Effect of Flame Retardants and 1% Stabilizer on Burning and Melt Dripping Behaviour of PP Thermoplastic Polymers

Abstract

This study aimed to understand the mechanism of combining the action of different types of flame retardants (FR) on melting, flammability behaviour and burning behaviour, and its moderation of the Polypropylene (PP) polymer. PP Polymer was chosen to be blent in a twin-screw extruder with the flame retardants and an additive, which is a 1% Stabilizer, to investigate Polypropylene's melting, flammability and burning moderation in order to reduce it. Burning and flammability behaviour test conditions, which are known as UL49 vertical and horizontal burning tests, were applied in this study. The flame was applied for 10 seconds and the length of time that the sample burned was measured. The flame was reapplied 10mm below the burned edge of the sample for a further 10 seconds. The length of time the sample burned for a second time was measured. The melting, dripping, and burning behaviour was recorded using high-speed video. These PP Polymer samples behave very differently in terms of upward flame spread. The study also indicates that the melting behaviour of thermoplastic materials is an important characteristic in fires which should be taken into account in the development of models, in particular for upward flame spread models. To study melt dripping behaviour, a burning methodology was developed. The results from these experiments have been analyzed to draw a relationship between melt dripping and burning behaviour. Most of the previous work on melt and dripping behaviour was concentrated on the study of fire operating conditions and modelling of the thermal process, however, no work has been reported on the quantitative relationship between melt and burning behaviour of thermoplastic polymers.