Poliuretano y Neem

7
Industrial Crops and Products 50 (2013) 550–556 Contents lists available at ScienceDirect Industrial Crops and Products journa l h om epa ge: www.elsevier.com/locate/indcrop Development of eco-friendly polyurethane coatings based on neem oil polyetheramide Ashok Chaudhari a , Vikas Gite a,, Sandip Rajput a , Pramod Mahulikar a , Ravindra Kulkarni b a Department of Polymer Chemistry, School of Chemical Sciences, North Maharashtra University, Jalgaon 425001, Maharashtra, India b School of Chemical Technology, North Maharashtra University, Jalgaon 425001, Maharashtra, India a r t i c l e i n f o Article history: Received 24 May 2013 Received in revised form 23 July 2013 Accepted 4 August 2013 Keywords: Neem oil polyetheramide Eco-friendly polyurethane coatings TiO2 nano particles Renewable sources a b s t r a c t Renewable sources like vegetable oils have been used to prepare many polymeric resins and the topic is gaining more importance due to the functional attributes to structure of oils. In the regard, renewable source based polyurethane coatings have been prepared from polyetheramide of neem oil in the labo- ratory. In the preparation of polyetheramide, first neem oil was allowed to react with diethanol amine. Obtained fatty amide was modified to the polyetheramide by reacting it with bisphenol-A. Spectroscopic techniques such as FT-IR and 1 H NMR confirmed the structures of fatty amide and polyetheramide. Polyurethane coatings were prepared from the polyetheramide by treating it with methylene diphenyl diisocyanate. Coating properties such as gloss, scratch hardness, adhesion, flexibility, thermal stability, impact and chemical resistances were evaluated using standard methods. The influence of surface modified TiO 2 nano particles on the properties of the neem oil based polyurethane coatings was examined by loading nano TiO 2 from 0 to 4%. The overall performance of coatings revealed that neem oil based polymeric coatings can be successfully used as coatings in industrial applications. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved. 1. Introduction The demand for polymers prepared from renewable sources is on the increase because of a number of reasons notably environ- mental concern, abundant availability and low price of renewable sources (Anand et al., 2012; Guner et al., 2006; Lligadas et al., 2012). Cellulose and vegetable oils are two major renewable sources present on the earth in large quantities. Applications of cellulose in polymeric coatings is limited while vegetable oils have been used most of the time to prepare polymeric binders for coatings formu- lations, flooring materials and resin applications (Gu et al., 2012; Opera, 2010). Vegetable oils obtained from different sources have also been widely used in preparation of inks, diluents, plasticizers, lubricants, agrochemicals, food industries, composite materials, etc. (Derksen et al., 1996; Kashif et al., 2011; Khot et al., 2001; Sharmin et al., 2006). Vegetable oils can be commonly converted Abbreviations: IPDI, Isophorone diisocyanate; MDI, Methylene diphenyl diiso- cyanate; PEthA, Polyetheramide; PEA, Polyesteramide; TTIP, Titanium isopropoxide; THF, Tetrahydrofuran; TEVS, Vinyltriethoxysilane; DBTDL, Dibutyltin dilaurate; MS, Mild steel; AIJFA, Azadirachta indica juss fattyamide; PU, Polyurethane. Corresponding author. Tel.: +91 257 2257431; fax: +91 257 2258403. E-mail addresses: [email protected], [email protected] (V. Gite). into derivatives such as alkyd resins and polyols based on alkyds (Nimbalkar and Athawale, 2010). Polyols are low molecular weight polymers that may be reacted with different diisocyanates such as isophorone diisocyanate (IPDI), methylene diphenyl diisocyanate (MDI) or others, to obtain polyurethane (PU) coatings (Gite et al., 2010). A number of reports have described the preparation of poly- ols from different vegetable oils such as jatropha, soya, cottonseed, linseed, neem oils and their subsequent use in the preparation of PU (Chaudhari et al., 2013a,b; Gite et al., 2006; Jaliliana et al., 2010; Meshram et al., 2013a,b; Zlantanic et al., 2004). PU of the kind of interpenetrating polymer networks have also been prepared using castor oil with styrenic-acrylic polymers and these have gained much attention due to their interesting properties (Meier et al., 2007). Epoxidized soybean oil has been studied by curing with var- ious cyclic acid anhydrides in presence of tertiary amines (Gerbase et al., 2002). Recent routes explored utilization of vegetable oils in coatings by preparing polyetheramides (PEthA) (Akintayo and Akintayo, 2010; Alam et al., 2004) and polyesteramides (PEA) (Dutta and Karak, 2005; Shende et al., 2004; Zafar et al., 2004). Azadirachta indica juss can be said to be underutilized when its available production potential is compared to its present limited applications in pharmaceuticals (Biswas et al., 2002) and agrochemicals sector as medicinal compound and bio pesticide (Bagle et al., 2013) respectively. Neem seed oil contains three 0926-6690/$ see front matter. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.indcrop.2013.08.018

