Tese: Bio-Based Flame Retardation of Acrylonitrile-Butadiene-Styrene
Aluno(a) : Gustavo SchinaziOrientador(a): José Roberto d'Almeida
Área de Concentração: Termociências
Data: 21/10/2020
Link para tese/dissertação: http://doi.org/10.17771/PUCRio.acad.55266
Resumo: Polymers are used in a wide variety of applications and are present in all aspects of people’s daily lives; one of the main drawbacks related to their use, however, is their flammability. Major advances have been made in developing flame retardants (FRs) to be used in polymers, but most of the commercial FR additives in use today, mainly halogenated FRs, are extremely toxic both to humans and to the environment and are thus being increasingly regulated or banned throughout the world. Research into the use of renewable products as FRs for polymers has grown exponentially in the past two decades as a result, leading to the creation of many bio-based, environmentally-friendly FR systems. Acrylonitrile-butadiene-styrene (ABS) is one of the most widely used polymers in the world, but it is also one of the most flammable and one of the most challenging to flame retard due to its complex terpolymer structure. It is currently used commercially with toxic halogenated FRs, which face global restrictions or bans. Very little work has been performed on reducing ABS’s flammability using nature-derived or low-toxicity flame retardants. There is therefore an urgent need for the development of low-toxicity, bio-based FR systems to substitute halogenated FRs for commercial use in ABS. The present work aims to contribute to the development of a bio-based flame-retardant solution for ABS. The first objective, a practical goal, is to develop a flame-retardant grade of ABS using mainly nature-derived additives, while maintaining acceptable mechanical properties. The second objective, having a scientific intent, is to comprehend the mechanisms of flame retardation of the bio-based FRs. The project consists of a two-phase study: (1) a Screening Phase, during which the effects of 8 different FRs and combinations thereof on ABS’s flammability are evaluated through microscale combustion calorimetry (MCC); and (2) a Detailed Analysis and Mechanistic Study Phase, in which the most promising candidates from Phase 1 are further analyzed through a variety of techniques with the objectives of better understanding their flammability and mechanical performances and of comprehending their mechanisms of flame retardation. Chapter 1 presents a brief introduction to the work followed by a literature review. Chapter 2 contains the experimental methodology used throughout the research. The Screening Phase is discussed in Chapter 3, which provides details about the experimental planning, preliminary tests, and the results of the screening experiments; the most promising samples and scientifically motivating synergies are identified. Chapter 4 contains the results of Phase 2, presenting in-depth discussions and hypotheses to explain the flame-retardation mechanisms of the bio-based FRs in ABS. Chapter 5 provides the main conclusions of the research and recommendations for future work.