The influence of binder content on the water transport properties of waterborne acrylic paints (original) (raw)
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Sorption and Transport of Water Vapour in Acrylic Paints
2014
ii ACKNOWLEDGEMENTS I am deeply grateful to my advisors Assoc. Prof. Sacide Alsoy Altınkaya and Prof. Devrim Balköse for their great support. Thanks to Yılmaz Yürekli and Burcu Alp Akta for their help in technical works. Special thanks to Mine Bahçeci and Gökhan Erdo an for their valuable suggestions and professional approaches during the characterization studies. I also wish to thank Dr. Dan Perera for his comments on my differential scanning calorimetry analysis results. Cafer Özgür prepared my sample holders voluntarily and he have taken great care. Gözde Genç made very useful comments on scanning electron microscope analysis and she shared her industrial experiences with me, related to paint materials. Ayben Top, Selda Gökta and ebnem im ek; my dear friends helped me sincerely whenever I met with a problem.
Progress in Organic Coatings, 2006
Recently, production of waterborne coatings has increased significantly as a consequence of strict pollution regulations. Waterborne coatings are sensitive to humidity, thus, their barrier properties with respect to permeation of moisture needs to be determined. Among various coating constituents, binder represents the matrix structure and its amount relative to the amounts of pigments and fillers can significantly affect the structure, hence the barrier property of the coating. In this study, waterborne acrylic based paints applied as protective coating on interior and exterior wall of the buildings are studied. The paint samples formulated with four different binder contents by a commercial paint company are used in the experiments. We first determine unknown ingredients of the paint samples using different characterization tools and then investigate the effect of the binder content on the structure of the paint films. In addition, water vapor permeability of the paint films is measured using a permeation cell. Results show that the barrier property of the waterborne acrylic based paint films against humidity decreases with decreased binder content due to uneven distribution of the pigments, consequently, porous structure formation in the films.
Unilateral NMR was used to monitor the penetration of water into acrylic emulsion paint-outs on canvas during cleaning simulations with five thickened conservation treatment systems – agarose gels, methylcellulose paste, Pemulen-TR2, poly(vinyl alcohol)-borax gels, and Velvesil Plus – and water-moistened swabs. Studies were also carried out to measure the rate of water penetration from the different treatment methods into acrylic paints during continuous exposure. Unilateral NMR is shown to be an effective technique for comparing depth penetration of water during cleaning treatments; the volume of paint occupied by water can be extracted from these measurements. The results show that young paint films (1 month) are more prone to swelling than aged paint films (2–50 years), with light aged paints having the highest resistance to water penetration during treatments. Aged organic pigmented acrylic paint (Hansa yellow light) shows a higher propensity for swelling during cleaning than aged titanium dioxide white paint. Cleaning simulations using water-moistened swabs and agar gels deposit approximately equivalent amounts of water into the paint films, whilst all other gel systems tested, with the exception of Velvesil Plus, tend to allow approximately 50% more water into the paint films. None of the aqueous thickened cleaning systems tested reduced the quantity of water which entered the paint films relative to swab cleaning.
Effect of curing on water diffusivities in acrylate free films as measured via a sorption technique
AAPS PharmSciTech, 2007
Studies were performed to investigate the effect of curing on the diffusion coefficients of water, as measured via the sorption technique, in acrylate polymeric films. The mathematical model selected for obtaining diffusion constants from the vapor-phase sorption studies was derived from the longtime Fourier equation used for diffusion into a planar sheet. For Eudragit NE films, the diffusion coefficients of water decreased continuously until a constant minimum value was reached. Diffusion coefficients in Eudragit RS films decreased initially but increased beyond 4 hours of curing at 70°C and 90°C. This latter result suggested the possible evaporation of plasticizer, which also results in a more dramatic increase in glass transition temperature with curing for the Eudragit RS free film in comparison to the Eudragit NE free film. Such loss of plasticizer could also lead to the formation of molecular-scale channels within the films, which would result in increased film permeability. To verify this proposed explanation, the amounts of triethyl citrate plasticizer in Eudragit RS free films were determined using Fourier-transform infrared spectrophotometry. An optimal curing condition was predicted for Eudragit NE and Eudragit RS films based upon the curing conditions at which a minimum value of the diffusion coefficient was reached.
