Poly (urethane fatty amide) resin from linseed oil—A renewable resource

Poly (urethane fatty amide) [PULFA] resin was synthesized by using a one-shot technique at room temperature from diol linseed fatty amide [DLFA; a monomer obtained from the aminolysis of renewable resource, such as linseed oil with diethanolamine and sodium methoxide used as a catalyst], 1.0 moles, and varying ratio of toluylene-2,4(6)-diisocyanate [TDI, 0.08–1.5 moles] in minimum amount of xylene without any chain extender and catalyst. In this process phthalic acid/anhydride which is normally used in the synthesis of polyesteramide was completely replaced by TDI as in case of uralkyd. The reaction mechanism of the same has been discussed here. The mode of reaction and structure of the resin was confirmed by physico-chemical tests and spectral analysis. The performance of the coatings on mild steel strips was tested by physico-mechanical and chemical/corrosion resistance tests. Thermo gravimetric analysis [TGA] and differential scanning calorimetry [DSC] techniques were used to investigate the thermal stability and curing behavior of the resin. The aforementioned properties of newly synthesized resin were compared with those of reported linseed oil-based polyesteramide urethane [Ur-LPEA, synthesized by partial replacement of phthalic anhydride by TDI] and uralkyd. The newly synthesized resin has shown improved physico-mechanical and corrosion resistance performance to Ur-LPEA and alkyd, whereas to those of uralkyd has comparable results. The PULFA resin exhibits not only superior properties to some of the reported resins, but also helps in the conservation of energy by being synthesized at room temperature as compared to other similar reported systems which were synthesized at reasonably high temperatures. The present study reveals that the PULFA resin can be used as a substitute to Ur-LPEA, alkyd and uralkyd in the field of corrosion protective paints and coatings.     

Studies on urethane‐modified alumina‐filled polyesteramide anticorrosive coatings cured at ambient temperature

Coatings prepared from polyesteramide resin synthesized from linseed oil, a renewable resource, have been found to show improved physicomechanical and anticorrosive characteristics. These properties are further improved when aluminum is incorporated in the polyesteramide resin. The coatings of this resin are generally obtained by baking at elevated temperatures. With a view toward the use of linseed oil, as a precursor for the synthesis of polyesteramide resins and to cure their coatings at ambient temperature, toluylene diisocyanate (TDI) was incorporated into polyesteramide and alumina‐filled polyesteramide in varying proportions to obtain urethane‐modified resins. The latter resins were found to cure at room temperature. The broad structural features of the urethane‐modified polyesteramide and alumina‐filled polyesteramide were confirmed by FTIR and ¹H–NMR spectroscopies. Scratch hardness; impact resistance; bending resistance; specular gloss; and resistance to acid, alkali, and organic solvents of the coatings of these resins were determined by standard methods. Physicomechanical and anticorrosive properties, specular gloss, and thermal stability of the urethane‐modified alumina‐filled polyesteramide coatings were found to be at higher levels among these resins. It was found that TDI could be incorporated in polyesteramide up to only 6 wt %, such that above this loading its properties started to deteriorate, whereas alumina‐filled polyesteramide could take up to 10 wt % TDI. Explanation is provided for the increase in scratch hardness and impact resistance above 6 and 10 wt % addition of TDI in polyesteramide and alumina‐filled polyesteramide, respectively, as well as for the decrease in flexibility and resistance to solvents, acid, and alkali of coatings of these resins above these limits of TDI addition. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1855–1865, 2001     

The usage of linseed oil‐based polyurethanes as a rheological modifier

Some oil‐based urethanes (urethane oils) were prepared from linseed oil, glycerol, and two types of diisocyanates, hexamethyle diisocyanate (HMDI) and 4,4′‐ diphenylmethane diisocyanate (MDI). These urethane oils were used as a rheological modifier in solvent‐based coatings. For this purpose the mixture prepared from urethane oil and alkyd resin (AR‐UO) was investigated in view of flow properties. Time dependence of AR‐UO was investigated by using the hysteresis loop method. None of the samples showed thixotropic flow behavior. The flow type was decided after calculation of the ratio of viscosity at low shear rate to viscosity at high shear rate. The results showed that HMDI‐based samples had the smallest viscosity ratio and increasing the amount of aromatic structure caused increasing shear thinning behavior. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1032–1035, 2005     

Synthesis and applications of cyclic carbonate functional polymers in thermosetting coatings

