This work is a follow up to our quest to develop emulsion paint from amino resin. Both pure urea methylol (MU) and methylol urea/Nature rubber (MU/NR) blend were prepared. Some physico-chemical properties such as viscosity, melting point, moisture uptake, refractive index, density, elongation at break and formaldehyde emission of both MU and MU/NR were evaluated. The result revealed that MU/NR blend possesses better water resistant, hardness, flexibility and low formaldehyde mission while the pure MU gave better refractive index. Emulsion paints were also formulated from both resins and some physico-chemical properties namely pH, viscosity, flexibility, hardness, tackiness, resistance to blistering, dry time, gloss and storage stability were investigated. Emulsion paint derived from MU/NR binder except for gloss passed the entire test conducted while the one from pure MU binder failed flexibility, adhesion, hardness, tackiness and dry time. This work presents MU/NR paint as a high quality one and hence, may introduce a novel emulsion paint derived from MU/NR binder into the coating industry.

This work investigates the effect of urea formaldehyde (UF) viscosity on a composite derived from copolymerization reaction between urea formaldehyde (UF) and urea proparaldehyde (UP). Some physical properties of the urea formaldehyde/urea proparaldehyde (UF/UP) copolymer obtained at different UF viscosities (3.91-207.08 mPa.s) were evaluated. The melting point, refractive index, density and formaldehyde emission were found to increase with increase in UF viscosity while the dry time, moisture uptake and elongation at break were found to decrease with increase in viscosity. UF viscosity below 10.82 mPa.s was found to produce UF/UP copolymer composite which is ductile and soluble in water. Beyond this value, the composite became insoluble in water. Thus processing of UF/PU copolymer resin for emulsion paint formulation should be carried out below 10.82 mPa.s viscosity level. The results obtained from this experiment will offer formulators different options and will help to control formulation processes towards developing UF/UP copolymer composite as a paint binder for emulsion paint formulation.