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Thermally curable polyurethanes with main-chain benzoxazine and pendant carboxylic acid groups and their use as electrically insulating coatings

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Abstract

This work describes the preparation of thermally curable benzoxazine-modified polyurethanes with pendant carboxylic acid moieties, which have potential as organic coatings with enhanced thermal stability and electrical insulation properties. Thermoplastic poly(urethane-co-benzoxazine)s (PUBs) were synthesized via the polyaddition reaction of a benzoxazine diol chain extender with isocyanate-terminated urethane oligomers made from poly(tetramethylene ether)glycol at various molecular weights, dimethylol propionic acid, and toluene diisocyanate. Spectroscopic methods were utilized to characterize the proposed structures of the starting materials and final polymeric coatings and confirmation of co-presence of urethane bonds and benzoxazine rings. The curing temperature of the cross-linked PUBs (XPUBs) was evaluated using differential scanning calorimetry analysis. A catalytic effect of free carboxylic acids was observed, resulting in a lowering of the curing temperature by up to 30 °C. The XPUBs exhibited excellent thermal stability and reduced flammability compared to common polyurethane due to the formation of phenolic cross-linked linkages. The tensile strength and modulus of the XPUBs were also improved, while the extensibility of the polymeric coatings was mostly preserved. The key parameters that determine the possible application of these materials as electrical insulator coatings were very promising. The XPUBs displayed high dielectric strength of up to 38 kV/mm, low dielectric constant of less than 3, and a dissipation factor of approximately 6.

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References

  1. Akindoyo JO, Beg M, Ghazali S et al (2016) Polyurethane types, synthesis and applications–a review. RSC Adv 6:114453–114482

    Article  CAS  Google Scholar 

  2. Das A, Mahanwar P (2020) A brief discussion on advances in polyurethane applications. Adv Ind Eng Polym Res 3:93–101. https://doi.org/10.1016/j.aiepr.2020.07.002

    Article  Google Scholar 

  3. Chattopadhyay DK, Webster DC (2009) Thermal stability and flame retardancy of polyurethanes. Prog Polym Sci 34:1068–1133. https://doi.org/10.1016/j.progpolymsci.2009.06.002

    Article  CAS  Google Scholar 

  4. Xie F, Zhang T, Bryant P et al (2019) Degradation and stabilization of polyurethane elastomers. Prog Polym Sci 90:211–268. https://doi.org/10.1016/j.progpolymsci.2018.12.003

    Article  CAS  Google Scholar 

  5. Luchkina LV, Askadskii AA, Bychko KA (2005) Composite polymeric materials based on polyisocyanurates and polyurethanes. Russ J Appl Chem 78:1337–1342. https://doi.org/10.1007/s11167-005-0511-9

    Article  CAS  Google Scholar 

  6. Sendijarevic A, Sendijarevic V, Frisch KCVM (1991) Novel heat-resistant isocyanate based polymers. J Elast Plast 23:192–217

    Article  Google Scholar 

  7. Merline JD, Reghunadhan Nair CP, Gouri C et al (2007) Poly(urethane–oxazolidone): synthesis, characterisation and shape memory properties. Eur Polym J 43:3629–3637. https://doi.org/10.1016/j.eurpolymj.2007.05.032

    Article  CAS  Google Scholar 

  8. Kitayama M, Iseda Y, Odako F, Anzai SIK (1980) Synthesis and properties of polyoxazolidone elastomers from diepoxides and diisocyanates. Rubber Chem Technol 53:1–13

    Article  CAS  Google Scholar 

  9. Lin C-L, Lin W-L, Rwei S-P (2023) Synthesis and characterization of poly(urethane-imide) derived from structural effect of diisocyanates. J Polym Res 30:54. https://doi.org/10.1007/s10965-022-03408-5

    Article  CAS  Google Scholar 

  10. Meena M, Kerketta A, Tripathi M et al (2022) Thermally stable poly(urethane-imide)s with enhanced hydrophilicity for waterproof-breathable textile coatings. J Appl Polym Sci. https://doi.org/10.1002/app.52508

