An insight into the mechanical properties of selected commercial oil and alkyd paint films containing cobalt blue

Abstract

Pigments and binders are known to influence drying and ageing mechanisms of paint films. However, the study of the long-term mechanical behaviour of paint films and its relationship with paint degradation and conservation still needs further investigation. This paper presents an insight into the role of cobalt blue pigment in the mechanical properties of some modern paint films by studying selected commercial oil and alkyd paint films containing cobalt blue. In addition, several representative mock-ups containing cobalt blue mixed with drying and semi-drying oils and some common additives were also tested for comparison purposes. Optical microscopy, SEM-EDX, XRF, VIS-reflectance spectroscopy, FTIR-ATR and GC-MS analysis were carried out to identify pigments, binders, additives and fillers. Uniaxial tensile measurements were run to test the mechanical performance of the studied paint films. The differences in the mechanical behaviour led to the evaluation of the discrepancies found in the chemical and physical properties of the different formulations studied.

Multianalytical Assessment of Armour Paints—The Ageing Characteristics of Historic Drying Oil Varnish Paints for Protection of Steel and Iron Surfaces in Sweden

“…According to a derivatisation method already tested on fatty acids from oil-based paints [47,[57][58][59][60][61][62] lipids contained in small amounts of paint samples (weight ranging from 0.10 to 0.20 mg) were transformed into their corresponding methyl esters by a one-step transesterification using 50 µL of m(trifluoromethylphenyl)trimethylammonium hydroxide, 2.5% in methanol, overnight reaction at room temperature. One microliter of each derivatised sample was automatically injected by an autosampler AS1310 (Thermoscientific) in a Trace GC 1300 system (Thermoscientific) equipped with a mass spectrometric detector ISQ 7000 with a quadrupole analyser (Thermoscientific).…”

After the paint has dried: a review of testing techniques for studying the mechanical properties of artists’ paint

“…The spread in the data for Titanium White is due to temperature variations. Data compiled in this graph are from [30,35,42,48,54,58] paint layers from two directions, which can be difficult to capture using only the uniaxial extension test. The way that paintings are mounted to stretchers is very similar to how they would be studied using biaxial extension (Fig.…”

Multi-Analytical Assessment of Bodied Drying Oil Varnishes and Their Use as Binders in Armour Paints

“…To fully characterise the organic lipidic fraction and better understand the effect of the ageing conditions on the paint mixtures, GC-MS was applied on both liquid oils and (unaged and aged) solid films. Following a GC-MS procedure already tested on modern lipidic mixtures [14][15][16][17][18][19][20][21], small samples of oil films (weights ranging from 0.10 to 0.20 mg) were treated with 50 µL of m(trifluoromethylphenyl)trimethylammonium hydroxide with 2.5% methanol in an overnight reaction at room temperature. One microlitre of the obtained derivatised solution was automatically injected by an AS1310 autosampler (Thermoscientific, Waltham, MA, USA) in a Trace GC 1300 system-equipped ISQ 7000 MS with a quadrupole analyser (Thermoscientific).…”