Characteristics of exterior emulsion paint using natural rubber latex binder

Abstract

Exterior paint protects buildings or infrastructures against weather conditions, contaminants, or other things that can degrade the building. Water-based exterior wall paint development currently uses acrylic-based binders with high adhesion, abrasion resistance, heat resistance and good weather. The combination of acrylic with natural rubber latex is expected to be a solution to improve the performance of natural rubber latex as an exterior paint binder to improve adhesion, cohesion, tensile strength, tear strength, modulus, and weather resistance. Natural rubber latex is modified by grafting acrylic resin into it. This method begins with mixing additives such as benzoyl peroxide, Sodium Lauryl Sulfate (SLS), Ethylenediaminetetraacetic Acid Disodium Salt (EDTA 2 Na), Sodium sulfite and Polypropylene glycol into natural rubber latex with operating conditions at a temperature of 85 °C for 60 min. The natural rubber latex binder was then mixed into the exterior paint base, and characterization was carried out using Fourier transform infrared (FT-IR) spectroscopy, scrub, abrasion test, opacity, contact angle, and scanning electron microscope (SEM). The test results showed that acrylic resin improved the performance of natural rubber latex-based paint as the acrylic resin content in the natural rubber latex increased. The best results were obtained on natural rubber latex grafted with acrylic resin at a ratio of 50:50 (NRL-AR (50:50)) with scrub and abrasion values ​​reaching 2400 cycles at a binder content of 18%, pigment volume concentration (PVC) 50% and a contact angle of 76°. Meanwhile, the scanning electron microscope (SEM) images showed that the acrylic resin-modified natural rubber latex binder did not agglomerate, and the distribution of paint components was better.