Polymer Bulletin

, Volume 71, Issue 5, pp 1241–1262 | Cite as

Influence of rubber on the curing kinetics of DGEBA epoxy and the effect on the morphology and hardness of the composites

  • Angel Romo-Uribe
  • Jose Antonio Arcos-Casarrubias
  • Araceli Flores
  • Cintya Valerio-Cárdenas
  • Agustin E. González
Original Paper


The influence of the end groups of two liquid rubbers on curing kinetics, morphology, and hardness behavior of diglycidyl ether of bisphenol-A based epoxy resin (DGEBA) has been studied. The rubbers are silyl-dihydroxy terminated (PDMS-co-DPS-OH) and silyl-diglycidyl ether terminated (PDMS-DGE). Crosslinking reactions, investigated by shear rheometry, ranged 90–110 °C, using a constant concentration (5 phr) of liquid rubbers and 1,2-Diamino cyclohexane (1,2-DCH) as hardener agent. The gel time, tgel, of the neat epoxy significantly decreased when adding the elastomers, more so for the silyl-dihydroxy terminated elastomer; at 110 °C the reaction was nearly complete before rheological test started. The results suggest that the elastomers induced a catalytic effect on the curing reaction. Scanning electron microscopy revealed phase separation of the elastomer during the curing reaction with rubber domains about 5 μm size. However, the DGEBA/dihydroxy terminated elastomer composite cured at 110 °C exhibited a homogenous morphology, that is, the rapid reaction time would not allow for phase separation. Water contact angle tests evidenced either more hydrophilic (silyl-diglycidyl ether terminated rubber) or more hydrophobic (silyl-dihydroxy terminated rubber) behavior than the neat epoxy. The latter effect is attributed to the presence of aromatic rings in the backbone structure of PDMS-co-DPS-OH. Microindentation measurements show that the elastomers significantly reduced the hardness of the epoxy resin, the DGEBA/ether terminated composite exhibiting the lowest hardness values. Moreover, hardness increased as reaction temperature did, correlating with a reduction of microdomains size thus enabling the tuning of mechanical properties with reaction temperature.


