Anagha Sabnis

Institute of Chemical Technology, Mumbai, Polymer Engineering and Technology, Faculty Member

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Clark University

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Universitat de València

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Central University of Kerala

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University of Illinois at Urbana-Champaign

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Universidad de Santiago de Chile

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Papers by Anagha Sabnis

Synthesis of Hydroxyl Terminated Fatty Ester Amide (DFEAm) from Dehydrated Castor Oil (DCO) and its Utilization in Various Polyurethane Coating Applications

Iranian polymer journal., Apr 9, 2024

Recycling of waste polyurethane shoe sole via aminolysis route

Journal of material cycles and waste management, Feb 6, 2024

Synthesis and Characterization of Imide Containing Hybrid Epoxy Resin with Improved Mechanical and Thermal Properties

International Journal of Polymer Science, 2014

Phosphorous containing amine, tripropyldiamine phosphine oxide (TPDAP), and hybrid monomer 4-(N-p... more Phosphorous containing amine, tripropyldiamine phosphine oxide (TPDAP), and hybrid monomer 4-(N-phthalimidophenyl) glycidylether (PPGE) were synthesized and characterized by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis (EDX). PPGE was incorporated in bisphenol A epoxy resin (BPA) in various concentrations (5% to 20%), based on a weight percentage of BPA resin. Curing was carried out with the stoichiometric amount of TPDAP and 1,3-propanediamine (PDA) to result in cross-link network. Various mechanical, chemical, thermal, and flame retardant properties of modified and unmodified epoxy resin were studied. The coatings obtained with the addition of PPGE were found to have improved properties as compared with those of the unmodified resin. Coatings with 15% loading of PPGE showed improved flame retardant and mechanical properties with stable thermal behaviour.

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Superhydrophobic polymer coating: A design perspective

Abstract Superhydrophobic surfaces have gained a lot of interest due to their water-repellent and... more Abstract Superhydrophobic surfaces have gained a lot of interest due to their water-repellent and self-cleaning properties which are also commonly identified as the “lotus-effect.” A superhydrophobic coating is a nanoscopic surface layer that repels water. Superhydrophobic surfaces show great promise for applications that range from self-cleaning windows to antiicing aircrafts. Two strategies are commonly employed in the fabrication of superhydrophobic coatings. First, the surface is coated with a low surface energy material which has a water contact angle greater than 150 degrees on a flat substrate. Second, the surface should have a sufficient level of roughness. An ideal surface should have a hierarchical topography that has features spanning multiple length scales that extend from micrometers to nanometers. There are two methods for formulating superhydrophobic polymer coatings. One can incorporate superhydrophobicity in the polymer backbone by chemical modification. Most of the materials used for this purpose contain fluorinated compounds and hydrocarbons. Polydimethylsiloxane (PDMS) and certain types of polyesters and polyurethanes are also used extensively in the fabrication of superhydrophobic coatings. The other technique includes the addition of superhydrophobic additives like nano TiO2 into the formulation. Generally, oxides, hydroxides, salts, and silicates are used as additives for imparting the superhydrophobicity. A typical fabrication approach to render a surface superhydrophobic, thus involves two steps, the first being generation of a roughness on the surface followed by functionalization with a low energy material. Highly durable superhydrophobic coatings could be obtained by deposition of fluorinated and siloxane- containing compounds on substrates benefiting from the presence of inherent microscale roughness in these materials.

Synthesis and characterization of emulsion polymers using isopropenyl acetate

International Journal of Industrial Chemistry, Oct 24, 2012

Background: Isopropenyl acetate (IPA) is one of the monomers from acetate family having an unsatu... more Background: Isopropenyl acetate (IPA) is one of the monomers from acetate family having an unsaturation with a methyl group attached to the ethylenic carbon. The unsaturation present in the monomer can be utilized for free radical polymerization. Irrespective of this, IPA is not studied much in emulsion polymer synthesis. In the current study, we report the preparation of emulsion polymers using IPA and other acrylic monomers. Terpolymers of butyl acrylate (BA), methyl methacrylate, and IPA were prepared via seeded emulsion polymerization with varying IPA proportions on molar basis. Potassium persulfate was employed as an initiator along with Dowfax 2A1 as surfactant (anionic). Results: The emulsions prepared thereof were characterized for particle size, zeta potential and molecular weight using gel permeation chromatography. The emulsion films were evaluated using Fourier transform infrared spectroscopy, as well as their thermal (differential scanning calorimetry, thermo gravimetric analysis) and mechanical properties to study the effect of isopropenyl acetate on their overall properties. Conclusions: With increasing proportion of IPA in the formulation, lower conversion was observed which could be due to the lower reactivity of IPA for radical polymerization in the presence of these comonomers. More study for the utilization of IPA in polymer synthesis is needed which, on successful optimization, would give a cost-effective alternative to various commercial acrylic monomers.

