Carbon Nanotube-Based Intumescent Flame Retardants Achieve High-Efficiency Flame Retardancy and Simultaneously Avoid Mechanical Property Loss

Abstract

Intumescent flame retardants (IFR) are an excellent solution to the problem of easy combustion of polymers. Still, the negative effect of the addition of flame retardants is the decline of the mechanical properties of polymers. In this context, carbon nanotubes (CNTs) are modified with tannic acid (TA) and then wrapped on the surface of ammonium polyphosphate (APP) to construct a special intumescent flame retardant structure (CTAPP). The respective advantages of the three components in the structure are explained in detail, especially the role of CNTs with high thermal conductivity in the flame retardant system. Compared with pure natural rubber (NR), the peak heat release rate (PHRR), total heat release (THR), and total smoke production (TSP) of the composites proposed with special structural flame retardants are decreased by 68.4%, 64.3%, and 49.3%, respectively, while the limiting oxygen index (LOI) increased to 28.6%. The TA-modified CNTs wrapped on the surface of APP can effectively reduce the mechanical damage caused by the flame retardant to the polymer. To sum up, the flame retardant structure of TA-modified CNTs wrapped on APP can effectively enhance the flame retardant properties of the NR matrix and reduce the negative impact on mechanics caused by adding APP flame retardant.

Microwave-Induced Construction of Flame-Retardant TPU Foams with Adjustable Sensitivity for Piezoresistive Sensing

“…However, after 700 °C, the quality of the TBC continued to decline slowly. This might have been due to the continued rise in temperature, causing the formed carbon layer to break and the smoke trapped by the carbon layer to escape, resulting in some quality loss …”

“…This might have been due to the continued rise in temperature, causing the formed carbon layer to break and the smoke trapped by the carbon layer to escape, resulting in some quality loss. 38 To compare the combustion performance of TPU and TBC materials, LOI and UL-94 tests were conducted. The LOI test results are shown in Figure 6c.…”

Facile preparation of a hydrophobic intumescent flame retardant toward simultaneously enhanced flame retardancy and smoke suppression of thermoplastic polyurethane

“…[20][21][22] TA can act as the char source for an IFR system owing to the large number of phenolic hydroxyl groups on its structure. [23][24][25] For instance, Qu 26 et al prepared a special IFR by using APP, carbon nanotubes (CNTs) and TA, and introduced the IFR into pure natural rubber (NR) to fabricate NR/IFR flame-retardant composites. When the addition of the IFR is 50.0 wt%, the peak heat release rate (PHRR) and total heat release (THR) are reduced by 68.4% and 64.3%, respectively.…”

Microporous Polyurethane Elastomer’s Comprehensive Properties Affected by Flame Retardant EG/APP

“…However, the mechanical strength, vibration reduction abilities, creep resistance, fatigue resistance, and other qualities frequently suffer significantly from the inclusion of flame retardants. Consequently, meeting the usage requirements becomes challenging [1][2][3] . To overcome this challenge, composite flame retardants have been developed.…”