Transcript of Poliuretano y Neem

  • Industrial Crops and Products 50 (2013) 550 556

    Contents lists available at ScienceDirect

    Industrial Crops and Products

    journa l h om epa ge: www.elsev ier .com

    Development of eco-friendly polyurethane coatinoil polyetheramide

    Ashok Ch ah

    a Department o on 42b School of Che

    a r t i c l

    Article history:Received 24 MReceived in reAccepted 4 Au

    Keywords:Neem oil polyEco-friendly pTiO2 nano particlesRenewable sources

    havefunctave rami

    the pR co

    fromdiisocyanate.

    Coating properties such as gloss, scratch hardness, adhesion, exibility, thermal stability, impact andchemical resistances were evaluated using standard methods. The inuence of surface modied TiO2nano particles on the properties of the neem oil based polyurethane coatings was examined by loadingnano TiO2 from 0 to 4%. The overall performance of coatings revealed that neem oil based polymericcoatings can be successfully used as coatings in industrial applications.

    1. Introdu

    The demon the incrmental consources (AnCellulose apresent on polymeric cmost of thelations, ooOpera, 2010also been wlubricants, etc. (DerkseSharmin et

    Abbreviaticyanate; PEthATHF, TetrahydMild steel; AIJ

    CorresponE-mail add

    0926-6690/$ http://dx.doi.oCrown Copyright 2013 Published by Elsevier B.V. All rights reserved.

    ction

    and for polymers prepared from renewable sources isease because of a number of reasons notably environ-cern, abundant availability and low price of renewableand et al., 2012; Guner et al., 2006; Lligadas et al., 2012).nd vegetable oils are two major renewable sourcesthe earth in large quantities. Applications of cellulose inoatings is limited while vegetable oils have been used

    time to prepare polymeric binders for coatings formu-ring materials and resin applications (Gu et al., 2012;). Vegetable oils obtained from different sources haveidely used in preparation of inks, diluents, plasticizers,agrochemicals, food industries, composite materials,n et al., 1996; Kashif et al., 2011; Khot et al., 2001;

    al., 2006). Vegetable oils can be commonly converted

    ons: IPDI, Isophorone diisocyanate; MDI, Methylene diphenyl diiso-, Polyetheramide; PEA, Polyesteramide; TTIP, Titanium isopropoxide;rofuran; TEVS, Vinyltriethoxysilane; DBTDL, Dibutyltin dilaurate; MS,FA, Azadirachta indica juss fattyamide; PU, Polyurethane.ding author. Tel.: +91 257 2257431; fax: +91 257 2258403.resses: [email protected], [email protected] (V. Gite).

    into derivatives such as alkyd resins and polyols based on alkyds(Nimbalkar and Athawale, 2010). Polyols are low molecular weightpolymers that may be reacted with different diisocyanates such asisophorone diisocyanate (IPDI), methylene diphenyl diisocyanate(MDI) or others, to obtain polyurethane (PU) coatings (Gite et al.,2010). A number of reports have described the preparation of poly-ols from different vegetable oils such as jatropha, soya, cottonseed,linseed, neem oils and their subsequent use in the preparation ofPU (Chaudhari et al., 2013a,b; Gite et al., 2006; Jaliliana et al., 2010;Meshram et al., 2013a,b; Zlantanic et al., 2004). PU of the kind ofinterpenetrating polymer networks have also been prepared usingcastor oil with styrenic-acrylic polymers and these have gainedmuch attention due to their interesting properties (Meier et al.,2007). Epoxidized soybean oil has been studied by curing with var-ious cyclic acid anhydrides in presence of tertiary amines (Gerbaseet al., 2002). Recent routes explored utilization of vegetable oilsin coatings by preparing polyetheramides (PEthA) (Akintayo andAkintayo, 2010; Alam et al., 2004) and polyesteramides (PEA)(Dutta and Karak, 2005; Shende et al., 2004; Zafar et al., 2004).

