Synthesis, characterization and photo – switching properties of azobenzene mesogen containing poly (ether - ester) s from cashew nut shell liquid

  • Natarajan Moorthy
  • Salem Chandrasekaran Murugavel


Poly(ether - ester)s containing azobenzene mesogen were prepared from cardanol, a natural renewable resource and waste of the cashew industry. The azobenzene group containing cardanol (HPPP) was synthesized by the coupling reaction between diazotized aminophenol and cardanol. Further, it was alkylated with 3 – bromopropanol by Williamson’s etherification process to 3- {4- [4-(3- hydroxy propoxy) phenylazo] -3- pentadecyl phenoxy} propan – 1 – ol(3-HPPP). This dihydroxy compound was characterized by CHN analyzer, UV and 1H and 13C - NMR spectroscopies. A series of azobenzene mesogen containing poly (ether – ester)s were synthesized from 3-HPPP and various aliphatic and aromatic diacid chlorides by solution polycondensation technique. The molecular structure of the monomer and polymers was confirmed by FTIR, 1H and 13C - NMR spectral analyses. These polymers were studied for their thermal stability and photochemical properties. Thermal properties were evaluated by TGA and DSC. Hot-stage optical polarizing microscopy (HOPM) study showed that most of the polymers exhibit smectic and highly ordered band structure. The photo-switching property of azopolymers was investigated using UV – Vis spectroscopy and noticed that trans to cis isomerization occurs within 35 s in DMF, whereas reverse process takes place in 4 h in DMF solvent.


Azopolymers Synthesis Thermal properties UV – vis spectroscopy Isomerization 



The authors gratefully acknowledge the Principal and Management, PSG College of Technology, Coimbatore for providing the necessary facilities. This work was supported by the University Grants Commission (UGC), India for financial assistance [Grant No. F.No.39-804/2010 (SR)]. Sincere thanks are also due to SAIF, Indian Institute of Science, Bangalore for NMR spectral studies and STIC - Cochin University for TGA analysis.


