M.P. Aji, N. Fitriya, I. Rahmawati, A. Priyanto, Yusmantoro, Sulhadi
We have easily investigated the negative thermal expansion of plastic bottle. Plastic bottle contracts its diameter due to the temperature enhancement when it loaded by heated water. Length ratio of diameter contraction compared with the initial diameter is considered as the negative thermal expansion. We have calculated the negative thermal coefficient in two kinds of plastic bottles as σA = 860 ×10-6/°C for bottle A and σB = 620 ×10-6/°C for bottle B. Those coefficients confirmed at the range thermal coefficient of polyethylene as common raw material of plastic bottles. This investigation completes the student understanding in term of thermal expansion subject in physics classroom. They shall not only learn the expansion due to the temperature enhancement but they also learn the contraction as well through negative thermal expansion of plastic bottle. © 2019 Published under licence by IOP Publishing Ltd.
Department of Physics, Universitas Negeri Semarang Jalan Raya Sekaran Semarang, Central Java, Indonesia