    Azadirachta indica juss can be said to be underutilized whenits available production potential is compared to its presentlimited applications in pharmaceuticals (Biswas et al., 2002) andagrochemicals sector as medicinal compound and bio pesticide(Bagle et al., 2013) respectively. Neem seed oil contains three

    see front matter. Crown Copyright 2013 Published by Elsevier B.V. All rights reserved.rg/10.1016/j.indcrop.2013.08.018audharia, Vikas Gitea,, Sandip Rajputa, Pramod M

    f Polymer Chemistry, School of Chemical Sciences, North Maharashtra University, Jalgamical Technology, North Maharashtra University, Jalgaon 425001, Maharashtra, India

    e i n f o

    ay 2013vised form 23 July 2013gust 2013

    etheramideolyurethane coatings

    a b s t r a c t

    Renewable sources like vegetable oilsgaining more importance due to the source based polyurethane coatings hratory. In the preparation of polyetheObtained fatty amide was modied totechniques such as FT-IR and 1H NMPolyurethane coatings were prepared/ locate / indcrop

    gs based on neem

    ulikara, Ravindra Kulkarnib

    5001, Maharashtra, India

    been used to prepare many polymeric resins and the topic isional attributes to structure of oils. In the regard, renewablebeen prepared from polyetheramide of neem oil in the labo-de, rst neem oil was allowed to react with diethanol amine.olyetheramide by reacting it with bisphenol-A. Spectroscopicnrmed the structures of fatty amide and polyetheramide.

    the polyetheramide by treating it with methylene diphenyl

  • A. Chaudhari et al. / Industrial Crops and Products 50 (2013) 550 556 551

    CH2

    OH CH2 CH2 CH2 OH

    CH2

    O C

    O

    RCH

    2CH

    2OH CH2 OH

    CH OH

    ietha

    NaOCH3

    A.

    saturated faand arachidacids viz. ol2013a). AlthIndia with alization of tnot been in2013a). Ourneem oil fa

    In the pamide (AIJFpolyetheramdiisocyanatEffects of peformance oinvestigatedusing stand

    2. Experim

    2.1. Chemic

    Neem seas it is. MDtriethoxysilChemicals, drofuran anfrom s.d. n

    2.2. Synthe

    AIJFA w(Chaudhari

    2.3. Synthe

    Mixture0.073 M) weDean and Smental. Theture of solveof dilute sulat 175 5 Ccollected inwater remoof reaction,under redu

    ntheg ag

    o TiOg vinratu

    epar

    coatiraturtalysn of e. PUdicat

    (basr adnicaixtu

    irredty. Thn M

    panexam

    were

    ract

    emic

    m oi D53(AST-86)

    ectro

    FT-Iphoof 40CH

    CH2

    O

    O C

    O

    R

    C

    O

    R

    CH2

    CH2

    OH

    NH+

    120 0C

    Neem oil Diethanol amine D

    Fig. 1. Synthesis of AIJF

    tty acids including palmitic (11.90%), stearic (29.96%)ic (2.94%) acids. It also contains two unsaturated fattyeic (50.04%) and linoleic (5.15%) acids (Chaudhari et al.,ough neem plant is widely cultivated in arid zones ofnnual neem oil production rate of 18,000 ton, the uti-he seed oil in the development of polymeric resins hasvestigated except our earlier report (Chaudhari et al.,

    previous report claims preparation of PU coatings fromtty amide using diisocyanate.resent work, further chemical modication of fattyA) prepared from neem oil has been carried to obtainide (PEthA). The synthesized PEthA was treated with

    e at room temperature to prepare the PU coatings.rcent loading of silane modied nano TiO2 on the per-f pristine neem oil PEthA based PU coatings have been

    rst time. Performance of PU coatings was evaluatedard methods.

    ental

    als and materials

    ed oil was purchased from local supplier and usedI, bisphenol-A, titanium isopropoxide (TTIP), vinyl-

    ane (TEVS) and dibutyltin dilaurate (DBTDL) (AldrichUK) were of laboratory grade. Cylcohexanone, tetrahy-d diethanolamine of analytical grade were obtainede-chemicals Ltd., India.

    sis of A. indica juss fatty amide (AIJFA)

    as synthesized (Fig. 1) according to our earlier report et al., 2013a).

    sis of polyetheramide (PEthA)

    2.4. Sycouplin

    Nanby usinthe lite

    2.5. Pr

    PU tempeof a casolutiomixtur04 in0 to 4%

    Afteon a sothen mwas stviscosicator ocoatingvisual panels

    3. Cha

    3.1. Ch

    Nee(ASTMcation D1957

    3.2. Sp

    Thespectrorange of AIJFA (20 g, 0.10 M) and bisphenol-A (16.65 g,re reacted (Fig. 2) in round bottom ask equipped withtark trap, nitrogen inlet tube, thermometer and rota

    mixture was allowed to react by dissolving it in a mix-nts (80:20 parts of xylene and n-butanone) in presencefuric acid as a catalyst. The reaction mixture was heated

    and reuxed until the theoretical amount of water was Dean and Stark trap. Once the theoretical amount ofved, reaction was allowed to stop. After the completion

    solvent was evaporated in a rotary vacuum evaporatorced pressure to obtain PEthA.

