Rheological, Thermal and Free Volume Studies of Blends Containing Two Thermotropic Liquid Crystalline Polymers

Hsieh TT; Tiu C; Hsieh KH; Simon GP

Korea Polymer Journal, Vol.6, No.1, 44-52, March, 1998

A melt blend of a rigid-chain copolyester and a terpolyester, thermotropic liquid crystalline polymer is described with reference to its miscibility, rheological and free volume properties. Dynamic rheometry is used to characterize the effect of blend concentration on rheological propeties, whilst capillary rheometer is used to quantify the efficacy of the reduction in viscosity of the more viscous component at higher shear rates. Dynamic mechanical thermal analysis indicates that the blend becomes two phase structures, transesterification being intrinsically low or sufficiently suppressed by the addition of inhibitor to prevent blocky or random copolymers forming via interchain reactions. There appears to be a limited miscibility of the copolyester in the other terpolyester phase and it is suggested that this may be due to differences in packing and chemistry of the two components. The density and free volume measurements show that the blends are denser (lower fractional free volume) than may be expected from linear additivity, even though the average size of the free volume pores in the blends is greater. This increase in size may be due to increased free volume at the interfaces between the two phases. The overall decrease in fractional free volume may be due to the slight miscibility of one phase in the other, leading tocloser packing within that phase, and thus explaining the greater than average density.

[References]

Kim HJ, Simon GP, Jackson WR, Polymer, 34, 3335 (1993)
Jin JI, Choi EJ, Lee KY, Polym. J., 18, 99 (1986)
Ballauff M, Polym. Adv. Technol., 1, 109 (1990)
Kiss G, U.S. Patent, 4,567,227 (1986)
Demeuse MT, Jaffe M, Mol. Cryst. Liq. Cryst., 157, 535 (1988)
DeMeuse MT, Jaffe M, Liquid-Crystalline Polymers, R.A. Weiss and C.K. Ober, Eds., Washington: ACS Symposium Series, vol. 435, pp. 439-457 (1990)
DeMeuse MT, Jaffe M, Polym. Adv. Technol., 1, 81 (1990)
Kenig S, DeMeuse MT, Jaffe M, Polym. Adv. Technol., 2, 25 (1991)
Lin YG, Winter HH, Polym. Eng. Sci., 32, 773 (1992)
Zipper MD, Simon GP, Cherry P, Hill AJ, J. Polym. Sci. B: Polym. Phys., 52, 1237 (1994)
Pethrick RA, Prog. Polym. Sci., 22, 1 (1997)
Jean YC, Microchem. J., 42, 72 (1990)
Zipper MD, Hill AJ, Mater. Forum., 18, 215 (1994)
Ferry JD, Viscoelastic Properties of Polymers, Wiley, New York (1980)
Hsieh TT, Tiu C, Simon GP, Andrews SR, Williams G, Hsieh KH, Chen CH, Polymer Alloys and Blends, G.O. Shonaike and G.P. Simon, Eds., in preparation, expected publication date Marcel Dekker, New York (1998)
Kim SS, Han CD, Polymer, 35(1), 93 (1994)
Graessley WW, Physical Properties of Polymers, J.E. Mark, A. Eisenberg, W.W. Graessley, L. Mandelkern, E.T. Samulski, J.L. Koenig, and G.D. Wignall, Joint authors, ACS Publications, Washington, pp. 97-144 (1993)
Simon GP, Polymer Liquid Crystals, W. Brostow, Ed., Chapman and Hall, vol. 3 (1997)
McCrum NG, Read BE, Williams G, Anelastic and Dielectric Effects in Polymeric Solids, Wiley, London (re-released by Dover Publications, New York) (1967)
Green DI, Collins TL, Davies GR, Ward IM, Polymer, 38(21), 5355 (1997)
Kwei TK, Nishi T, Roberts RF, Macromolecules, 7, 667 (1974)
Fried JR, Karasz FE, MacKnight WJ, Macromolecules, 11, 150 (1978)
Campbell JA, Goodwin AA, Safari Ardi M, Simon GP, Landry-Coltrane CJT, Macromol. Chem., 118, 383 (1997)
Hsieh TT, Tiu C, Simon GP, unpublished data
Zipper MD, Simon GP, Stack GM, Tant M, Hill AJ, Polym. Int., 36, 127 (1995)
Turek DE, Simon GP, unpublished data
Windle AH, Viney C, Golombeck R, Donald AM, Mitchell DR, Faraday Discussion Chem. Soc., 79, 55 (1985)
Biswas A, Balckwell J, Macromolecules, 21, 3146 (1988)
Liu J, Jean YC, Yang HJ, Macromolecules, 28(17), 5774 (1995)

