Search results

To evaluate the performance of the blends of Mesua ferrea L. seed oil based polyurethane resins with a commercially available bisphenol‐A epoxy resin at different weight ratios.

For effective improvement of their various properties, polyurethane‐ester (PE) and polyurethane‐amide (PA) resins of Mesua ferrea L. seed oil were blended with a commercially available bisphenol‐A‐based epoxy (EP) in different ratios (PE or PA:EP = 100:40, 100:50 and 100:60 by weight) by using the solution blending technique in xylene. The tensile strength, impact strength, adhesive strength, flexibility, hardness, elongation at break, swelling behaviour and chemical resistance in different media of the films for both the blends have been studied.

The blending of PE and PA resins of Mesua ferrea L. seed oil with a commercially available bisphenol‐A‐based epoxy (EP) showed very good compatibility of the components as observed by SEM study. The blending also significantly improved the performance characteristics such as drying time, tensile strength, impact strength, adhesive strength, chemical resistance, etc. of the films.

The epoxy resin and the hardener are used of a particular grade of a particular manufacturer. Further, it could be obtained from different sources and of different grades. In addition, the performance characteristics could also be studied to optimise the exact blend ratio.

The method developed provided a simple and practical solution to improve the performance characteristic of polyurethane resin with less than one NCO/OH ratio.

The method for improving the performance characteristics of epoxy modified vegetable oil based polyurethane is something novel and could find numerous applications in surface coatings, adhesive and thin film.

The purpose of this study was to overcome discomfort associated with it, a resin finish was applied in conjunction with hydrophilic polyurethane.

The process variables included concentrations of polyurethane and resin finishes, and pH under central composite design (CCD). The fabric specimens were assessed for crease recovery angle (CRA), tensile strength and moisture management properties.

Some models were developed for prediction of CRA and overall moisture management capability (OMMC) of treated fabric. It was observed that polyurethane concentration showed a parabolic relationship with CRA and a direct relationship with OMMC, whereas resin concentration showed a parabolic relationship with CRA and an inverse relationship with OMMC. Increase in pH from acidic to alkaline resulted in a decrease in CRA but an increase in OMMC. The untreated specimen had the highest tensile strength, whereas the specimen treated with polyurethane showed the least tensile strength loss, and the one treated with resin showed the highest loss in tensile strength.

As the polyurethane-based finish is soft and hydrophilic, so it was expected that it would overcome the uncomfortable feature of durable press finish, and with its flexibility, the strength losses might reduce.

This is the first report about the investigation of effects of increasing flexibility of the cross-link by incorporating polyurethane compounds into a typical dimethylol dihydroxy ethylene urea durable press resin formulation.

An important development in the urethane coating area is the use of polyisocyanates, in combination with hydroxylated acrylic resins, to provide room‐temperature‐curing coatings. These new formulations, according to Klein and Elms [Journal of Paint Technology, 43, November (1971) p. 68], demonstrate lightfastness, good outdoor durability and solvent resistance when the acrylic resin is coreacted with an aliphatic polyisocyanate. The acrylic resins are copolymers which contain either the hydroxypropyl or hydroxybutyl ester of acrylic or methacrylic acid as one component. Hydroxypropyl acrylate acetoacetate extends the potlife of this two‐component coating. The authors describe work in which glass transition temperature is used as a means for selecting the correct hydroxylated acrylic resins for use in the system. If the glass transition temperature is between 22 and 54°C, a flexible coating with good impact resistance results, but the system requires baking. At a glass transition temperature of 54° and a hydroxyl value of 26, a composition results which dries rapidly at ambient temperatures and which provides good hardness and mar resistance. The coreactant in this instance is an aliphatic diisocyanate composition based on hexamethylene diisocyanate.

The aim of this paper is to synthesise polyester/silica hybrid resins and their hybrid polyurethanes via in situ (IS) and blending (BL) methods and to evaluate the effect of preparation method, interaction type and silica content on the physico‐chemical and thermal properties of polyurethane/silica (PU/Silica) hybrid coatings.