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Anhydride-cured epoxidized dehydrated castor oil (EDCO) containing organically modified zinc oxide (ZnO) nanoparticles

Journal of Industrial and Engineering Chemistry, Jul 1, 2023

Recent Advances in Polyurethane Coatings and Adhesives Derived from Vegetable Oil-Based Polyols

Journal of Polymers and the Environment

(Ethylene Terephthalate) for Coating Application

The recycling of post-consumer poly(ethylene terephthalate) (PET) is a worldwide concern due to i... more The recycling of post-consumer poly(ethylene terephthalate) (PET) is a worldwide concern due to its environmental impact and large volume of these waste materials produced by society. Current work aims at effective recycling of waste PET from soft drink bottles by glycolysis method and thereby utilization of recycled product for coating application. In the investigation, Ethylene Glycol (EG) was used for glycolysis of PET in presence of 0.5% zinc acetate as transesterification catalyst. PET & EG were taken on molar basis at 1:4 and 1:6. The glycolyzed product was characterized by hydroxyl and acid values, FTIR, 1 HNMR spectroscopy. Polyester polyol was successfully synthesized by esterification of glycolyzed product, Adipic acid, Phthalic anhydride and Neopentyl glycol. The produced resin was cured with different polyisocyanate curing agents. The mechanical properties of the cured resins were evaluated. The chemical resistances of cured coatings were evaluated for water, solvents, salt spray, acid and alkali resistance.

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Development of bio-based polyester-urethane-acrylate (PUA) from citric acid for UV-curable coatings

Journal of Coatings Technology and Research

Synthesis and characterization of citric acid and itaconic acid-based two-pack polyurethane antimicrobial coatings

Polymer Bulletin, Jan 4, 2023

Synthesis and characterization of sol–gel derived CNSL based hybrid anti-corrosive coatings

Journal of Sol-Gel Science and Technology, Oct 31, 2013

ABSTRACT Thermally cured cashew nut shell liquid based hybrid coatings have been successfully dev... more ABSTRACT Thermally cured cashew nut shell liquid based hybrid coatings have been successfully developed using three step processes of malenization, silane modification and subsequent hydrolysis and condensation with tetra ethyl orthosilicate for corrosion protection of mild steel. The synthesized precursor was then characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy (1H-NMR, 13C-NMR and 29Si-NMR) for structural elucidation. Four different coating formulations were developed on the basis of silane content (5, 10, 15 and 20 %) in the coating and cured with hexabutoxymethylmelamine at 120 °C for 1 h. The completely cured coatings were evaluated for mechanical properties, solvent resistance, chemical resistance, hydrolytic stability and accelerated weathering properties. Scanning electron microscope/energy dispersive spectroscopy was used to analyse the morphological behaviour and elemental distribution of the coating. Results revealed that 20 % silane modification showed better overall properties as compared to other formulations due to formation of more metal–oxygen–silicon covalent bond at metal-coating interface.

Antimicrobial uv curable wood coatings based on citric acid

Pigment & Resin Technology, 2021

Purpose Epoxy acrylate which is commercially utilized for UV curable coatings although has excell... more Purpose Epoxy acrylate which is commercially utilized for UV curable coatings although has excellent adhesion, flexibility, hardness and chemical resistance, they lack in antimicrobial properties. Citric acid (CA) is economical as well as a bio-based compound which possess an antimicrobial activity. So, the purpose of this research investigation is the preparation of CA-based oligomer which can be further incorporated with epoxy acrylate and tri (propylene glycol) Diacrylate (TPGDA) to form uv curable coating and the study of its antimicrobial property. Design/methodology/approach A UV-curable unsaturated oligomer (CUV) was synthesized from CA and glycidyl methacrylate (GMA). The chemical structure of CUV was confirmed by FTIR, 1H NMR, GPC, hydroxyl value, acid value and iodine value. Further, CUV was assimilated as an antimicrobial as well as crosslinking agent to copolymerize with epoxy acrylate oligomer and a series of UV-cured antimicrobial coatings were concocted by employing U...

