High Gloss Research Articles

Functional anti-corrosive and anti-bacterial surface coatings based on mercaptosuccinic and thiodipropionic acids and algae oil as renewable feedstock

Renewable source based anticorrosive and antimicrobial polyesteramide polyols were synthesized by reacting algae oil with diethanolamine and thio diacids viz. mercaptosuccinic (MSA) and thiodipropionic (TPA) acids. The confirmation of structures and molecular weights of prepared polyols were done by 1H NMR and FTIR spectroscopic techniques, and size exclusion chromatography (SEC), respectively. The polyols were used to prepare PU which showed excellent adhesion (100%) as compared to algae oil fatty amide (AOFA) (88%) high gloss (118 and 115). This PU passed flexibility test and showed good chemical resistance in comparison to the AOFA based PU coatings. The prepared PU coatings were checked for the anticorrosive property by dipping and electrochemical method performed against 3.5 wt% NaCl and 5 wt% HCl corrosive media. The PEA- PU possessed lower corrosion rate (mm/year) and Icorr values as well as high polarization resistance (Rp) and inhibition efficiency, than uncoated (blank) and AOFA based PU (PU-AOFA). Both MSA and TPA based PU coatings showed good antimicrobial potential and reduction in bacterial attachment, against Gram - negative (E. coli) and Gram - positive (S. aureus) bacteria in comparison to the control and AOFA PU coatings as observed through SEM and the thermal stability of modified PUs was also improved.

Analysis and Characterization of Machined Surfaces with Aesthetic Functionality

The generation of fine machined surfaces with high gloss is an important topic in mould manufacturing. The surface gloss can be characterized by means of scattered light sensors and a representative parameter such asAq. In this paper, in-line measurements of scattered light distribution are compared with roughness parameters calculated using a confocal microscope, in order to assess surface aesthetic quality. Several surfaces have been machined by means of high precision milling, producing different surface topographies. Surface characterization has been performed on a machine using a scattered light sensor, and using a confocal microscope in laboratory conditions. The calculatedAqparameter is compared with the amplitude roughness parametersSaandSq, and with hybrid parametersSdqandRdqrepresenting the average slope of the surface features. Scanning electron microscope (SEM) images are used as visual benchmarks to identify the parameters’ correlation with the visual appearance. A different linear trend of the relationship betweenAq,Rdq, andSdqis observed. The description of the surface quality throughSaorSqinstead is found to be insufficient. This is explained by means of SEM pictures showing a dramatic influence of the smeared material over the machined surface.

COATING PERFORMANCES OF CRIMEAN JUNIPER (Juniperus excelsa M. BIEB.) WOOD

ABSTRACT The purpose of this study is to determine the varnish layer hardness and varnish adhesion strength of the varnished Crimean juniper (Juniperus excelsa M. Bieb.) wood growing naturally in the Kastamonu region of Turkey. Test samples were varnished with UV-resistant polyurethane alkyd resin high gloss varnish (PAV) and water-based acrylic resin gloss varnish (WBAV). The varnish adhesion strength test was carried out by using universal testing machine. The varnish layer hardness was measured by using Konig pendulum hardness tester. Additionally, the colour properties were measured by spectrophotometer equipment that used the L*a*b* colour space. The adhesion strength of the polyurethane varnish and the water-based varnish were determined 2.81 MPa and 2.25 MPa respectively. Surface hardness value for water-based varnish and polyurethane varnish were determined 71 and 25 oscillation respectively. Detecting the performance of polyurethane and water-based varnish applications for the Crimean juniper wood will provide guidance in which type of varnish will be better for finishing. As a result, in varnish applications of the wood, it is recommended that water-based acrylic varnish should be applied when surface hardness is required. In addition, polyurethane alkyd varnish should be applied when better surface adhesion strength is desired.

In Vitro Analysis of Different Polishing Systems on the Color Stability and Surface Roughness of Nanocomposite Resins

