Molecular weight and tacticity effect on morphological and mechanical properties of Ziegler–Natta catalyzed isotactic polypropylenes
Amer, Ismael; Reenen, Albert van; Mokrani, Touhami
Polímeros: Ciência e Tecnologia, vol.25, n6, p.556-563, 2015
Abstract
The morphological and mechanical properties of Ziegler–Natta catalyzed isotactic polypropylenes as influenced by the molecular weight and tacticity was investigated. Polypropylene samples were injection moulded into standard disks with a HAAKE MiniJet II injection moulder at 190 °C and 200 bar for morphological and mechanical tests. The morphological and mechanical properties of specimens were investigated by means of optical microscope (OM), scanning electron microscopy (SEM), microhardness (MH) and dynamic mechanical analysis (DMA). The samples exhibited a typical α-modification spherulite structure of isotactic polypropylenes crystallized from the melt. It was found that the most important factor affecting the structure and properties of these polymers is the isotacticity content. A clear molecular weight effect was also found for samples with low molecular weights. The microhardness and storage modulus values increased as crystallinity did. Accordingly, isotacticity degree is considered as the main parameter affecting the crystallinity of samples.
Keywords
mechanical property, molecular weight, morphological property, polypropylene, tacticity.
References
1. Moore, J. E. P., & Larson, G. A. (1996). Introduction to PP business, polypropylene handbook. Munich: Hanser Publishers.
2. Lima, M. F. S., Vasconcellos, M. A., & Samios, D. (2002). Crystallinity changes in plastically deformed isotactic polypropylene evaluated by x-ray diffraction and differential scanning calorimetry methods. Journal of Polymer Science. Part B, Polymer Physics, 40(9), 896-903. http://dx.doi.org/10.1002/polb.10159.
3. Asano, T., Calleja, F. J. B., Flores, A., Tanigaki, M., Mina, M. F., Sawatari, C., Itagaki, H., Takahashi, H., & Hatta, I. (1999). Crystallization of oriented amorphous poly(ethylene terephthalate) as revealed by X-ray diffraction and microhardness. Polymer, 40(23), 6475-6484. http://dx.doi.org/10.1016/S0032-3861(98)00839-8.
4. Bedia, E., Murakami, S., Kitade, T., & Kohjiya, S. (2001). Structural development and mechanical properties of polyethylene naphthalate/polyethylene terephthalate blends during uniaxial drawing. Polymer, 42(17), 7299-7305. http://dx.doi.org/10.1016/S0032-3861(01)00236-1.
5. Hoffman, J. D., & Miller, R. L. (1988). Test of the reptation concept: crystal growth rate as a function of molecular weight in polyethylene crystallized from the melt. Macromolecules, 21(10), 3038-3051. http://dx.doi.org/10.1021/ma00188a024.
6. Cheng, S. Z., Janimak, J. J., Zhang, A., & Cheng, H. N. (1990). Regime transitions in fractions of isotactic polypropylene. Macromolecules, 23(1), 298-303. http://dx.doi.org/10.1021/ma00203a051.
7. Carvalho, B., & Bretas, R. E. (1998). Quiescent crystallization kinetics and morphology of isotactic polypropylene resins for injection molding. I. Isothermal crystallization. Journal of Applied Polymer Science, 68(7), 1159-1176. http://dx.doi.org/10.1002/(SICI)1097-4628(19980516)68:7<1159::AID-APP13>3.0.CO;2-T.
8. Stern, C., Frick, A., & Weickert, G. (2007). Relationship between the structure and mechanical properties of polypropylene: Effects of the molecular weight and shear-induced structure. Journal of Applied Polymer Science, 103(1), 519-533. http://dx.doi.org/10.1002/app.24156.
9. Phillips, P. J., & Vatansever, N. (1987). Regime transitions in fractions of cis-polyisoprene. Macromolecules, 20(9), 2138-2146. http://dx.doi.org/10.1021/ma00175a016.
10. Cheng, S. Z., Janimak, J. J., Zhang, A., & Hsieh, E. T. (1991). Isotacticity effect on crystallization and melting in polypropylene fractions: 1. Crystalline structures and thermodynamic property changes. Polymer, 32(4), 648-655. http://dx.doi.org/10.1016/0032-3861(91)90477-Z.
11. Janimak, J. J., Cheng, S. Z., Giusti, P. A., & Hsieh, E. T. (1991). Isotacticity effect on crystallization and melting in polypropylene fractions. II. Linear crystal growth rate and morphology study. Macromolecules, 24(9), 2253-2260. http://dx.doi.org/10.1021/ma00009a020.