Thermosetting coatings based on the cyclic carbonate–amine reaction are attractive since polyurethane coatings can be made without the use of isocyanates. Cyclic carbonate functional polymers were prepared via the free radical solution copolymerization of vinyl ethylene carbonate with vinyl ester monomers. The level of vinyl ethylene carbonate was varied from 10 to 50%. In order to develop an understanding of the kinetics of the reaction of cyclic carbonates with amines, kinetics of a number of amines were determined with a model cyclic carbonate, propylene carbonate. The kinetic information was used to help select appropriate amine crosslinkers and develop thermosetting coatings using cyclic carbonate functional polymers and oligomers. For screening of coating properties, clear coating formulations were applied to pretreated metal panels and cured at 80°C for 45 min. A number of coatings were prepared to study the effect of amine, stoichiometry, solvent, and copolymer composition on the coatings properties. Coatings prepared had excellent solvent resistance, good gloss, and high pendulum hardness.     

Synthesis,characterization and self-crosslinking of glycidyl carbamate functional resins

Multifunctional glycidyl carbamate functional resins were synthesized, characterized, and self-crosslinked coatings were prepared and characterized. Coatings based on glycidyl carbamate (GC) functional oligomers are attractive because they combine polyurethane properties with epoxide reactivity. The glycidyl carbamate functional resins were synthesized via reactions of the biuret adduct and isocyanurate trimer of hexamethylene diisocyanate (HDI) with glycidol. Resins were characterized using gel permeation chromatography (GPC), Fourier transform infrared (FTIR) spectroscopy and ¹³C NMR spectroscopy. Coatings were prepared to study the self-crosslinking reaction without additional hardener. Self-crosslinked coatings had an excellent combination of solvent resistance, good hardness and high impact resistance. The glycidyl carbamate resin from the biuret isocyanate adduct (BGC) was found to be more reactive during cure than glycidyl carbamate from the isocyanurate isocyanate trimer (IGC) as determined by hardness, solvent resistance, and T_g measurements. Thermogravimetric analysis (TGA) of the resins did not show thermal decomposition below 250 °C.     

Organic–inorganic hybrid linseed oil‐based urethane oil wood coatings

To prepare alkoxysilane‐functionalized urethane oil (AFUO) using linseed oil, 3‐aminopropyltriethoxysilane (APTES) was first reacted with diisocyanate to obtain an NCO‐terminating oligomer. The reaction was continued by adding linseed oil glyceride to form an AFUO prepolymer. The auto‐oxidative drying coating was obtained after adding a metal dryer to the AFUO prepolymer. Urethane oil (UO) coating, as a control, was obtained by the same procedure as that for AFUO, but without containing alkoxysilane‐functional groups in the formation. Siloxane hybrid urethane oil (SHUO) wood coatings were prepared by mixing tetraethyl orthosilicate (TEOS) solutions, as an external crosslinking agent by sol–gel process, with the AFUO and UO coatings. We found that introducing of APTES into the molecular chains of the UO coating resulted in a film with superior impact and abrasion resistance, and it is the most efficient process to enhance the UO films. The addition of TEOS into AFUO coatings shortened the curing time and further improved the crosslinking density of the AFUO films; however, the physical properties like impact resistance, bending resistance, and gloss were even worse than AFUO films. Mixing of TEOS and UO coating also shorten the curing time and improved the heat resistance, lightfastness, and hardness of the UO coating. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44562.     

Design and synthesis of bio-based epoxidized alkyd resin for anti-corrosive coating application

Alkyd resins with long aliphatic chain in their backbone are not suitable for high-performance applications. To overcome this limitation of alkyd resins, their backbone structure is usually chemically modified. In this study, an alkyd resin was successfully synthesized from renewable resources, including itaconic acid and linseed oil. Subsequently, the unsaturated backbone of the alkyd resin was converted to oxirane ring through epoxidation reaction in the presence of hydrogen peroxide and acetic acid. The epoxidized alkyd (EA) resin backbone was modified with various amounts of 3-amino propyltrimethoxysilane (APTMS) from 10 to 40 mol percent to enhance the anti-corrosive properties of coatings prepared from the alkyd resins. The structural elucidation of synthesized resins was described by physicochemical analysis and Fourier transform infrared and ¹H nuclear magnetic resonance spectroscopies. The EA resin and APTMS-modified EA resin were cured by itaconic acid in 1:1 stoichiometric ratio on the equivalent weight basis. The differential scanning calorimetric and thermogravimetric analysis results showed that thermal properties improved with increasing APTMS content. The cured coatings were characterized for their mechanical properties, chemical and solvent resistance, gel content, and water absorption. The corrosion-resistance performance of coatings was evaluated by electrochemical impedance spectroscopy and salt-spray test. It was observed that the highly cross-linked structure of the APTMS-modified EA coatings enhanced the corrosion protective property of coating films.     

