Synthesis of Anti-Corrosion Coconut Oil-Based Polyurethane Coating Nanocomposites with Functionalized Carbon Nanotubes
Seigfred M. John Miranda (1, a), Marloie T. Menchavez (1, b), Jumel Vincent R. Garnica (1, c), Abhel Y. Ananoria (1, 2, d), Dave Joseph E. Estrada (1, e), Roberto M. Malaluan (1, 2, f), and Arnold A. Lubguban (1, 2, g)

Author Affiliations
1) Department of Chemical Engineering and Technology, Mindanao State University - Iligan Institute of Technology, Andres Bonifacio Avenue, Tibanga, 9200 Iligan City, Philippines
2) Center for Sustainable Polymers, Mindanao State University - Iligan Institute of Technology, Andres Bonifacio Avenue, Tibanga, 9200 Iligan City, Philippines

Author Emails
a) seigfredjohn.miranda[at]g.msuiit.edu.ph
b) marloie.menchavez[at]g.msuiit.edu.ph
c) jumelvincent.garnica[at]g.msuiit.edu.ph
d) abhel.ananoria[at]g.msuiit.edu.ph
e) davejoseph.estrada[at]g.msuiit.edu.ph
f) Roberto.malaluan[at]g.msuiit.edu.ph
g) arnold.lubguban[at]g.msuiit.edu.ph

Abstract

Abstract. PU coating is a barrier material applied to the surface of a substrate to protect it from various types of deterioration processes. The rise of PU synthesized from bio-based polyol has drawn attention to both research and industry, as the scarcity of petrochemical resources paved the way to consider other alternatives. However, pristine bio-based PU isn^t capable of withstanding high thermal and mechanical stress conditions. To achieve properties comparable to petrochemical-based PU, bio-based PU coatings are commonly modified via filler addition. One of the most commonly used fillers is carbon nanotubes (CNTs) since it possess excellent thermal, mechanical, and barrier properties. In this study, coconut oil-based PU (CCOPU) coating reinforced with functionalized multi-walled carbon nanotubes (MWCNTs) was synthesized through in situ polymerization. MWCNT fillers, varied at three different weight percent loading, (0%, 0.1%, and 1%), were added to the CCOPU matrix with the aid of ultrasonication to determine its effects on the different properties of CCOPU. Results show that the addition of MWCNT to the CCOPU matrix resulted in a significant increase of the thermal stability, signified by an increase in the onset of degradation temperature, due to appearance of a tortuous path that hinders escape of volatile degradation products. Oppositely, filler loading has a negative effect in the barrier property of the rCCOPU coatings. This may be because of hydrophilic -OH group overpowering the hydrophobic MWCNT at higher filler loading, the increase in coating capacitance due to addition of conductive MWCNT, and the appearance of void areas due to agglomerations. Filler loading also has a positive effect in water contact angle which is due to the filler present in the surface layer of the rCCOPU coating. Lastly, the adhesiveness of CCOPU did not change even with the presence of fillers.

Keywords: MWCNT- anti-corrosion polyurethane coating- ultrasonication

Topic: Material and Applied Chemistry