Environmental stress cracking of poly(vinyl chloride) in alkaline solutions |
| |
Authors: | S Bishop D H Isaac P Hinksman P Morrissey |
| |
Institution: | a Department of Materials Engineering, University of Wales Swansea, Swansea SA2 8PP, UK b National Power Innogy, Harwell International Business Centre, Harwell, Didcot OX11 0QA, UK |
| |
Abstract: | The environmental stress cracking (ESC) effects on PVC of various high pH sodium hydroxide environments have been studied. The behaviour of PVC specimens in air and pH 12, 13, 13.5 and 14.39 sodium hydroxide solutions has been examined under three-point bend, tensile and creep conditions. Two parameters were used in three-point bend testing to determine the effect of an applied strain and high pH environment on the stability of PVC, namely time to craze initiation and width of crazing. It was found that, in general, crazing occurred sooner and to a greater degree with increasing strain and pH, although there was some evidence that craze growth was most rapid at pH 13.5. The results also indicated a critical strain value of 1.5–1.6%, below which crazing was not observed in any of these alkaline environments. Creep and tensile testing revealed that the time for which a PVC specimen was immersed in the environment was very important in determining the severity of the environmental effect. Creep tests at elevated temperatures showed that the time for the effects to be manifest decreased with increasing temperature. Creep rates were highest in pH 13.5 sodium hydroxide solution indicating that this was the most hostile of the environments considered. |
| |
Keywords: | Poly(vinyl chloride) (PVC) Environmental stress cracking (ESC) Crazing |
本文献已被 ScienceDirect 等数据库收录! |
|