Recycling of an acrylate–glass fiber reinforced polyester composite

Recycling possibilities were evaluated for a composite waste composed of glass fiber reinforced polyester bound to a layer of crosslinked polymethylmethacrylate. Grinding allowed removal of a majority of glass fibers; however, the two constituent materials remained bonded. The ground material was extruded as filler with polypropylene, polymethylmethacrylate, and acrylonitrile–butadiene–styrene, allowing maximum filling of 90, 60, and 70%, respectively. The highly filled materials had acceptable impact resistance but possessed processing limitations. Alternatively, the ground waste was mixed with unsaturated polyester resins, compacted and crosslinked to yield boards of various dimensions. With 10% resin addition, crosslinking at 80 °C and compression moulding at pressures above 200 bar boards comparable to wood particleboards were prepared. Mechanical properties, water uptake, and resistance to solvents of the boards were determined. Larger boards prepared by this method were successfully used in an industrial test production of bathtubs.