The Flame Retardancy of Polyethylene Composites: From Fundamental Concepts to Nanocomposites

Abstract

Polyethylene (PE) is one the most used plastics worldwide for a wide range of applications due to its good mechanical and chemical resistance, low density, cost efficiency, ease of processability, non-reactivity, low toxicity, good electric insulation, and good functionality. However, its high flammability and rapid flame spread pose dangers for certain applications. Therefore, different flame-retardant (FR) additives are incorporated into PE to increase its flame retardancy. In this review article, research papers from the past 10 years on the flame retardancy of PE systems are comprehensively reviewed and classified based on the additive sources. The FR additives are classified in well-known FR families, including phosphorous, melamine, nitrogen, inorganic hydroxides, boron, and silicon. The mechanism of fire retardance in each family is pinpointed. In addition to the efficiency of each FR in increasing the flame retardancy, its impact on the mechanical properties of the PE system is also discussed. Most of the FRs can decrease the heat release rate (HRR) of the PE products and simultaneously maintains the mechanical properties in appropriate ratios. Based on the literature, inorganic hydroxide seems to be used more in PE systems compared to other families. Finally, the role of nanotechnology for more efficient FR-PE systems is discussed and recommendations are given on implementing strategies that could help incorporate flame retardancy in the circular economy model.

Kinetic Modeling and Degradation Study of Liquid Polysulfide Resin-Clay Nanocomposite

“…In general, it can be observed from Table 3 and Figure 5 that the inhibitory effect of CNPs increases the thermal stability of the final nanocomposites, which is typically the primary effect at low clay concentrations. The thermal stability of the samples at low percentage clay incorporation is due to the proper interaction between the CNPs and the LPS matrix as shown in Figure 1 , as well as the shielding effect of the charred polymer on the surface, which stops oxygen from being widely absorbed into the polymer matrix and raises the temperature of degradation [ 21 , 31 ].…”

“…The increase in the temperature of the heat degradation of nanocomposites containing lower percentages of CNPs than 5% can be justified by the decrease in the free movement of volatile products in polymer nanocomposites due to the heat degradation (gases emitted during sample pyrolysis) [17,30] In general, it can be observed from Table 3 and Figure 5 that the inhibitory effect of CNPs increases the thermal stability of the final nanocomposites, which is typically the primary effect at low clay concentrations. The thermal stability of the samples at low percentage clay incorporation is due to the proper interaction between the CNPs and the LPS matrix as shown in Figure 1, as well as the shielding effect of the charred polymer on the surface, which stops oxygen from being widely absorbed into the polymer matrix and raises the temperature of degradation [21,31].…”

Non-Isothermal Thermogravimetry of Selected Tropical Woods and Their Degradation under Fire Using Cone Calorimetry

“…This was valid for Cumaru, Ipe, and Kempas while Garapa and Merbau decline. This is probably due the fact that the latter two woods give the decomposition phenomenon composed formally from two processes [ 19 , 32 , 33 , 34 , 35 , 36 ].…”

Circular Economy: a Comparison Between the Case of Singapore and France

“…However, most of these valuable resources eventually end up as waste materials. Hence, global waste management should be implemented to develop an economic material use model to stop the waste of materials and consuming them wisely (Baldé et al 2017;Rezvani Ghomi et al 2020b;Shanmugam et al 2020;Telega and Telega 2020). Developing a circular economy system (CES) provides sufficient management in handling the life cycle of raw materials and enables economic development which is lucrative for society, businesses, and the environment.…”