    sample in action of 12ple. 1HNMR300 MHz spence of CDC

    3.3. Transm

    The synfor their sizanalysis waN

    CO

    R

    CH2

    OH

    +

    nol amide (AIJFA) Glycerol

    sis of nano TiO2 and their modication by silaneent

    2 was synthesized (Mahshid et al., 2006) and modiedyltriethoxysilane (TEVS) coupling agent as reported inre (Chaudhari et al., 2013b; Sabzi et al., 2009).

    ation of PU coatings based on PEthA

    ngs were obtained (Fig. 3) by reacting PEthA at roome with MDI using NCO/OH ratio 1.1:1 in the presencet DBTDL (0.5%). In a typical process 50% solid contentPEthA was prepared in cyclohexanone and THF (80:20)

    were coded as PU0, PU1, PU2, PU3 and PU4 where sufxed the percentage of modied nano TiO2 ranging fromed on amount of PEthA) in PU coatings.dition of nano TiO2, reaction mixtures were sonicatedtor for the proper dispersion of modied nano TiO2 andre was treated with MDI. The entire reaction mixture

    for next 5 min at room temperature to attain pourableis mixture was applied as a coating by using bar appli-S steel panels of 4 6 in. dimensions. The preparedels were allowed curing at room temperature underination. Prior to application of the coatings, the steel

    pretreated by sand paper and washed with acetone.

    erization

    al analysis

    l, AIJFA and PEthA were characterized for specic gravity55 - 95), refractive index (ASTM D1747 - 09), saponi-M D464 - 05), acid (ASTM D5768 - 02), hydroxyl (ASTMand iodine values (ASTM D5768-02).

    scopic analysis

    R spectra of the prepared resins were recorded on FTIRtometer (Shimadzu, Japan, Model No. 8400) from the00500 cm1 as KBr pellets. Homogenous mixture of

    KBr was prepared by grinding in mortar and by the

    ton lab press to diminish moisture present in the sam- spectra of samples were recorded on Varian Mercuryectrometer using TMS as an internal standard in pres-l3 as a solvent.

    ission electron microscopy (TEM)

    thesized nano titanium dioxide particles were studiede by using TEM (TEM, Philips, CM-200, Holland). Thes carried out by accelerating voltage in the range of

  • 552 A. Chaudhari et al. / Industrial Crops and Products 50 (2013) 550 556

    C

    CH3

    CH3

    OH OH

    CH2

    OH CH2

    N

    CH2

    CH2

    OH

    CO

    R

    CH2

    O CH2

    N

    CH2

    CH2

    O

    CO

    C

    CH3

    CH3

    O CH2 CH2

    N

    CH2

    CH2

    OH

    CO

    RR

    H n

    Polyethe ramide (PEthA)

    (AIJFA)

    +

    Diethanol amide Bispheno l - A

    R = Fatty acid chain

    Dil. H2SO4

    Fig. 2. Synthesis of polyetheramide (PEthA).

    20200 kV with ultrason Cu grid a

    3.4. Field em

    Morphonano particgold on a FEJapan, Mod

    3.5. PU coa

    The PU Additive & 60 on the ccoatings wathe conicalbai). Pencil hardness teaccording tD-3359-02)

    , Elc set PU coed in. of t

    g and

    emic

    estims, sa4OHylenday fon, b

    erma

    rmalrmowith resolution of 2.4 A by dispersing TiO2 in acetoneonic wave for sufcient time. Samples were depositednd viewed at high magnication.

    ission scanning electron microscopy (FE-SEM)

    logies of TiO2 nano particles and silane modied TiO2les were studied using thin layer of samples coated withSEM (FE-SEM, HITAHCI High Technologies Corporation,el No. S-4800) with voltage range from 0.5 to 30 kV.

    tings characterizations

    coating panels were tested for the gloss (Model BYKInstruments, Germany) measurement at an angle ofalibrated digital gloss meter. Elasticity of the prepareds measured in the range of 45180 angles by using

    mandrel instrument (Raj Scientic Company, Mum-hardness of the coatings was measured with the pencilster (Model BYK Additive & Instruments, Germany)

    no 107closedtance, weightto 40 inpeelin

    3.6. Ch

    Forcoatingand NHvent (xevery adhesi

    3.7. Th

    Thethe theo ASTM D-3363 standards. Adhesion of coatings (ASTM was tested on the cross cut adhesion tester (model

    USA) in th20 C/min i

    CH2

    O CH2

    N

    CH2

    CH2

    O

    CO

    C

    CH3

    CH3

    O CH2 CH2

    N

    CH2

    CH2

    O

    CO

    RR

    H n

    CH2

    CH2

    N

    CH2CH

    2O

    CO

    C

    CH3

    CH3

    O CH2 CH2

    N

    CH2

    CH2

    O

    CO

    R

    C

    O

    R

    n

    DBTDL

    PU coatings

    PEthA

    Fig. 3. Preparation of PU coatings.ometer, U.K.) consisting of a die with 11 number ofof parallel blades. For measurement of impact resis-ated panels were deformed rapidly by application of thedenter (1.818 lb) from variable heights starting from 5he tubular impact tester. After falling weighted indenter

    cracking of the coatings from substrate was examined.

