Abstract
Homopolymer poly(ethylene terephthalate) (PET) and nylon-6 (PA6) and a blend (1 : 1 by weight) of these polymers, were extruded as strips and ultraquenched from the melt. After zone drawing and additional annealing at temperatures, T a, of 220 or 240 °C for 5 or 25 h in vacuum, the samples were studied by scanning electron microscopy (SEM), wide-angle X-ray scattering, solubility and microhardness, H, tests. In conformity with previous studies of the same system, the present SEM observations show that mechanical drawing results in the formation of a highly oriented fibrillar structure of PET which is preserved even after annealing above the melting point of PA6. Furthermore, raising of both annealing temperature and duration up to 240 °C and 25 h, respectively, results in a strong decrease of the solubility of the PA6 fraction in formic acid (five-fold). This is attributed to intensive chemical interactions between components, drastically improving the adhesion between matrix and reinforcing microfibrils. From the dependence of H on degree of crystallinity, w c, the hardness values for completely amorphous, H a, and fully crystalline, H c, neat homopolymers were extrapolated (H a PET = 128 MPa, H c PET = 294 MPa, H a PA = 52 MPa and H c PA = 283 MPa). Using these values and applying the additive law, the H-value of the microfibrils is derived. The high value obtained for PET fibrils (360 MPa) is explained by the peculiarity in the structure formation of these microfibrils. The effect of crystal size on the formation of H is also discussed. The H-value of infinite large PA6 crystals is derived to be H ∞ = 460 MPa. It is shown that the type and extent of the mutual dispersion of the components, as well as the adhesion between them, are important factors for the proper applicability of the additive law.
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References
L. A. UTRACKI, “Polymer Alloys and Blends” (Hanser, Munich, 1989).
M. EVSTATIEV and S. FAKIROV, Polymer 33 (1992) 877.
S. FAKIROV, M. EVSTATIEV and J. M. SCHULTZ, ibid. 34 (1993) 4669.
Idem, Macromolecules 26 (1993) 5219.
S. FAKIROV and M. EVSTATIEV, Adv. Mater. 6 (1994) 395.
M. EVSTATIEV, S. FAKIROV and K. FRIEDRICH, Appl. Compos. Mater. 2 (1995) 93.
T. SERHATKULU, B. ERMAN, I. BAHAR, S. FAKIROV, M. EVSTATIEV and D. SAPUDJIEVA, Polymer 36 (1995) 2371.
M. EVSTATIEV, N. NIKOLOV and S. FAKIROV, ibid. 37 (1996) 4455.
M. EVSTATIEV, J. M. SCHULTZ, S. PETROVICH and S. FAKIROV, Polymer, submitted.
P. J. FLORY, “Principles of Polymer Chemistry” (Cornell University Press, Ithaca, NY, 1953).
S. FAKIROV, in “Solid State Behavior in Linear Polyesters and Polyamides”, edited by J. M. Schultz and S. Fakirov (Prentice Hall, Englewood Cliffs, NJ, 1990) p. 1.
M. FISCHER, in “The Interfacial Interactions in Polymeric Composites”, edited by G. Akovali (Kluwer, Dordrecht, 1992) p 415.