To assess the different polishing systems on the color stability and surface roughness of nanocomposite resins. A total of 60 composite resin samples were fabricated. The Tetric N Ceram composite was compacted into the custom-made cylindrical metallic mold of internal diameter 6 × 6 mm. Based on the polishing system used, sixty samples were divided into three groups. Group I: Sof-Lex, group II: Shofu super-snap polishing disks, and group III: Astropol. The samples in each group were immersed in beverage, that is tea. Spectrophotometer was used to measure the color of the samples after staining period. And surface profilometer was used to measure all surface roughness. Of the three groups, Sof-Lex polishing group reported the least mean value of 0.458 ± 0.118 succeeded by Astropol polishing group (0.494 ± 0.121) and Shofu super-snap polishing group (0.540 ± 0.031) having the higher mean value. Statistically significant difference was found between the different polishing systems calculated by analysis of variance. And color change between the groups was not statistically significant. We conclude that a composite polished with Sof-Lex was a superior polish compared to Astropol polishing group and Shofu super-snap polishing group. There was only a minimal difference in the color stability of the composite between the groups. Excellent finishing and polishing are the critical steps to enhance the esthetics and longevity of the composite restorations. High strength, fracture toughness, surface hardness, optimum polishability, and gloss are the functional properties which need assessment while a resin composite is used for restoration. How to cite this article: Dhananjaya KM, Vadavadagi SV, Almalki SA, et al. In Vitro Analysis of Different Polishing Systems on the Color Stability and Surface Roughness of Nanocomposite Resins. J Contemp Dent Pract 2019;20(11):1335-1338.

Operational limits of blade coating associated with high aspect ratio pigments: Part II—cylindrical laboratory coater

Process issues such as blade deposits, scratches, spits, and defects on the coating surface develop during blade coating of paper at high solids content and fast machine speeds. Coatings that contain high aspect ratio pigments display these issues at lower solids concentrations and slower web speeds than spherical or block shaped pigments. The shape of the pigment particles influences the characteristics of the coating formulation after drying, and high aspect ratio pigments can lead to high gloss surfaces that have good printing properties and are of interest in barrier coatings. The rheology, particle packing, and water retention are all functions of the pigment shape and size distribution. The base sheet properties of porosity, surface roughness, and permeability interact with the coating and the blade coater operating conditions. The possible causes of poor runnability are part of an interrelated and complex system. A cylindrical laboratory coater (CLC) was utilized to determine the speed at which operational and quality issues begin at varying solids concentration for two pigments with different shape factors on two different paper surfaces with varying absorption rates. An operational window was developed for both pigments. Characteristics of the pigment suspensions were explored in order to find a relationship with the onset of operational problems. The high shear rate viscosity of these suspensions did not explain the operational windows. The difference between the solids concentration and the immobilization solids, which is a function of the shape factor, has a linear relationship to the runnability limits. This could be ascribed to the tight packing structure of the particles as the solids content approaches the immobilization solids.

Screen printing of uv curable polyurethane acrylate binder prepared with different pigment concentrations on synthetic leather and gloss and hardness properties of printed films

In this paper, UV curing technology and screen printing method were firstly together applied on synthetic leather, in order to determine the gloss and hardness values of screen printed UV curable polyurethane acrylate binder films prepared with different pigment concentrations. UV curable water-borne pigmented formulations were prepared with different pigment concentration (3%, 5% and 7%) and two types of photoinitiators (Omnirad® 500 and Omnirad® 819 DW). The curing process were conducted under different combinations of lamps (Ga, Hg, GaHg and GaGaHg) at three power levels. Pendulum hardness and gloss values of printed films were investigated. In gloss measurements, higher gloss values were obtained at the pigment concentration of 3% at all lamp combinations. Moreover, the highest gloss value (20.96) of the sample printed with 3% pigment concentration was obtained at GaHg lamp combination at 679 mJ/cm2 energy density. The higher hardness values were obtained at a pigment concentration of 3% at all lamp combinations. The highest hardness value (9.8) of the pigmented polymeric films with 3% pigment concentration was obtained at GaGaHg lamp combination at 966 and 1663 mJ/cm2 energy densities. The results show that high gloss and hardness values can be achieved at lower pigment concentration of 3%. Considering energy efficiency, curing under the GaHg lamp combination at an energy intensity of 679 mJ/cm2 can be recommended for synthetic leather samples, which are printed with low pigment concentration (3%).

Systematic alteration survey and stone provenance for restoring heritage buildings: Punta Begoña Galleries (Basque-Country, Spain)

Punta Begoña Galleries (Getxo, Spain) are a fine example of early twentieth century architectural heritage. Built during the early years of reinforced concrete usage, they were decorated inside with ornamental stones to project an image of exclusivity and luxury. After years of neglect, it is essential to characterise construction materials, including the determination of their origin, current state of conservation and restoration options, before undertaking a recovery project respectful with the original edifice. With this aim, a detailed study was made of the current state of conservation of the lithologies that decorate the salon of the building using an alphanumerical matrix of alterations to define the type of existing disturbances and assess their intensity. Complementarily, a petrological, isotopic and mineralogical study of these materials was made in order to determine their provenance. They include Carrara marbles and a local limestone (Red Ereño) which was internationally renowned, in particular being used in buildings such as St. Peter's Basilica in the Vatican. In this paper a first complete description of this stone has been made. By combining the two sources of information, guidance on the most appropriate restoration options in each case is given. The option of polishing materials includes a specific study of the degree of wear. By means of which it is verified that small wear (<350 μm) is sufficient to produce high gloss values (100GU).