    al resistance

    ating chemical resistance (ASTM D 543-67/1972) ofmple panels were dipped in 5% alkali solutions (NaOH), 25% acid solutions (H2SO4 and CH3COOH) and a sol-e) for 7 days. During the test, the panels were taken outor once from solutions. Softness, loss in gloss, loss inlister and rupture were examined during the test.

    l analysis of PU coatings

    behavior of the prepared PU coatings was studied by gravimetric analysis (Model - TGA 4000, PerkinElmer,

    e range of 30600 C temperature at heating rate ofn presence of N2 as an inert atmosphere.

    CH2

    NCOOCNH

    NH CH2NH C

    O

    O

    +

    MDI

  • A. Chaudhari et al. / Industrial Crops and Products 50 (2013) 550 556 553

    3620

    25

    30

    35

    40

    45

    50

    55

    60

    65

    70

    75

    %T

    Liqu

    4. Results

    4.1. Charac

    Specic and iodine

    Specic PEthA, whiThe hydroxmay be duePEthA.

    4.2. Spectro

    The formspectral ana2013a).

    4.3. FTIR of

    Fig. 4 is agroups of P

    The spepresence o1246 cm1

    for C O C bands at 2and asymmtively. The cof C O strecated the Cbands at 83of bispheno

    4.4. 1H NM

    1H NMRspectra revmoiety) aroeld becausatom. A pr1.23 ppm. Tto electron bisphenol-Aeld i.e. 4.0assigned toat 3.313.4

    nitrogen as it is less electronegative, while peaks at 2.212.40 ppmwere assigned to CH2 linked to amide carbonyl. Peaks seen at2.012.15 ppm were of CH2 attached to olenic double bondsand peak at 1.35 ppm was of internal CH2 of fatty amide chain.

    lene .45 pf olee con

    M im

    partge ocopy

    M im

    morgatehowed nat shae midividc meed nowe

    ating

    poliO2 waluatf PU-

    20, 1 of Tcratced i3 and

    hight of mcreas

    the ecrea

    kindas foo aciicao acias foed fr4006008001200160020002800001/cm

    33

    00

    .31

    29

    29

    .97

    28

    58

    .60

    23

    33

    .94

    18

    86

    .44

    16

    10

    .61

    14

    60

    .16

    13

    63

    .72

    12

    46

    .06

    10

    64

    .74

    93

    9.3

    6

    83

    1.3

    5

    64

    2.3

    2

    56

    3.2

    3

    id

    Fig. 4. FTIR spectral analysis of neem oil based PEthA.

    and discussion

    teristic properties of neem oil, AIJFA and PEthA

    gravity, refractive index, saponication, acid, hydroxylvalues of raw materials are given in the Table 1.gravity increased in the sequence of neem oil, AIJFA andle iodine value was decreased for the same sequence.yl value also decreased from AIJFA to PEthA. The trend

    to increase in molar masses from neem oil to AIJFA and

    scopic analysis of AIJFA

    ation of AIJFA was conrmed by FT-IR and 1H NMRlysis according to our earlier report (Chaudhari et al.,

    PEthA

    FTIR spectrum presenting the frequencies of functionalEthA prepared from neem oil.ctrum showed a broad band at 3300 cm1 indicatingf OH stretching of PEthA. The characteristic bands atand 1064 cm1 were due to aryl alkyl ether linkagesasymmetrical and symmetrical stretchings. Absorption859 and 2930 cm 1 were attributed to symmetricaletrical stretchings of CH2 and CH3 groups respec-haracteristic band at 1611 cm1 indicated the presencetching of amide carbonyl group and 1460 cm1 indi-

    N stretching vibrations. The characteristic absorption1939 cm1 represented the presence of aromatic ring

    Methy3.403peak odata w

    4.5. TE

    Thethe ranmicros

    4.6. SE

    Theinvestiticles smodiwithouinto thed inorganimodiTiO2 sh

    4.7. Co

    Thenano Tthe evtime o27, 21,in the %TiO2. Sincreasof PU-TiO2 atamounalso inness ofthen dand no

    It wtance tno signthem tgloss wpreparl-A in PEthA.

