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Natural and artificial ageing of an alkyd based wood finish
Calorimetric investigations
Abstract
Wood protection in exterior use is generally achieved with a stain. This protective product is often obtained from an alkyd resin. A natural and artificial agening have been studied by measuring the glass transition temperature (T g) of the finish variations in terms of time. In both ageings, theT g variations are the same; there is an increase inT g during the first steps of ageing and then a stabilization. A behaviour equation is proposed and is perfectly suitable to both ageings. Time constants are calculated. This equation shows that the artificial ageing machine chosen is a good means of artificial ageing. It allows the reproduction and the acceleration by 10 times of phenomena which are observed during the natural ageing.
Abstract
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 (E a) 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 E a values for the cure process. A Kinetic compensation effect (KCE), represented by the equation InA=−2.70+0.31E a 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.
Alkyd-based-thermosetting resin
Calorimetric investigations of the curing process
Abstract
In this work, the rate of cure of different oxidative drying oil modified alkyd resins are investigated by DSC measurements. We determine, from the Kissinger equation, the apparent activation energy of the curing process. We show that this activation energy depends on the curing duration and that these variations lead to the determination of a time constant, characteristic of the material.
Characterization of alkyd based thermosetting resins
Calorimetric investigations
Abstract
The rate of cure of different oxidative drying oil modified alkyd resins are investigated by DSC, when the cure is made under UV light or not. We determine, from the Kissinger equation, the apparent activation energy at different stages of the curing process. This activation energy depends on the curing conditions (temperature, illumination or not). These variations lead to the determination of a time constant, characteristic of the curing kinetics. Two particular values of the apparent activation energy are also defined. The first one called ΔE o is a characteristic of the varnish at the liquid state, the second one called ΔE inf characterizes the stability of the structural state of the final film.
Abstract
The recycling of soft drink bottles poly(ethylene terephthalate) (PET) has been used as an additive in varnish containing alkyd resin. The PET, called to recycled PET (PET-R), was added to the varnish in increasing amounts. Samples of varnish containing PET-R (VPET-R) were used as a film onto slides and its thermal properties were evaluated using thermogravimetry (TG). Throughout the visual analysis and thermal behavior of VPET-R it is possible to identify that the maximum amount of PET-R added to the varnish without changing in the film properties was 2%. The kinetic parameters, such as activation energy (E) and the pre-exponential factor (A) were calculated by the isoconversional Flynn-Wall-Ozawa method for the samples containing 0.5 to 2.0% PET-R. A decrease in the values of E was verified for lower amounts of PET-R for the thermal decomposition reaction. A kinetic compensation effect (KCE) represented by the lnA=−13.42+0.23E equation was observed for all samples. The most suitable kinetic model to describe this decomposition process is the autocatalytic Šesták-Berggren, being the model applied to heterogeneous systems.
50 °C. At that same 4.26g of extract weight in primer (AEP), an optimum I.E. of 90% was achieved at 75% weight, further increase of extract weight led to reduction in efficiency at that same temperature of 50 °C. At attainment of 63.33% by alkyd resin
negatively influence the cross-linking density and curing of an alkyd resin. They showed that, the increased viscosity of coating, in the presence of nanoparticles, is responsible for such an observation. This study aims to investigate the effect of ZnO
, “ Synergized plant leave extracts as substitute to toxic additives in alkyd resin primer for corrosion inhibition of steel ,” American , 2016 . [25
Cerqueira HMG . Application of nonisothermal cure kinetics on the interaction of poly(ethylene terephthalate)—Alkyd resin paints . J Therm Anal Calorim. 2008 ; 91 : 409 – 12 http://dx.doi.org/10.1007/s10973
