Bio-coating is a natural anti-corrosion coating material that can be easily degraded and renewed. Rice husk extract and damar resin are alternative natural materials believed to have a relatively high silica content, so they can be used as a substitute for synthetic chemicals in protecting metals from corrosion. This research aims to determine the heat resistance ability of bio-coating on mild steel in a 1 M H2SO4 acid corrosive medium.
The experimental object used rice husk waste and damar resin as raw materials. The analytical method used is the weight loss method. Damar resin and silica sol, obtained from rice husks' ashing, are mixed to form a homogeneous product. Metal samples coated with bio-coating material were immersed in 1 M sulfuric acid solution, with silica concentrations of 1500 ppm, variation times 1, 3, and 5 hours, and at temperatures of 30, 40, 60, and 80 °C. At 80 °C, the corrosion rate is very high, which proves that the temperature significantly affects the corrosion rate of mild steel immersed in an acid solution. The results showed that the best conditions were four hours of immersion time temperature of 40 0C, with an inhibition efficiency of 98%.
- INTRODUCTION
Corrosion is common in everyday life. We often encounter this phenomenon. Generally, people are more familiar with corrosion than rusting. Corrosion is a process of degradation of metal materials against environmental influences. Corrosion can occur on various metals, including copper, zinc, steel, and mild
steel. The industry's common use of metal materials makes the destructive symptoms a significant roblem
hindering industrial equipment performance.
Other impacts caused by corrosion are technical losses, reduced efficiency, reduced construction strength, poor appearance, and increased maintenance costs. The development of technology for corrosion prevention continues, with the coating being one of them coating the surface of the material as a form of protection to prevent corrosion of metal materials. The use of primary coating material often used is synthetic chemical compounds.
However, using these basic materials has a negative impact if used in the long term, especially on preserving nature and living things around it. Coating materials based on synthetic chemicals can be categorized into fluid flows, affecting the characteristics of the fluids used in an industry (Susilo Wati, 2018). Therefore, natural-based or bio-coatings are necessary to protect metals from forming corrosion. In addition, the use of natural materials also has a positive impact on the environment in maintaining its sustainability. Bio-coating is a coating material that can be easily degraded and is renewable (Pal et al., 2020). Coating materials derived from natural materials (bio-coating) can be safer than synthetic chemicals.
Several studies have been conducted to determine the ability of extracts of natural materials as coating materials, including flamboyant resin (Pramudita et al., 2013), Aster koroensis (Mayakhrisnan et al., 2017), citrus aurantium (Hassan et al., 2016), Pisum sativum peels extract (Srivastava et al., 2018), lemon seeds (Hassannejad et al., 2018) and Cuscuta reflexi extract (Saxena et al., 2018). Damar resin is one of the most abundant plants in Indonesia's tropical forests and belongs to the genus of Shorea and Hopea. Bio-coating is a breakthrough that can be applied to support and create eco-friendliness in industrial areas by changing the process of making coatings which initially used synthetic chemicals into natural or organic ingredients. There are many advantages to using bio-coating, including being environmentally friendly, materials that are easy to obtain, do not require high costs, and can minimize adverse effects on the health of living things and the environment.
Rice husk and damar resin are alternative materials for coatings derived from natural materials that can replace coating materials made from synthetic chemicals for metal protection. Rice husk extract has a relatively high silica content, ranging from 87-97%. The sol-gel method can synthesize silica in rice husks (Kuljana and Rodiah, 2019). Silica is known to have good adhesion and holding roperties. On this basis