Iranian Journal of Polymer Science and Technology

Iranian Journal of Polymer Science and Technology

Effect of Aromatic Amine Structure as a Curing Agent on Molecular Packing and Mechanical Properties of Cured Epoxy Resin

Document Type : Research Paper

Authors
Mehran Jahani
Hasan Fatahi
Mehrzad Mortezaeei
Department of Polymer Engineering, Faculty of Composite Engineering, Malek-e-Ashtar University of Technology, P.O. Box: 15875-1774, Tehran, Iran
10.22063/jipst.2019.1664
Abstract
Hypothesis: Epoxy resins are one of the most prominent resins in the world. Many factors affect the mechanical properties of this family of polymers, but the effects of parameters such as molecular packing on mechanical properties are less investigated. The most important factor in molecular packing and mechanical properties is the chemical structure of the curing agent. Herein, we report the effect of aromatic structure of the curing agent on the molecular packing and mechanical properties of the cured epoxy resin.
Methods: The curing of the epoxy resin was performed by melting the curing agent and addition of the epoxy resin. To study the effect of curing agent structure, three different curing agents including meta-phenylenediamine (m-PDA), ortho-phenylenediamine (o-PDA) and 2,4-diamino toluene (2,4-DAT) were used. The molecular packing was studied by X-ray diffraction (XRD) technique. Also, the density measurements of cured epoxy resins were carried out using the Archimedes method and finally, the effect of molecular packing on the mechanical properties was investigated by tensile test.
Findings: The results obtained from XRD and tensile test measurements showed that there is a direct relationship between the molecular packing and mechanical strength which by increases in the molecular packing the tensile strength increased as well. By changing the curing agent from m-PDA to o-PDA, the molecular packing was increased and consequently, led to an increase in the tensile strength of the epoxies. In using 2,4-DAT as a curing agent, the molecular packing and hence the mechanical strength were decreased due to the steric hindrance of the methyl group.

