TGA of Flame Retardants in EVA

Purpose

The Al(OH)₃ (ATH) and Mg(OH)₂ (MDH) flame retardants analyzed in Section 4.7.1. TGA of aluminum trihydrate and magnesium hydroxideare analyzed in an ethylene-vinylacetate copolymer (EVA)

Sample

Three EVA samples analyzed were:

EVA with ATH

EVA with MDH

EVA with ATH and MDH  

Conditions

Measuring cell: TGA/SDTA851e

Pan: Alumina 70 ul

Sample preparation: Approx. 20 mg

TGA measurement: From 35 °C to 600 °C under nitrogen atmosphere (200 ml/min), then from 600 °C to 850 °C under oxygen (200 ml/min)

                                    Heating rate: 30 K/min 

Atmosphere: Nitrogen then oxygen, automatically switched  

The diagram displays the TGA and DTG curves of the three samples as a function of temperature.  

Interpretation

A large step due to the pyrolysis of the EVA is observed around 460 °C. The elimination of the water from the flame retardants can be seen in the range 300 °C to 400 °C. A quantitative analysis is however difficult because EVA eliminates acetic acid between 360 °C and 400 °C. 

Conclusions 

The presence of flame-retarding materials in polymers can be detected using simple TGA measurements. 

^{TGA of Flame Retardants in EVA | Thermal Analysis Application No. HB 485 | Application published in METTLER TOLEDO TA Application Handbook Elastomers Volume 2}