Performance of CTBN(carboxyl-terminated poly (butadiene-co-acrylonitrile))-EP(diglycidyl ether of bisphenol-A (DGEBA)) prepolymers and CTBN-EP/polyetheramine (PEA) system

Abstract

CTBN-EP prepolymers were synthesized from CTBN and epoxy resin under the catalysis of HTMAB. FTIR analyses indicate the formation of ester group between the carboxyl group of CTBN and the oxirane group of epoxy resin. The viscosity of modified prepolymer increases with CTBN content increasing, but the epoxy value of the prepolymer decreases greatly. DSC analyses verify that CTBN affects the curing process of CTBN-EP/PEA system. Mechanical testing presents the improved toughness of CTBN-EP/PEA curings for the decrease of tensile strength, flexural strength and compressive strength, and increase of impact strength and elongation-at-break with the CTBN content increasing. SEM micrographs show the rubber phase with many holes in diameter about 0.5–1.5 µm is formed when CTBN content is lower than 10 phr. However, the pattern of SEM graph shows some stalactite-like strips when CTBN content is higher than 15 phr. Furthermore, the SEM image of 25 phr CTBN sample forms a kind of co-continuous structure.

Keywords

carboxyl-terminated butadiene acrylonitrile (CTBN) copolymer / epoxy resin / prepolymer / epoxy value / mechanical properties

References

[1] Xiong Y. L., Wang N. M., Zheng G. Research Progress of Toughening Epoxy Resin[J]. China Adhesives, 2005, 14(7): 27-32.

[2] Hao D. M., Wang X. L., Tang X. Z. Study on Kinetics of Curing Reaction of Epoxy Resin Toughened by Amino Polycarbonate[J]. Polymeric Materials Science and Engineering, 2002, 8(2): 541-547.

[3] Wei Y. B., Zhang L., Li J. Study on Toughening Epoxy Adhesive by IPN[J]. China Adhesives, 2001, 11(1): 76-81.

[4] Lijima T., Nishin T., Fukuda W., . Effect of Matrix Compositions on Modification of Bismaleimide Resin by N-phenylmaleimide-styrene Copolymers[J]. Journal of Applied Polymer Science, 1996, 60: 37-45.

[5] Xiao K. Rate-effect on Fracture Behavior of Core-shell-rubber (CSR)-modified Epoxy[J]. Polymer Engineering Science, 2000, 40(1): 70-81.

[6] Harani H., Fellahi S., Bakar M. Toughening of Epoxy Resin Using Synthesized Polyurethane Prepolymer Based on Hydroxyl-terminated Polyesters[J]. Applied Polymer Science, 1998, 70(13): 2603-2618.

[7] Tripathi G., Srivastava D. 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[J]. Materials Science and Engineering A, 2007, 443: 262-269.

[8] Nigam V., Setua D. K., Mathur G. N. Characterization of Liquid Carboxy Terminated Copolymer of Butadiene Acrylonitrile Modified Epoxy Resin[J]. Polymer Engineering and Science, 1999, 39(8): 1425-1432.

[9] Arias M. L., Frontini P. M., Williams R. J. J. Analysis of the Damage Zone Around the Crack Tip for Two Rubber-modified Epoxy Matrices Exhibiting Different Toughen Ability[J]. Polymer, 2003, 44: 1537-1546.

[10] Wise C. W., Cook W. D., Goodwin A. A. CTBN Rubber Phase Precipitation in Model Epoxy Resins[J]. Polymer, 2000, 41: 4625-4633.

[11] Calabrese L., Valenza A. Effect of CTBN Rubber Inclusions on the Curing Kinetic of DGEBA-DGEBF Epoxy Resin[J]. European Polymer Journal, 2003, 39: 1355-1363.

[12] Ramos V. D., Costa H. M., Soares V. L. P., . Modification of Epoxy Resin: a Comparison of Different Types of Elastomer[ J]. Polymer Testing, 2005, 24: 219-226.

[13] He M. L. Epoxy Resin Adhesive[M], 2004 Beijing Petrochemical Press of China

[14] Wu Z. G., Li S. R., Lu J. C. Improved Method for Determining Epoxy Value[J]. Journal of Wuhan Institute of Chemical Technology, 2006, 28(1): 5-7.

[15] An Y., Li S. R. The Development on the Epoxy Resin Measurement Method[J]. Anhui Chemical Industry, 2003, 4: 7-9.

[16] Horie K., Hiura H., Sawada M., . Calorimetric Investigation of Polymerisation Reactions: Curing Reaction of Epoxides with Amins[J]. Journal of Polymmer. Science, 1970, 8: 1357-1372.

[17] Kinloch A. J., Shaw S. J., Tod D. A. Deformation and Fracture Behaviour of a Rubber Toughened Epoxy[J]. Polymer, 1983, 24: 1341-1354.

[18] Wu X. G., Cui J., Ding Y. F., . Studies on the Phase Separation of Poly(ether imide)-Modified Epoxy Resin[J]. Macromolecular, Rapid Communications, 2001, 22(6): 409-413.