A Study on Mechanical Properties of Alternative Insulation Composite Made from Rice Straw Waste and Polyvinyl Alcohol Binder

Abstract

This research aims to develop a sustainable alternative composite insulation material using rice straw as the main raw material to reduce deforestation, biomass waste, and open burning by farmers, which releases CO₂ into the atmosphere. Polyvinyl Alcohol (PVA) was used as a binder instead of conventional adhesives containing formaldehyde, in order to reduce emissions of Volatile Organic Compounds (VOCs) that are harmful to human health and the environment. Particle boards were fabricated from rice straw with varying PVA contents of 25%, 30%, and 35% by total weight, incorporating Citric Acid and Calcium Carbonate as additives. The samples were high-pressure hot press and tested for mechanical, physical, and thermal properties. Results showed that increasing the PVA content improved mechanical strength, especially bending resistance. The sample with 35% PVA exhibited the highest mechanical strength, while the sample with 30% PVA achieved the lowest thermal conductivity at 0.069 W/m·K, indicating good thermal insulation performance. Additionally, the material exhibited low moisture absorption and lower density compared to commercial products, making it suitable for building applications that require lightweight and environmentally friendly materials.

Keywords: Insulation composite, rice straw, polyvinyl alcohol, mechanical properties, sustainability.