Epoxy DGEBA Rubber Shear rheometry Curing reaction 


  1. 1.
    Winter HH (1987) Can the gel point of a cross-linking polymer be detected by the G′–G′′ crossover? Polym Eng Sci 27:1698–1702CrossRefGoogle Scholar
  2. 2.
    Winter HH (1987) Evolution of rheology during chemical gelation. Progr Col Poly Sci 75:104–110CrossRefGoogle Scholar
  3. 3.
    Larson RG (1999) The structure and rheology of complex fluids, 2nd edn. Oxford University Press, OxfordGoogle Scholar
  4. 4.
    Winter HH, Chambon F (1986) Analysis of linear viscoelasticity of a crosslinking polymer at the gel point. J Rheol 30:367–382CrossRefGoogle Scholar
  5. 5.
    Tung C-YM, Dynes PJ (1982) Relationship between viscoelastic properties and gelation in thermosetting systems. J Appl Polym Sci 27:569–574CrossRefGoogle Scholar
  6. 6.
    Núñez L, Gómez-Barreiro S, Gracia-Fernández CA (2005) Study of the influence of isomerism on the curing properties of the epoxy system DGEBA (n = 0)/1,2-DCH by rheology. Rheol Acta 45:184–191CrossRefGoogle Scholar
  7. 7.
    Rudin A (1999) The elements of polymer science and engineering, 2nd edn. Academic Press, New York, p 11Google Scholar
  8. 8.
    Liu P, He L, Song J, Liang X, Ding H (2008) Microstructure and thermal properties of silyl-terminated polycaprolactone-polysiloxane modified epoxy resin composites. J Appl Polym Sci 109:1105–1113CrossRefGoogle Scholar
  9. 9.
    Laza JM, Julian CA, Larrauri E, Rodríguez M, León LM (1999) Thermal scanning rheometer analysis of curing kinetic of an epoxy resin: 2. An amine as curing agent. Polymer 40:35–45CrossRefGoogle Scholar
  10. 10.
    Carrozzino S, Levita G, Rolla P, Tombari E (1990) Calorimetric and microwave dielectric monitoring of epoxy resin cure. Polymer Eng Sci 30:366–373CrossRefGoogle Scholar
  11. 11.
    Vyazovkin S, Sbirrazzuoli N (1996) Mechanism and kinetics of epoxy-amine cure studied by differential scanning calorimetry. Macromolecules 29:1867–1873CrossRefGoogle Scholar
  12. 12.
    Zhao F, Sun Q, Fang DP, Yao K (2000) Preparation and properties of polydimethylsiloxane-modified epoxy resins. J Appl Polym Sci 76:1683–1690CrossRefGoogle Scholar
  13. 13.
    Hou S-S, Chung Y-P, Chan C-K, Kuo P-L (2000) Function and performance of silicone copolymer. Part IV. Curing behavior and characterization of epoxy-siloxane copolymers blended with diglycidyl ether of bisphenol-A. Polymer 41:3263–3272CrossRefGoogle Scholar
  14. 14.
    Rey L, Poisson N, Maazouz A, Sautereau H (1999) Enhancement of crack propagation resistance in epoxy resins by introducing poly(dimethylsiloxane) particles. J Mater Sci 34:1775–1781CrossRefGoogle Scholar
  15. 15.
    Könczol L, Döll W, Buchholz U, Mülhaupt R (1994) Ultimate properties of epoxy resins modified with a polysiloxane-polycaprolactone block copolymer. J Appl Polym Sci 54:815–826CrossRefGoogle Scholar
  16. 16.
    Anand Prabu A, Alagar M (2005) Thermal and morphological properties of silicone-polyurethane-epoxy intercrosslinked matrix materials. J Macromol Sci Part A Pure Appl Chem 42:175–188CrossRefGoogle Scholar
  17. 17.
    Lin S-T, Huang S-K (1996) Preparation and structural determination of siloxane-modified sulfone-containing epoxy resins. J Polym Sci Part A Polym Chem 34:869–884CrossRefGoogle Scholar
  18. 18.
    Lin S-T, Huang S-K (1996) Synthesis and impact properties of siloxanes-DGEBA epoxy copolymers. J Polym Sci Part A Polym Chem 34:1907–1922CrossRefGoogle Scholar
  19. 19.
    Tripathi G, Srivastava D (2007) Effect of carboxyl-terminated poly(butadiene-co-acrylonitrile) (CTBN) concentration on thermal and mechanical properties of binary blends of diglycidyl ether of bisphenol-A (DGEBA) epoxy resin. Mat Sci Eng A 443:262–269CrossRefGoogle Scholar
  20. 20.
    Ramos VD, da Costa HM, Soares VLP, Nascimento RSV (2005) Modification of epoxy resin: a comparison of different types of elastomers. Polym Test 24:387–394CrossRefGoogle Scholar
  21. 21.
