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The purpose of this paper is to develop eco‐friendly coatings based on low‐cost epoxide resins prepared by using a natural phenolic material such as cardanol (non‐toxic)…
The purpose of this paper is to develop eco‐friendly coatings based on low‐cost epoxide resins prepared by using a natural phenolic material such as cardanol (non‐toxic), in place of ordinary phenol (toxic), which can be self‐curable at an optimum temperature.
Cardanol‐formaldehyde novolac resins (CNs) were prepared by reacting cardanol with formaldehyde in different molar ratios varying from 1:0.6 to 1:0.9. Prepared CNs were epoxidised by reacting with epichlorohydrin to produce epoxide resins, which would be called as epoxidised CNs (ECNs). Further, ECNs were modified by reacting with diethanolamine (DEtOA), a secondary amine to introduce tertiary amino group(s) into the molecules, required for self‐curability of ECNs. These modified ECNs are referred to as MECNs. The molar ratio of ECNs to DEtOA was taken in accordance with epoxy functionality of epoxide resins (ECNs) which ranged from 0.5 to 2.9. Nine numbers of MECNs (MECN1 to MECN9) were prepared by using four epoxide resins. These resins viz. CNs, ECNs and MECNs were characterized by 1H NMR and FTIR spectroscopic methods for their structure elucidatation, and by gel permeation chromatography for determining their molecular weights.
The most suitable molar ratio of ECN:DEtOA for the preparation of MECNs was found to be 1:1. The CN prepared by using cardanol and formaldehyde in the molar ratio of 1:0.7 was used for the preparation of ECN2 and MECN2. Applied films of epoxide resins, designated as MECN2, had reasonably good physical and chemical resistance properties. With a wide cure window, the films of MECN2 were found to be self‐curable at an optimum cure schedule of 160°C/30 min. Owing to self‐curability of the developed epoxide resins, the coatings based on them did not require any additional/external crosslinker to be incorporated in the coating composition.
The prepared epoxide resins (MECNs) had good physical and chemical resistance properties, but demonstrated low stability and low resistance to xylene, in particular.
The paper shows how the epoxide resins were prepared by using a low‐cost phenolic material (cardanol) which is obtained from natural renewable resources, instead of petroleum, and is non‐toxic. These developed coatings can be applied as primer coat and top coat on metallic substrates. True self‐curability of the coating films has been achieved via anionic polymerization.
Developments in the area of epoxy resins make rich contributions to the patent literature. The single subject on which more patents are issued than any other is curing agents. Accordingly, this section will describe some of the patents on epoxy resin curing agents that have been issued in the past few years. Associated with the curing agents are catalysts, coreactants, and modifiers.
Paliogen Black L 0084 is a perylene pigment that can reflect infra‐red radiation and is being launched on the market by BASF. At about 650 nm, the slope of the infra‐red reflection curve for Paliogen Black L 0084 commences to rise steeply. This property is of great significance for camouflage paints, and the pigment's green undertone in the visible range is in line with this application. Paliogen Black L 0084 is suitable for outdoor applications.
Oleochemicals are derivatives of the components of vegetable, marine and animal oils and fats, glycerides, i.e. glycerol and fatty acids substantially, and include the…
Oleochemicals are derivatives of the components of vegetable, marine and animal oils and fats, glycerides, i.e. glycerol and fatty acids substantially, and include the fatty acids such as and their derivatives including fatty alcohols, fatty esters, amides, amines and other nitrogen derivatives and also the heavy metal soaps and the water soluble alkali metal soaps, polyoxyethylated materials, polyoxypropylated products, sulphated and sulphonated derivatives and the quarternary ammonium compounds. Although only normally used in small amounts, oleo chemicals are amongst the important raw materials, additives, for aiding the production of paints, capable of having a profound effect in these preparations.