Silica particle‐containing silica sol was prepared according to Stöber method using tetraethylorthosilicate as the precursor and then introduced into polyester matrix by in situ and direct blending method. The modified polyester/silica resin was further crosslinked with TMP‐TDI adduct to synthesise PU/Silica hybrid coatings and studied for thermo‐mechanical, physico‐chemical properties.

It was found IS polymerisation caused more polyester segments to chemically bond onto the surface of silica particles than BL process. Results also reveal that due to stronger interaction between silica particles and PU matrix, hybrid resins prepared by IS method confers better properties than BL method and exhibit optimal properties at the critical concentration of 8 wt% silica.

In the present study, silica particles are used to modify properties of polyurethane resins. Many other countless combinations in terms of inorganic filler or organic matrices can be explored to obtain a wide range of interesting properties and applications.

The results obtained in this study will be extremely useful to enhance the understanding of this class of hybrid materials.

Hybrid organic‐inorganic networks offer a new area of material science that has extraordinary implications for developing novel materials that exhibit a diverse range of multi‐functional properties.

The binder or media component of surface coatings can be subdivided into two broad groups, non‐convertible and convertible, which differ in their mode of film formation. Binders of the non‐convertible type do not undergo chemical conversion reactions whenthey cure, and film formation here involves loss or evaporation of a volatile solvent and concomitant deposition of the solid binder. Important members of this group are the rubber derivatives and the many examples of vinyl copolymers; some recent developments in the technology of these polymers were described in the previous article in this series. This article will consider the convertible media used in coatings, where film formation involves some form of chemical reaction. Commencement of this reaction is dependent upon either the presence of a suitable initiator, or by exposure to some form of radiant energy, which causes the binder (in the form of a monomer or partially‐polymerised component) to rapidly polymerise. This polymerisation reaction can take one of several forms though the result is the same; the binder and hence the liquid paint is converted into a solid material which is substantially insoluble in the original carrier solvent. This review will consider some of the recent literature concerned with three important members of the convertible group of media; alkyd, epoxy and polyurethane resins.

Poly(ethylene terephthalate) (PET) waste from soft drink bottles was incorporated into palm olein alkyd to produce new polyol for use in polyurethane resins as surface protection on metal surfaces.

Alkyd was prepared from palm olein, glycerol and phthalic anhydride. PET underwent simultaneous glycolysis and transesterification reactions with the alkyd. Varying the amount of PET has led to polyols with different viscosities. Polyurethane resins were produced by reacting the polyols with toluene diisocyanate. The resins were coated on mild steel panels and cured. Performances of the cured films were tested.

The polyurethanes (PU) resin cured to a harder film with better thermal stability. Films showed excellent adhesion properties, while higher content of PET exhibited higher pencil hardness, better water, salt, acid and alkali resistance.

Other vegetable oils could also be used. The alkyd structure could be changed by formulation to have different functionality and the ability to incorporate higher amount of PET waste. Rate of glycolysis of PET could be increased by higher amount of ethylene glycol.

This method has managed to use waste PET in producing new polyol and PU resins. The cured films exhibit good mechanical and chemical properties, as well as excellent adhesion and thermal stability.

The non-biodegradable PET has created environmental pollution problems connected to littering and illegal landfilling. It has become necessary to pay greater attention to recycling PET bottles for obtaining valuable products.

This approach is different from the earlier reports, where PET was recycled to recover the raw materials.

The purpose of this paper is to synthesise environment friendly UV curable polyurethane acrylate resins for various industrial applications and study the performance properties of the cured coating films applied over metal surfaces.

