Abstract
Blends containing 5% poly(butylene terephthalate) (PBT) in an anhydride-cured epoxy with three different PBT morphologies were studied. The three morphologies were a dispersion of spherulites, a structureless gel and a gel with spherulites. The average fracture toughnesses, K Ic, and fracture energies, G Ic, for those morphologies were 0.83, 2.3 and 1.8 MPa m1/2 and 240, 2000 and 1150 J m−2, respectively. These values should be compared with the values of 0.72 MPa m1/2 and 180 J m−2, respectively, for the cured epoxy without PBT. The elastic moduli and yield strengths in compression for all three blend morphologies remained essentially unchanged from those of the cured epoxy without PBT, namely, 2.9 GPa for the modulus and 115 MPa for the yield strength. The fracture surfaces of the cured spherulitic dispersion blends indicate the absorption of fracture energy by crack bifurcation induced by the spherulites. The fracture surfaces of the cured structureless gel blends indicate that fracture energy was absorbed by matrix and PBT plastic deformation and by spontaneous crack bifurcation. But phase transformation of the PBT and anelastic strain of the matrix below the fracture surfaces may account for most of the large fracture energy of the cured structureless gel blends.
Similar content being viewed by others
References
J. N. Sultan and F. J. McGarry, J. Polym. Sci., Polym. Phys. Ed. 13 (1973) 29.
C. B. Bucknall, “Toughened plastics” (Applied Science, London, 1977).
W. D. Bascom, R. Y. Ting, R. J. Moulton, C. K. Riew and A. R. Siebert, J. Mater. Sci. 16 (1981) 2657.
A. J. Kinloch, S. J. Shaw, D. A. Tod and D. L. Hunston, Polymer 24 (1983) 1341.
A. F. Yee and R. A. Pearson, J. Mater. Sci. 21 (1986) 2462.
R. A. Pearson and A. F. Yee, 21 (1986) 2475.
R. A. Pearson and A. F. Yee, J. Mater. Sci. 24 (1989) 2571.
A. C. Garg and Y.-W. Mai, Compos. Sci. Technol. 31 (1988) 179.
W. B. Cherry and K. W. Thompson, J. Mater. Sci. 16 (1981) 1913.
T. D. Chang and J. O. Brittain, Polym. Engng. Sci. 22 (1982) 1228.
C. B. Bucknall and I. K. Partridge, Polymer 24 (1983) 639.
J. L. Hedrick, I. Yilgor, G. L. Wilkes and J. E. McGrath, Polym. Bull. 13 (1985) 201.
C. B. Bucknall and I. K. Partridge, Polym. Engng. Sci. 26 (1986) 54.
R. S. Raghava, J. Polym. Sci., Polym. Phys. Ed. 25 (1987) 1017.
S. C. Kim and H. R. Brown, J. Mater. Sci. 22 (1987) 2589.
R. S. Raghava, J. Polym. Sci., Polym. Phys. Ed. 26 (1988) 65.
C. B. Bucknall and A. H. Gilbert, Polymer 30 (1989) 213.
J. L. Hedrick, I. Yilgor, M. Jurek, J. C. Hedrick, G. L. Wilkes and J. E. McGrath, Polymer 32 (1991) 2020.
G. S. Bennett, R. J. Farris and S. A. Thompson, 32 (1991) 1633.
J. K. Kim and R. E. Robertson, J. Mater. Sci. 27 (1992) 161.
J. K. Kim and R. E. Robertson, J. Mater. Sci. 27 (1992) 3000.
J. K. Kim and R. E. Robertson, in “Toughened plastics I”, edited by C. K. Riew and A. J. Kinloch (American Chemical Society, Washington, DC, 1993) pp. 427–49.
W. N. Kim and L. M. Burns, Makromol. Chem. 190 (1988) 661.
M. E. Nichols and R. E. Robertson, J. Polym. Sci., Polym. Phys. Ed. 32 (1994) 573.
M. E. Nichols and R. E. Robertson, J. Polym. Sci., Polym. Phys. Ed. 32 (1994) 1607.
A. J. Kinloch and R. J. Young, “Fracture behaviour of polymers” (Elsevier, London, 1983).
R. J. Young and P. W. R. Beaumont, J. Mater. Sci. 12 (1977) 684.
T. Ricco, R. Frassine and A. Pavan, 25 (1990) 1517.
A. Takahashi, T. Nakamura and I. Kagawa, Polym. J. 3 (1972) 207.
E. D. T. Atkins, D. H. Issac, A. Keller and K. Miyasaka, J. Polym. Sci., Polym. Phys. Ed. 15 (1977) 211.
S. Wellinghoff, J. Shaw and E. Baer, Macromolecules 12 (1979) 932.
J.-M. Guenet, B. Lotz and J.-C. Wittmann, 18 (1985) 420.
R. C. Domszy, R. Alamo, C. O. Edwards and L. Mandelkern 19 (1986) 310.
J.-M. Guenet, 19 (1986) 1961.
W. Stoks, H. Berghmans, P. Molddenaers and J. Mewis, Brit. Polym. J. 20 (1988) 361.
J. H. Aubert, Macromolecules 21 (1988) 3468.
K. H. Hsieh and J. L. Han, J. Polym. Sci., Polym. Phys. Ed. 28 (1990) 623.
K. H. Hsieh and J. L. Han, J. Polym. Sci., Polym. Phys. Ed. 28 (1990) 783.
H. Xiao, Z. H. Ping, J. W. Xie and T. Y. Yu, J. Polym. Sci., Polym. Chem. Ed. 28 (1990) 585.
R. E. Robertson and V. E. Mindroiu, Polym. Engng. Sci. 27 (1987) 55.
J. S. Covavisaruch, R. E. Robertson and F. E. Filisko, J. Mater. Sci. 27 (1992) 990.
R. E. Robertson, V. E. Mindroiu and M.-F. Cheung, Compos. Sci. Technol. 22 (1985) 197.
S. Kunz-Douglass, P. W. R. Beaumont and M. F. Ashby, J. Mater. Sci. 15 (1980) 1109.
L. F. R. Rose, Mech. Mater. 8 (1987) 11.
F. F. Lange and K. C. Radford, J. Mater. Sci. 6 (1971) 1197.
S. Wu, J. Polym. Sci., Phys. Ed. 21 (1983) 699.
S. Wu, Polymer 26 (1985) 1855.
A. Margolina and S. Wu, 29 (1989) 2170.
R. A. Pearson, PhD Thesis, The University of Michigan, Ann Arbor (1990).
K. Tashiro, Y. Nakai, M. Kobayashi and H. Tadokoro, Macromolecules 13 (1980) 137.
Z. Mencik, J. Polym. Sci., Polym. Phys. Ed. 13 (1975) 2173.
I. M. Hall and M. G. Pass, Polymer 17 (1976) 807.
M. Yokouchi, Y. Sakakibara, Y. Chatani, H. Tadokoro, T. Tanaka and K. Yoda, Macromolecules 9 (1976) 266.
B. Stambaugh, J. L. Koenig and J. B. Lando, J. Polym. Sci., Polym. Phys. Ed. 17 (1979) 1053.
B. Stambaugh, J. B. Lando and J. L. Koenig, 17 (1979) 1063.
B. R. Lawn and T. R. Wilshaw, “Fracture of brittle solids” (Cambridge University Press, Cambridge, 1975) pp. 52–6.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Nichols, M.E., Robertson, R.E. The toughness of epoxy-poly(butylene terephthalate) blends. JOURNAL OF MATERIALS SCIENCE 29, 5916–5926 (1994). https://doi.org/10.1007/BF00366876
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF00366876