12. Janimak, J. J., Cheng, S. Z., Zhang, A., & Hsieh, E. T. (1992). Isotacticity effect on crystallization and melting in polypropylene fractions: 3. Overall crystallization and melting behavior. Polymer, 33(4), 728-735. http://dx.doi.org/10.1016/0032-3861(92)90329-U.
13. De Rosa, C., & Auriemma, F. (2006). Structural−mechanical phase diagram of isotactic polypropylene. Journal of the American Chemical Society, 128(34), 11024-11025. http://dx.doi.org/10.1021/ja063464r. PMid:16925410.
14. Lu, H., Qiao, J., Xu, Y., & Yang, Y. (2002). Effect of isotacticity distribution on the crystallization and melting behavior of polypropylene. Journal of Applied Polymer Science, 85(2), 333-431. http://dx.doi.org/10.1002/app.10637.
15. Bruckner, S., Meille, S. V., Petraccone, V., & Pirozzi, B. (1991). Polymorphism in isotactic polypropylene. Progress in Polymer Science, 16(2-3), 361-404. http://dx.doi.org/10.1016/0079-6700(91)90023-E.
16. Samios, D., Tokumoto, S., & Denardin, E. L. G. (2006). Investigation of the large plastic deformation of iPP induced by plane strain compression: stress–strain behavior and thermo-mechanical properties. International Journal of Plasticity, 22(10), 1924-1942. http://dx.doi.org/10.1016/j.ijplas.2006.02.009.
17. Amer, I., & van Reenen, A. (2009). Fractionation and crystallization of isotactic poly(propylenes) prepared with a heterogeneous transition metal catalysts. Macromolecular Symposia, 282(1), 33-40. http://dx.doi.org/10.1002/masy.200950804.
18. Olley, R. H., Hodge, A. M., & Bassett, D. C. (1979). A permanganic etchant for polyolefines. Journal of Polymer Science. Part B, Polymer Physics, 17(4), 627-643. http://dx.doi.org/10.1002/pol.1979.180170406.
19. Freedman, A. M., Bassett, D. C., Vaughan, A. S., & Olley, R. H. (1986). On quantitative permanganic etching. Polymer, 27(8), 1163-1169. http://dx.doi.org/10.1016/0032-3861(86)90003-0.
20. Olley, R. H., & Bassett, D. C. (1982). An improved permanganic etchant for polyolefines. Polymer, 23(12), 1707-1710. http://dx.doi.org/10.1016/0032-3861(82)90110-0.
21. Aboulfaraj, M., Ulrich, B., Dahoun, A., & G’Sell, C. (1993). Spherulitic morphology of isotactic polypropylene investigated by scanning electron microscopy. Polymer, 34(23), 4817-4825. http://dx.doi.org/10.1016/0032-3861(93)90003-S.
22. Lotz, B., Wittmann, J. C., & Lovinger, A. J. (1996). Structure and morphology of poly(propylenes): a molecular analysis. Polymer, 37(22), 4979-4992. http://dx.doi.org/10.1016/0032-3861(96)00370-9.
23. Morrow, D. R., & Newman, B. A. (1968). Crystallization of low-molecular-weight polypropylene fractions. Journal of Applied Physics, 39(11), 4944-4950. http://dx.doi.org/10.1063/1.1655891.
24. van der Burgt, F. (2002). Crystallization of isotactic polypropylene: the influence of stereo-defects (Masters thesis). Technical University of Eindhoven, Eindhoven.
25. Park, J., Eom, K., Kwon, O., & Woo, S. (2001). Chemical etching technique for the investigation of melt-crystallized isotactic polypropylene spherulite and lamellar morphology by scanning electron microscopy. Microscopy and Microanalysis, 7(3), 276-286. http://dx.doi.org/10.1017/S1431927601010285. PMid:12597818.
26. Wang, J., & Dou, Q. (2008). Crystallization behaviors and optical properties of isotactic polypropylene: comparative study of a trisamide and a rosin-type nucleating agent. Colloid & Polymer Science, 286(6-7), 699-705. http://dx.doi.org/10.1007/s00396-007-1821-7.
27. Olley, R. H., & Bassett, D. C. (1989). On the development of polypropylene spherulites. Polymer, 30(3), 399-409. http://dx.doi.org/10.1016/0032-3861(89)90004-9.
28. Rybnikář, F. (1985). Selective etching of polyolefines. I. Isotactic polypropylene. Journal of Applied Polymer Science, 30(5), 1949-1961. http://dx.doi.org/10.1002/app.1985.070300513.