Improving hydrophobic and oleophobic performances of high-pressure laminates

High-pressure laminates are decorative materials that are widely used in furnishing and building industries. One of their major handicaps, especially in the case of high gloss laminates, is the ease of staining by fingerprints. This problem can a priori be minimized by increasing the hydrophobicity and oleophobicity of the surface. To improve hydrophobicity, the chemical composition of the resin used for impregnation of the laminate’s top layer decorative paper was modified. A melamine-benzoguanamine-formaldehyde resin was used as starting point, and caprinoguanamine was added as a comonomer at different stages of the synthesis. Addition at the end of the synthesis process showed to be the most promising approach for achieving a water contact angle of 91.2°, while the contact angle for a commercial laminate, impregnated with a standard melamine–formaldehyde resin, is 58°. Regarding oleophobicity, several commercial additives were tested with the previously formulated resin. A fluorocarbon additive showed the best result, leading to contact angles of 114° for water and 76° for an artificial fingerprint liquid. In addition, it was shown that fingerprints were easier to clean from the modified laminate surface.

Biobased waterborne, tough hyperbranched polyester thermosets as environmentally benign polymeric materials

ABSTRACTHigh‐performing water‐dispersible polyester synthesized under facile and ecofriendly reaction conditions has gained substantial interest because it has zero volatile organic compounds and is nontoxic. However, such polyester suffers from poor mechanical performance, so it is unsuitable for modern applications. In the present study, we focused on synthesis of a water‐dispersible polyester that contains aromatic and aliphatic moieties in the polymer backbone and can be readily synthesized from biobased and well‐defined reactants. We have synthesized water‐dispersible hyperbranched polyesters using three different weight percents of glycerol‐based hyperbranched polyol as a branch‐generating moiety containing both aromatic and aliphatic units along with citric acid, poly(ethylene glycol), and 2,2‐bis(hydroxymethyl) propionic acid through a solvent‐, catalyst‐, and neutralizing agent‐free facile route. The chemical structures of these polyesters were elucidated using various instrumental analyses. Hyperbranched epoxy and poly(amido amine) cured thermosets of these polyesters exhibited high tensile strength, toughness, impact resistance, scratch resistance, high gloss, biodegradability, and good chemical resistance without much effect on their elongation at break. Therefore, this high‐performing, sustainable, tough water‐dispersible thermosetting polyester has strong potential as an environmentally friendly polymeric material. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46738.

Bacterial cellulose for increasing barrier properties of paper products

Bacterial cellulose was combined with wood cellulose papers in order to obtain biomaterials with increased barrier properties. For this purpose, different parameters were assessed: two producing bacterial strains (Komagataeibacter xylinus and Gluconacetobacter sucrofermentans), two paper supports to hold bacterial cellulose (filter paper and eucalyptus paper), two kinds of combined biomaterials (composite and bilayer) and two drying temperatures (90 °C and room temperature). Papers with increased barrier properties (100° of water contact angle, 1220 s of water drop test and air permeability < 1 µm (Pa s)−1) were obtained by the addition of bacterial cellulose to each paper support. However, due to the lower initial barrier properties of filter paper, higher improvements were produced with this paper. In addition, bacterial cellulose provided smoother surfaces with higher gloss without a detrimental effect on physical properties. Higher resistance to water absorption was obtained with K. xylinus possibly explained by its longer size fibers than G. sucrofermentans, as analysed by SEM. Smoothness and gloss were specially increased in the bilayer biomaterial although resistance to air and water were further improved in the composite. In this biomaterial drying at high temperature had a detrimental effect. SEM analysis of the products obtained showed the intimate contact among fibers of bacterial cellulose and wood paper. Results obtained show the contribution of bacterial cellulose to improve the properties of paper and its potential for the design of new added value paper products from biomass.

