The β-Spherulite Morphology of Isotactic Polypropylene Investigated by Raman Spectroscopy

Abstract

Raman spectroscopy is used to investigate the α- and β-crystalline polymorphs of isotactic polypropylene. Raman spectra of the polymorphs show some minor differences, in particular the wavenumber shifting of certain scattering bands, which reflect the environment of an isolated macromolecular chain within the packing unit cell of the different crystal forms. For example, the shifting of the 842 cm⁻¹ scattering band, which is the most susceptible band to cause intermolecular interactions, is used to generate a structural map of one β-spherulite among α-spherulites with a well-defined resolution. Anisotropy of the crystalline phase orientation within a β-spherulite is also investigated by performing polarized Raman spectroscopy measurements. Differences in the polarized spectra are then finely exploited to map the radial lamellae orientation distribution within one β-spherulite.

Keywords

Raman spectroscopy Isotactic polypropylene Crystalline polymorphs Lamellae orientation

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References

Ward

I. M.

, Mechanical Properties of Solid Polymer (Wiley-Interscience, London, 1971).

Cheng

S. Z. D.

Janimak

J. J.

and Rodriguez

, “Crystalline structures of polypropylene homo- and copolymers”, in Polypropylene: Structure, Blends and Composites, Karger-Kocsis

, Ed. (Chapman and Hall, London, 1995), Vol. 2, Chap. 2, p. 31.

Lotz

Wittmann

J. C.

and Lovinger

A. J

, Polymer 37, 4979 (1996).

Fillon

Thierry

Wittmann

J. C.

and Lotz

, J. Polym. Sci. B 31, 1407 (1993).

Varga

, “Crystalline, melting and supermolecular structure of isotactic polypropylene”, in Polypropylene: Structure, Blends and Composites, Karger-Kocsis

, Ed. (Chapman and Hall, London, 1995), Vol. 2, Chap. 3, p. 56.

Natta

and Corradini

, Nuovo Cimento Suppl. 15, 40 (1960).

Turner-Jones

Aizelwood

J. M.

and Beckett

D. R

, Makromolek. Chem. 75, 134 (1964).

Turner-Jones

and Cobbold

A. J

, J. Polym. Sci. B 6, 539 (1968).

Meille

S. V.

Ferro

D. R.

Brückner

Lovinger

A. J.

and Padden

F. J

, Macromol. 27, 2615 (1994).

10.

Turner-Jones

, Polymer 12, 487 (1971).

11.

Lotz

Graff

and Wittmann

J. C

, J. Polym. Sci. B 24, 2017 (1986).

12.

McAllister

P. B.

Carter

T. J.

and Hinde

R. M

, J. Polym. Sci. 16, 49 (1978).

13.

Tadokoro

Kobayashi

Ukita

Yasufuku

Murahashi

and Torii

, J. Chem. Phys. 42, 1432 (1965).

14.

Snyder

R. G.

and Schachtschneider

J. H

, Spectrochim. Acta 20, 853 (1964).

15.

Minogianni

Gatos

K. G.

and Galiotis

, Appl. Spectrosc. 59, 1141 (2005).

16.

Gatos

K. G.

Minogianni

and Galiotis

, Macromol. 40, 786 (2007).

17.

Painter

P. C.

Coleman

M. M.

and Koenig

J. L

, The Theory of Vibrational Spectroscopy and Its Application to Polymeric Materials (Wiley-Interscience, New York, 1982), Chap. 11, p. 227.

18.

Beckett

D. R.

Chalmers

J. M.

Mackenzie

M. W.

Willis

H. A.

Edwards

H. G. M.

Lees

J. S.

and Long

D. A

, Eur. Polym. J. 21, 849 (1985).

19.

Goldstein

Seeley

M. E.

Willis

H. A.

and Zichy

V. J. I

, Polymer 14, 530 (1973).

20.

Chalmers

J. M.

Edwards

H. G. M.

Lees

J. S.

Long

D. A.

Mackenzie

M. W.

and Willis

H. A

, J. Raman Spectrosc. 22, 613 (1991).

21.

Ellis

Gómez

M. A.

and Marco

, Int. J. Vib. Spectrosc. 5, 7 (2001).

22.

Ellis

, Macromol. Symp. 184, 37 (2002).

23.

Kressler

Schäfer

and Thomann

, Appl. Spectrosc. 52, 1269 (1998).

24.

Ellis

Marco

and Gómez

M. A

, Infrared Phys. Tech. 45, 349 (2004).

25.

Wunderlich

, Macromolecular Physics: Crystal structure, Morphology, Defects (Academic Press, New York, 1973), Chap. 3, p. 313.

26.

Samuels

R. J.

and Yee

R. Y

, J. Polym. Sci. 10, 385 (1972).

27.

Padden

F. J.

and Keith

H. D

, J. Appl. Phys. 44, 1217 (1973).

28.

Treloar

L. R. G.

, The Physics of Rubber Elasticity (Clarendon, Oxford, 1975).

29.

Bower

D. I.

, J. Polym. Sci. 10, 2135 (1972).

30.

Cambon

L. D.

and Luu

D. V

, J. Raman Spectrosc. 14, 291 (1983).

31.

Cambon

L. D.

Ramonja

J. L.

and Luu

D. V

, J. Raman Spectrosc. 18, 129 (1987).

32.

de Baez

Arruebarrena M.

Hendra

P. J.

and Judkins

, Spectrochim. Acta, Part A 51, 2117 (1995).

33.

Schultz

J. M.

, Polymer Materials Science (Prentice-Hall, Englewood Cliffs, 1974), Chap. 3, p. 154.

34.

Aboulfaraj

Ulrich

Dahoun

and G'Sell

, Polymer 34, 4817 (1993).

35.

Weynant

Haudin

J. M.

and G'Sell

, J. Mater. Sci. 15, 2677 (1980).