Ternary condensate finish. The coating compositions described are designed primarily for application to household appliances fabricated from sheet metal for protection against corrosive environments. When pigmented, these compositions are particularly useful as metal primers: although the pigmented finishes are clear, they can be used equally well as top coats. The components consist of an organic film‐forming material composed of an inter‐polymer of styrene with meth‐acrylic acid and an ester of the acid; a drying ester varnish having a resinous epoxyhydroxy‐polyether and esterified drying‐oil fatty acid; and a heat‐reactive urea or other amine resin. Compositions based on these components can be applied by spraying, brushing, dipping, roller coating and flow coating. They are subsequently dried and cured at 350°F for 15–20 min or 30–40 min at 280°F. (909,322—E. I. Du Pont de Nemours & Co., U.S.A.)
Doverstrand Ltd, a company owned by Revertex Chemicals Ltd, of Harlow, Essex, jointly with Reichhold Chemicals Inc, of White Plains, USA, has agreed to acquire from May 1, 1977, the know‐how, patents and goodwill of Borg‐Warner's Chemicals latex business in the UK and Europe under an agreement signed in Harlow on March 29.
The purpose of this paper is to describe the synthesizing of polyesteramide (PEA) resins using an acid functional acrylic copolymer (ACR) and hydroxy ethyl fatty amide…
The purpose of this paper is to describe the synthesizing of polyesteramide (PEA) resins using an acid functional acrylic copolymer (ACR) and hydroxy ethyl fatty amide (HEFA) of dehydrated castor oil (DCO) and to study the effect of HEFA on the performance properties of the coating films of PEA resins.
The PEA resins are synthesised by using ACR (synthesised by using butyl methacrylate (BMA) and maleic anhydride (MA)), and HEFA. Different formulations are developed by using ACR and HEFA. The coatings are made using xylene/acetone as a solvent. These coatings are applied on mild steel panels and are cured at 110°C. Various mechanical, optical and chemical properties of the coating films are evaluated.
The study reveals that, HEFA of DCO is used successfully as a cross‐linking agent for the ACR to form the PEA resins. Incorporation of long chain fatty acid (C18) moieties of the fatty amide in the PEA resins backbone is thought to serve as flexibliser, which lead to improved mechanical and chemical properties of the films. The optimum results are obtained from composition three of copolymer A having (3:1) (ACR:HEFA) molar ratio.
The PEA resins synthesised here are made up of ACR (synthesised by using BMA and MA), and HEFA of DCO. Besides, this ACRs can be synthesised from acrylic acid. In addition to this, one can also use HEFA synthesised from other oils.
This method provides a simple solution for the synthesis of PEA resins and resulting to their improved mechanical properties. The developed product is also an environment friendly product.
The method developed here for the synthesis of PEA resins form ACRs and HEFA is unique and can be used as an effective surface coating material. These studies will help to develop low volatile organic compounds product which could find numerous industrial applications in surface coatings for metal surfaces.
Epoxy resins are compounds which contain in their molecule more than one 1,2 epoxy group capable of undergoing polyreactions, referred to as curing reactions. The presence…
Epoxy resins are compounds which contain in their molecule more than one 1,2 epoxy group capable of undergoing polyreactions, referred to as curing reactions. The presence of epoxy groups may be either internal, terminal or on cyclic structures. Polyreactions take place at varying temperatures from low room temperature cure to high temperature cure systems upon addition of curing agents such as amines, amides or carboxylic acid anhydrides. The uncured resins which range from low viscosity liquids to high melting solids, soluble in organic solvents, become insoluble, infusible hard materials on curing due to crosslinked structure of the cured products.
Various reviews have appeared in earlier years dealing with several aspects of gelatin. Articles have also appeared dealing with the structure of the material and its…
Various reviews have appeared in earlier years dealing with several aspects of gelatin. Articles have also appeared dealing with the structure of the material and its properties, and with its properties in the solid state. Specifications for the purer form of gelatin have appeared in a number of Pharmacopiea, and commercial specification covering several qualities of the material have also been published.