Abstract
Industrial wastes of urea-formaldehyde (UF) and melamine-formaldehyde (MF) resins have been collected from industrial sources in Jeddah. Such wastes were classified, with the exclusion of unsuitable fractions, according to color or shape. After that, classified wastes were ground into relatively fine powder and the coarse granular parts were excluded with the aid of special sieves. The powdered wastes were mixed in different compositions with unsaturated polyester (UP) in the presence of cobalt octanoate activator and methylethylketone peroxide initiator for crosslinking. Different mixtures were prepared in a cylindrical form and characterized through their ability to absorb water and their compression strength. Results have been discussed according to the variation of the chemical structure of the waste resins used. They reflect the ability of thermosetting polymeric wastes, especially those of UF and MF resins, to be utilized as fillers and reinforcing materials in UP end-products.