Effect of solution pH on crack initiation and propagation in glass-polyester pipes subjected to impact

Abstract

The objective of this study was the determination of the influence of alkaline and acidic solutions on the impact properties of glass-polyester composite pipes. First, the impact test was performed on virgin samples (without the influence of any liquid) to obtain knowledge about the original material properties. Subsequently, the specimens were soaked in water and in alkaline and acidic solutions: sodium hydroxide, ammonium hydroxide, phosphoric acid, and nitric acid. The specimens were left in each liquid for 3, 10, 30, and 60 days at room temperature. The impact toughness and the crack initiation and propagation energies were recorded for all samples. A comparison of the results was made based on the pH values of the aggressive media, as well as based on the original impact properties and number of days of treatment. This way, the service life of pipes for transport of theexamined solutions could be predicted. POLYM. COMPOS., 2012.