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This paper aims to discuss about the benefits of Cu(NO₃)₂ applied in coating paint film that consists of plant extract from Cassia Alata. Cu(NO₃)₂ has been added to the coating paint film as a colour stabilizer and as an antifungal property by forming a zone of inhibition towards fungal growth.

The coating paint film resin consists of a mixture of poly (methyl methacrylate) (PMMA) and acrylic polyol. The coating paint film’s performances were observed in terms of visible optical and physical appearance.

When exposed to the fungus Trichoderma Sp., a zone of inhibition of 208 mm² was formed around the coating paint film and therefore it gave the coating paint films an antifungal property. The commission internationale de l’éclairage (CIE) L*a*b* colour coordinate system was used to identify the colour changes in the coating paint film and it was found that the addition of Cu(NO₃)₂ to the coating paint film has a better colour stability, as it has a lower standard deviation (STD) value of 6.46 than the pure dye coating paint film of 8.95. The gloss of coating paint film with the addition of Cu(NO₃)₂ was found to be have a more stable gloss based on its smaller STD value at both angles taken at 20° and 60°.

The Cassia Alata plant has different amount of antifungal properties based on location its growth.

The coating paint film developed in this study is suitable for indoor applications.

The plant extract from the Cassia Alata gives the coating paint film an antifungal property.

The physical properties of two types of silicone resin were examined. The resin was coated on mild steel panels and allowed to cure for one week. The resin‐coated panels were heated according to ASTM specification D 2485. The thermal stability of the resin coatings was examined by electrochemical impedance spectroscopy (EIS) technique and thermogravimetric analyses (TGA). The chemical resistance property of the resin coatings was also studied.

This paper aims to study the colour stability of chlorophyll and the effect of copper (II) nitrate – Cu(NO₃)₂ – as an additive in natural dye coating films after being exposed to ultraviolet-A (UV-A).

The natural dye was extracted from the leaves of Cassia alata L. using absolute ethanol as the solvent. The extract was divided into two parts and, one of it was added with 3 wt.% Cu(NO₃)₂ as an additive. The polymer blend of poly(methyl methacrylate) (PMMA) and acrylic polyol was used as the coating binder. Both parts of the dye with and without additive were mixed with the blended polymer in a specific ratio. The resulted mixtures were applied as coating films on glass substrates. The colour stability of the coating films on exposure to UV-A with the time of exposure was observed with Commission internationale de l’éclairage (CIE) L*a*b* colour coordinates. The hidden power by the means of reflectivity and glossiness of the coatings was also studied. Statistical standard deviation (STD) was used to analyse the data.

The test showed that the coating films containing Cu(NO₃)₂ had smaller colour differences, (ΔE*) indicating higher colour stability. The analysis on hidden power also showed that the coating film with Cu(NO₃)₂ was 1.6 times more stable than the film without additive. All the measurements in this study were observed within 35 days of duration.

This paper implies the potential of using natural dye extracted from Cassia alata L. leaves as a stable dye colourant for coating applications.

The coating film developed in this study is suitable for glass substrate applications.

A new method of preparing solvent-based coating film from PMMA–acrylic polyol with chlorophyll colourant is introduced in this study.

This paper aims to analyse the coating behaviour in corrosion environment as well as to evaluate the best percentage amount of copper oxide and copper needed for organic coating in order to prevent the corrosion degradation. Electrochemical impedance spectroscopy (EIS) studies have been conducted in order to evaluate the corrosion performance of polyester-epoxy-copper oxide and polyester-epoxy-copper coating systems.

The availability of this modem instruments is used to obtain impedance data as well as computer programs to interpret the results that made the technique popular. In addition, EIS is well suited to the study of polymer-coated metals.

The results showed that samples containing 25 weight per cent of copper oxide and copper (90P25CuO and 90P25Cu) obtained the excellent corrosion properties from the first day up to 30 days of NaCl immersion. The highest corrosion resistance values obtained by 90P25CuO and 90P25Cu on the 30th day were 7.107 × 108 O and 5.701 × 108 O, respectively, with lower double layer capacitance of 1.407 × 10⁻⁹ Farad and 3.935 × 10⁻⁹ Farad, respectively. Moreover, the water uptake gained by these two coating samples was the lowest at the end of immersion, which was 0.0084 for 90P25CuO and 0.1592 for 90P25Cu, showing that the sample has good corrosion performance.