    R spectra of PEthA

    spectra of PEthA is shown in Fig. 5. The 1H NMRealed peaks for protons of aromatic ring (bisphenol-Aund 7.126.62 ppm, which was shifted to the down-e aromatic ring is attached to electron donating oxygenoton of geminal dimethyl group was found aroundhe formation of ether linkages ( CH2 group attacheddonating oxygen) through the reaction of AIJFA with

    were conrmed by the appearance of peaks at down-14.28 ppm. Peaks in the range of 0.900.81 ppm were

    terminal CH3 of long fatty chain. Downeld peaks0 ppm were assigned to the CH2 attached to amide

    toward acid

    4.8. Thermo

    Thermogof percent all the coatdegradationresulted intwhich was Second stepperature ansecond stagcontributedtook place iprotons attached to the hydroxyl OH were seen atpm. Proton of OH occurred at 5.91 ppm. Characteristicnic unsaturation occurred at 5.11 ppm. From 1H NMRrmed the structure of PEthA as proposed in the Fig. 5.

    ages of nano TiO2

    icle size of the TiO2 nano particles was found to be inf 100150 nm, as conrmed by transmission electron

    and it is shown in Fig. 6.

    ages of nano TiO2

    phology of nano and silane modied nano TiO2 wered by FE-SEM images. SEM image of unmodied TiO2 par-ed aggregates and sharp edges (Fig. 7a), while silaneno TiO2 (Fig. 7b) particles were spherical in shape andrp edges. The modication of TiO2 may have resultednimum agglomeration of nano particles. These modi-ual particles may have good tendency to disperse in andia like PU coatings because of hydrophobic nature ofano TiO2 particles. SEM images of the modied nanod upto 200 nm.

    properties

    yetheramide based polyurethane coatings containingere applied on the MS panels using the bar coater and

    ed coating properties are given in Table 2. Surface dry0, PU-1 PU-2, PU-3 and PU-4 coatings were found to be9 and 20 min respectively. This indicated that increaseiO2 decreased the curing time of coatings upto 3% nanoh hardness and cross cut adhesion of coatings weren PU-0, PU-1 and PU-2 while it decreased in the case

    PU-4. This may be due to poor dispersion of the nanoer loadings. In the case of gloss, it was observed that asodied nano TiO2 in PU coatings increased, gloss was

    ed from 92 to 98. Impact resistance and pensile hard-coatings were found to increase upto 3% nano TiO2 andsed. All PU samples passed the mandrell exibility test

    of failure was observed.und that the prepared PU samples displayed good resis-ds, alkalis and solvent. Chemical resistance test showednt changes in the appearance of coatings, after exposingds, alkalis and solvent. In acid specimens, slight loss inund after drying the panels. In general we can say the PUom neem oil polyetheramide showed good resistances, alkalis and solvent.

    gravimetric analysis (TGA)

    rams of the PU samples prepared from PEthA and effectof nano TiO2 on PU are given in Fig. 8. TGA curves ofing samples showed three steps degradation. First step

    was started in the range of 220247 C and degradationo 0714% weight losses for all PEthA based PU coatingsattributed to the decomposition of urethane moieties.

    degradation started in between 313 and 316 C tem-d degradation resulted in 2835% weight losses. Thise degradation may be due to the decomposition of parts

    by polyol (soft segment). Last or third step degradationn the range of 433451 C and resulted in 5275% weight

  • 554 A. Chaudhari et al. / Industrial Crops and Products 50 (2013) 550 556

    Table 1Characteristic properties of neem oil, AIJFA and PEthA.

    Properties Specic gravity Refractive index Sap value Acid value OH value Iodine value

    Neem oil 0.920 1.503 186 1.3 000 64.55AIJFA 0.927 1.542 00 205 59.82PEthA 0.929 1.495 00 190 54.46

    Fig. 5. 1H NMR spectra of PEthA of neem oil.

    Fig. 6. TEM images of nano TiO2 particles.

    Table 2PU coatings properties.

    Sample/properties Dry to touch (min) Scratch hardness (kg) Cross cut adhesion (%) Gloss 60 Impact resistance (lb in.) Pencil hardness

    PU-0 27 1.5 96 92 58.18 2HPU-1 21 1.6 97 93 61.81 2HPU-2 20 1.8 98 95 65.45 3HPU-3 19 1.7 97 96 67.27 4HPU-4 20 1.7 96 98 63.63 3H

  • A. Chaudhari et al. / Industrial Crops and Products 50 (2013) 550 556 555

    odie

    0

    20

    40

    60

    80

    100

    % w

    t los

    s

    losses. ThirdhydrocarboPU-2 samplity was obscoatings.

