Sustainable hybrid composites of recycled polypropylene and construction debris

Abstract

We prepared composites of recycled polypropylene and construction debris aiming to obtain a sustainable hybrid material, with prospective application in the construction industry. We varied the amount of debris in 0, 1, 2, 3 and 7 m/m/% and the compounded materials were analysed by scanning electron microscopy, thermogravimetry/derivative thermogravimetry, differential scanning calorimetry, Fourier-transform infrared spectroscopy, melt flow rate, wide angle X-ray diffractometry, nuclear magnetic resonance relaxation time and dynamic mechanical analysis. The melt flow rate varied non-linearly according to the debris content. The thermal stability of recycled polypropylene was slightly improved due to the presence of debris particles. The degree of crystallinity of the recycled polypropylene also showed a non-linear change, and we noticed some transcrystallization phenomenon in the polymeric matrix. The glass transition temperature decreased for all composites, denoting an increase in the segmental mobility of the polymeric chains. Considering the domains curves of the nuclear magnetic resonance, there was some interaction between polymer and debris particles, mainly ascribed to the nanometric portion of the hybrid debris particles. We concluded that this hybrid composite may become of great interest to the construction industry, used as replacement for closing boards.