This paper discussed on the highest corrosion resistance, double layer capacitance and the water uptake of the copper (Cu) and copper oxide (CuO) coating system obtained from the EIS measurements.

The purpose of this paper is to study the electrochemical, mechanical and thermal characteristics of polyester – epoxy coating systems using electrochemical impedance spectroscopy (EIS), pull-off test and differential scanning calorimetry (DSC). These are very important properties to evaluate the performance of a coating system. Proper measurement and analysis techniques are needed for a proper evaluation of these properties to ensure the coating performance.

Different ratios of polyester and epoxy resins have been blended to formulate good anticorrosive, mechanically strong and thermally stable binder coating system. EIS, pull-off test and DSC were used to evaluate these properties.

The sample containing 90 wt.% polyester exhibited the best corrosion resistance from the beginning until the end of exposure time. The value of corrosion resistance (R_c) obtained on the 30th day of exposure was found to be 2.89 × 108 ohm cm⁻². The glass transition temperature (T_g) was found to be increasing with the incorporation of epoxy to the binder system. The result from pull-off test showed the best adhesion with the sample containing 90 wt.% polyester which also has the lowest T_g promoted better adhesion properties.

The curing time must be reduced for practical applications.

Hybrid coatings systems have been formulated. This paper discusses on the highest coating resistance obtained polymer-substrate mechanical properties and thermal characteristic of the polyester/epoxy binder resin using DSC.

The purpose of this paper is to study the colour stability and water content resistivity of the green colour coating paint film (consisting of chlorophyll) during exposure to ultraviolet A (UV-A).

The natural green dye was prepared by immersing Cassia alata L. leaves in absolute ethanol. The extract was prepared in two batches of dye samples where one of it was a pure dye and the other was added with 3 Wt. % Cu(NO₃)₂ as an additive. Polymer blend as a binder was prepared by mixing poly(methyl methacrylate) (PMMA) and commercial acrylic polyol. The blended polymer was mixed with the natural dye in a specific ratio and applied as coating paint film on glass panel surfaces. The visible spectrum stability (colour stability) and water content resistivity of the coating paint films during exposure to UV-A were monitored.

Addition of Cu(NO₃)₂ had improved the colour stability of the coating paint film. Fourier transform infrared spectroscopy analysis showed that both coating paint films do not absorb water and are resistive to water content.

The ability of Cu(NO₃)₂ as an colour stability additive to the natural green dye applied in the coating paint film.

The coating paint film developed in this work is suitable to be applied on glass substrates.

The colour stability of the coating paint film was analysed by using the reflectance spectrum.

To evaluate the degradation of silicone based coatings that protect the mild steel surfaces from corrosion in high temperature atmospheres, the coatings were exposed to muffle furnace for heating ‐ cooling cycle (as per ASTM specification D 2485) up to 700°C. The ability of the paint film to withstand the temperature is related to its resistance as well as microcracks. These factors are very useful in precisely quantifying the degree of deterioration of the protective film. In the present work, two types of silicone based paints (silicone‐titanate, rhodorsil silicone) were prepared and the surface degradation of these coatings were studied by EIS technique and SEM with EDAX analysis. The chemical resistance properties were also analyzed.

This paper aims to focus on a comparison study of the visible stability of natural blue dye consisting anthocyanin molecules extracted from Clitoria ternatea in coating films.

