Description of complementary actions of mineral and organic additives in thermoplastic polymer composites by Flame Retardancy Index

Abstract

This work visualizes the complementary actions of organic and mineral additives in model thermoplastic polymer composites in terms of Flame Retardancy Index (FRI). Thermal and flame retardancy behaviors of ethylene-vinyl acetate copolymer (EVA) composites containing calcium carbonate (CC) mineral and ammonium polyphosphate (APP) organic additives were studied varying composition of additives in the 80/20 EVA/(xCC + (20 − x)APP) composites with x denoting 0, 5, 10, 15, and 20 wt%. Thermogravimetric analysis (TGA) revealed that the onset temperature of composites and the remaining residue were increased by combination of APP and CC, while cone calorimetry results were indicative of a promising flame retardancy performance at a given composition of APP and CC. Based on FRI values, we made distinguished samples from flame retardancy performance viewpoint, where the best flame retardancy was obtained by combination of 15 wt% APP and 5 wt% CC, as reflected in FRI value of 3.08. By contrast, samples containing only APP or CC revealed low resistance against flame, as signaled by FRI values of 0.99 and 0.89, respectively. X-ray diffraction (XRD) analysis was made on remaining residue collected at the end of cone calorimetry measurements. Moreover, Raman analysis confirmed barrier effect of flame retardancy for EVA/(5APP + 15CC) sample, featured by a higher graphitization level as well as a thicker yet more homogenous char layer. Mechanical behavior analysis of composites revealed an acceptable level of properties, particularly high elongation at break, which was almost independent of formulation. However, a minor loss in yield stress was observed, especially for EVA(10CC + 10APP) sample.

Flame Retardant Polypropylenes: A Review

“…As observed in previous sections, using an additive alone can to a limited extent improve flame-retardant properties of PP. Combination of flame retardants is a strategy to improve further the flame retardancy via synergism between various flame retardants [ 140 , 141 , 142 ]. Moreover, the quantity of the used flame retardant can be reduced in polymer so as to prevent mechanical properties deterioration.…”

Flame Retardant Epoxy Composites on the Road of Innovation: An Analysis with Flame Retardancy Index for Future Development

“…By the use of dimensionless Cure Index [21] and dimensionless Flame Retardancy Index (FRI) [22], it was demonstrated that the quality of cure in epoxy composites ( Poor , Good , or Excellent ) can be correlated to the performance of flame retardancy ( Poor , Good , or Excellent ). The FRI was also powerful in exploring the complementary actions of mineral and organic additives in polymer systems in terms of the peak of HRR (pHRR), the total heat release (THR), and the time to ignition (TTI) of neat polymer and polymer composites [23]. In this work, with the aim of recognizing the future ahead of innovations in flame-retardant epoxy composites, reports on flame-retardant epoxy composites were comprehensively reviewed and then classified as a function of their flame retardancy performance by the use of the FRI criterion.…”

A Modified 3D-QSAR Model Based on Ideal Point Method and Its Application in the Molecular Modification of Plasticizers with Flame Retardancy and Eco-Friendliness

“…In order to evaluate the molecules comprehensively, it is necessary to treat a variety of indicators with different dimensions using mathematical methods or equations. For example, Vahabi et al [ 25 , 26 ] defined a simple universal dimensionless index for the first time, known as the flame retardancy index (FRI), which was useful for the comparative evaluation of the flame retardancy performance of thermoplastic systems regardless of the types of polymers and additives used. Li et al [ 27 ] evaluated molecules’ multi-effect comprehensively via a simplified formula method and standard deviation score method.…”