EFFECT OF AGING ON MINERAL-FILLED NANOCOMPOSITES

摘要

Nanocomposites are a new class of mineral-filled plastics that offer above-average mechanical properties, heat resistance, and gas-barrier properties. Injection-molded clay-filled poly(butylene terephthalate) nanocomposites and pure PBT were exposed to artificial weathering conditions for up to 36 weeks. Using X-ray diffraction, the degree of crystallinity and crystal size were measured for samples exposed up to 6000 hrs. At exposures less than 400 hrs, crystallinity and crystal size increased for the pure PBT samples. At longer exposures, the crystallinity reached a plateau while the crystal size dropped after 1200 hrs. UV-radiation penetrates ≈25μm into the exposed surface for the nanocomposite and ≈50 μm for pure PBT. For longer exposures the degradation is higher for the unfilled material than the filled grades. The material service life significantly increased by using nanocomposites.