29. Seidler, S., & Koch. T. (2002). Determination of local mechanical properties of α- and β- PP by means of microhardness measurements. Journal of Macromolecular Science, Part B: Physics, 41(4-6), 851-861. http://dx.doi.org/10.1081/MB-120013069.
30. Arranz-Andrés, J., Peña, B., Benavente, R., Pérez, E., & Cerrada, M. L. (2007). Influence of isotacticity and molecular weight on the properties of metallocenic isotactic polypropylene. European Polymer Journal, 43(6), 2357-2370. http://dx.doi.org/10.1016/j.eurpolymj.2007.03.034.
31. Koch, T., Seidler, S., Halwax, E., & Bernstorff, S. (2007). Microhardness of quenched and annealed isotactic polypropylene. Journal of Materials Science, 42(14), 5318-5326. http://dx.doi.org/10.1007/s10853-006-0960-4.
32. Flores, A., Aurrekoetxea, J., Gensler, R., Kausch, H. H., & Calleja, F. J. B. (1998). Microhardness structure correlation of iPP/EPR blends: influence of molecular weight and EPR particle content. Colloid & Polymer Science, 276(9), 786-793. http://dx.doi.org/10.1007/s003960050311.
33. Harding, G. W., & van Reenen, A. J. (2011). Polymerisation and structure–property relationships of Ziegler–Natta catalysed isotactic polypropylenes. European Polymer Journal, 47(1), 70-77. http://dx.doi.org/10.1016/j.eurpolymj.2010.10.019.
34. Sakurai, T., Nozue, Y., Kasahara, T., Mizunuma, K., Yamaguchi, N., Tashiro, K., & Amemiya, Y. (2005). Structural deformation behavior of isotactic polypropylene with different molecular characteristics during hot drawing process. Polymer, 46(20), 8846-8858. http://dx.doi.org/10.1016/j.polymer.2005.01.106.
35. De Rosa, C., Auriemma, F., Di Capua, A., Resconi, L., Guidotti, S., Camuratie, I., Nifant’ev, I., & Laishevtsev, I. (2004). Structure−property correlations in polypropylene from metallocene catalysts: stereodefective, regioregular isotactic polypropylene. Journal of the American Chemical Society, 126(51), 17040-17049. http://dx.doi.org/10.1021/ja045684f. PMid:15612743.
36. Jourdan, C., Cavaille, J. Y., & Perez, J. (1989). Mechanical relaxations in polypropylene: a new experimental and theoretical approach. Journal of Polymer Science. Part B, Polymer Physics, 27(11), 2361-2384. http://dx.doi.org/10.1002/polb.1989.090271115.
37. Pluta, M., Bartczak, Z., & Galeski, A. (2000). Changes in the morphology and orientation of bulk spherulitic polypropylene due to plane-strain compression. Polymer, 41(6), 2271-2288. http://dx.doi.org/10.1016/S0032-3861(99)00364-X.
2. Lima, M. F. S., Vasconcellos, M. A., & Samios, D. (2002). Crystallinity changes in plastically deformed isotactic polypropylene evaluated by x-ray diffraction and differential scanning calorimetry methods. Journal of Polymer Science. Part B, Polymer Physics, 40(9), 896-903. http://dx.doi.org/10.1002/polb.10159.
3. Asano, T., Calleja, F. J. B., Flores, A., Tanigaki, M., Mina, M. F., Sawatari, C., Itagaki, H., Takahashi, H., & Hatta, I. (1999). Crystallization of oriented amorphous poly(ethylene terephthalate) as revealed by X-ray diffraction and microhardness. Polymer, 40(23), 6475-6484. http://dx.doi.org/10.1016/S0032-3861(98)00839-8.
4. Bedia, E., Murakami, S., Kitade, T., & Kohjiya, S. (2001). Structural development and mechanical properties of polyethylene naphthalate/polyethylene terephthalate blends during uniaxial drawing. Polymer, 42(17), 7299-7305. http://dx.doi.org/10.1016/S0032-3861(01)00236-1.
5. Hoffman, J. D., & Miller, R. L. (1988). Test of the reptation concept: crystal growth rate as a function of molecular weight in polyethylene crystallized from the melt. Macromolecules, 21(10), 3038-3051. http://dx.doi.org/10.1021/ma00188a024.
6. Cheng, S. Z., Janimak, J. J., Zhang, A., & Cheng, H. N. (1990). Regime transitions in fractions of isotactic polypropylene. Macromolecules, 23(1), 298-303. http://dx.doi.org/10.1021/ma00203a051.
