehensive analysis using dynamic rheological analysis (DRA), tensile and impact tests, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide-angle X-ray scattering (WAXS), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) was conducted. The results revealed contrasting effects on the two polymers. In HDPE, Diatomaceous earth alone decreased mechanical performance due to aggregation, but surprisingly enhanced crystallinity. The RXR agent improved HDPE's tensile and impact strengths through crosslinking, but lowered crystallinity. Conversely, in PB-1, the RXR agent increased viscosity while Diatomaceous earth displayed minimal rheological impact. However, the combined addition of Diatomaceous earth and RXR significantly reduced PB-1's mechanical properties and increased the crystallization temperature. Thermal stability improved with Diatomaceous earth in both polymers. FTIR and WAXS analysis indicated minimal changes in crystalline structure for both additives in either polymer. SEM micrographs revealed Diatomaceous earth clustering in, suggesting weak filler-matrix interactions, which likely explains the observed decrease in mechanical properties.