Evaluation of KHSO4 as a recyclable catalyst in the production of dehydrated castor oil to be applied in alkyd resins

Hyperbranched alkyds based on trimethylolpropane, dimethylol propionic acid and castor oil were synthesized. The process implied preparing the three samples with ZnO nanoparticles in an amount of 0, 1, and 3 wt%. Commercial melamine resin was used as a crosslinking agent. Curing was carried out firstly in a drying oven at the 120 °C for half an hour, and afterward for seven days at room temperature. Thermal properties, physico-mechanical characteristics, and chemical resistance of cured coated were determined. An increasing amount of the ZnO nanoparticles in hyperbranched alkyd resins leads to the improvement of the properties of the cured coating. Based on the results, it was concluded that the hyperbranched alkyds with ZnO nanoparticles could be employed as binders in environment-friendly coatings due to lower viscosity (less content of organic solvent) compared to conventional alkyd resins.

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Possibilities of affecting the chemical resistances of the coatings formed by reaction of amino resins with alkyd resins

Pigment & Resin Technology ◽

10.1108/03699420210412566 ◽

2002 ◽

Vol 31 (1) ◽

pp. 27-32 ◽

Cited By ~ 7

Author(s):

P. Kalenda ◽

A. Kalendová

Keyword(s):

Chemical Stability ◽

Alkyd Resin ◽

Castor Oil ◽

Film Formation ◽

Urea Formaldehyde ◽

Melamine Formaldehyde ◽

Coating Films ◽

Alkyd Resins ◽

Solid Films

The paper deals with the mode of film formation from urea–formaldehyde and melamine–formaldehyde resins combined with alkyd resin based on castor oil‐modified alkyd. The properties of hardened coatings (such as hardness, chemical stability, and adhesion to substrate) were followed in dependence on the ratios of reaction components. An apparatus was built for measuring the formaldehyde emissions escaping from the solid coating films. The determination was performed by the pararosaniline method. The addition of imidazolidine in a concentration up to 10 per cent can reduce the emissions of formaldehyde escaping from the solid films to a considerable amount.

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Curing kinetics of alkyd/melamine resin mixtures

Hemijska industrija ◽

10.2298/hemind0906629j ◽

2009 ◽

Vol 63 (6) ◽

pp. 629-635 ◽

Cited By ~ 1

Author(s):

Mirjana Jovicic ◽

Radmila Radicevic

Keyword(s):

Castor Oil ◽

Protective Coatings ◽

Curing Kinetics ◽

Isoconversional Method ◽

Curing Temperature ◽

Melamine Resin ◽

Alkyd Resins ◽

Synthetic Resins ◽

Isothermal Kinetic ◽

Kinetics Of

Alkyd resins are the most popular and useful synthetic resins applied as the binder in protective coatings. Frequently they are not used alone but are modified with other synthetic resins in the manufacture of the coatings. An alkyd/melamine resin mixture is the usual composition for the preparation of coating called 'baking enamel' and it is cured through functional groups of resins at high temperatures. In this paper, curing kinetics of alkyd resins based on castor oil and dehydrated castor oil with melamine resin, has been studied by DSC method with programmed heating and in isothermal mode. The results determined from dynamic DSC curves were mathematically transformed using the Ozawa isoconversional method for obtaining the isothermal data. These results, degree of curing versus time, are in good agreement with those determined by the isothermal DSC experiments. By applying the Ozawa method it is possible to calculate the isothermal kinetic parameters for the alkyd/melamine resin mixtures curing using only calorimetric data obtained by dynamic DSC runs. Depending on the alkyd resin type and ratio in mixtures the values of activation energies of curing process of resin mixtures are from 51.3 to 114 kJ mol-1. The rate constant of curing increases with increasing the content of melamine resin in the mixture and with curing temperature. The reaction order varies from 1.12 to 1.37 for alkyd based on dehydrated castor oil/melamine resin mixtures and from 1.74 to 2.03 for mixtures with alkyd based on castor oil. Based on the results obtained, we propose that dehydrated castor oil alkyd/melamine resin mixtures can be used in practice (curing temperatures from 120 to 160?C).

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