7. Carvalho, B., & Bretas, R. E. (1998). Quiescent crystallization kinetics and morphology of isotactic polypropylene resins for injection molding. I. Isothermal crystallization. Journal of Applied Polymer Science, 68(7), 1159-1176. http://dx.doi.org/10.1002/(SICI)1097-4628(19980516)68:7<1159::AID-APP13>3.0.CO;2-T.
8. Stern, C., Frick, A., & Weickert, G. (2007). Relationship between the structure and mechanical properties of polypropylene: Effects of the molecular weight and shear-induced structure. Journal of Applied Polymer Science, 103(1), 519-533. http://dx.doi.org/10.1002/app.24156.
9. Phillips, P. J., & Vatansever, N. (1987). Regime transitions in fractions of cis-polyisoprene. Macromolecules, 20(9), 2138-2146. http://dx.doi.org/10.1021/ma00175a016.
10. Cheng, S. Z., Janimak, J. J., Zhang, A., & Hsieh, E. T. (1991). Isotacticity effect on crystallization and melting in polypropylene fractions: 1. Crystalline structures and thermodynamic property changes. Polymer, 32(4), 648-655. http://dx.doi.org/10.1016/0032-3861(91)90477-Z.
11. Janimak, J. J., Cheng, S. Z., Giusti, P. A., & Hsieh, E. T. (1991). Isotacticity effect on crystallization and melting in polypropylene fractions. II. Linear crystal growth rate and morphology study. Macromolecules, 24(9), 2253-2260. http://dx.doi.org/10.1021/ma00009a020.
12. Janimak, J. J., Cheng, S. Z., Zhang, A., & Hsieh, E. T. (1992). Isotacticity effect on crystallization and melting in polypropylene fractions: 3. Overall crystallization and melting behavior. Polymer, 33(4), 728-735. http://dx.doi.org/10.1016/0032-3861(92)90329-U.
13. De Rosa, C., & Auriemma, F. (2006). Structural−mechanical phase diagram of isotactic polypropylene. Journal of the American Chemical Society, 128(34), 11024-11025. http://dx.doi.org/10.1021/ja063464r. PMid:16925410.
14. Lu, H., Qiao, J., Xu, Y., & Yang, Y. (2002). Effect of isotacticity distribution on the crystallization and melting behavior of polypropylene. Journal of Applied Polymer Science, 85(2), 333-431. http://dx.doi.org/10.1002/app.10637.
15. Bruckner, S., Meille, S. V., Petraccone, V., & Pirozzi, B. (1991). Polymorphism in isotactic polypropylene. Progress in Polymer Science, 16(2-3), 361-404. http://dx.doi.org/10.1016/0079-6700(91)90023-E.
16. Samios, D., Tokumoto, S., & Denardin, E. L. G. (2006). Investigation of the large plastic deformation of iPP induced by plane strain compression: stress–strain behavior and thermo-mechanical properties. International Journal of Plasticity, 22(10), 1924-1942. http://dx.doi.org/10.1016/j.ijplas.2006.02.009.
17. Amer, I., & van Reenen, A. (2009). Fractionation and crystallization of isotactic poly(propylenes) prepared with a heterogeneous transition metal catalysts. Macromolecular Symposia, 282(1), 33-40. http://dx.doi.org/10.1002/masy.200950804.
18. Olley, R. H., Hodge, A. M., & Bassett, D. C. (1979). A permanganic etchant for polyolefines. Journal of Polymer Science. Part B, Polymer Physics, 17(4), 627-643. http://dx.doi.org/10.1002/pol.1979.180170406.
19. Freedman, A. M., Bassett, D. C., Vaughan, A. S., & Olley, R. H. (1986). On quantitative permanganic etching. Polymer, 27(8), 1163-1169. http://dx.doi.org/10.1016/0032-3861(86)90003-0.
20. Olley, R. H., & Bassett, D. C. (1982). An improved permanganic etchant for polyolefines. Polymer, 23(12), 1707-1710. http://dx.doi.org/10.1016/0032-3861(82)90110-0.
21. Aboulfaraj, M., Ulrich, B., Dahoun, A., & G’Sell, C. (1993). Spherulitic morphology of isotactic polypropylene investigated by scanning electron microscopy. Polymer, 34(23), 4817-4825. http://dx.doi.org/10.1016/0032-3861(93)90003-S.
22. Lotz, B., Wittmann, J. C., & Lovinger, A. J. (1996). Structure and morphology of poly(propylenes): a molecular analysis. Polymer, 37(22), 4979-4992. http://dx.doi.org/10.1016/0032-3861(96)00370-9.