[Referenced By]

[1] Kim HJ, Simon GP, Jackson WR, Polymer, 34, 3335 (1993)

[2] Jin JI, Choi EJ, Lee KY, Polym. J., 18, 99 (1986)

[3] Ballauff M, Polym. Adv. Technol., 1, 109 (1990)

[4] Kiss G, U.S. Patent, 4,567,227 (1986)

[5] Demeuse MT, Jaffe M, Mol. Cryst. Liq. Cryst., 157, 535 (1988)

[6] DeMeuse MT, Jaffe M, Liquid-Crystalline Polymers, R.A. Weiss and C.K. Ober, Eds., Washington: ACS Symposium Series, vol. 435, pp. 439-457 (1990)

[7] DeMeuse MT, Jaffe M, Polym. Adv. Technol., 1, 81 (1990)

[8] Kenig S, DeMeuse MT, Jaffe M, Polym. Adv. Technol., 2, 25 (1991)

[9] Lin YG, Winter HH, Polym. Eng. Sci., 32, 773 (1992)

[10] Zipper MD, Simon GP, Cherry P, Hill AJ, J. Polym. Sci. B: Polym. Phys., 52, 1237 (1994)

[11] Pethrick RA, Prog. Polym. Sci., 22, 1 (1997)

[12] Jean YC, Microchem. J., 42, 72 (1990)

[13] Zipper MD, Hill AJ, Mater. Forum., 18, 215 (1994)

[14] Ferry JD, Viscoelastic Properties of Polymers, Wiley, New York (1980)

[15] Hsieh TT, Tiu C, Simon GP, Andrews SR, Williams G, Hsieh KH, Chen CH, Polymer Alloys and Blends, G.O. Shonaike and G.P. Simon, Eds., in preparation, expected publication date Marcel Dekker, New York (1998)

[16] Kim SS, Han CD, Polymer, 35(1), 93 (1994)

[17] Graessley WW, Physical Properties of Polymers, J.E. Mark, A. Eisenberg, W.W. Graessley, L. Mandelkern, E.T. Samulski, J.L. Koenig, and G.D. Wignall, Joint authors, ACS Publications, Washington, pp. 97-144 (1993)

[18] Simon GP, Polymer Liquid Crystals, W. Brostow, Ed., Chapman and Hall, vol. 3 (1997)

[19] McCrum NG, Read BE, Williams G, Anelastic and Dielectric Effects in Polymeric Solids, Wiley, London (re-released by Dover Publications, New York) (1967)

[20] Green DI, Collins TL, Davies GR, Ward IM, Polymer, 38(21), 5355 (1997)

[21] Kwei TK, Nishi T, Roberts RF, Macromolecules, 7, 667 (1974)

[22] Fried JR, Karasz FE, MacKnight WJ, Macromolecules, 11, 150 (1978)

[23] Campbell JA, Goodwin AA, Safari Ardi M, Simon GP, Landry-Coltrane CJT, Macromol. Chem., 118, 383 (1997)

[24] Hsieh TT, Tiu C, Simon GP, unpublished data

[25] Zipper MD, Simon GP, Stack GM, Tant M, Hill AJ, Polym. Int., 36, 127 (1995)

[26] Turek DE, Simon GP, unpublished data

[27] Windle AH, Viney C, Golombeck R, Donald AM, Mitchell DR, Faraday Discussion Chem. Soc., 79, 55 (1985)

[28] Biswas A, Balckwell J, Macromolecules, 21, 3146 (1988)

[29] Liu J, Jean YC, Yang HJ, Macromolecules, 28(17), 5774 (1995)