Green acoustic insulator derived from cellulose and silica

Abstract

Acoustic insulator is one the way to overcome noise that can interfere with human health. The existing acoustic insulator is made of petroleum which affects the environment. Potential cellulose source as an acoustic insulator matrix can be found from wood, hemp, and newspaper waste. The newspaper waste contains of 61% cellulose. It is considered that the newspaper waste can act as an economically potential raw material for acoustic insulator. The nature of the cellulose with strong hydrogen bonding requires a suitable solvent. Solvents that are widely used today are only limited to the laboratory scale, toxic, volatile, and can cause effect the environment. The type of solvent that is more environmentally friendly is NaOH/polyethylene glycol (PEG). Based on the literature review, cellulose added with silica can improve the previous cellulose properties, where the addition of silica can increase thermal stability, mechanical strength, increase flexibility, increase surface area, reduce thermal conductivity. Potential silica source can be found from geothermal solid waste. Geothermal solid waste contains of 85.6% silica. The process of adding silica to cellulose is carried out through the in-situ method because it is more efficient than the impregnation method. The preparation of acoustic insulators from cellulose and silica requires drying process. There are various types of drying methods, including freeze drying, supercritical CO2, and ambient pressure drying. This paper recommends the manufacture of acoustic insulator made from cellulose and silica by in situ method followed by ambient pressure drying.