EFFECTS OF CLEANING GEL SYSTEMS ON PLASTICS
BY CLEMENTINE BOLLARD ET AL

Short and long term effects of cleaning gel systems were investi- gated in order to determine whether these gels are suitable for the cleaning of plastics. Tests were performed on pristine samples of plasticised poly(vinyl chloride).
PemulenTM TR2 based gel systems without and with the ad- dition of chelating agents (triammonium citrate) and solvent (cyclohexane) were tested. To assess the benefits and disadvantages of using gels pure cyclohexane and triammonium citrate solution were also tested.
The tests were evaluated using various scientific techniques, providing information on the physical and chemical changes induced by the cleaning techniques as well as on their potential to accelerate the ageing rate of poly(vinyl chloride).
To study the short-term effects of the tested cleaning meth- ods, the sample surfaces were examined before and after cleaning at different magnifications using the naked eye, a stereomicroscope and a scanning electron microscope. Furthermore, gloss and surface roughness were measured using a gloss meter and confocal white light microtopography).
Plasticizer extraction was investigated by analysing the gels recovered after cleaning. Plasticizer distribution was estimated by comparing spectroscopic mappings of poly(vinyl chloride) at the sample surfaces and edges before and after cleaning.
Long-term effects were evaluated by exposing the samples to artificial light and climate ageing, and by studying them again with the same scientific techniques previously used.