  1. 1.
    Voirin C, Caillol S, Sadavarte NV, Tawade BV, Boutevin B, Wadgaonkar PP (2014) Functionalization of cardanol: towards biobased polymers and additives. Polym Chem 5:3142–3162CrossRefGoogle Scholar
  2. 2.
    Lochab B, Shukla S, Varma IK (2014) Naturally occurring phenolic sources: monomers and polymers. RSC Adv 4:21712–21752CrossRefGoogle Scholar
  3. 3.
    Raquez J-M, Deléglise M, Lacrampe M-F, Krawczak P (2010) Thermosetting (bio)materials derived from renewable resources: a critical review. Prog Polym Sci 35:487–509CrossRefGoogle Scholar
  4. 4.
    Balachandran VS, Jadhav SR, Vemula PK, John G (2013) Recent advances in cardanol chemistry in a nutshell: from a nut to nanomaterials. Chem Soc Rev 42:427–438CrossRefGoogle Scholar
  5. 5.
    Darroman E, Bonnot L, Auvergne R, Boutevin B, Caillol S (2015) New aromatic amine based on cardanol giving new biobased epoxy networks with cardanol. Eur J Lipid Sci Technol 117:178–189CrossRefGoogle Scholar
  6. 6.
    Yang P, Sun H, Fan H, Shi B (2016) Novel environmentally sustainable cardanol-based plasticizers: synthesis and properties. Polym Int 65:464–472CrossRefGoogle Scholar
  7. 7.
    Li X, Nie X, Chen J, Wang Y (2017) Preparation of epoxidized cardanol butyl ether as a novel renewable plasticizer and its application for poly(vinyl chloride). Polym Int 66:443–449CrossRefGoogle Scholar
  8. 8.
    Natarajan M, Murugavel SC (2013) Synthesis, spectral and thermal degradation kinetics of novolac resins derived from cardanol. High Perform Polym 25:685–696CrossRefGoogle Scholar
  9. 9.
    Natarajan M, Murugavel SC (2016) Cure kinetics of bio-based epoxy resin developed from epoxidized cardanol-formaldehyde and diglycidyl ether of bisphenol-a networks. J Therm Anal Calorim 125:387–396CrossRefGoogle Scholar
  10. 10.
    Natarajan M, Murugavel SC (2017) Thermal stability and thermal degradation kinetics of bio-based epoxy resins derived from cardanol by thermogravimetric analysis. Polym Bull 74:3319–3340CrossRefGoogle Scholar
  11. 11.
    Tyman JHP, Tychopoulos V, Chan P (1984) Long-chain phenols : XXV. Quantitative analysis of natural cashew nut-shell liquid (Anacardium occidentale) by high-performance liquid chromatography. J Chromatogr 303:137–150CrossRefGoogle Scholar
  12. 12.
    Tyman JHP, Wilczynski D, Kashani MA (1978) Compositional studies on technical cashew nutshell liquid (CNSL) by chromatography and mass spectroscopy. J Am Oil Chem Soc 55:663–668CrossRefGoogle Scholar
  13. 13.
    Griffiths J (1972) II. Photochemistry of azobenzene and its derivatives. Chem Soc Rev 1:481–493CrossRefGoogle Scholar
  14. 14.
    Sudesh Kumar G (1992) Azo functional polymers: functional group approach in macromolecular design. Lancaster, PennsylvaniaGoogle Scholar
  15. 15.
    Zhang C, Du MH, Cheng HP et al (2004) Coherent electron transport through an azobenzene molecule: a light-driven molecular switch. Phys Rev Lett 92:158301CrossRefGoogle Scholar
  16. 16.
    Sekkat S, Knoll W (2002) Photoreactive organic thin films. Academic, AmsterdamGoogle Scholar
  17. 17.
    Tsutsumi N, Morishima M, Sakai W (1998) Nonlinear optical (NLO) polymers. 3. NLO polyimide with dipole moments aligned transverse to the imide linkage. Macromolecules 31:7764–7769CrossRefGoogle Scholar
  18. 18.
    Singer KD, Kuzyk MG, Holland WR et al (1988) Electro-optic phase modulation and optical second-harmonic generation in corona-poled polymer films. Appl Phys Lett 53:1800–1802CrossRefGoogle Scholar
  19. 19.
    Bahulayan D, Sreekumar K (1999) Chiral polyesters with azobenzene moieties in the main chain, synthesis and evaluation of nonlinear optical properties. J Mater Chem 9:1425–1429CrossRefGoogle Scholar
  20. 20.
    Kim DY, Li L, Jiang XL et al (1995) Polarized laser induced holographic surface relief gratings on polymer films. Macromolecules 28:8835–8839CrossRefGoogle Scholar
  21. 21.
    Tsutsumi N, Matsumoto O, Sakai W et al (1996) Nonlinear optical polymers. 2. Novel NLO linear polyurethane with dipole moments aligned transverse to the main backbone. Macromolecules 29:592–597CrossRefGoogle Scholar
  22. 22.
    Bhunia HP, Jana RN, Basak A et al (1998) Synthesis of polyurethane from cashew nut shell liquid (CNSL), a renewable resource. J Polym Sci A Polym Chem 36:391–400CrossRefGoogle Scholar
  23. 23.
    Saminathan M, Pillai CKS (2000) Synthesis of novel liquid crystalline polymers with cross-linked network structures. Polymer 41:3103–3108CrossRefGoogle Scholar
  24. 24.
    Saminathan M, Pillai CKS (2000) Thermotropic side chain polyacrylates with azobenzene mesogenic groups: synthesis and thermal behaviour. Macromol Chem Phys 201:2475–2483CrossRefGoogle Scholar
  25. 25.
    Sandhya KY, Pillai CKS, Sato M et al (2002) Nonlinear optical properties and liquid-crystalline behavior of new polyesters with dipole moments aligned transverse to the backbone. Macromol Chem Phys 203:1126–1134CrossRefGoogle Scholar
