Plasticized polyvinyl chloride/melamine-cyanurate modified Mg(OH)2@bentonite nanocomposites; mechanical, thermal, and flame retardant properties

In this work, a strategy was used to combine Mg(OH)(2) nanoparticles (MDH), the bentonite nano-sheets, and melamine cyanurate (MC) to prepare dioctyl phthalate (DOP) plasticized polyvinyl chloride (PVC) nanocomposites with increased thermal stability, Limiting Oxygen Index (LOI), and tensile strength as well as reduced total heat release. To prepare MC-modified Mg(OH)(2)@bentonite nanohybrid (MMHB), MDH was installed on the calcined bentonite and consequently modified with MC. The nanocomposite thin films were prepared from plasticized-PVC and MMHB using the solvent casting method. It was found that the combination of MDH and the bentonite nano-sheets in the presence of MC could improve the PVC properties. Thermogravimetric analysis (TGA) in both N-2 and air atmospheres, indicated that the thermal stability of PVC was enhanced via adding MMHB, which was evident by the increased thermal decomposition temperature. The microscale combustion calorimetry (MCC) results of the PVC nanocomposites with 5% and 8% by mass of MMHB revealed that an optimal isolating layer is formed, which increased flame retardant properties. The PVC matrix nanocomposite containing 8% by mass of MMHB with LOI value of 33.4% exhibited high flame retardancy. Moreover, the tensile strength and elastic modulus of the sample containing 5% by mass of MMHB increased by 65.5% and 55.2% compared to those of pristine PVC, respectively.

Automated summary

In this study, a strategy was used to prepare dioctyl phthalate (DOP) plasticized polyvinyl chloride (PVC) nanocomposites with improved thermal stability, Limiting Oxygen Index (LOI), tensile strength, and reduced total heat release. This was achieved by combining Mg(OH)(2) nanoparticles, bentonite nano-sheets, and melamine cyanurate (MC). The addition of MC-modified Mg(OH)(2)@bentonite nanohybrid (MMHB) enhanced the thermal stability of PVC, as shown by increased thermal decomposition temperature. The PVC nanocomposites containing MMHB also exhibited higher flame retardancy and improved mechanical properties.