23. Morrow, D. R., & Newman, B. A. (1968). Crystallization of low-molecular-weight polypropylene fractions. Journal of Applied Physics, 39(11), 4944-4950. http://dx.doi.org/10.1063/1.1655891.
24. van der Burgt, F. (2002). Crystallization of isotactic polypropylene: the influence of stereo-defects (Masters thesis). Technical University of Eindhoven, Eindhoven.
25. Park, J., Eom, K., Kwon, O., & Woo, S. (2001). Chemical etching technique for the investigation of melt-crystallized isotactic polypropylene spherulite and lamellar morphology by scanning electron microscopy. Microscopy and Microanalysis, 7(3), 276-286. http://dx.doi.org/10.1017/S1431927601010285. PMid:12597818.
26. Wang, J., & Dou, Q. (2008). Crystallization behaviors and optical properties of isotactic polypropylene: comparative study of a trisamide and a rosin-type nucleating agent. Colloid & Polymer Science, 286(6-7), 699-705. http://dx.doi.org/10.1007/s00396-007-1821-7.
27. Olley, R. H., & Bassett, D. C. (1989). On the development of polypropylene spherulites. Polymer, 30(3), 399-409. http://dx.doi.org/10.1016/0032-3861(89)90004-9.
28. Rybnikář, F. (1985). Selective etching of polyolefines. I. Isotactic polypropylene. Journal of Applied Polymer Science, 30(5), 1949-1961. http://dx.doi.org/10.1002/app.1985.070300513.
29. Seidler, S., & Koch. T. (2002). Determination of local mechanical properties of α- and β- PP by means of microhardness measurements. Journal of Macromolecular Science, Part B: Physics, 41(4-6), 851-861. http://dx.doi.org/10.1081/MB-120013069.
30. Arranz-Andrés, J., Peña, B., Benavente, R., Pérez, E., & Cerrada, M. L. (2007). Influence of isotacticity and molecular weight on the properties of metallocenic isotactic polypropylene. European Polymer Journal, 43(6), 2357-2370. http://dx.doi.org/10.1016/j.eurpolymj.2007.03.034.
31. Koch, T., Seidler, S., Halwax, E., & Bernstorff, S. (2007). Microhardness of quenched and annealed isotactic polypropylene. Journal of Materials Science, 42(14), 5318-5326. http://dx.doi.org/10.1007/s10853-006-0960-4.
32. Flores, A., Aurrekoetxea, J., Gensler, R., Kausch, H. H., & Calleja, F. J. B. (1998). Microhardness structure correlation of iPP/EPR blends: influence of molecular weight and EPR particle content. Colloid & Polymer Science, 276(9), 786-793. http://dx.doi.org/10.1007/s003960050311.
33. Harding, G. W., & van Reenen, A. J. (2011). Polymerisation and structure–property relationships of Ziegler–Natta catalysed isotactic polypropylenes. European Polymer Journal, 47(1), 70-77. http://dx.doi.org/10.1016/j.eurpolymj.2010.10.019.
34. Sakurai, T., Nozue, Y., Kasahara, T., Mizunuma, K., Yamaguchi, N., Tashiro, K., & Amemiya, Y. (2005). Structural deformation behavior of isotactic polypropylene with different molecular characteristics during hot drawing process. Polymer, 46(20), 8846-8858. http://dx.doi.org/10.1016/j.polymer.2005.01.106.
35. De Rosa, C., Auriemma, F., Di Capua, A., Resconi, L., Guidotti, S., Camuratie, I., Nifant’ev, I., & Laishevtsev, I. (2004). Structure−property correlations in polypropylene from metallocene catalysts: stereodefective, regioregular isotactic polypropylene. Journal of the American Chemical Society, 126(51), 17040-17049. http://dx.doi.org/10.1021/ja045684f. PMid:15612743.
36. Jourdan, C., Cavaille, J. Y., & Perez, J. (1989). Mechanical relaxations in polypropylene: a new experimental and theoretical approach. Journal of Polymer Science. Part B, Polymer Physics, 27(11), 2361-2384. http://dx.doi.org/10.1002/polb.1989.090271115.
37. Pluta, M., Bartczak, Z., & Galeski, A. (2000). Changes in the morphology and orientation of bulk spherulitic polypropylene due to plane-strain compression. Polymer, 41(6), 2271-2288. http://dx.doi.org/10.1016/S0032-3861(99)00364-X.
Facebook
Google+
Twitter
LinkedIn
Mendeley
StumbleUpon
CiteULike
Reddit
Email