Water-Based Polymers and Emulsions

This is the oldest and initially the only polymer available for latex paints. It is a copolymer of polystyrene, a hard, colorless resin and butadiene, a soft, tacky, rubberlike polymer. Paints based on styrene edition polymers have some disadvantages in their tendency toward poor freeze-thaw stability and low critical PVC. There is also a greater tendency toward efflorescence, the appearance of a white crystalline deposit on a painted surface. Styrene-butadiene polymers are rarely used now. 

Unlike PVAs, acrylics are basic (i.e., nonacid), thus reducing the danger that they will cause containers to rust. Moreover, since acrylics are almost completely polymerized prior to application as a paint film, there is practically no brittleness nor yellowing with age. These features improve the durability of acrylic paints in fact, durability is a special feature of acrylics. 

The major disadvantage of acrylics is cost, which is higher than other latices. In partial compensation, acrylics take higher pigmentation, so more low-cost extenders can be used. 

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