Cooperative Effect of Chemical and Physical Processes for Flame Retardant Additives in Recycled ABS

Alicia Rodriguez; Manuel Herrero; Maria Asensio; Mercedes Santiago-Calvo; Julia Guerrero; Esteban Cañibano; Maria Teresa Fernández; Karina Nuñez

doi:10.3390/polym15112431

Cooperative Effect of Chemical and Physical Processes for Flame Retardant Additives in Recycled ABS

Polymers (Basel). 2023 May 24;15(11):2431. doi: 10.3390/polym15112431.

Authors

Alicia Rodriguez¹, Manuel Herrero¹, Maria Asensio¹, Mercedes Santiago-Calvo¹, Julia Guerrero¹, Esteban Cañibano^{1

2}, Maria Teresa Fernández¹, Karina Nuñez¹

Affiliations

¹ Foundation for Research and Development in Transport and Energy (CIDAUT), Parque Tecnológico de Boecillo, 47051 Valladolid, Spain.
² Department of Architectural Construction, Geotechnical Engineering, Continuum Mechanics and Structure Theory, School of Industrial Engineering, University of Valladolid, Paseo del Cauce 59, 47011 Valladolid, Spain.

Abstract

In the present work, the effectiveness of four non-halogenated flame retardants (FR) (aluminium trihydroxide (ATH), magnesium hydroxide (MDH), Sepiolite (SEP) and a mix of metallic oxides and hydroxides (PAVAL)) in blends with recycled acrylonitrile-butadiene-styrene (rABS) was studied in order to develop a more environmentally friendly flame-retardant composite alternative. The mechanical and thermo-mechanical properties of the obtained composites as well as their flame-retardant mechanism were evaluated by UL-94 and cone calorimetric tests. As expected, these particles modified the mechanical performance of the rABS, increasing its stiffness at the expense of reducing its toughness and impact behavior. Regarding the fire behavior, the experimentation showed that there is an important synergy between the chemical mechanism provided by MDH (decomposition into oxides and water) and the physical mechanism provided by SEP (oxygen barrier), which means that mixed composites (rABS/MDH/SEP) can be obtained with a flame behavior superior to that of the composites studied with only one type of FR. In order to find a balance between mechanical properties, composites with different amounts of SEP and MDH were evaluated. The results showed that composites with the composition rABS/MDH/SEP: 70/15/15 wt.% increase the time to ignition (TTI) by 75% and the resulting mass after ignition by more than 600%. Furthermore, they decrease the heat release rate (HRR) by 62.9%, the total smoke production (TSP) by 19.04% and the total heat release rate (THHR) by 13.77% compared to unadditivated rABS; without compromising the mechanical behavior of the original material. These results are promising and potentially represent a greener alternative for the manufacture of flame-retardant composites.

Keywords: acrylonitrile-butadiene-styrene; mechanical properties; non-halogenated flame retardants; recycled.

Grants and funding

The research was funded by the CREATOR PROJECT (European Union’s Horizon 2020 Research and Innovation Programme under the Grant Agreement no. 820477) and the Osiris Network (funded by the CDTI within the framework of aid for Technological Centres of Excellence “Cervera”. CER-20211009). The authors acknowledge the financial support of the Ministry of Economy and Competitiveness (MINECO) of Spain through the PTQ2020-010968 project (M. Asensio) and the PTQ2021-011628 project (M. Santiago-Calvo).