Using the Essential Work of Fracture Method for Studying Physical Aging in Thin, Ductile, Polymeric Films
نویسنده
چکیده
Water-filled, drop impact tests on full-scale, blow-molding polyester bottles showed that impact properties change significantly after 30 days of aging at 50°C. To q u a n e this deleterious effect of aging, we did small-scale laboratory experiments using the essential work of fracture method (EWFM). We measured the essential work of fracture of thin specimens cut from the sides of blow-molded bottles and aged under various conditions. Similar to the impact results, s i w c a n t drops in essential work occurred after relatively short amounts of aging. Additional experiments confirmed that the decreases in essential work were due to physical aging and not to chemical degradation. A comparison of the essential work results to the full-scale, bottle-drop impact tests showed some inconsistencies that need to be resolved before EWFM can be recommended as a quantitative method for studying physical aging of blow-molding polyester resins.
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تاریخ انتشار 2004