latices

Latices are colloidal suspensions of polymer particles dispersed in water. They are designed to form solid films when the water evaporates and the particles coalesce, enabling their use as binders in coatings, adhesives, textiles, and paper products.

Natural latices originate from rubber trees as natural rubber latex, a suspension of rubber particles in water containing proteins and lipids. Synthetic latices are produced by emulsion polymerization to yield polymers such as styrene–butadiene, acrylics, vinyl acetate, and polyurethane. The plural form latices is commonly used in technical contexts to refer to these colloidal systems.

Manufacture typically involves emulsion polymerization with surfactants and protective colloids to stabilize the growing polymer particles. Solids content generally ranges from about 20 to 60 percent, and particle sizes are tens to hundreds of nanometers. Stability depends on pH, electrolytes, temperature, and the choice of stabilizers; improper conditions can lead to coagulation. Film formation occurs after water removal, with particle deformation and coalescence; high-gloss or high-performance films may require coalescing agents or plasticizers, especially for polymers with high glass transition temperatures.

Properties of latices include rheology, drying behavior, film hardness, water resistance, and adhesion to substrates. The choice of monomers and continuous phase, along with additives such as crosslinkers and stabilizers, determines the final performance. Latices are widely used in latex paints and coatings, adhesives, paper coatings, textile finishes, and binders for nonwoven materials.

Health and safety considerations include potential latex allergies in natural latex systems; appropriate handling, ventilation, and personal protective equipment are advised. Environmentally, water-based latices typically offer lower volatile organic compound emissions than solvent-based binders, aligning with regulatory and sustainability goals.