Keywords
molecular packing
epoxy resin
curing agent structure
X-ray diffraction
mechanical properties
  1. Akherati Sany S.R., Mortezaei M., and Amiri Amraei I., Improving Fracture Toughness of Epoxy Nanocomposites by Silica Nanoparticles Iran. J. Polym. Sci. Technol. (Persian), 30, 3-17, 2017.
  2. Abbandanak S.N.H., Siadati S.M.H., and Eslami-Farsani R., Graphene Surface Treatment Effects on Mechanical Behavior of Basalt Fibers Epoxy Composites, Iran. J. Polym. Sci. Technol. (Persian), 31, 155-170, 2018.
  3. Jahani M. and Mortezaei M., Effective factors on Molecular Packing and It’s Effect on Mechanical Properties of Epoxy, Polymerization (Persian), 9, 44-56, 2019.
  4. Song Q., Ji Y., Li S., Wang X., and He L., Adsorption Behavior of Polymer Chain with Different Topology Structure at the Polymer-Nanoparticle Interface, Polymers, 10, 590, 2018.
  5. Wang S., Hong Y.L., Yuan S., Chen W., Zhou W., Li Z., Wang K., Min X., Konishi T., and Miyoshi T., Chain Trajectory, Chain Packing, and Molecular Dynamics of Semicrystalline Polymers as Studied by Solid-State NMR, Polymers, 10, 775, 2018.
  6. Saha S. and Bhowmick A.K., An Insight into Molecular Structure and Properties of Flexible Amorphous Polymers: A Molecular Dynamics Simulation Approach, J. Appl. Polym. Sci., 136, 47457, 2019.
  7. Ronova I. and Pavlova S., The Effect of Conformational Rigidity on Several Physical Properties of Polymers, High Perform. Polym., 10, 309-329, 1998.
  8. Hamciuc C., Hamciuc E., Bruma M., and Ronova I.A., Effect of Conformational Rigidity on Physical Properties of Some Poly(imide–amide) Containing Dimethylsilane Units, J. Macromol. Sci., Part A, 42, 61-69, 2005.
  9. Ronova I., Structural Aspects in Polymers: Interconnections between Conformational Parameters of the Polymers with Their Physical Properties, Struct. Chem., 21, 541-553, 2010.
  10. Bondi A., Van Der Waals Volumes and Radii, J. Phys. Chem., 68, 441-451, 1964.
  11. Ronova I.A., Rozhkov E.M., Alentiev A.Y., and Yampolskii Y.P., Occupied and Accessible Volumes in Glassy Polymers and Their Relationship with Gas Permeation Parameters, Macromol. Theory Simul., 12, 425-439, 2003.
  12. Ronova I.A., Sokolova E.A., and Bruma M., Influence of Chemical Structure of the Repeating Unit on Physical Properties of Aromatic Polymers Containing Phenylquinoxaline Rings, J. Polym. Sci., Part B: Polym. Phys., 46, 1868-1877, 2008.
  13. Uedono A., Sako K., Ueno W., and Kimura M., Free Volumes Introduced by Fractures of CFRP Probed Using Positron Annihilation, Composites, Part A: Appl. Sci. Manufac., 122, 54-58, 2019.
  14. Choi J.H., Song H.J., Jung J., Yu J.W., You N.H., and Goh M., Effect of Crosslink Density on Thermal Conductivity of Epoxy/Carbon Nanotube Nanocomposites, J. Appl. Polym. Sci., 134, 44253, 2017.
  15. Kumar S., Krishnan S., Samal S.K., Mohanty S., and Nayak S.K., Toughening of Petroleum Based (DGEBA) Epoxy Resins with Various Renewable Resources Based Flexible Chains for High Performance Applications: A Review, Ind. Eng. Chem. Res., 57, 2711-2726, 2018.
  16. Shiota A. and Ober C.K., Rigid Rod and Liquid Crystalline Thermosets, Prog. Polym. Sci., 22, 975-1000, 1997.
  17. Mossety-Leszczak B., Wlodarska M., Galina H., and Bak G., Comparing Liquid Crystalline Properties of Two Epoxy Compounds Based on the Same Azoxy Group, Mol. Cryst. Liq. Crystals, 490, 52-66, 2008.
  18. Kumar S. and Adams W.W., Structural Studies of Epoxy Resins, Acetylene Terminated Resins and Polycarbonate, Polymer, 28, 1497-1504, 1987.
  19. Pan G., Du Z., Zhang C., Li C., Yang X., and Li H., Effect of Structure of Bridging Group on Curing and Properties of Bisphenol-A Based Novolac Epoxy Resins, Polym. J., 39, 478-487, 2007.
  20. Detwiler A.T. and Lesser A.J., Characterization of Double Network Epoxies with Tunable Compositions, J. Mater. Sci., 47, 3493-3503, 2012.
  21. Lin K.F. and Chung U.L., Phase-inversion Investigations of Rubber-Modified Epoxies by Electron Microscopy and X-ray Diffraction, J. Mater. Sci., 29, 1198-1202, 1994.
  22. Kwon S.C., Adachi T., Araki W., and Yamaji A., Thermo-viscoelastic Properties of Silica Particulate-Reinforced Epoxy Composites: Considered in Terms of the Particle Packing Model, Acta Mater., 54, 3369-3374, 2006.
  23. Piscitelli F., Lavorgna M., Buonocore G.G., Verdolotti L., Galy J., and Mascia L., Plasticizing and Reinforcing Features of Siloxane Domains in Amine-Cured Epoxy/Silica Hybrids, Macromol. Mater. Eng., 298, 896-909, 2013.
  24. Grishchuk S., Schmitt S., Vorster O., and Karger-Kocsis J., Structure and Properties of Amine-hardened Epoxy/Benzoxazine Hybrids: Effect of Epoxy Resin Functionality, J. Appl. Polym. Sci., 124, 2824-2837, 2012.
  25. Guo H., Li Y., Zheng J., Gan J., Liang L., Wu K., and Lu M., Reinforcement in the Mechanical Properties of Shape Memory Liquid Crystalline Epoxy Composites, J. Appl. Polym. Sci., 132, 42616, 2015.
  26. Zheng Y., Zou B., and Yuan L., Structure and Properties of Novel Epoxy Resins Containing Naphthalene Units and Aliphatic Chains, Iran. Polym. J., 22, 325-334, 2013.
  27. Giang T. and Kim J., Effect of Liquid-Crystalline Epoxy Backbone Structure on Thermal Conductivity of Epoxy–Alumina Composites, J. Electron. Mater., 46, 627-636, 2017.
  28. Xu K., Chen M., Zhang K., and Hu J., Synthesis and Characterization of Novel Epoxy Resin Bearing Naphthyl and Limonene Moieties, and Its Cured Polymer, Polymer, 45, 1133-1140, 2004.
  29. Ochi M., Tsuyuno N., Sakaca K., Nakanishi Y., and Murata Y., Effect of Network Structure on Thermal and Mechanical Properties of Biphenol-type Epoxy Resins Cured with Phenols, Polym. Sci., 56, 1161-1167, 1995.
  30. Dai Z., Li Y., Yang S., Zong C., Lu X., and Xu J., Preparation, Curing Kinetics, and Thermal Properties of Bisphenol Fluorene Epoxy Resin, J. Appl. Polym. Sci., 106, 1476-1481, 2007.
  31. Liu Y., Chen J., Zhang Y., Gao S., Lu Z., and Xue Q., Highly Thermal Conductive Benzoxazine-Epoxy Interpenetrating Polymer Networks Containing Liquid Crystalline Structures, J. Polym. Sci., Part B: Polym. Phys., 55, 1813-1821, 2017.
  32. Park S.J., Jin F.L., and Shin J.S., Physicochemical and Mechanical Interfacial Properties of Trifluorometryl Groups Containing Epoxy Resin Cured with Amine, Mater. Sci. Eng.: A, 390, 240-245, 2005.
  33. Kozlov G., Beloshenko V., Varyukhin V., and Lipatov Y.S., Application of Cluster Model for the Description of Epoxy Polymer Structure and Properties, Polymer, 40, 1045-1051, 1999.
  34. Kozlov G.V. and Novikov V.U., A Cluster Model for the Polymer Amorphous State, Phys. USP., 44, 681-724, 2001.
  35. Halasa A., Wathen G., Hsu W., Matrana B., and Massie J., Relationship between Interchain Spacing of Amorphous Polymers and Blend Miscibility as Determined by Wide-Angle X-Ray Scattering, J. Appl. Polym. Sci., 43, 183-190, 1991.
  36. Hussain R. and Mohammad D., X-Ray Diffraction Study of the Changes Induced During the Thermal Degradation of Poly(methyl methacrylate) and Poly(methacryloyl chloride), Turk. J. Chem., 28, 725-730, 2004.
Iranian Journal of Polymer Science and Technology
Volume 32, Issue 3 - Serial Number 161
September and October 2019
Pages 267-276