    Article  Google Scholar 

  11. Lubczak J, Chmiel E (2019) Polyurethane foams with 1,3,5-triazine ring and silicon atoms. Macromol Res 27:543–550. https://doi.org/10.1007/s13233-019-7068-6

    Article  CAS  Google Scholar 

  12. Garg K, Chatterjee D, Wadgaonkar PP (2017) Clickable polyurethanes based on s- triazine ring containing aromatic diisocyanate bearing pendent alkyne group: synthesis and postmodification. J Polym Sci Part A Polym Chem 55:1008–1020. https://doi.org/10.1002/pola.28461

    Article  CAS  Google Scholar 

  13. Issam AM, Ismail J (2006) Improvement of thermal stability of new heteroaromatic poly(azomethine urethane)s. J Appl Polym Sci 100:1198–1204. https://doi.org/10.1002/app.23461

    Article  CAS  Google Scholar 

  14. Baqar M, Agag T, Ishida H, Qutubuddin S (2011) Poly(benzoxazine-co-urethane)s: aA new concept for phenolic/urethane copolymers via one-pot method. Polymer (Guildf) 52:307–317. https://doi.org/10.1016/j.polymer.2010.11.052

    Article  CAS  Google Scholar 

  15. Zeng M, Pang T, Chen J et al (2018) Facile preparation of the novel castor oil-based benzoxazine–urethane copolymer with improved high-frequency dielectric properties. J Mater Sci Mater Electron 29:5391–5400. https://doi.org/10.1007/s10854-017-8505-y

    Article  CAS  Google Scholar 

  16. Gaina C, Ursache O, Gaina V, Varganici CD (2014) Poly(urethane-benzoxazine)s. J Polym Res 21:586. https://doi.org/10.1007/s10965-014-0586-1

    Article  CAS  Google Scholar 

  17. Yildirim C, Erciyes AT, Yagci Y (2013) Thermally curable benzoxazine-modified vegetable oil as a coating material. J Coatings Technol Res 10:559–569. https://doi.org/10.1007/s11998-013-9472-8

    Article  CAS  Google Scholar 

  18. Taşdelen-Yücedağ Ç, Erciyes AT (2013) Preparation of oil-modified polycaprolactone and its further modification with benzoxazine for coating purposes. Prog Org Coatings 76:137–146. https://doi.org/10.1016/j.porgcoat.2012.08.022

    Article  CAS  Google Scholar 

  19. Wang Y-X, Ishida H (2000) Synthesis and properties of new thermoplastic polymers from substituted 3,4-dihydro-2 H -1,3-benzoxazines. Macromolecules 33:2839–2847. https://doi.org/10.1021/ma9909096

    Article  CAS  Google Scholar 

  20. Lochab B, Monisha M, Amarnath N et al (2021) Review on the accelerated and low-temperature polymerization of benzoxazine resins: addition polymerizable sustainable polymers. Polymers (Basel) 13:1260. https://doi.org/10.3390/polym13081260

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Dunkers J, Ishida H (1999) Reaction of benzoxazine-based phenolic resins with strong and weak carboxylic acids and phenols as catalysts. J Polym Sci Part A Polym Chem 37:1913–1921. https://doi.org/10.1002/(SICI)1099-0518(19990701)37:13%3c1913::AID-POLA4%3e3.0.CO;2-E

    Article  CAS  Google Scholar 

  22. Andreu R, Reina JA, Ronda JC (2008) Carboxylic acid-containing benzoxazines as efficient catalysts in the thermal polymerization of benzoxazines. J Polym Sci Part A Polym Chem 46:6091–6101. https://doi.org/10.1002/pola.22921

    Article  CAS  Google Scholar 

  23. Kiskan B, Yagci Y, Ishida H (2008) Synthesis, characterization, and properties of new thermally curable polyetheresters containing benzoxazine moieties in the main chain. J Polym Sci Part A Polym Chem 46:414–420. https://doi.org/10.1002/POLA.22392

