Evaluation flammability, mechanical and electrical properties of polypropylene after using zinc borates and montmorillonite

Abstract

This manuscript was built on studying the ignition, thermal, mechanical and electrical conductivity properties of the polypropylene by blending with different weight percentages of zinc borate (ZB) and potassium montmorillonite (MM). The tensile strength (TS) and elongation percentage ( E%) of the specimen were investigated. The thermogravimetric analysis (TGA) and differential thermal analysis (differential scanning calorimetry) were examined. LCR Meter instrument (Agilent E4980A, USA) was used to measure the electrical characteristics of the specimens. The heat capacity of the test specimens was determined according to EN ISO 1716:2004 (oxygen bomb calorimeter). By comparing the heat capacity results of the unblended with composite specimens, the difference in values is noticed. The flammability behaviours of the specimen were investigated by Underwriters Laboratories Horizontal Burning (UL-94HB) and limiting oxygen index (LOI) tests. The burning rate decreased by increasing the time of ignition with slightly LOI increased. These prove the main role of the ZB and MM at increasing the mechanical properties and electrical resistivity. The ash residue increased as the percentage of MM increased, while the heat capacity deceased.