Development of high gloss plastic for injection molding by utilizing wollastonite(CaSiO3) and talc fillers

The gloss of plastic products is an important factor with which customers rapidly and directly decide the value of product. In general, these high-gloss plastic molded parts are produced through the injection molding of glass fiber-added plastic resin using a high temperature mold with the fine surfaces like glass. However, making the mold temperature higher causes the cooling time of injection molding longer, and the prolongation of cooling time leads to the extension of whole cycle of injection molding process. In order to resolve this problem, we developed a resin which makes the high-gloss injection modeling possible at low mold temperature by replacing conventional glass fiber filler with wollastonite filler. The tensile strength, flexural strain, impact strength, flow rate, gloss level and so on of the developed resin were tested with respect to the content of wollastonite. The results show that most of the properties except for the flow rate and gloss level are reduced in the newly developed resin. However, the decline in these properties was not enough to limit the use of new resins. In the gloss level test, as for the equal gloss of injection molded parts, the mold temperature for the developed resin was 30 °C lower than the mold temperature for the conventional resin. The difference of gloss between two injection molded parts using two different resins has been confirmed from the surface inspection of injection molded parts by SEM (scanning electron microscope).

Functional polymers from renewable plant oils

This focus review addresses recent progress on plant oil-based functional polymers and composites. Plant oils are one of the most ideal chemical feedstocks to replace fossil resources for a variety of industrial chemicals in the polymer industry. In this focus review, an environmentally benign coating system is demonstrated using plant oils as the starting substrate for the preparation of artificial urushi with high hardness and a high gloss surface. Epoxidized plant oils, mainly epoxidized soybean oil, are polymerized with designed inorganics, cellulose, and biodegradable aliphatic polyesters to afford functional biobased polymers and composites. Castor oil is used as the core of branched poly(lactic acid) to improve the physical properties of biobased plastics. These plant oil-based materials are significant for the molecular design of functional and high-performance biobased products for industrial applications to contribute to the reduction of greenhouse emissions. This focus review addresses recent progress on plant oil-based functional polymers and composites. An environmentally benign coating system is demonstrated using plant oils as the starting substrate for the preparation of artificial urushi with high hardness and a high gloss surface. Epoxidized plant oils are polymerized with designed inorganics, cellulose, and biodegradable aliphatic polyesters to afford functional biobased polymers and composites. Castor oil is used as the core of branched poly(lactic acid) to improve the physical properties of biobased plastics.

Synthetic biology in high gloss

Synthetic biology in high gloss

High-performance one-pack ambient cross-linking latex binders containing low-generation PAMAM dendrimers and ZnO nanoparticles

This study focuses on ambient-temperature self-crosslinking acrylic latex coating compositions containing poly(amidoamine) (PAMAM) dendrimers and ZnO nanoparticles in the role of inter-particle cross-linking agents and flash rust inhibitors. Low-generation amine-terminated PAMAM dendrimers as aqueous solutions were added into latices containing diacetone acrylamide repeat units in their polymer structure. The incorporation of ZnO nanoparticles (without any surface treatment) was performed during the synthesis of a polymer dispersion carried out by the semi-continuous emulsion polymerization technique. The latex storage stability and coating performance with respect to zinc oxide and PAMAM presence were evaluated and compared with a conventional zinc oxide-free coating composition containing adipic acid dihydrazide as the cross-linking agent. It was found that the novel latices containing both PAMAM dendrimers and ZnO nanoparticles exhibited a long-term storage stability and provided crosslinked transparent coating films of high gloss, enhanced mechanical properties, solvent resistance and excellent water whitening resistance. Moreover, the latex compositions containing PAMAM dendrimers as the inter-particle cross-linkers were shown to provide flash rust resistance.

EFFECTS OF ADDITIVES, PIGMENT AND FILLER ON PHYSICO- MECHANICAL PROPERTIES AND WEATHER RESISTANCE OF POLYUREA COATINGS

Polyurea coatings are known to provide high hardness, stable color, excellent weather durability and good scratch resistance. Being cured, the coatings can also express heat resistance up to 150 oC, good resistance to acids, oils, as well as other chemicals, high flexibility and strain, excellent adhesion to various substrate materials such as concrete, steel, ceramic, glass and others. In this paper, a polyurea coating has been developed on basis of polyaspartic acid esters and polyisocyanate curing agent, using 3 % nanoclay additive. The physical, mechanical, and chemical properties of the coatings were examined by current technical specifications. The results for developed coating were recorded as follow: 76 in.lb impact strength, 7.5 mm elongation, and 0.7 relative hardness; no blistering was observed after 30 days of immersion in 5 % HCl and 5 % NaOH solutions. Weather resistance of the coatings was also evaluated with full absence of peeling, blistering and high gloss retention after 500 h accelerated UV testing.