Phenalkamine curing agents for epoxy resin: characterization and structure property relationship

Pigment & Resin Technology, Aug 6, 2018

Purpose The purpose of this study is to synthesize structurally different phenalkamines based on ... more Purpose The purpose of this study is to synthesize structurally different phenalkamines based on cardanol, a renewable material obtained from cashew nut shell liquid, and to evaluate their effect on performance properties of the coatings. Design/methodology/approach For this purpose, the Mannich reaction between cardanol, formaldehyde and various diamines such as diaminodiphenyl methane (DDM), hexamethylene diamine, Jeffamine D400 and Jeffamine T403 were carried out to produce novel phenalkamines. Resultant phenalkamines were used as curing agents for commercial DGEBPA epoxy resin and were evaluated for performance properties. Findings The mechanical, optical, chemical, thermal and anticorrosive properties were evaluated and compared with those of commercial phenalkamine AG141. It was observed that anticorrosive properties evaluated using a salt spray test and electrochemical impedance spectroscopy revealed significant improvement in anticorrosive performance of coatings cured with synthesized phenalkamines based on DDM and T403 as compared to the coatings based on commercial phenalkamine AG141. Research limitations/implications To obtain optimum performance properties of the coatings, a combination of phenalkamines can be used. Practical implications Curing time and gel times of all the phenalkamines can be further studied under wet and humid conditions. In addition, the variation in coating properties under humid conditions can be investigated. Originality/value In this study, newer phenalkamines were synthesized and used as curing agents for epoxy coatings. So far, there have been no reports indicating the synthesis and application of phenalkamines based on polyetheramines, namely, Jeffamine D400 and Jeffamine T403, in coating applications.

Synthesis and Characterization of Cardanol-Based Epoxy Systems

Designed Monomers and Polymers, 2008

The use of cardanol, a renewable natural resource, in place of a phenol or diphenol, in the synth... more The use of cardanol, a renewable natural resource, in place of a phenol or diphenol, in the synthesis of two different epoxy systems has been studied in this work. Cardanol, prepared by the distillation of cashew nut shell liquid (CNSL), was epoxidised using epichlorohydrin in presence of caustic soda catalyst at different reaction intervals and the products were characterized by spectroscopy, gel-permeation chromatography and by determining the epoxide equivalent. The epoxide equivalent increased sharply with time of epoxidation and reached almost a limiting value around 9 h. Cardanol, being less reactive, undergoes epoxidation to a smaller extent than phenol or bisphenol. Although these epoxy compounds do not form cross-linked networks due to being mono-functional, they are found to be effective in producing relatively flexible systems when reactive blended with commercial DGEBA. Co-epoxides containing bisphenol A and cardanol in varying molar compositions were also synthesised and characterised. Introduction of 20 mol% cardanol into bisphenol A resulted in a resin having reduced tensile, impact and compressive strengths upon curing by a polyamine hardener. However, the resin showed considerable improvement in elongation-at-break without much decrease in energy absorption.

Synergistic effect of P S and crosslink density on performance properties of epoxy coatings cured with cardanol based multifunctional carboxyl curing agents

Reactive and Functional Polymers, 2018

In the present study, phosphorus-sulphur containing di and tetra functional carboxyl curing agent... more In the present study, phosphorus-sulphur containing di and tetra functional carboxyl curing agents were synthesized from renewable resource, cardanol and used in the preparation of high performance epoxy coatings. Structure of the curing agents was analysed by evaluating its acid and iodine number as well as spectroscopic and chromatographic techniques. Coatings were formulated by varying the ratio of epoxy adduct to curing agents on equivalent basis such as 1:0.6, 1:0.8 and 1:1. Further, the prepared coatings were characterized for mechanical, chemical, optical, thermal, anticorrosive and flame retardant properties. It was concluded that, with increase in concentration of flame retardant curing agents, anticorrosive as well as flame retardant properties of the coatings improved. This enhancement in the properties could be related to the synergistic effect of phosphorus and sulphur as well as chemical structure of curing agents.