Cure characterization of the ring‐opening metathesis polymerization of linseed oil‐based thermosetting resins

BACKGROUND: Bio‐based polymers from vegetable oils are excellent alternatives to petroleum‐based resins for both environmental and economic reasons. A detailed understanding of the cure behavior of bio‐based polymers is essential to optimize cure schedules and the final properties of the polymers. In this work, the cure of newly developed linseed oil‐based thermosetting resins, synthesized using Grubbs' first‐generation catalyst and a bis‐norbornadiene cross‐linking agent by ring‐opening metathesis polymerization, is characterized using differential scanning calorimetry (DSC) and parallel plate oscillatory rheometry. RESULTS: Experimental results reveal that the rate of cure increases and the gel time decreases with increasing cross‐linker loading; however, the activation energy of the cure does not vary systematically with cross‐linker loading. Phenomenological reaction models are used to describe the dynamic DSC measurements and to determine the kinetic parameters which facilitate cure predictions under isothermal conditions. CONCLUSION: This work demonstrates that the cure kinetics of a linseed oil‐based thermosetting resin can be controlled by varying the cross‐linker loading. Furthermore, the kinetic parameters and cure rates at any cross‐linker loading for this system can be described by a simple autocatalytic reaction model which facilitates development of cure schedules. Copyright © 2009 Society of Chemical Industry     

Chemoenzymatic synthesis and characterization of urethane oils for surface coatings

Two-step chemoenzymatic synthesis of urethane oils has been studied. Initially, the partial esters were prepared by lipase-catalyzed transesterification of soybean and linseed oils with n-butanol. Partial esters were further reacted with different diisocyanates to obtain urethane oils. The composition of the partial esters was varied with reaction time in the transesterification step. Among all the lipases, the lipozyme was found to be the most suitable lipase for the transesterification reaction, yielding 80–85%. All of the urethane oils were of low molecular weights irrespective of the type of oil used in their preparation. Urethane oils, based on MDI, exhibited the best scratch resistance. All of the urethane oils showed good acid and alkali resistance and excellent solvent resistance. These oils also satisfactorily passed the impact resistance and the flexibility tests. Department of Chemistry, Vidyanagari, Mumbai-400 098, India.     

Plant oil polyol based poly (ester urethane) metallohybrid coatings

Research efforts are being focused to develop polymers from bioresources such as plant oils from ecological and economical viewpoints, both in academic research and chemical industry worldwide. Plant oil polymers, their organic-inorganic hybrids and composites find versatile applications today. In the present work, we have reported the preparation and characterization of linseed oil based poly (ester urethane) metallohybrids [PEUMH] from linseed oil polyol [LPO], phthalic anhydride [PAN], toluylene-2,4-diisocyanate [TDI] as organic and copper (II) acetate [Cu-Ac] (in different amount) as inorganic precursors, respectively, in “one-pot, multi-step” reaction. PEUMH were characterized by spectral, physico-chemical, thermal (TGA and DSC) and morphological analyses by standard methods. The potentiality of the same as promising coating material was also evaluated. PEUMH are foreseen as prospective candidates for application as antibacterial self-sterilizing protective coatings due to oligodynamic effect of metal.     

Synthesis and photopolymerization of norbornyl epoxidized linseed oil

Norbornyl epoxidized linseed oil was synthesized via Diels-Alder reaction of cyclopentadiene with linseed oil at high pressure (∼200 psi) and high temperature (240 °C), followed by an epoxidation using hydrogen peroxide with a quaternary ammonium tetrakis(diperoxotungsto) phosphate(3−) epoxidation catalyst. The products were characterized using ¹H and ¹³C NMR, FT-IR, and electrospray ionization mass spectroscopy. Photo-induced curing kinetics of norbornyl epoxidized linseed oil coatings was investigated using real-time FT-IR spectroscopy with a fiber optic UV-curing system. The norbornyl epoxidized linseed oil was formulated with three different divinyl ether reactive diluent. The effect of divinyl ether concentration and types of divinyl ether on the curing reaction was investigated. It was found that the curing rate of norbornyl epoxidized linseed oil was lower than that of cycloaliphatic epoxide, but higher than epoxidized linseed oil. The incorporation of divinyl ethers increased the curing rate and overall conversion of the epoxide groups. Of the three divinyl ethers used, coating with triethyleneglycol divinyl ether showed the highest curing rate and coating with cyclohexane dimethanol divinyl ether showed the lowest curing rate.     

