Studies of sedimentation behaviour of high pigmented alkyd primer: A rheological approach

Analysing the large amplitude oscillatory shear of the Cross and Cross–Maxwell models with the aid of Fourier transform rheology using the example of a solvent-borne alkyd primer

“…Figure 1(a) shows that storage and loss moduli decrease as strain amplitude increases. This supports [20] the application of a shear-thinning viscoelastic material model, for example a Maxwell model whose viscous part is defined by a reduced form of the Cross model.…”

“…As such, the more strain amplitude exceedsγ ≈ 10 −1 the greater deviations in model predictions become. Angular frequency dependent storage and loss moduli have already been measured within the LVE [20], with a result ofγ ≲ 10 −3 obtained from G ′ meas (γ) ( figure 1(a)). As G ′ meas (ω) and G ′′ meas (ω) are not used for parameter identification, it is not self-evident that loss modulus should also match measurements.…”

“…This paper describes the modelling of the LAOS behaviour of a solvent-borne alkyd primer [20]. This necessitated the calculation of the large strain amplitude oscillatory shear responses of a reduced Cross model (known as a "rCross model") and a Maxwell model whose viscosity function equals that of the rCross model.…”

“…Approximately rCross-Maxwell-like behaviour (equation (72)) is denoted by the -⋅ -⋅ -lines. This section applies the theory presented in previous sections to the solvent-borne alkyd primer [20] in order to explain the benefits of the characteristic points identified with the aid of analytical calculations. The qualitative characteristics for the strain amplitude dependent storage and loss moduli ( figure 1(a)) are relatively similar to MODE ω/3a of the rCross-Maxwell model ( figure 15(a)).…”

Effect of surface modified TiO2 nanoparticles on thermal, barrier and mechanical properties of long oil alkyd resin-based coatings

“…However, due to their micro-sizes, densities different from the density of alkyd resins, and other various effects, sedimentation of pigments occurs, leading to different problems considering final alkydbased coatings (viscosity changes, covering power deterioration, poor adhesion, loss of optical transparency, low scratch and impact resistance, delamination, reduction of the storage time, etc.) [22]. Sedimentation issue can be avoided if small quantities of nano-sized pigments are used in the alkyd resin formulations instead of micro-sized ones.…”