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Cardanol based anhydride curing agent for epoxy coatings

Progress in Organic Coatings, 2018

In the present research work, cardanol based di-anhydride curing agent was synthesized and used i... more In the present research work, cardanol based di-anhydride curing agent was synthesized and used in the preparation of anticorrosive epoxy coatings. For this purpose, cardanol and glycidyl methacrylate were first reacted and subsequently malenized using maleic anhydride to yield di-anhydride compound which was used as a curing agent for commercial epoxy resin. Structure of the curing agent was confirmed by evaluating its acid and iodine value as well as Fourier transform infrared spectroscopy, proton and carbon nuclear magnetic resonance spectroscopy and gel permeation chromatography techniques. Coatings were formulated by varying the ratio of epoxy adduct to anhydride on equivalent basis such as 1:0.6, 1:0.8, 1:1. Further, the prepared coatings were characterized for mechanical, chemical, optical, thermal, insulating, anticorrosive properties etc. and compared with commercial methyltetrahydrophthalic anhydride cured epoxy coatings. It was observed that curing agent based on cardanol performed well in all aspects as compared to commercial curing agent.

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High performance polyurea coatings based on cardanol

Progress in Organic Coatings, 2017

Present research work deals with synthesis of phenalkamines and their use as curing agents for bl... more Present research work deals with synthesis of phenalkamines and their use as curing agents for blocked polyisocyanates to yield high performance polyurea coatings. In this work, several phenalkamines were synthesized by conventional Mannich reaction; selecting various structural amines such as hexamethylene diamine (HMDA), isophorone diamine (IPDA), diaminodiphenyl methane (DDM), Jeffamine D-400 and Jeffamine T-403. Structures of these phenalkamines were confirmed by FTIR, 1 H NMR spectroscopy and evaluation of amine value. These curing agents were mixed with HDI and IPDI based blocked polyisocyanates to obtain polyurea coatings which were subsequently characterized for mechanical, chemical, optical, thermal and anticorrosive properties. In addition, structure property relationship of all the systems was studied and compared with commercial phenalkamine (AG-141). Anticorrosive properties evaluated by salt spray test and electrochemical impedance spectroscopy (EIS) revealed significant improvement in anticorrosive performance when compared with commercial phenalkamine. All polyurea coatings exhibited excellent performance properties irrespective of the isocyanates used.

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Flammability behavior of unsaturted polyesters modified with novel phosphorus containing compounds

Polymer Composites

Effect of γ-irradiation on glycolysis of PET waste and preparation of ecofriendly coatings using bio-based and recycled materials

Polymer Engineering & Science, 2015

Recycling of postconsumer poly (ethylene terephthalate) (PET) is a worldwide concern due to large... more Recycling of postconsumer poly (ethylene terephthalate) (PET) is a worldwide concern due to large increasing volume of these materials produced by society. In the present study, we report the effect of gamma irradiation on degradation of PET and its subsequent effect on glycolysis by using excess ethylene glycol (EG). The results as analyzed by molecular weight determination showed that extent of depolymerization of PET were dose dependent. The doses of 30, 50, 70, and 100 kGy resulted in decrease in the molecular weight by about 15%, 25%, 30%, and 40% respectively. The irradiated waste PET samples were further subjected to glycolysis using EG by conventional and microwave method which resulted in increased yield of monomeric product, bis (2-hydroxyethylterephthalate) (BHET). The recycled material, BHET, was then used in combination with bio-based monomers to prepare a new eco-friendly polyester polyol which was analyzed for hydroxyl, saponification, acid value and further characterized by FTIR, 1 HNMR, and GPC techniques for molecular weight determination. Polyurethane coatings were prepared from the polyester polyol and various commercial polyisocyanate curing agents. The coated films were evaluated for their performance properties. Thermal properties of coatings were investigated by differential scanning calorimetry and thermogravimetric analysis. POLYM. ENG.

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Synthesis and characterization of ricinoleic acid derived monomer and its application in aqueous emulsion and paints thereof

Pigment & Resin Technology, 2019

PurposeThis paper aims to prepare acrylic functional ricinoleic acid monomer and incorporate it i... more PurposeThis paper aims to prepare acrylic functional ricinoleic acid monomer and incorporate it in conventional miniemulsion polymerization. Subsequently, paints were formulated to study the variation in final coating properties.Design/methodology/approachSynthesis process involved the esterification of ricinoleic acid with 2-hydroxy methyl methacrylate in the presence of FASCAT-4100 catalyst. The final product of the reaction, methacrylated ricinoleic acid (MRA), was confirmed using Fourier-transform infrared spectroscopy and1H-nuclear magnetic resonance spectroscopy and determining acid and iodine value. Further, MRA was incorporated in various concentrations (1, 2 and 3 Wt.%) along with methyl acrylate and butyl acrylate in conventional miniemulsion polymerization and paints were formulated thereof.FindingsIt was observed that with the addition of MRA monomer, flexibility of emulsion films increased as indicated by glass transition temperature and elongation value (percentage). M...