Coatings from epoxidized (polyurethane-polyester) resin system

Epoxidized polyurethane was synthesized from the reaction of the prepared epoxidized linseed oil with toluene diisocyanate (TDI) at a NCO-to-OH ratio equal to 5. The prepared epoxidized linseed oil was also reacted with phthalic anhydride at a molar ratio of 1 : 4 to give epoxidized polyester. Epoxidized polyurethane and epoxidized polyester were mixed in different weight ratio percentages to give three types of epoxidized (polyurethane-polyester) resin systems. These resin systems were tested physically and chemically and evaluated as coatings for both metal and glass panels. The data obtained indicate an exceptional combination of properties, such as adhesion, bending, and chemical resistance of the epoxidized (polyurethane-polyester) resin system of the weight ratio percentage of 15 : 85. Thus, these materials can be recommended to be used as coating materials. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 577–581, 1998     

Photocrosslinkable modified vegetable oil based resin for wood surface coating application

An acrylated epoxidized linseed oil (AELO) was synthesized from epoxidized linseed oil through ring opening of the oxirane group using acrylic acid as ring opening agent. The occurrence of the acrylate group and the ring opening of oxirane group was monitored using FT-IR spectroscopy. The AELO was mixed with three different photoinitiators at two different concentrations. Wood surfaces were coated with the mixtures, subsequently cured under UV light and the resulting surface properties of the coated samples gloss, scratch resistance, solvent resistance, and coating adhesion were characterized. The efficiency of the photoinitiators and the influence of their concentration on the rate and the extent of the curing were studied by curing the AELO mixtures under a monochromatic wavelength of 365 nm and measuring absorption spectra during the cure by real time FT-IR spectroscopy. The decrease of absorption in the measured spectra at 1406 cm⁻¹ was used to calculate the conversion of acrylic double bonds with increasing time of UV light exposure to obtain information on the cure kinetics for each photoinitiator and concentration.     

A renewable approach toward the development of mahua oil‐based wood protective polyurethane coatings: Synthesis and performance evaluation

In the current scenario, the demand for renewable resources is increasing day by day due to numerous factors. In view of this, current work represents the preparation of wood protective polyurethane (PU) coatings from mahua oil. Mahua oil was used as a starting material for the synthesis of fatty amide by base catalyzed aminolysis reaction. The synthesized fatty amide was converted into the polyetheramide polyols by a condensation reaction with bisphenol C. The structure of the synthesized products was confirmed by the attenuated total reflection‐Fourier transform infrared and ¹H‐NMR spectroscopy. The synthesized polyetheramide polyols were used as precursors for the preparation of PUs and the prepared PUs were applied on the wood surface as a protective coating. The coating performance of the PUs was evaluated by the measurement of mechanical, thermal, and microbial properties as well as water, solvent, and chemical resistance. The coating performance revealed that mahua oil can be used as a renewable resource for the preparation of wood protective PUs. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46722.     

Cyclic fatty acid yields from linseed oil

Increased yields of saturated cyclic fatty acids which are fluid at −50C have been obtained from linseed oil. Depending on reaction conditions, yields varied from 20–42 g of cyclic acids per 100 g of linseed oil. Solvent ratios of 6, 3, and 1.5∶1; catalyst concentrations of 10, 30, 60, and 100%; and reaction temps of 225, 275, 295, and 325C were evaluated. Ethylene glycol and diethylene glycol were compared as reaction solvents. In general, high solvent ratios favored high cyclic acid yields at the lower reaction temperature, but as the temperature increased the effect of solvent ratio decreased. Increasing the percentage excess of sodium hydroxide increased the cyclic acid yield. Diethylene glycol gave higher yields than ethylene glycol at comparable conditions. Presented at the AOCS meeting in Chicago, Ill., October, 1961. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

Synthesis and solid‐state properties of crosslinked alternating copolymers of phenyl vinylethylene carbonate and N‐substituted maleimides

The copolymers of phenyl vinylethylene carbonate (PVEC) and N‐phenylmaleimide were prepared with various monomer feeds by using a radical initiator. These copolymers were crosslinked by aminolysis between hexamethylenediamine (HMDA) and cyclic carbonate moiety in the side‐chain to obtain the networked polymers having the hydroxyurethane structure. Furthermore, the crosslinked copolymers having the polar cyclic carbonate in the side‐chain were synthesized from PVEC and several bifunctional maleimides, and their double networked polymers were prepared with HMDA. These copolymers and networked polymers exhibited color changes depending on their structures based on the acid–base switching in the solid‐state. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45247.     

