Purification and Modification of Araucaria (Araucaria excelsa R. Brown) Resin for Paint Formulations

Author : Avanzado, Marlon B.
Major Adviser : Fernandez, Elvira C.
Major Co-Adviser : Valencia, Sixto A.
Committee Members : Movillon, Jovita A. 
Year : 1996
Month : May
Type : Thesis
Degree: BS
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Freshly tapped resin exudates from Araucaria (Araucaria excelsa R. Brown) were dried, purified using 95% ethanol as solvent and then modified at 330 °C – 350 °C. The effect of the volume of solvent used in the purification of resin on the % yield, and % solvent recovery was studied. Also studied was, the effect of time of modifying at different temperatures on the % yield and acid number of the modified resin.

The results showed that as the volume of the solvent used in purifying the resin increased, the % yield and % solvent recovery also increased. The best resin-solvent ratio was determined to be at 350 ml. Thermal processing is a feasible process of chemically modifying the Araucaria resin to a form suitable as a binder and film former in paint manufacture. The run resin at 340 °C and 1.5 hrs. was the most appropriate condition for the thermal processing, for at this condition lesser time is needed to produce a modified resin that has the lighter color and has an acid number of 16.96 (mg. NaOH/g sample) which was compatible with paint.

Energy balance calculations revealed an average energy requirement per unit of resin of 2.7374 w-h/g for ethanol recovery at 50 g : 350 ml resin-solvent ratio and 0.4798 w-h/g for modifying the resin at 340 °C for 1.5 hrs.

Ten experimental paint formulations using modified and synthetic resins were subjected to standard test for specific properties. The viscosity of the paint formulations were low. The color of the paints was off-white due to the dark color of the resin and oil. All the formulated paints exhibited better specific gravity, flow brushing, adhesion and resistance to staining agents as compared to a white commercial paint.

Using Friedman’s statistical test, one formulation, M10-F3C, with modified to synthetic resin ratio of 70 : 30, performed satisfactorily and equally to that of the commercial paint.

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