    All modimal stabilitstability inctially thermin amount then it incrPU coatingsthermal sta

    5. Conclus

    Neem oisuccessfullyits intermednano TiO2 wpling agent.pencil hardcoatings. Tused as ecopetroleum b

    Acknowled

    The authCommissionto the prese

    nces

    , C.O.ethera., Shar

    polye. Org. ., Kul

    pack rovem.V., Jadse stucticideK., Chities a134ri, A.Bharaces (A

    Coat.,ri, A.Bd polyicati, J.T.P.gy: a , Karak

    nahaFig. 7. SEM images of unmodied and m

    100 20 0 30 0 40 0 50 0 60 0

    Temp (OC)

    PU0

    PU1

    PU2

    PU3

    PU4

    Fig. 8. TGA curve of PEthA based polyurethanes.

    step degradation may be a result of decomposition ofn chains. Highest thermal stability was observed for thee at the second and last step, while least thermal stabil-erved to the pristine PU-0 amongst all PEthA based PU

    Refere

    Akintayopoly

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    Dutta, S.fromed nano TiO2 loaded PU coatings showed better ther-y than the pristine PU-0 sample. In the series thermalreased in the trend PU-0, PU-1, PU-3, PU-4 and PU-2. Ini-al stability of the PU coatings increased with increaseof nano ller from 0 to 1 weight percent loading andeased for 3 and 4 weight percents. From the TGA of, we can conclude that the PU-2 sample had superiorbility compared to all other samples.

    ions

    l based polyetheramide for PU coatings were prepared. The neem oil fatty amide based polyetheramide andiate were characterized by the proper techniques. Theere synthesized and modied by using the silane cou-

    The presence of nano TiO2 signicantly increased gloss,ness, chemical resistance and thermal stability of thehe neem oil based resins have good potential to be-friendly resins in surface coatings or can substitute toased binders.

    gement

    ors would like to acknowledge to University Grants (UGC), Govt. of India, New Delhi for nancial supportnt work.

    Gerbase, A.E.,mal behav797802.

    Gite, V.V., Kulkterization (IPDI) and

    Gite, V.V., Mapolyurethcyanate. P

    Gu, R., Konar,polyureth

    Guner, F.S., YaSci. 31, 63

    Jaliliana, M., Yof polyurebased poly

    Kashif, M., Sharicinoleam

    Khot, S.N., LasS.H., Woolmers and

    Lligadas, G., Rrenewable2, 44045

    Mahshid, S., Gcles by hydPhys. Quan

    Meier, M.A.R.,green alte

    Meshram, P.Dcured polytonseed oi

    Meshram, P.Dof modieOrg. Coat.

    Nimbalkar, R.Valkyd resin947954.d nano TiO2.

    , Akintayo, E.T., 2010. Studies on newly developed urethane modiedmide coatings from albizia benth oil. Adv. Nat. Appl. Sci. 4, 210220.min, E., Ashraf, S.M., Ahmad, S., 2004. Newly developed urethane mod-theramide based anti-corrosive coatings from a sustainable resource.Coat. 50, 224230.karni, R.D., Gite, V.V., 2012. Preparation and properties of eco-friendlyPU coatings based on renewable source (sorbitol) and its propertyent by nano ZnO. Prog. Org. Coat. 74, 764767.hav, R.S., Gite, V.V., Hundiwale, D.G., Mahulikar, P.P., 2013. Controlleddy of phenol formaldehyde microcapsules containing neem oil as an. Int. J. Polymer. Mater. Polymer. Biomater. 62, 421425.attopadhyay, I., Banerjee, R.K., Bandyopadhyay, U., 2002. Biologicalnd medicinal properties of neem (Azadirachta indica). Curr. Sci. 82,5.., Anand, A., Rajput, S.D., Kulkarni, R.D., Gite, V.V., 2013a. Synthe-terization and application of Azadirachta indica juss (neem oil) fattyIJFA) based polyurethanes coatings: a renewable novel approach. Prog.

    http://dx.doi.org/10.1016/j.porgcoat.2013.05.016.., Hundiwale, D.G., Kulkarni, R.D., Gite, V.V., 2013b. Renewable sourceurethane coatings by using monoglycerides of vegetable oils and itson by nano TiO2. Pigm. Resin Technol. in press., Cuperus, F.P., Kolster, P., 1996. Renewable resources in coatings tech-review. Prog. Org. Coat. 27, 4553., N., 2005. Synthesis, characterization of poly (urethane amide) resinsr seed oil for surface coating applications. Prog. Org. Coat. 53, 147152.

    Petzhold, C.L., Costa, A.P.O., 2002. Dynamic mechanical and ther-ior of epoxy resins based on soybean oil. J. Am. Oil Chem. Soc. 79,

    arni, R.D., Hundiwale, D.G., Kapadi, U.R., 2006. Synthesis and charac-of polyurethane coatings based on trimer of isophorone diisocyanate

    monoglycerides of oils. Surf. Coat. Int. Part B, 117122.hulikar, P.P., Hundiwale, D.G., 2010. Preparation and properties ofane coatings based on acrylic polyols and trimer of isophorone diiso-rog. Org. Coat. 68, 307312.

