Enhancement of flame retardancy and mechanical properties of poly(butylene succinate) composites by adding hybrid fillers

Abstract

Poly(butylene succinate) (PBS) is a biodegradable polymer that has attracted increasing commercial interest due to the environmental concern. PBS has similar mechanical properties and processing performance to commodity polymers, e.g. polypropylene and polyethylene. However, its poor flame retardancy, especially heavy plastic melt dripping has restricted its potential applications in electronic devices, construction, automobiles, etc. To improve flame retardancy and keep bio-based characteristic of PBS, PBS composites were prepared using ammonium polyphosphate (APP), water hyacinth flour (WHF), and montmorillonite (MMT) as fillers. Total weight of the fillers was kept constant at 30 wt%. The weight ratio of APP to WHF was 2:1 while the added MMT contents were varied. Mechanical properties of the PBS composites were investigated using tensile, flexural, and impact testing. In addition, their flammability and thermal properties were determined by vertical burning test, horizontal burning test, and thermogravimetric analysis. APP/WHF/PBS composites showed the improved tensile modulus, flexural modulus, flexural strength, and notched impact strength with respect to those of neat PBS. Nonetheless, the incorporation of MMT insignificantly altered tensile and flexural properties of MMT/APP/WHF/PBS composites. Although both APP/WHF/PBS and MMT/APP/WHF/PBS composites exhibited the improved flame retardancy as compared with the neat PBS, they still had plastic melt dripping.