The polyurethane acrylate resin was synthesised using polyester polyol (synthesised using ethylene glycol, adipic acid and 1,6 hexane diol), isophorone diisocynate (IPDI) and 2‐hydroxy ethyl methacrylate (HEMA). The different formulations were developed using various reactive diluents viz. monofunctional, difunctional, trifunctional and tetrafunctional (ethoxylated phenol monoacrylate, 1, 6 hexane diol di acrylate, dipropylene glycol di acrylate, trimethylol propane triacrylate, propoxylated trimethylol propane triacrylate, pentaerythrol triacrylate – PETA). These samples were cured under UV radiation. For effective curing, various compositions of oligomers, photoinitiator and reactive diluents were used. The mechanical, optical, rheological, chemical and stain resistance properties were evaluated.

The designed polyurethane acrylate gave good performance properties when used with reactive diluents having different functionality in different ratios for application over metal surfaces as protective coatings for various industrial applications. While using reactive diluents, the coating compositions showed significant enhancement of mechanical, physical and chemical resistance properties. Owing to different functionality of reactive diluents used, highly cross‐linked structures are formed, which lead to excellent mechanical and chemical properties. The optimum results were obtained with PETA as reactive diluent.

The polyurethane resin has been synthesised from polyester polyol (made up of ethylene glycol, adipic acid and 1, 6 hexane diol), IPDI, 2‐HEMA. Besides, this, it can be synthesised from some other polyester polyol or polyether polyol. In addition to this, some other isocyanates such as TDI, MDI, HDI, HMDI, etc. may be used.

The study has provided a better solution for developing low volatile organic compound (VOC) products by using UV radiations, which can be cured within a minimum period of time and can save significant application curing time for the end‐users. The developed product is also an environmentally friendly product.

Metallic surfaces are widely used in packaging industry in rigid and semi‐rigid forms. One of the prime requirements of the surface is an attractive printing on it. Conventionally used coating system on metallic surfaces are not holding or retaining their decorative effect/gloss level to a large extent. For this purpose, an overprint varnish is normally used which is mostly solvent based. This paper has been able to suggest very good formulations for printing of metallic surfaces for packaging and for overprinting in particular, which is radiation curable and environment friendly.

Describes experiments with the use of coconut coir dust extract as a raw material in the production of polyurethane and epoxy resin wood finishes, using benzoylated and methylated derivatives of the extract modified with isocyanates to produce polyurethane resins, or with epichlorohydrin to give epoxy resins, and using the copolymer resins formed in the formulation of wood finishes. Finds that the incorporation of cashew nut shell liquid into the copolymer resins further enhances the film‐forming properties of the finishes.

Studies the effects of non‐isometric pigments on the anticorrosion properties of coating films. The optimum concentrations for using iron mica, muscovite, and graphite have been determined. The results obtained on using the natural iron mica are compared to those obtained with a synthetic product. As binders for the coatings epoxy resin, polyurethane and alkyd resins were used. The results allow the conclusion that on the pigmentation with iron mica the protection function of top coatings against the corrosive media can be considerably increased.

This study aims to investigate the influence of commercially available resins in water-based magenta pigment inkjet ink formulations on the properties of ink printability and the characteristics of ink application in food packaging. The impact of the resin on the jettability of the existing printability phase diagrams was also assessed.

Inks with different resin loadings were tested for selected properties, such as viscosity, particle size and surface tension. Stability was determined using a Turbiscan AGS turbidimeter and LumiFuge photocentrifuge analyzer. The ink layer fastness against abrasion and foodstuffs was evaluated using an Ugra device and according to PN-EN 646, respectively. JetXpert was used to assess Ricoh printhead jetting performance.

Printability diagrams successfully characterized the jettability of polyurethane inkjet inks on a multi-nozzle printhead and the binder improved droplet formation and printing precision.

Magenta water-based inkjet inks with commercial resins have been developed for printing on paper substrates. To the best of the authors’ knowledge, for the first time, inkjet ink stability was evaluated using the Turbiscan AGS and LumiFuge analyzers, and jettability models were verified using an industrial multi-nozzle printhead.