Statistical Approach for the Evaluation and Selection of Medium DensityPolyethylenes for Chemical Storage Canisters

摘要

Several specially compounded and commercially available olefinic materials wereinvestigated in the presence of an organic liquid, Igepal CO-630, to test their environmental stress-crack (ESC) resistance (ASTM D1693). Chemical and physical characterization techniques were used to evaluate the proposed alternate medium density polyethylenes (MDPE) and antioxidants. Molecular weight, amount of antioxidant consumed during processing, and oxidation induction times were determined using size exclusion chromatography (SEC), reverse phase high performance liquid chromatography (RPHPLC), and differential scanning calorimetry (DSC), respectively. In addition, mechanical properties and strengths (ASTM D638) were determined in an attempt to obtain a quicker, more reproducible test. These properties were compared to a baseline material. Results showed that the commercial polyethylene, the baseline material, had the higher resistance to ESC. jg p.3.