Mechanical Properties of Corroded Polypropylene
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
To improve the service reliability of polymeric materials used in pickling environments the aim for this research project was to investigate how the corrosion of PP, exposed to mixed acid, changes its mechanical properties. It was found that PPH-β and PPB has a better resistance to the mixed acid environment both in the corrosion rate and impact strength compared to PPH-α and PPR. Further investigation showed that the penetration depth of the nitration is equal in the material exposed to only nitric acid. A useful method has been developed that can, in a relative short time period, give answers to the selected material´s adequacy for this specific environment. Materials that were tested were in the form of commercially available pipes. The samples were exposed to mixed acid from the inside for 7-27 days at temperatures of 60°C and 80°C. The corrosion rates were determined by pH-indicator and FTIR line-scans. The results were compared to pipes that had been in service for 2 years. The impact strength was determined by Charpy impact testing both on the inside and outside of the pipe walls. No changes in impact properties were found from impacts made to the inside of the pipe.
Place, publisher, year, edition, pages
2012. , 29 p.
Polypropylene, PP, corrosion, pickling, mechanical properties
IdentifiersURN: urn:nbn:se:kth:diva-158489OAI: oai:DiVA.org:kth-158489DiVA: diva2:777114