    Article  CAS  Google Scholar 

  24. Rimdusit S, Mongkhonsi T, Kamonchaivanich P et al (2008) Effects of polyol molecular weight on properties of benzoxazine-urethane polymer alloys. Polym Eng Sci 48:2238–2246. https://doi.org/10.1002/pen.21171

    Article  CAS  Google Scholar 

  25. Takeichi T, Guo Y (2001) Preparation and properties of poly(urethane-benzoxazine)s based on monofunctional benzoxazine monomer. Polym J 33:437–443. https://doi.org/10.1295/polymj.33.437

    Article  CAS  Google Scholar 

  26. Sperling LH (2005) Introduction to physical polymer science. Wiley, Hoboken

    Book  Google Scholar 

  27. Feng Z, Zeng M, Meng D et al (2020) A novel bio-based benzoxazine resin with outstanding thermal and superhigh-frequency dielectric properties. J Mater Sci Mater Electron 31:4364–4376. https://doi.org/10.1007/s10854-020-02995-7

    Article  CAS  Google Scholar 

  28. Xu Q, Zeng M, Feng Z et al (2016) Understanding the effects of carboxylated groups of functionalized graphene oxide on the curing behavior and intermolecular interactions of benzoxazine nanocomposites. RSC Adv 6:31484–31496. https://doi.org/10.1039/C5RA28016H

    Article  CAS  Google Scholar 

  29. Zúñiga C, Larrechi MS, Lligadas G et al (2011) Polybenzoxazines from renewable diphenolic acid. J Polym Sci Part A Polym Chem 49:1219–1227. https://doi.org/10.1002/pola.24541

    Article  CAS  Google Scholar 

  30. Petrović ZS, Zavargo Z, Flyn JH, Macknight WJ (1994) Thermal degradation of segmented polyurethanes. J Appl Polym Sci 51:1087–1095. https://doi.org/10.1002/app.1994.070510615

    Article  Google Scholar 

  31. Su Y-C, Chang F-C (2003) Synthesis and characterization of fluorinated polybenzoxazine material with low dielectric constant. Polymer (Guildf) 44:7989–7996. https://doi.org/10.1016/j.polymer.2003.10.026

    Article  CAS  Google Scholar 

  32. Zhang K, Han L, Froimowicz P, Ishida H (2017) A smart latent catalyst containing o -trifluoroacetamide functional benzoxazine: precursor for low temperature formation of very high performance polybenzoxazole with low dielectric constant and high thermal stability. Macromolecules 50:6552–6560. https://doi.org/10.1021/acs.macromol.7b00887

    Article  CAS  Google Scholar 

  33. Jamshidi S, Yeganeh H, Mehdipour-Ataei S (2011) Preparation and properties of one-pack polybenzoxazine-modified polyurethanes with improved thermal stability and electrical insulating properties. Polym Int. https://doi.org/10.1002/pi.2921

    Article  Google Scholar 

  34. Jamshidi S, Yeganeh H, Mehdipour-Ataei S (2011) Poly(urethane-co-benzoxazine)s via reaction of phenol terminated urethane prepolymers and benzoxazine monomer and investigation of their properties. Polym Adv Technol. https://doi.org/10.1002/pat.1634

    Article  Google Scholar 

  35. Yeganeh H, Razavi-Nouri M, Ghaffari M (2008) Synthesis and properties of polybenzoxazine modified polyurethanes as a new type of electrical insulators with improved thermal stability. Polym Eng Sci. https://doi.org/10.1002/pen.21098

    Article  Google Scholar 

  36. Yeganeh H, Razavi-Nouri M, Ghaffari M (2008) Investigation of thermal, mechanical, and electrical properties of novel polyurethanes/high molecular weight polybenzoxazine blends. Polym Adv Technol 19:1024–1032. https://doi.org/10.1002/pat.1070

    Article  CAS  Google Scholar 

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Moeini, H., Pourmahdian, S. & Yeganeh, H. Thermally curable polyurethanes with main-chain benzoxazine and pendant carboxylic acid groups and their use as electrically insulating coatings. Polym. Bull. 81, 3599–3619 (2024). https://doi.org/10.1007/s00289-023-04890-7

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