    S., Sain, M., 2012. Preparation and characterization of sustainableane foams from soybean oils. J. Am. Oil Chem. Soc. 89, 21032111.gei, Y., Erciyes, A.T., 2006. Polymers from triglycerides oil. Prog. Polym.3670.eganeha, H., Haghighi, M.N., 2010. Preparation and characterizationthane electrical insulating coatings derived from novel soybean oil-ols. Polym. Adv. Technol. 21, 118127.rmin, E., Zafar, F., Ahmad, S., 2011. Synthesis and characterization ofide-based polyurethane. J. Am. Oil Chem. Soc. 88, 19891996.cala, J.J., Can, E., Morye, S.S., Williams, G.I., Palmese, G.R., Kusefoglu,, R.P., 2001. Development and applications of triglyceride-based poly-composites. J. Appl. Polym. Sci. 82, 703723.onda, J.C., Galia, M., Lodiz, V., 2012. Oleic and undecyleric acids as

    feed stocks in the synthesis of polyols and polyurethanes. Polymer

    3.hamsari, M., Askari, M., Afshar, N., 2006. Synthesis of TiO2 nanoparti-rolysis and peptization of titanium isopropoxide solution. Semicond.t. Electr. Optoelectr. 9, 6568.

    Metzgerb, J.O., Schubert, U.S., 2007. Plant oil renewable resources asrnatives in polymer science. Chem. Soc. Rev. 36, 17881802.., Puri, R.G., Patil, A.L., Gite, V.V., 2013a. High performance moisture(etherurethane) amide coatings based on renewable resource (cot-l). J. Coat. Technol. Res. 10, 331338.., Puri, R.G., Patil, A.L., Gite, V.V., 2013b. Synthesis and characterizationd cottonseed oil based polyesteramide for coating applications. Prog.76, 11441150.., Athawale, V.D., 2010. Synthesis and characterization of canola oils based on novel acrylic monomer (ATBS). J. Am. Oil Chem. Soc. 87,

  • 556 A. Chaudhari et al. / Industrial Crops and Products 50 (2013) 550 556

    Opera, S., 2010. Synthesis and properties of polyurethane elastomers with castor oilas crosslinker. J. Am. Oil Chem. Soc. 87, 313320.

    Sabzi, M., Mirabedini, S., Zohuriaan, J., Atai, M., 2009. Surface modication ofTiO2 nano-particles with silane coupling agent and investigation of its effecton the properties of polyurethane composite coating. Prog. Org. Coat. 65,222228.

    Sharmin, E., Ashraf, S.M., Ahmad, S., 2006. Epoxidation, hydroxylation, acrylation andurethanation of Linum ussitatissimum seed oil and its derivatives. Eur. J. Lipid.Sci. Technol. 109, 134146.

    Shende, P.G., Dabhade, S.B., Phalke, Y.D., 2004. Preparation and characterization oflinseed oil modied polyesteramide resins for surface coatings. Pigm. Resin.Technol. 33, 8590.

    Zafar, F., Sharmin, E., Ashraf, S.M., Ahmad, S., 2004. Studies on poly (styrene-co-maleic anhydride)-modied polyesteramide-based anticorrosive coatingssynthesized from a sustainable resource. J. Appl. Polym. Sci. 92, 25382544.

    Zlantanic, A., Lava, C., Zhang, W., Petrovic, Z.S., 2004. Effect of structure on propertiesof polyols and polyurethanes based on different vegetable oil. J. Polym. Sci. PartB: Polym. Phys. 42, 809819.

    Development of eco-friendly polyurethane coatings based on neem oil polyetheramide1 Introduction2 Experimental2.1 Chemicals and materials2.2 Synthesis of A. indica juss fatty amide (AIJFA)2.3 Synthesis of polyetheramide (PEthA)2.4 Synthesis of nano TiO2 and their modification by silane coupling agent2.5 Preparation of PU coatings based on PEthA

    3 Characterization3.1 Chemical analysis3.2 Spectroscopic analysis3.3 Transmission electron microscopy (TEM)3.4 Field emission scanning electron microscopy (FE-SEM)3.5 PU coatings characterizations3.6 Chemical resistance3.7 Thermal analysis of PU coatings

    4 Results and discussion4.1 Characteristic properties of neem oil, AIJFA and PEthA4.2 Spectroscopic analysis of AIJFA4.3 FTIR of PEthA4.4 1H NMR spectra of PEthA4.5 TEM images of nano TiO24.6 SEM images of nano TiO24.7 Coating properties4.8 Thermo gravimetric analysis (TGA)

    5 ConclusionsAcknowledgementReferences