R. HOLSTI-MIETTINEN, J. SEPPAELAE and O. T. IKKALA, Polym. Engng Sci. 32 (1992) 868.
A. R. PADWA, ibid. 32 (1992) 1703.
F. J. BALTA CALLEJA, C. SANTA CRUZ, C. SAWATARI and T. ASANO, Macromolecules 23 (1990) 5352.
J. MARTINEZ-SALAZAR and F. J. BALTA CALLEJA, J. Mater. Sci. Lett. 4 (1985) 324.
T. A. EZQUERRA, F. J. BALTA CALLEJA, L. GIRI and Z. ROSLANIEC, J. Macromol. Sci. Phys., B36 (1997) 335.
F. ANIA, J. MARTINEZ-SALAZAR and F. J. BALTA CALLEJA, J. Mater. Sci. 24 (1989) 2934.
F. J. BALTA CALLEJA, L. GIRI, T. A. EZQUERRA, S. FAKIROV and Z. ROSLANIEC, J. Macromol. Sci. Phys., B36 (1997) 655.
T. KUNUGI, C. ICHJINOSE and A. SUZUKI, J. Appl. Polym. Sci. 31 (1981) 429.
T. KUNUGI, I. AKIYAMA and M. HASHIMOTO, Polymer 23 (1982) 1199.
S. GOGOLEWSKI, and A. J. PENNINGS, ibid. 18 (1977) 654.
B. WUNDERLICH, Polym. Engng Sci. 18 (1979) 431.
F. J. BALTA CALLEJA and C. G. VONK, “X-ray Scattering of Synthetic Polymers” (Elsevier, Amsterdam, 1989) p. 129.
F. J. BALTA CALLEJA, Adv. Polym. Sci. 66 (1985) 117.
C. SANTA CRUZ, F. J. BALTA CALLEJA, H. G. ZACHMANN and D. CHEN, J. Mater. Sci. 27 (1992) 2161.
D. HULL, “An Introduction to Composite Materials” (Cambridge University Press, Cambridge, 1987).
F. J. BALTA CALLEJA, D. R. RUEDA, J. M. AYRES DE CAMPOS and M. E. CAGIAO, J. Mater. Sci. 23 (1988) 4487.
S. FAKIROV, “Structure and Properties of Polymers” (Sofia Press, Sofia, 1985) (distributed by Martin-Nijhoff, Holland).
E. W. FISCHER and S. FAKIROV, J. Mater. Sci. 11 (1976) 1041.
S. FAKIROV, Polymer 21 (1980) 373.
S. FAKIROV, I. SEGANOV and L. PRANGOVA, Makromol. Chem. 184 (1984) 807.
E. ANDRESEN and H. G. ZACHMANN, Coll. Polym. Sci. 272 (1994) 1352.
M. KIMURA and R. S. PORTER, J. Polym. Sci. Polym. Phys. Ed. 21 (1983) 267.
M. R. KAMAL, M. A. SAHTO and L. A. UTRACKI, Polym. Engng Sci. 22 (1982) 1127.
J. DEVAUX P. GODARD and J. P. MERCIER, ibid. 22 (1982) 229.
E. GATTIGLIA, F. P. LA MANTIA, A. TARTURRO and A. VALENZA, Polym. Bull. 21 (1989) 47.
Y. TAKEDA and D. R. PAUL, Polymer 32 (1991) 2171.
K. L. L. EERSELS and G. GROENINCKX, ibid. 37 (1996) 983.
D. ROGER MOORE and L. J. MATHIAS, J. Appl. Polym. Sci. 32 (1986) 6299.
T. S. ELLIS, Polymer 33 (1992) 1469.
Idem, Macromolecules 22 (1989) 712.
A. VERMA, B. L. DEOPURA and A. K. SENGUPTA, J. Appl. Polym. Sci. 31 (1986) 747.
N. STRIBECK, H. G. ZACHMANN, R. K. BAYER and F. J. BALTA CALLEJA, J. Mater. Sci. 32 (1997) 1639.
J. PETERMANN and R. M. GOHIL, J. Mater. Sci. 14 (1979) 2260.
Idem, J. Polym. Sci. Polym. Lett. Edn 18 (1980) 781.
J. PETERMANN, Makromol. Chem. 182 (1981) 613.
J. PETERMANN, R. M. GOHIL, J. M. SCHULTZ, R. W. HENDRICKS and J. S. LIN, J. Mater. Sci. 16 (1981) 265.
J. RAU, R. M. GOHIL, J. PETERMANN and J. M. SCHULTZ, Coll. Polym. Sci. 259 (1981) 241.
R. MURRAY, H. A. DAVIS and P. TUCKER, J. Appl. Polym. Sci. Appl. Polym. Symp. 33 (1978) 177.
J. PETERMANN and U. RIECK, J. Mater. Sci. 22 (1987) 1120.
H. CHANG, J. M. SCHULTZ and R. M. GOHIL, J. Macromol. Sci. Phys. B32 (1993) 99.
J. M. SCHULTZ and J. PETERMANN, Coll. Polym. Sci. 262 (1984) 294.
DuPont de Nemours International SA, Switzerland, Brochure E-52863 (1986).
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Krumova, M., Fakirov, S., Calleja, F.J.B. et al. Structure development in PET/PA6 microfibrillar-reinforced composites as revealed by revealed by microhardness. Journal of Materials Science 33, 2857–2868 (1998). https://doi.org/10.1023/A:1017594021634
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DOI: https://doi.org/10.1023/A:1017594021634