Some synergisms in the laboratory degradation of a polypropylene geotextile

This paper studies the existence of synergisms between some degradation agents of geotextiles. For that purpose, a polypropylene geotextile (stabilised with Chimassorb 944) was exposed to some degradation tests: immersion in liquids (water, sulphuric and nitric acids, sodium hydroxide and metallic ion solutions), thermo-oxidation and artificial weathering. The geotextile was (1) exposed individually to each degradation agent (single exposure) and (2) exposed successively to some combinations of two agents (multiple exposures). Results showed that, in some cases, the combined action of two degradation agents was more damaging than the sum of the individual effects of each agent. The most relevant examples of this included: (1) immersion in sodium hydroxide and thermo-oxidation, (2) immersion in iron nitrate and thermo-oxidation and (3) immersion in cadmium or copper nitrate and artificial weathering.