## 3 Results
### Washability (Wet Scrub Resistance)
In contrast to the styrene monomer grafted NRL, the methyl methacrylate (MMA) monomer grafted NRL (NRL\(-\)g\(-\)MMA) showed improved performance with frequent MMA ratio increases in NRL. The performance improvement of the NRL binder grafted with MMA began at a ratio of 20% MMA and reached its optimum at 30% MMA. The NRL sample grafted with 30% MMA (NRL\(-\)g\(-\)30% MMA) showed the best washability, reaching 12 cycles at the same binder concentration (sample NgMMA30-4). MMA grafted NRL is just as good as styrene. MMA promises much better performance on wet scrub and abrasion resistance. NRL grafted MMA promises better wet resistance, and grafted MMA in NRL polymer shows better compatibility with marked changes in hydrophilicity, increased adhesion, and film hardness. NRL grafted MMA monomer increases polarity and hydrophilicity, leading to high wettability resistance. In addition, the resulting film has a high adhesiveness and higher scrub resistance [34,36,49]. Another method was applied to improve the performance of NRL in terms of tackiness and water resistance. The method can change the hydrophilicity and polarity by mixing NRL\(-\)g\(-\)20% St and NRL\(-\)g\(-\)30% MMA with a ratio of 1:1 (Sample NgSt\(/\)NgMMA). The  
Figure 2: Washability of Various Types of Emulsion Paint Binders with Variations in Monomer Concentration. results can be seen in Figure 2; there was an increase in washability, indicating that adhesion and water resistance increased. The overall performance of mixing NRL\(-\)g\(-\)St and NRL\(-\)g\(-\)MMA at a ratio of 1:1 was still below NRL\(-\)g\(-\)30%MMA and NRL\(-\)g\(-\)20%St at their respective optimum concentrations. The mixing of NRL\(-\)g\(-\)30%MMA and NRL\(-\)g\(-\)20%St could not achieve optimal performance, and a binding competition occurred between the radicals formed by styrene and MMA. The radicals formed in the MMA-grafted NRL were active in scavenging radicals apart from the styrene-grafted NRL. There is competition for the binding of radicals in the NRL chain, which affects the total number of radical sites, limits polarity, and makes the performance of the binder in binding paint components not optimal [47,50]. The performance of the binder is influenced by the concentration of the binder in the paint mixture. The increase in the concentration of the binder is directly proportional to the increase in the ability of the paint to overcome wet scrub and abrasion. It can be seen in Figure 3 that the washability of the emulsion paint increased along with the increase in the concentration of the binder, which was observed in all samples. Among all the samples presented, the concentrated NRL-based binder (CNRL sample) has the lowest performance compared to PVAc-based paint at various binder concentrations. Sample CNRL has a performance in overcoming wet scrub and abrasion only half of that of PVAc, indicating that the performance of concentrated NRL-based binders (CNRL sample) cannot compete with commercial binders such as PVAc. Different things were observed in the NRL sample grafted with 20% styrene (sample NgSt20), the NRL grafted with 30% MMA (sample NgMMA30), and the combination of NRL grafted styrene and MMA (sample NgSt20/NgMMA30). As a result, all samples achieved optimal performance at 10% binder concentration, NgSt20-10 with 22 cycles, NgMMA30-10 with 23 cycles, and NgSt20/NgMMA30-10 with 21 cycles. Increasing the concentration of the binder in the paint mix not only increases the paint's resistance to wet rubbing and abrasion; increasing the binder concentration also improves adhesion, gloss, moisture resistance, weather resistance, and oil and solvent resistance [51,52]. Although the use of NRL-based binders grafted with styrene or MMA showed a very satisfactory paint performance, it should be noted that using NRL-based binders has a higher production cost. Therefore, combining NRL grafted with styrene or MMA with synthetic polymers should be considered to reduce production costs. Figure 3: Washability of Various Types of NRL Binders at Various Concentrations.