Synthesis and characterization of poly(esteramide‐urethane) from linseed oil as anticorrosive coatings

Ethylene diamine polyesteramide (Ed‐PEA) was synthesized from N, N‐bis (2‐hydroxy ethyl) linseed oil fattyamide and ethylene diamine tetra acetic acid through condensation polymerization. It was further treated with toluylene 2,4‐diisocyanate (TDI) in different weight percentage to obtain urethane‐modified polyesteramide (Ed‐UPEA). The structural elucidation of Ed‐PEA and Ed‐UPEA were carried out by FTIR, ¹H‐NMR, and ¹³C‐NMR spectroscopic techniques. Thermal studies of these resins were carried by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The coatings of urethane‐modified polyesteramide were prepared on mild steel strips and their anticorrosive behavior of in acid, alkali, water, and xylene were investigated. Thermal stability performance suggests that the system could be safely used upto 200°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Modeling solubility parameters and permeation data of organic solvents versus butyl gloves from four manufacturers

Polyurethanes by a nonisocyanate route were prepared by reacting carbonated soybean oil with different diamines. The effect of amine structure and carbonate to amine ratio on polyurethane structure and mechanical, physical, and swelling properties was studied. The reactants 1,2-ethylenediamine, 1,4-butylenediamine, and 1,6-hexamethylenediamine were used with the carbonate to amine ratio of 1 : 0.5, 1 : 1, and 1 : 2. It was found that along with urethane formation, the amine group reacted with ester groups to form amides. All amines produced elastomeric polyurethanes with glass transitions between 0 and 40°C and hardness between 40 and 90 Shore A. The reaction of epoxidized soybean oil with carbon dioxide was optimized resulting in complete conversion of epoxy to cyclic carbonate groups ending in polyurethanes with higher crosslinking density and much higher tensile strength than previously reported for similar polyurethanes. Swelling in toluene and water depended on crosslinking density and the polarity of polyurethane networks controlled by the cyclic carbonate-to-amine-ratio. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation of novel CNSL‐based urethane polyol via nonisocyanate route: Curing with melamine‐formaldehyde resin and structure–property relationship

In this study, we report preparation of a novel cashew nut shell liquid (CNSL)‐based polyol bearing urethane groups. The urethane group in the polyol was induced via isocyanate free route from the reaction of cyclic carbonate with primary amine. The polyol was characterized by determination of hydroxyl number, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and so forth. The polyol was then used as coating component and cured with hexamethoxy methylene melamine (HMMM). Another CNSL‐based polyol without urethane moiety from our earlier reported work was used for preparation of coating for comparative study to determine the effect of urethane group on the coating properties. The coating formulations based on these two polyols were cured with variable amounts of HMMM hardener to optimize coating properties. All the coatings were evaluated for mechanical properties such as adhesion, flexibility, pencil and scratch hardness, impact resistance, pull‐off, and adhesion. The optimized coatings were also evaluated for chemical and thermal properties. It was observed that the urethane containing polyol resulted in better adhesion to the metal substrate at higher quantity of HMMM hardener compared to the other polyol providing significant improvement in various coating properties. The final coating properties were also compared with the acrylic polyurethane coatings. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41391.     

Synthesis,characterization and application of Azadirachta indica juss (neem oil) fatty amides (AIJFA) based polyurethanes coatings: A renewable novel approach

Number of diethanol amides has been developed by scientist using various vegetable oils and not from neem seed oil. Most of the research work on neem seed oil has explored its applications in pharmaceutical and pesticides fields. This paper representing new area of application of neem seed oil for polymeric resin, in which we attempted to synthesize the neem seed oil based poly(urethane fatty amides) by reaction of neem oil fatty amide (AIJFA) with trimer of isophorone diisocyanate (IPDI). Spectral study of AIJFA was carried out by using FT-IR and ¹H NMR techniques. Molecular weight of AIJFA was determined by gel permeation chromatography (GPC). Fatty acid composition of neem seed oil was obtained by gas chromatographic method. The coatings applied on mild steel plates were evaluated by determining coating properties, chemical and corrosion resistances. TGA study of coatings showed higher thermal stability to AIJFA based PU coatings compared to normal urethane and alkyd coatings.