The effect of PMMA on physical properties of dammar for coating paint application

Abstract

Purpose

The aim of this paper is to describe the preparation and characterisation of poly(methyl methacrylate) (PMMA) (Mw: 996,000) and dammar mixtures to obtain a new series of natural coating materials for application on mild steel substrates. Dammar is a natural resin extracted from Dipterocarpus Grandiflorus sp., or kruing trees, which grow mainly in the tropical Asia Pacific forest.

Design/methodology/approach

Natural dammar resin was mixed with PMMA at different weight percentages in xylene as a solvent and dammar as dominant component. The mixtures were applied on mild steel Q‐panels to form dry coating films. The coating films were investigated under Attenuated Total Reflection‐Fourier Transforms Infrared (ATR‐FTIR) technique to observe the presence of functional groups from PMMA and dammar. Resistivity of coating films against corrosive agents from electrolytes was measured by using potential time measurement (PTM) technique. ASTM D3359 (cross‐hatch) technique was used to measure the coating film adhesion strength on the substrate. The entire tests were conducted at 28°C.

Findings

Natural dammar resins is potentially applicable for coating on cold rolled mild steel Q‐panel when mixed with PMMA. Blended dammar resin with PMMA in 5:5 ratio (coded as DP50) was found to give the highest energy of rapid impact indenter. Cross‐hatch test under ASTM D3359 revealed that 50 percent w/w of dammar in PMMA had increased the adhesion strength of the coating film where there was no coating area peeling off from the substrate after the test. DP50 also had the longest time to resist penetration of electrolytes through the coating film when immersed in salt water.

Research limitations/implications

Decreasing the amount of dammar lower than 50 percent weight ratio with PMMA will cause high viscosity and inhomogeneous mixtures.

Originality/value

Natural dammar resin mixed with PMMA (behaviour naturally in free standing film) for coating paint application was formulated.

Citation

Nasir, K.M., Halim, N.A., Tajuddin, H.A., Arof, A.K. and Abidin, Z.H.Z. (2013), "The effect of PMMA on physical properties of dammar for coating paint application", Pigment & Resin Technology, Vol. 42 No. 2, pp. 137-145. https://doi.org/10.1108/03699421311301133