Ambient temperature self-crosslinking latices using low generation PAMAM dendrimers as inter-particle crosslinking agents

This study focuses on one-component ambient temperature self-crosslinking latex coating compositions containing poly(amidoamine) (PAMAM) dendrimers in the role of eco-friendly crosslinking agents. Low generation amine-terminated PAMAM dendrimers of in the form of aqueous solution were added into acrylic latices containing diacetone acrylamide (DAAM) repeat units in their polymer structure. The latex storage stability and coating performance were evaluated and compared with the coating compositions containing the conventional adipic acid dihydrazide (ADH) crosslinking agent. It was found that the latices containing PAMAM dendrimers, exhibited a long-term storage stability and provided crosslinked coating films of high gloss, transparency and mechanical performance comparable to ADH-based self-crosslinking latices. Moreover, PAMAM-crosslinked coatings exhibited excellent water-whitening resistance.

Poly-Siloxane Modified Poly-Urethane based Long Life, High Gloss and Colour Retaining Coatings for Marine Applications

Poly-Siloxane Modified Poly-Urethane based Long Life, High Gloss and Colour Retaining Coatings for Marine Applications

Tuning inkjet printability of hydroxypropylated-starch-based coatings by mineral selection

Coatings based on hydroxypropylated starch (HPS) provide extraordinary print density with dye-based inkjet inks, but their suitability for pigment-based inks can be limited due to inadequate carrier medium (water) absorption and colorant fixation. In the present work, HPS-based coatings were tailored for both a pigmentbased and a dye-based ink by adding silicate minerals or acid clay (both Lewis and Br&#xF6;nstedt acid sites present in the acid clay). Substrate-ink interaction and colorant distribution were investigated via uncoated gloss and print quality indicators such as print density, ink bleeding tendency and delta gloss after printing with desktop printers. Three-dimensional z-stack CLSM images taken from printed samples revealed substantial differences in ink holdout and penetration characteristics between the studied materials. Pigment-filled HPS coatings showed up to 60% increase in print density compared to uncoated reference substrate and an increase of up to 35% compared to plain HPS coating with dyebased inks. In case of pigment-based ink, the increase was 17% between plain HPS coating and acid-clay-filled HPS coating. In addition, a combination of HPS and silicate mineral decreased ink bleeding substantially, but lower print gloss compared to substrate initial gloss was observed with the majority of experimental coatings. It was found that the pigment type affects substantially the unprinted gloss, which is naturally high in the case of pure HPS coating, but also the observed drastic difference in substrate permeability may explain the differences in print quality. The findings suggest that coating morphology, together with chemical interactions between starch and mineral and coated substrate and ink, has a key role in achieving high gloss and good print quality.

Development of spinel opaque glazes for ceramic tiles

The feasibility of developing fast-firing opaque wall tile glazes obtained from zircon-free frits was studied. The structural and morphological characteristics of the glazes were determined by differential scanning calorimetry, an optical dilatometer, X-ray diffraction and scanning electron microscopy. The studied glaze was characterized by a high whiteness value L* greater than 94, very low values of a* and b* which is about −0.65 and 0.01, respectively, and a high gloss value above 98%. The opaque effect is due to the presence of spinel crystals with a size range of 0.2–1.0μm, which is formed by devitrification during fast-firing. The Vickers micro-hardness of the studied glaze is higher than the one of the commercial zircon based glass-ceramic glazes. This type of frit can be an alternative one for fabricating opaque ceramic glazes.

The petrography - mineral characteristics and the ability used as decorative stone of magmatic acid eruptive rock having flow structure in Binh Thuan province of Vietnam

Vietnam's natural resources are plentiful and variuos, researching, searching, evaluating the quality and reserves of minerals resources in order to meet the needs of socio-economic development is the responsibility of the geological industry. To initially investigate, evaluate and introduce to the market the construction of a new decorative material of high quality and value, and provide materials and samples for the training of geology students of Ho Chi Minh City University of Technology, the author has used many methods: field working, measurement, photographing, taking and analyzing samples to research of petrography - mineral characteristics and preliminary evaluation of the ability to use decorative stone of the effusive magmatic acid rock in the South Middle region of Vietnam. After polishing samples, the author find that the high gloss (75-85%), beautifully curly color pattern, each sample has an unique beauty and aesthetics. Preliminary evaluation is samples can be used like decorative stones.