The coating films were prepared by mixing the blue dye with poly(acrylamide-co-acrylic acid) in three different weight ratios. Samples were coded as 10PBA, 15PBA and 20PBA, where PBA is the abbreviation for poly acrylamide-co-acrylic acid, blue dyes and anthocyanin. The number at the beginning of each code represents the weight percentage of poly(acrylamide-co-acrylic acid) to natural blue dye. The mixtures were applied on separate glass substrates to form coating films. Another set of samples were prepared for the comparison study with a commercial acrylic clear coat (cc) applied on the surface of the 10PBA, 15PBA and 20PBA coating films. These coating films were coded 10PBAcc, 15PBAcc and 20PBAcc. The purpose of the clear coat is to observe how it affects the colour stability of the blue coating films with respect to time. All samples were exposed to the ultraviolet (UV) source, an 18 W Philips TL-D 18w/830 UV fluorescent lamp. The UV lamp was placed 15 cm above the surface of the samples for 35 days. The colour of the coatings was measured using CIE L*a*b* colour space coordinate.

The results obtained show 10PBA and 10PBAcc have the highest colour stability after 35 days of exposure to UV light. The reflectivity of the coating films was also measured during exposure to UV lamp. Reflectivity measurements also showed that 10PBA and 10PBAcc coating films had the highest reflective stabilities.

The potential of using natural blue dye consisting anthocyanin in coating film to obtain high colour stability.

The coating film developed in this work is suitable to be applied on glass substrates.

The application of anthocyanin dye extracted from the Clitoria ternatea L. as a colourant in coating films

The purpose of the paper is to study the effect of color stability on introducing chenodeoxycholic acid (CDCA) into a colored liquid extract from saffron and determine the color quality of the extract over a nine-month period.

Six colored liquid samples with different CDCA contents ranging from 0 to 45 Wt.% have been successfully prepared. Chromaticity (C*), color saturation (s), UV-Vis spectroscopy and coloring strength studies have been assessed to determine how CDCA influences the color properties and to study the color quality over time. The color quality was analyzed using the Commission Internationale de l’Eclairage (CIE) system.

All results obtained revealed that the addition of CDCA significantly influenced the overall color performance of the saffron extraction. However, the most pronounced improvement was recorded with the use of 45 Wt.% CDCA. The sample exhibited the highest color quality at the end of nine months of storage with highest absorbance: C* value = 91.38, color saturation = 0.96 and coloring strength = 687.

This preliminary study offers significant findings for further research focused on stability of natural colorants extracted from Spanish saffron that can provide benefits for future applications especially in coating industry, food, agriculture, medicine and others.

The values of this work can be observed from the information and evidence provided by CIE color stability in terms of chromaticity and saturation, as well as UV-Vis spectrophotometric measurement. It showed that the addition of CDCA additive can help to prolong and enhance the natural colorant properties from Spanish saffron (Crocus sativus L.) for nine month of storage. This proved that by adding additives such as CDCA the saffron colorant can be maintained. To the best of the authors’ concern, this is the first time CDCA is used to prevent color degradation of natural colorant from saffron.

The purpose of this paper is to observe the colour and thermal stability of natural red dye consisting of anthocyanin with addition of different aqueous acids and applied as coating films.

The natural red dye was extracted from Hibiscus sabdariffa L. (roselle) flowers and mixed with 1 per cent hydrochloric acid, 5 per cent acetic acid, 5 per cent citric acid and 5 per cent oxalic acid. All the dye samples were exposed to heat and UV-B to observe the colour stability by calculating the half-life and rate of reaction. In coating film application, each of the dye samples was mixed with 25 wt% of poly(vinyl alcohol) (PVA) and applied on to a glass substrate. The coating samples’ colour stability was observed by using CIE L*a*b* colour space coordinates. The coating films’ weight loss stability against temperature was observed by using thermogravimetric analysis.

Addition of hydrochloric acid enhances the thermal and UV stability of the anthocyanin natural dye. This can be observed from the calculation of the half-life of the dye. The half-life values for the thermal and UV stability studies were 1,155 hours and 210 hours, respectively. In coating films, the sample with addition of acetic acid showed the highest colour stability with colour difference (ΔE*) value 8.95.

The coating films developed in this work are not suitable to be applied on metal substrates due to the presence of water, which can contribute to the corrosion formation.

The coating films developed in this work are suitable for washable coating application. In other words, they are non-permanent coatings applied on a glass substrate.

Development of water-based coatings from PVA binder with anthocyanin colourant is introduced in this study.