Journal of Zhejiang University SCIENCE A
ISSN 1673-565X(Print), 1862-1775(Online), Monthly

2008   Vol. 9   No. 11   p. 1614~1620

“Cutting effect” of organoclay platelets in compatibilizing immiscible polypropylene/polystyrene blends

Yan ZHU¹, Hai-yun MA¹, Li-fang TONG¹, Zheng-ping FANG^†‡1,2

(¹MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Institute of Polymer Composites, Zhejiang University, Hangzhou 310027, China)
(²Department of Biochemical and Chemical Engineering, Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China)
^‡ Corresponding Author
^†E-mail: zpfang@zju.edu.cn
Received Feb. 2, 2008; revision accepted June 5, 2008

Abstract: In this work, polypropylene (PP)/polystyrene (PS) blends with different organoclay concentrations were prepared via melt compounding. Differing from the results of previous reports, the organoclay platelets are mostly located in the dispersed PS phase instead of the interface. The dimensions of the dispersed PS droplets are greatly reduced and apparent compatibilization effect still exists, which cannot be explained by the traditional compatibilization mechanism. A novel compatibilization mechanism, “cutting” to apparently compatibilize the immiscible PP/PS blends was proposed. The organoclay platelets tend to form a special “knife-like structure” in the PS domain under the shear stress of the continuous PP phase during compounding. The “clay knife” can split the dispersed PS domain apart and lead to the dramatic reduction of the dispersed domain size.

Key words: Compatibilization, Organoclay, Polymer blends, Polypropylene (PP), Polystyrene (PS)
doi:10.1631/jzus.A0820104             CLC number: X5

References:

[1] Chow, W.S., Ishak, Z.A.M., Karger-Kocsis, J., 2005. Atomic force microscopy study on blend morphology and clay dispersion in polyamide-6/polypropylene/organoclay systems. Journal of Polymer Science Part B: Polymer Physics, 43(10):1198-1204.

[2] Dharaiya, D.P., Jana, S.C., 2005. Nanoclay-induced morphology development in chaotic mixing of immiscible polymers. Journal of Polymer Science Part B: Polymer Physics, 43(24):3638-3651.

[3] Dijkstra, M., Hansen, J.P., Madden, P.A., 1995. Gelation of a clay colloid suspension. Physical Review Letters, 75(11): 2236-2239.

[4] Fang, Z.P., Xu, Y.Z., Tong, L.F., 2007. Effect of clay on the morphology of binary blends of polyamide 6 with high density polyethylene and HDPE-graft-acrylic acid. Polymer Engineering and Science, 47(5):551-559.

[5] Galgali, G., Ramesh, C., Lele, A., 2001. A rheological study on the kinetics of hybrid formation in polypropylene nanocomposites. Macromolecules, 34(4):852-858.

[6] Gonzalez, I., Eguiazabal, J.I., Nazabal, J., 2006. Nanocomposites based on a polyamide 6/maleated styrene-butylene-co-ethylene-styrene blend: Effects of clay loading on morphology and mechanical properties. European Polymer Journal, 42(11):2905-2913.

[7] Haraguchi, K., Li, H.J., Mastuda, K., Takehisa, T., Elliott. E., 2005. Mechanism of forming organoic/inorganic networking structures during in-situ free-radical polymerization in PNIPA-clay nanocomposite hydrogels. Macromolecules, 38(8):3482-3490.

[8] Hong, J.S., Namkung, H., Ahn, K.H., Lee, S.J., Kim, C., 2006. The role of organically modified layered silicate in the breakup and coalescence of droplets in PBT/PE blends. Polymer, 47(11):3967-3975.

[9] Khatua, B.B., Lee, D.J., Kim, H.Y., Kim, J.K., 2004. Effect of organoclay platelets on morphology of nylon-6 and poly(ethylene-ran-propylene) rubber blends. Macromolecules, 37(7):2454-2459.

[10] Kontopoulou, M., Liu, Y., Austin, J.R., Parent, J.S., 2007. The dynamics of montmorillonite clay dispersion and morphology development in immiscible ethylene-propylene rubber/polypropylene blends. Polymer, 48(15):4520-4528.

[11] Lee, M.H., Dan, C.H., Kim, J.H., Cha, J., Kim, S., Hwang, Y., Lee, C.H., 2006. Effect of clay on the morphology and properties of PMMA/poly(styrene-co-acrylonitrile)/clay nanocomposites prepared by melt mixing. Polymer, 47(12):4359-4369.

[12] Li, Y.J., Shimizu, H., 2004. Novel morphologies of poly(phenylene oxide) (PPO)/polyamide 6 (PA6) blend nanocomposites. Polymer, 45(22):7381-7388.

[13] Li, Y.J., Shimizu, H., 2005. Co-continuous polyamide 6 (PA6)/ acrylonitrile-butadiene-styrene (ABS) nanocomposites. Macromolecular Rapid Communications, 26(9):710-715.

[14] Lipatov, Y.S., Nesterov, A.E., Ignatova, T.D., Nesterov, D.A., 2002. Effect of polymer-filler surface interactions on the phase separation in polymer blends. Polymer, 43(3):875- 880.

[15] Nesterov, A.E., Lipatov, Y.S., 1999. Compatibilizing effect of a filler in binary polymer mixtures. Polymer, 40(5): 1347-1349.

[16] Nesterov, A.E., Lipatov, Y.S., Ignatova, T.D., 2001. Effect of an interface with solid on the component distribution in separated phases of binary polymer mixtures. European Polymer Journal, 37(2):281-285.

[17] Ren, J.X., Casanueva, B.F., Mitchell, C.A., Krishnamoorti, R., 2003. Disorientation kinetics of aligned polymer layered silicate nanocomposites. Macromolecules, 36(11):4188- 4194.

[18] Si, M., Araki, T., Ade, H., Kilcoyne, A.L.D., Fisher, R., Sokolov, J.C., Rafailovich, M.H., 2006. Compatibilizing bulk polymer blends by using organoclays. Macromolecules, 39(14):4793-4801.

[19] Sinha Ray, S., Bousmina, M., 2005a. Compatibilization efficiency of organoclay in an immiscible polycarbonate/ poly(methyl methacrylate) blend. Macromolecular Rapid Communications, 26(6):450-455.

[20] Sinha Ray, S., Bousmina, M., 2005b. Effect of organic modification on the compatibilization efficiency of clay in an immiscible polymer blend. Macromolecular Rapid Communications, 26(20):1639-1646.

[21] Sinha Ray, S., Pouliot, S., