Nanoclay-modified microcapsules as a latent curing agent in epoxy


Application of microcapsules as a latent curing agent has been attracted a lot of attention, recently. However, in this type of latent curing agent, the leakage of core material from the microcapsule shell is a major problem. In this study, nanoclay particles were used as a promising approach to prevent the flow out of core materials from the microcapsules’ shell. To this end, nanoclay particles were dispersed in a solution of solid epoxy resin in acetone under sonication process and then were used for microencapsulation of 1-methylimidazole (1-MI) via solvent evaporation method. Scanning electron microscopy was used to study the shape and morphology of the prepared microcapsules. 1-MI content of microcapsules was measured using thermal gravimetry analysis. Curing behavior of microcapsule-embedded epoxy resin was investigated using differential scanning calorimetry and rheometry measurement. In comparison with the neat microcapsules, nanocomposite microcapsules showed better barrier property and longer gel time at high temperature, which can be attributed to the presence of platelet nanoclay particles throughout the microcapsules’ shell.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10


  1. 1.

    Tomuta AM, Ramis X, Ferrando F, Serra A (2012) The use of dihydrazides as latent curing agents in diglycidyl ether of bisphenol A coatings. Prog Org Coat 74:59–66

    CAS  Article  Google Scholar 

  2. 2.

    Sarkar S, Kim B (2018) Synthesis of graphene oxide-epoxy resin encapsulated urea-formaldehyde microcapsule by in situ polymerization process. Polym Compos 39:636–644

    CAS  Article  Google Scholar 

  3. 3.

    Yin T, Rong MZ, Zhang MQ, Yang GC (2007) Self-healing epoxy composites-preparation and effect of the healant consisting of microencapsulated epoxy and latent curing agent. Compos Sci Technol 67:201–212

    CAS  Article  Google Scholar 

  4. 4.

    Hesabi M, Salimi A, Beheshty MH (2018) Development of amine-based latent accelerator for one-pot epoxy system with low curing temperature and high shelf life. Eur Polym J

  5. 5.

    Neumeyer T, Staudigel C, Bonotto G, Altstaedt V (2015) Influence of an imidazolium salt on the curing behaviour of an epoxy-based hot-melt prepreg system for non-structural aircraft applications. CEAS Aeronaut J 6:31–37

    Article  Google Scholar 

  6. 6.

    Ham YR, Lee DH, Kim SH et al (2010) Microencapsulation of imidazole curing agent for epoxy resin. J Ind Eng Chem 16:728–733

    CAS  Article  Google Scholar 

  7. 7.

    Xu H, Fang Z, Tong L (2008) Effect of microencapsulated curing agents on the curing behavior for diglycidyl ether of bisphenol A epoxy resin systems. J Appl Polym Sci 107:1661–1669

    CAS  Article  Google Scholar 

  8. 8.

    Sittipummongkol K, Chuysinuan P, Techasakul S et al (2019) Core shell microcapsules of neem seed oil extract containing azadirachtin and biodegradable polymers and their release characteristics. Polym Bull 76:3803–3817

    CAS  Article  Google Scholar 

  9. 9.

    Jacobson JM, Morrison ID, Wilcox RJ, Drzaic P (2016) Methods for achieving improved color in microencapsulated electrophoretic devices. US Pat 9(293):511

    Google Scholar 

  10. 10.

    Koh E, Park S (2017) Self-anticorrosion performance efficiency of renewable dimer-acid-based polyol microcapsules containing corrosion inhibitors with two triazole groups. Prog Org Coat 109:61–69

    CAS  Article  Google Scholar 

  11. 11.

    Szmechtyk T, Sienkiewicz N, Strzelec K (2018) Polythiourethane microcapsules as novel self-healing systems for epoxy coatings. Polym Bull 75:149–165

    CAS  Article  Google Scholar 

  12. 12.

    Fan J, Zheng Y, Xie Y et al (2017) Effect of solvent evaporation technique on the characteristics of curing agent microcapsules and the curing process. Compos Sci Technol 138:80–90

    CAS  Article  Google Scholar 

  13. 13.

    Shin MJ, Shin YJ, Shin JS (2018) Latent imidazole curing agents by microencapsulation with copolymers. Part Sci Technol 36:112–116

    CAS  Article  Google Scholar 

  14. 14.

    Hara O (1990) Curing agents for epoxy resin. Three Bond Tech News 32:1–10

    Google Scholar 

  15. 15.

    Ham YR, Kim SH, Shin YJ et al (2010) A comparison of some imidazoles in the curing of epoxy resin. J Ind Eng Chem 16:556–559

    CAS  Article  Google Scholar 

  16. 16.

    Ma A, Zhang Q, Zhang H et al (2015) A novel single component epoxy resin adhesive with microcapsule latent curing agent of 2-phenylimidazole/polymethyl acrylic glycidyl ester. J Elastomers Plast 47:439–448

    CAS  Article  Google Scholar 

  17. 17.

    Xing S, Yang J, Huang Y et al (2015) Preparation and characterization of a novel microcapsule-type latent curing agent for epoxy resin. Mater Des 85:661–670

    CAS  Article  Google Scholar 

  18. 18.

    Fuensanta M, Grau A, Romero-Sánchez MD et al (2013) Effect of the polymer shell in imidazole microencapsulation by solvent evaporation method. Polym Bull 70:3055–3074

    CAS  Article  Google Scholar 

  19. 19.

    Lee DH, Yang M, Kim SH et al (2011) Microencapsulation of imidazole curing agents by spray-drying method. J Appl Polym Sci 122:782–788

    CAS  Article  Google Scholar 

  20. 20.

    Shin MJ, Kim JG, Shin JS (2012) Microencapsulation of imidazole curing agents by spray-drying method using W/O emulsion. J Appl Polym Sci 126

  21. 21.

    Shin MJ, Shin YJ, Hwang SW, Shin JS (2013) Microencapsulation of imidazole curing agent by solvent evaporation method using W/O/W emulsion. J Appl Polym Sci 129:1036–1044

    CAS  Article  Google Scholar 

  22. 22.

    Mozaffari SM, Beheshty MH, Mirabedini SM (2016) Microencapsulation of 1-methylimidazole using solid epoxy resin: study on microcapsule residence time and properties of the system. Iran Polym J 25:385–394

    CAS  Article  Google Scholar 

  23. 23.

    Mozaffari SM, Beheshty MH, Mirabedini SM (2017) Effect of processing conditions on the microencapsulation of 1-methylimidazole curing agent using solid epoxy resins. Iran Polym J 26:629–637

    CAS  Article  Google Scholar 

  24. 24.

    Mozaffari SM, Beheshty MH, Mirabedini SM (2016) Dynamic mechanical thermal analysis of cured epoxy resin by capsulated 1-methylimidazole curing agent for making advanced composites. In: 5th International conference on composites: charac; fabrication and application. Tehran

  25. 25.

    Mozaffari SM, Beheshty MH, Mirabedini SM (2016) Effect of encapsulated curing agent on viscosity of the liquid epoxy system. In: 12th International seminar on polymer science and technology

  26. 26.

    Chuanjie F, Xiaodong Z (2009) Preparation and barrier properties of the microcapsules added nanoclays in the wall. Polym Adv Technol 20:934–939

    Article  Google Scholar 

  27. 27.

    Bharadwaj RK (2001) Modeling the barrier properties of polymer-layered silicate nanocomposites. Macromolecules 34:9189–9192

    CAS  Article  Google Scholar 

  28. 28.

    Choudalakis G, Gotsis AD (2009) Permeability of polymer/clay nanocomposites: a review. Eur Polym J 45:967–984

    CAS  Article  Google Scholar 

  29. 29.

    Miyagawa H, Drzal LT, Carsello JA (2006) Intercalation and exfoliation of clay nanoplatelets in epoxy-based nanocomposites: TEM and XRD observations. Polym Eng Sci 46:452–463

    CAS  Article  Google Scholar 

  30. 30.

    Wang H, Hoa SV, Wood-Adams PM (2006) New method for the synthesis of clay/epoxy nanocomposites. J Appl Polym Sci 100:4286–4296

    CAS  Article  Google Scholar 

  31. 31.

    Dean K, Krstina J, Tian W, Varley RJ (2007) Effect of ultrasonic dispersion methods on thermal and mechanical properties of organoclay epoxy nanocomposites. Macromol Mater Eng 292:415–427

    CAS  Article  Google Scholar 

  32. 32.

    Takahashi M, Taguchi Y, Tanaka M (2010) Microencapsulation of hydrophilic solid powder as a flame retardant with epoxy resin by using interfacial reaction method. Polym Adv Technol 21:224–228

    CAS  Article  Google Scholar 

  33. 33.

    Zhang L, Wang X (2015) Curing behavior for microencapsulated curing agents on epoxy resin systems. In: 5th International Conference on civil engineering and transportation

  34. 34.

    Jelvehgari M, Atapour F, Nokhodchi A (2009) Micromeritics and release behaviours of cellulose acetate butyrate microspheres containing theophylline prepared by emulsion solvent evaporation and emulsion non-solvent addition method. Arch Pharm Res 32:1019–1028

    CAS  Article  Google Scholar 

  35. 35.

    O’Donnell PB, McGinity JW (1997) Preparation of microspheres by the solvent evaporation technique. Adv Drug Deliv Rev 28:25–42

    Article  Google Scholar 

  36. 36.

    Wu J-C, Su S-G, Shyu S-S, Chen H (1994) Effect of the solvent-non-solvent pairs on the surface morphology and release behaviour of ethylcellulose microcapsules prepared by non-solvent-addition phase separation method. J Microencapsul 11:297–308

    CAS  Article  Google Scholar 

  37. 37.

    Al-Safy R, Al-Mahaidi R, Simon GP, Habsuda J (2012) Experimental investigation on the thermal and mechanical properties of nanoclay-modified adhesives used for bonding CFRP to concrete substrates. Constr Build Mater 28:769–778

    Article  Google Scholar 

  38. 38.

    Morintale E, Harabou A et al (2013) Use of heat flows from DSC curve for calculation of specific heat of the solid materials. Phys AUC 23:89–94

    Google Scholar 

  39. 39.

    Chen J-S, Poliks MD, Ober CK et al (2002) Study of the interlayer expansion mechanism and thermal–mechanical properties of surface-initiated epoxy nanocomposites. Polymer (Guildf) 43:4895–4904

    CAS  Article  Google Scholar 

  40. 40.

    Prolongo MG, Martinez-Casado FJ, Masegosa RM, Salom C (2010) Curing and dynamic mechanical thermal properties of epoxy/clay nanocomposites. J Nanosci Nanotechnol 10:2870–2879

    CAS  Article  Google Scholar 

  41. 41.

    Sahoo SK, Mohanty S, Nayak SK (2015) A study on effect of organo modified clay on curing behavior and thermo-physical properties of epoxy methyl ester based epoxy nanocomposite. Thermochim Acta 614:163–170

    CAS  Article  Google Scholar 

Download references

Author information



Corresponding authors

Correspondence to Sayed Morteza Mozaffari or Mohammad Hosain Beheshty.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Mozaffari, S.M., Beheshty, M.H. Nanoclay-modified microcapsules as a latent curing agent in epoxy. Polym. Bull. (2020).

Download citation


  • 1-Methylimidazole
  • Microencapsulation
  • Nanoclay
  • Solid epoxy shell
  • Latent curing agent