The Migration of Surfactants in Acrylic Emulsion Paint Films
Studies in Conservation, 2004
Artists' acrylic emulsion paints are formulated using many constituents. Non-ionic surfactants such as those based on polyethylene oxides (PEOs) have been found in acrylic paint films, which may function both to stabilize the acrylic polymer in the aqueous emulsion phase and to aid pigment wetting and dispersion. PEOs that remain relatively mobile in the dried polymer film may affect surface gloss in a painting, the extent and nature of dirt pickup , and the sensitivity of the film to methods used for surface cleaning. The present study aimed to characterize the migration of PEO surfactant in selected contemporary acrylic emulsion paints made by Winsor & Newton and Golden Artist Colors, and to assess the effects of swab-rolling with water and non-polar solvent, used for surface cleaning paintings, on dried and light-aged paint films. Methods for characterization included light microscopy (LM) and scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and matrix assisted laser desorption/ionization-mass spectrometry (MALDI-MS). The results show that PEOs, present as characteristic aggregates at the surface of films, are light-sensitive, hygroscopic, and readily soluble in water applied using a swab in cleaning tests. These findings may be relevant to the methods used for the surface cleaning of acrylic paintings.
Water and oxygen transport as performance parameters of paint films
Journal of Membrane Science, 1990
Measurements of water diffusion coefficient, water solubility and oxygen permeability have been performed at 25°C on free standing membranes of epoxy-based organic coatings (paints) containing different levels of curing agent: 2, 8, 16 and 20% by weight. All measurements were carried out in a liquid-paint-liquid configuration, which simulates fully immersed painted structures. Concomitant electrochemical measurements were carried out on painted mild steel in order to investigate the protection exhibited by the coatings in neutral aerated 0,5 M NaCl. The performance parameter was the corrosion rate, which is related to the degradation of the metallic substrate.
ChemPhysChem, 2019
Heavy metal carboxylate degradation severely affects thousands of oil paintings. Relative humidity has been reported to accelerate the rate of the reactions. To evaluate its role further, water diffusion and molecular mobility of protons in linseed oil-based lead white paints were studied by unilateral NMR and 1 H HRMAS spectroscopy. The results indicate that exposure to high %RH for relatively long times affects the dynamics of the oil paint's mobile fraction and that the effect is more pronounced as the thickness of the film increases. It was found that the paint can absorb appreciable amounts of water and has a porosity of approximately 6% available for the diffusion of water, for which a regime of restricted diffusion was observed. Furthermore, the presence of bound and free-moving water, due to the possible formation of hydrated ionic groups clusters, supports the hypothesis of a polymeric/ionomeric network, as well as regions of essentially water free to move as in the bulk. The findings allow a better understanding of the role of water as a factor activating the degradation process in linseed oil-based lead white paints.
Effect of latex paint compositions on the water transport mechanism
1998
Absorbed water is the main deterioration factor of building materials, mainly for external wall surfaces. These surfaces can be protected by paints which may reduce the volume of absorbed water from external sources. At the same time, mould growth on coated external wall surfaces is also an important durability problem. A knowledge of the degradadion factors is important for increasing the service life of paintwork and for reducing maintenance costs. The rate of absorption and evaporation of water through the paint film affects the moisture content in the substrate. This property is also related to the time of wetness which affects the growth of fungus. In order to understand the water transport mechanism, the water absorption and evaporation of latex paints with different pigment/binder ratios was studied. The tests were done applying paints to mortar and concrete substrates. The results show that there is a correlation between paint composition and the rate of absorption and evapo...
ChemPhysChem, 2019
Heavy metal carboxylate degradation severely affects thousands of oil paintings. Relative humidity has been reported to accelerate the rate of the reactions. To evaluate its role further, water diffusion and molecular mobility of protons in linseed oil-based lead white paints were studied by unilateral NMR and 1 H HRMAS spectroscopy. The results indicate that exposure to high %RH for relatively long times affects the dynamics of the oil paint's mobile fraction and that the effect is more pronounced as the thickness of the film increases. It was found that the paint can absorb appreciable amounts of water and has a porosity of approximately 6% available for the diffusion of water, for which a regime of restricted diffusion was observed. Furthermore, the presence of bound and free-moving water, due to the possible formation of hydrated ionic groups clusters, supports the hypothesis of a polymeric/ionomeric network, as well as regions of essentially water free to move as in the bulk. The findings allow a better understanding of the role of water as a factor activating the degradation process in linseed oil-based lead white paints.