Authors:B. Ormsby, G. Foster, T. Learner, S. Ritchie, and M. Schilling
Issues encountered with dynamic mechanical analysis of artists’ acrylic emulsion paint films are presented alongside modifications
to improve controlled relative humidity (RH) experiments using isothermal and thermal scanning conditions. Free films of titanium
white (PW6) artists’ acrylic emulsion paints were cast as free films and their viscoelastic properties measured using the
tensile mode of the dynamic mechanical analyser (DMA). Artists’ acrylic emulsion paints are within their glass transition
temperature region at room temperature and are highly responsive to changes in ambient temperature and relative humidity,
hence controlling relative humidity during analysis is vital to the successful analysis of these paints.
A description is given of modifications to a dynamic mechanical analyser (DMA) to allow controlled relative humidity (RH) experiments to be performed under isothermal or thermal scanning conditions. Free film samples of polyester melamine paints
(under-cured, normal-cured and over-cured) were supplied and the viscoelastic properties measured in the tensile mode of the
DMA. A reduction in the glass transition temperature (Tg) of up to 10C was found as the controlled RH was increased.
Thermal analysis coupled with the measurement of temperatures at which colour changes are observed in situ was used to test various inorganic pigments with the aim of introducing them into the compositions of thermo-indicating paints. Through a reversible or irreversible modification of the colour these can indicate an undesired increase in temperature of a fluid in a metallic enclosure. Three such pigments are described, which indicate temperatures of 110, 300 and 400°C. The paint contains the thermo-indicator pigment, soluble glass as binder and either ultrafine silica or silica gel, or a mixture of Na2SiF6 and finely-ground sand as hardener. Such paints are used for damage warning.
Authors:D. Thompson, S. Parry, R. Benzing, J. Williams, and K. Jarvis
The use of paint as a coating for toys intended for sale on the European market is controlled by a European Standard (EN 71-3:
1994-European Standard for the Safety of Toys, Part 3—Migration of Elements). This work is the result of a preliminary study
organised by the European Commission to produce a new paint reference material which can be used to validate the test methods
given in the European Standard. The migration of elements from painted panels and comminuted paint produced by the Laboratory
of the Government Chemist, (U.K.) was studied. Several methods were used in this certification exercise and this work reports
the recults of neutron activation analysis and inductively coupled plasma mass spectrometry to determine the migration of
As, Ba, Cd, Cr, Hg, Pb, Se and Sb into a simulated stomach environment. Replicate extracts obtained from paint samples gave
a precision of within 10% for most elements by both analytical techniques for the paint panels and for the comminuted paint
sample. This preliminary study has shown that the standard method can provide reproducible results for each of the paint materials
studied and indicates that the study should be continued to produce a fully certified paint reference material.
The paint-shop wastes under study originated from metallurgical factory painting houses. Displaying a high toxicity and flammability, they are classified as specifically hazardous to the natural environment. Paint-shop wastes can be disposed of in the following ways:solidification and deposition in sanitary landfills;storage on a special dumping ground;incineration.
Authors:D. Dias, M. Crespi, C. Ribeiro, J. Fernandes, and H. Cerqueira
Samples of paint (P), reused PET (PET-R) and paint/PET-R mixtures (PPET-R) were evaluated using DSC to verify their physical-chemical
properties and thermal behavior. Films from paints and PPET-R are visually similar. It was possible to establish that the
maximum amount of PET-R that can be added to paint without significantly altering its filming properties is 2%. The cure process
(80–203°C) was identified through DSC curves. The kinetic parameters, activation energy (Ea) and Arrhenius parameters (A) for the samples containing 0.5 to 1% of PET-R, were calculated using the Flynn-Wall-Ozawa isoconversional method. It was
observed that for greater amounts of PET-R added, there is a decrease in the Ea values for the cure process. A Kinetic compensation effect (KCE), represented by the equation InA=−2.70+0.31Ea was observed for all the samples. The most suitable kinetic model to describe this cure process is the autocatalytic Šesták-Berggreen,
model applied to heterogeneous systems.
The degradation of art objects is caused by the combination of all indoor environmental factors. To investigate the deterioration processes in paintings and at the same time to design a risk assessment system, chemical sensors based on artist's materials are developed. Therefore standard paint films of egg yolk tempera with lead white 2PbCO3·Pb(OH)2, azurite 2CuCO3·Cu(OH)2 or smalt were investigated. With accelerated ageing experiments the simulation of natural degradation processes is aimed. First markers for chemical changes were found in the FTIR and TG/DSC measurements.
Authors:H. Pant, V. Sharma, S. Naik, Gursharan Singh, D. Kalgutkar, S. Patil, N. Jayachandran, and V. Unni
A radiotracer technique was used to investigate the leaching of an antifouling agent from different marine paint formulations
with an objective to select the best paint formulation for bulk production. The antifouling agent (Diuron) itself was labeled
with carbon-14 (half-life: 5,730 years, β-energy: 156 keV) and used as a radiotracer. The different paint formulations added
with radiolabeled Diuron were applied onto suitably selected substrates and measured for initial intensity of β-radiation
using a Geiger-Muller detector connected to a ratemeter. The painted substrates were subjected to shower tests for a pre-decided
time and subsequently measured for β-radiations. The comparison of intensity of β-radiations in substrates prior and post
shower tests provides information about leaching of antifouling agent Diuron from the paint formulation. The high leaching
percentage of antifouling agent Diuron post shower tests indicates non-suitability of paint formulation for marine and civil
structures. However, low leaching rate of Diuron will make a paint formulation more efficient and suitable. Based on the results
of investigation, a paint formulation with minimum leaching rate was identified and selected for bulk production by a paint
The fragments of a high quality, enamel painted, blue glass bottle with the date 1671 on its shoulder were found in the Castle District of Buda, in a huge pit dated to the period of the Ottoman occupation. The shape of the object shows eastern influences, while its decoration is clearly western. The origin of the bottle is probably Transylvanian, based on its characteristics and a small group of parallels.