Prakash Mahanwar, Abhijit Sathyanarayana, Vaishali Bambole and Sunil Sabharwal
– The paper aims to discuss the evaluation of anti-corrosive efficiency of conducting polymer, polypyrrole in water borne epoxy-polyamine coatings.
Abstract
Purpose
The paper aims to discuss the evaluation of anti-corrosive efficiency of conducting polymer, polypyrrole in water borne epoxy-polyamine coatings.
Design/methodology/approach
Polypyrrole (PPy) is synthesised by chemical oxidative polymerisation. The synthesised PPy is characterised by employing FT-IR, XRD, SEM and EDX analysis. The coatings are formulated using water borne epoxy cross-linked with aliphatic polyamine adduct and the effect of PPy on corrosion prevention is studied. PPy was used as anti-corrosive pigment in concentration varying from 1 to 5 wt.%. In addition to anti-corrosive property; mechanical properties, chemical resistance and weathering properties of the coatings containing PPy are studied, thereby obtaining a wholesome data about the quality and performance of these coatings.
Findings
The result obtained through various tests showed that the coating with 1 and 2% PPy exhibited excellent weathering resistance, mechanical properties and improved chemical resistance. Higher percentage loading of PPy (beyond 3 per cent) proves to be disastrous, as extended percolation networks are formed which results in rapid intense corrosion leading to fast coating breakdown.
Research limitations/implications
The anti-corrosion property of the coating can be tested by means of atmospheric exposure such as Florida test which produces a real time evaluation of the anti-corrosive nature of the coating at natural condition rather than accelerated weathering, thereby providing more reliable performance data for intended application purpose.
Practical implications
The results find application in anti-corrosive/performance paints for industrial application.
Originality/value
This research paper presents the results of anti-corrosion behaviour of PPy in water borne epoxy-polyamide coating. Based on this result, a highly effective anti-corrosive coating can be formulated by the addition of small percentage of PPy in combination with other conventional pigments, thereby enhancing corrosion protection. But care must be taken so as to avoid formation of extended percolation network of PPy which leads to rapid coating breakdown.
Details
Keywords
S. Abhijit, Prakash A. Mahanwar and V.A. Bambole
The aim of this paper is to conduct a real time evaluation of polypyrrole as an anti‐corrosive pigment in epoxy polyamide coating.
Abstract
Purpose
The aim of this paper is to conduct a real time evaluation of polypyrrole as an anti‐corrosive pigment in epoxy polyamide coating.
Design/methodology/approach
This study deals with synthesis of polypyrrole (PPy) by chemical oxidative polymerisation in laboratory conditions. The synthesised PPy was characterised by employing FT‐IR, XRD, SEM and EDX analysis. Epoxy film of bisphenol type hardened with polyamide based curing agent was used as the binder. PPy was used as anti‐corrosive pigment in concentrations varying from 0 to 5 wt% in the coating. In addition to anti‐corrosive property, mechanical, chemical and weathering properties of the coating containing PPy were studied and compared with epoxy polyamide coating without PPy.
Findings
The result obtained through various tests showed that the coating with 1 and 2% PPy exhibited excellent weathering resistance, mechanical properties and improved chemical resistance.
Research limitations/implications
The anti‐corrosion property of the coating can be tested by means of atmospheric exposure such as Florida test or by means of electrochemical impedance spectroscopy.
Practical implications
The results find application in anti‐corrosive paints for industrial application.
Originality/value
This research paper presents the results of anti‐corrosion behaviour of PPy in epoxy‐polyamide coating. Based on this result, a highly effective anti‐corrosive coating can be formulated by addition of small percentage of PPy in combination with other conventional pigments, thereby enhancing corrosion protection.
Details
Keywords
Pallavi P. Deshmukh, Prakash A. Mahanwar and Sunil S. Sabharwal
Urethane Acrylate Oligomer with 100% solids was synthesised and characterised in order to study the application in electron beam curing with varying ratio of Trimethylol propane…
Abstract
Purpose
Urethane Acrylate Oligomer with 100% solids was synthesised and characterised in order to study the application in electron beam curing with varying ratio of Trimethylol propane triacrylate (TMPTA). The purpose of this paper is to study effect of TMPTA addition on the crosslink density and different coating properties.
Design/methodology/approach
Polyester polyol was synthesised by reacting single diacid, adipic acid (AA), with Pentaerythritol (PENTA) and 1,6‐hexanediol (HD). Further, Urethane acrylate resin was synthesised by using Isophorone diisocyanate (IPDI), hydroxy ethyl acrylate (HEA) and Polyester polyol. The polyester polyol and urethane acrylate oligomer were characterised by 1H NMR, 13C NMR, FTIR and GPC. Further, TMPTA was added as a crosslinker to the urethane acrylate oligomer and cured by electron beam radiation. The cured UA films having varying concentration of TMPTA were employed to evaluate thermal property, contact angle analysis, mechanical and chemical properties.
Findings
The obtained results showed improvement in their chemical properties, mechanical properties, thermal properties and water contact angle at 20% of TMPTA iconcentration. The TMPTA also reduced the dose required for the curing.
Research limitations/implications
The resin can be synthesised from different isocyanates as TDI, MDI and HMDI, etc. The study can also be done with different multi or mono functional monomers such as methacrylate, hexanediol diacrylate, ethylene glycol diacrylate, etc.
Practical implications
The paper provides the better solution to reduce the cost of the electron beam radiation required for the curing.
Social implications
The method presented in the paper could be very useful for controlling environmental pollution; as the conventional method of curing releases volatile organic compounds (VOC).
Originality/value
In this paper, urethane acrylate and TMTPA cured with electron beam are shown to offer good coating properties. A high‐solid urethane acrylate coating would find numerous industrial applications in surface coatings.
Details
Keywords
Nishant Bhore and Prakash Mahanwar
The purpose of this paper is to synthesise UV curable emulsion latex and to study characteristics and various performance properties such as tackiness, peel adhesion and cohesive…
Abstract
Purpose
The purpose of this paper is to synthesise UV curable emulsion latex and to study characteristics and various performance properties such as tackiness, peel adhesion and cohesive strength for pressure sensitive adhesive (PSA) application after UV curing.
Design/methodology/approach
The two component water‐based ultraviolet (UV) curable acrylate PSAs were synthesised by emulsion copolymerization. The synthesised emulsion samples were characterised and various performance properties such as tackiness, peel adhesion and cohesive strength for PSAs were tested after UV curing.
Findings
The thermal analysis showed the effect of methyl methacrylate (MMA) content on the glass transition temperature of emulsions, which had significant effect on tack. Effects of varying concentration of multifunctional monomer trimethylolpropane triacrylate (TMPTA) and UV exposure time on properties of UV curable PSA were also studied.
Research limitations/implications
The results associated with the UV curable water based PSA has certain advantages, such as low VOC and fast curing rate and with the scope for further research by using the radiations with different intensities or other radiation systems such as electron beam curing.
Practical implications
Practically the UV water based PSAs are already in industrial use for glass lamination, silicon semiconductor dicing, and in medical use for band aids and drug delivery systems and for dental applications for cavity filling.
Originality/value
The water based UV curable PSA synthesised by emulsion polymerization had very good tackiness properties with lower MMA content. It was observed that the lower the concentration of TMPTA, the better the performance properties, such as tack and peel strength. It was also observed that with increasing TMPTA concentration the cohesive strength increased.