  26. 26.
    Sandhya KY, Pillai CKS, Sato M et al (2003) Highly stable rigid main-chain nonlinear optical polymers with nematic phase: effect of liquid-crystalline phase on nonlinear optical response. J Polym Sci A Polym Chem 41:1527–1535CrossRefGoogle Scholar
  27. 27.
    Smitha P, Pillai CKS, Asha SK (2005) Synthesis, characterization, and hyperpolarizability measurements of main-chain azobenzene molecules. J Polym Sci A Polym Chem 43:4455–4468CrossRefGoogle Scholar
  28. 28.
    Armarego WLF, Chai CLL (2003) Purification of laboratory chemicals. Butterworth Heinemann, New YorkGoogle Scholar
  29. 29.
    Paramashivappa R, Phanikumar P, Vithayathil PJ et al (2001) Novel method for isolation of major phenolic constitutents from cashew (Anacardium Occidentale L.) nut shell liquid. J Agric Food Chem 49:2548–2551CrossRefGoogle Scholar
  30. 30.
    Phanikumar P, Paramashivappa R, Vithayathil PJ et al (2002) Process for isolation of cardanol from technical cashew (Anacardium Occidentale L.) nut shell liquid. J Agric Food Chem 50:4705–4708CrossRefGoogle Scholar
  31. 31.
    Pansare VS, Kulkarni AB (1964) Azodyes from cashew nut shell liquid derivatives. J Indian Chem Soc 41:251–255Google Scholar
  32. 32.
    Saminathan M, Pillai CKS, Krishna C et al (1993) Synthesis and characterization of main-chain liquid-crystalline polymers containing a p-phenyleneazo group. Macromolecules 26:7103–7105CrossRefGoogle Scholar
  33. 33.
    Balaji K, Murugavel SC (2011) Synthesis, spectral, and thermal characterization of photosensitive poly(ether–ester)s containing α,β-unsaturated ketone moieties in the main chain derived from 2,6-bis[4-(3-hydroxypropyloxy)-3-methoxybenzylidene]cyclohexanone. J Appl Polym Sci 120:3141–3150CrossRefGoogle Scholar
  34. 34.
    Muthusamy A, Balaji K, Murugavel SC (2013) Synthesis, thermal, and photocrosslinking studies of thermotropic liquid crystalline poly (benzylidene-ether) esters containing α, β-unsaturated ketone moiety in the main chain. J Polym Sci A Polym Chem 51:1707–1715CrossRefGoogle Scholar
  35. 35.
    Saminathan M (1995) Synthesis and characterization of novel liquid crystal polymers containing azobenzene mesogen chemistry [dissertation]. University of Kerala, ThiruvanathapuramGoogle Scholar
  36. 36.
    Muthusamy A, Murugavel SC (2006) Studies on photoreactive polyesters containing α, β-unsaturated carbonyl group in the main chain. High Perform Polym 18:227–240CrossRefGoogle Scholar
  37. 37.
    Silverstein RM, Webster FX, Kiemle DJ (2005) Spectroscopic identification of organic compounds. Wiley, New YorkGoogle Scholar
  38. 38.
    Bashir Z (1993) Double endothermic and exothermic transitions during heating and cooling of thermoreversible polyacrylonitrile gels. J Mater Sci Lett 12:598–601Google Scholar
  39. 39.
    Bashir Z, Odell JA, Keller A (1986) Stiff and strong polyethylene with shish kebab morphology by continuous melt extrusion. J Mater Sci 21:3993–4002CrossRefGoogle Scholar
  40. 40.
    Nichols ME, Robertson RE (1992) The multiple melting endotherms from poly(butylene terephthalate). J Polym Sci Phys Ed 30:755–768CrossRefGoogle Scholar
  41. 41.
    Marin L, Cozan V, Bruma M (2006) Comparative study of new thermotropic polyazomethines. Polym Adv Technol 17:664–672CrossRefGoogle Scholar
  42. 42.
    Rovielo A, Sirigu A (1982) Odd- even effect in polymeric liquid crystals. Makromol Chem 183:895–904CrossRefGoogle Scholar
  43. 43.
    Blumstein A, Thomas O (1982) Odd-even effect in thermotropic liquid crystalline 4,4'-dihydroxy-2,2'-dimethylazoxybenzene-alkanedioic acid polymer. Macromolecules 15:1264–1267CrossRefGoogle Scholar
  44. 44.
    Iimura K, Koide N, Ohta R et al (1981) Syntheses of thermotropic liquid crystalline polymers, 1. Azoxy and azo type polyesters. Makromol Chem 182:2563–2568CrossRefGoogle Scholar
  45. 45.
    Rahman L, Kumar S, Tschierskec C et al (2009) Synthesis and photoswitching properties of bent-shaped liquid crystals containing azobenzene monomers. Liq Cryst 36:397–407CrossRefGoogle Scholar
  46. 46.
    Srinivasn MV, Kannan P (2011) Photo-switching and nonlinear optical behaviors of center linked bent-core azobenzene liquid crystalline polymers. J Mater Sci 46:5029–5043CrossRefGoogle Scholar
  47. 47.
    Wei-Guang Diau E (2004) A new Trans-to-cis photoisomerization mechanism of azobenzene on the S1 (n,π*) surface. J Phys Chem A 108:950–956CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V., part of Springer Nature 2018

Authors and Affiliations

  • Natarajan Moorthy
    • 1
  • Salem Chandrasekaran Murugavel
    • 1
  1. 1.Polymer Research Laboratory, Chemistry Division, Department of Applied SciencePSG College of TechnologyCoimbatoreIndia

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