Preparation and properties of rubber powder from modified-SBR latex by spray drying process

In this work, rubber powders were obtained by spraydrying of styrene-butadiene latex modified with a colloidal oxide, methyl methacrylate and sodium 4-styrene sulfonate. After the modification step, the particle size of latex dispersions was determined by photon correlation spectroscopy and showed an average diameter of about 100 nm. The latex dispersions were spray dried to obtain a particulate rubber. After the drying process, the morphology of the rubber powder particles was evaluated by scanning electronic microscopy. The micrographs revealed a coalesced system for unmodified styrene-butadiene latex and particulate systems for modified lattices containing colloidal oxide, both dried in the same conditions. The particle size of rubber powders analyzed by scanning electronic microscopy ranged from approximately 1 μm to 10 μm. Differential scanning calorimeter analysis indicated that the glass transition temperatures did not change significantly, and thermogravimetric analysis showed thermal stability until approximately 200 °C.