A Química dos Incêndios no Ensino de Termoquímica: Vídeos com Abordagem em Aditivos Retardantes de Chama e Ensaios de Inflamabilidade para o Ensino Médio

Resumo

This work used two videos as complementary teaching tools for learning thermochemistry concepts, using the flammability of polymers and the action of a class of flame retardant additives, metallic hydroxides, for contextualization. With this novel approach, the videos were exhibited during a thematic workshop held with third-year high school students from two public schools. The first video, 8 minutes long, addressed the polymer combustion process, a real-life fire case, and the importance of flame retardant materials. The second video, 12 minutes long, showed tests for evaluating flame retardancy: cone calorimetry, limit oxygen index, UL-94, and glow-wire test. The workshop lasted approximately 90 minutes and also included a dialogued lesson and the application of a questionnaire before and after the activity. Learning gain was calculated using Hake’s method. The results indicated that the videos aided in learning thermochemistry concepts and raised students’ awareness of fire safety. Furthermore, the videos allowed them to learn about experiments that could only be seen in laboratories conducting research in this area and serve as a helpful tool for high school chemistry teachers, as they are relatively short, adaptable to different uses, and can even be shown during a regular class.