    Tripathi G, Srivastava D (2009) Toughened cycloaliphatic epoxy resin for demanding thermal applications and surface coatings. J Appl Polym Sci 114:2769–2776CrossRefGoogle Scholar
  22. 22.
    Thomas R, Durix S, Sinturel C, Omonov T, Goossens S, Groeninckx G, Moldenaers P, Thomas S (2007) Cure kinetics, morphology, and miscibility of modified DGEBA-based epoxy resin: effects of a liquid rubber inclusion. Polymer 48:1695–1710CrossRefGoogle Scholar
  23. 23.
    Thomas R, Yumei D, Yuelong H, Le Y, Moldenaers P, Weimin Y, Czigany T, Thomas S (2008) Miscibility, morphology, thermal and mechanical properties of a DGEBA based epoxy resin toughened with a liquid rubber. Polymer 49:278–294CrossRefGoogle Scholar
  24. 24.
    Calabrese L, Valenza A (2003) Effect of CTBN rubber inclusions on the curing kinetic of DGEBA-DGEBF epoxy resin. Eur Polym J 39:1355–1363CrossRefGoogle Scholar
  25. 25.
    ImageJ®. Software developed by the National Institutes of Health, USAGoogle Scholar
  26. 26.
    Castillo-Perez R, Romo-Uribe A (2012) Diseño y construcción de un instrumento para medir ángulo de contacto. Memorias del XVIII Congreso Internacional Anual de la SOMIM, ISBN: 978-607-95309-6-9, pp 772–779Google Scholar
  27. 27.
    Flores A, Ania F, Balta-Calleja FJ (2009) From the glassy state to ordered polymer structures. A microhardness study. Polymer 50:729–746CrossRefGoogle Scholar
  28. 28.
    Ferry JD (1980) Viscoelastic properties of polymers. Wiley, New YorkGoogle Scholar
  29. 29.
    Cañamero-Martínez P, Fernández-García M, de la Fuente JL (2010) Rheological cure characterization of a polyfunctional epoxy acrylic resin. React Funct Polym 70:761–766CrossRefGoogle Scholar
  30. 30.
    Wisanrakkit G, Gillham JK (1990) The glass transition temperature (T g) as an index of chemical conversion for a high-T g amine/epoxy system: chemical and diffusion-controlled reaction kinetics. J Appl Polym Sci 41:2885–2929CrossRefGoogle Scholar
  31. 31.
    Mortimer S, Ryan AJ, Stanford JL (2001) Rheological behavior and gel-point determination for a model lewis acid-initiated chain growth epoxy resin. Macromolecules 34:2973–2980CrossRefGoogle Scholar
  32. 32.
    Takiguchi O, Ishikawa D, Sugimoto M, Taniguchi T, Koyama K (2008) Effect of rheological behavior of epoxy during procuring on foaming. J Appl Polym Sci 110:657–662CrossRefGoogle Scholar
  33. 33.
    Choe Y, Kim M, Kim W (2003) In situ detection of the onset of phase separation and gelation in epoxy/anhydride/thermoplastic blends. Macromol Res 11:267–272CrossRefGoogle Scholar
  34. 34.
    Neumann AW, Good RJ, Hope CJ, Sejpal M (1974) An equation-of-state approach to determine surface tensions of low-energy solids from contact angles. J Colloid Interface Sci 4:291–304CrossRefGoogle Scholar
  35. 35.
    Spelt JK, Li D, Neumann AW (1992) Modern approaches to wettability. In: Schrader ME, Loeb GI (eds) Plenum Press, New York, pp 101–142Google Scholar
  36. 36.
    Grundke K, Bogumil T, Werner C, Janke A, Pöschel K, Jacobasch H (1996) Liquid-fluid contact angle measurements on hydrophilic cellulosic materials. J Colloid Surf A Physicochem Eng Asp 116:79–91CrossRefGoogle Scholar
  37. 37.
    Güleç HA, Sarioglu K, Mutlu M (2006) Modification of food contacting surfaces by plasma polymerization technique. Part I: determination of hydrophilicity, hydrophobicity and surface free energy by contact angle method. J Food Eng 75:187–195CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Angel Romo-Uribe
    • 1
  • Jose Antonio Arcos-Casarrubias
    • 2
  • Araceli Flores
    • 3
  • Cintya Valerio-Cárdenas
    • 1
  • Agustin E. González
    • 1
  1. 1.Laboratorio de Nanopolimeros y Coloides, Instituto de Ciencias FisicasUniversidad Nacional Autonoma de MexicoCuernavacaMexico
  2. 2.Division de Ingenieria Quimica y BioquimicaTecnológico de Estudios Superiores de EcatepecEcatepecMexico
  3. 3.Instituto de Estructura de la MateriaIEM-CSICMadridSpain

Personalised recommendations