EFFECTS OF CLEANING GEL SYSTEMS ON PLASTICISED POLY(VINYL CHLORIDE) : NEW INSIGHTS
BY CLEMENTINE BOLLARD
In 2011, short and long term effects of cleaning gel systems were investigated in order to determine whether these gels are suitable for the cleaning of plasticised poly(vinyl chloride) (PVC). PemulenTM TR2 based gel systems without and with the addition 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.
During this first stage of the research, tests were performed on pristine samples of plasticised PVC and 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 plasticized PVC. To study the short-term effects of the tested cleaning methods, 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). Plasticiser extraction was investigated by LCMS by analysing the gels recovered after cleaning. Plasticiser 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.
Preliminary results were presented at the conference Future Talks 011 and in 2012 a second stage of research took place. The same cleaning agents than in 2011 were this time tested on artificially aged plasticised PVC samples and the ame methodology and scientific techniques were used in order to assess their effect on the material. Results on un-aged plasticized PVC and artificially aged plasticized PVC were then compared, providing interesting information about the sensitivity of plasticised PVC to cleaning agents according to the age of the material.
The compared results will be presented as well as the numerous new interrogations and research perspectives which arose from this research.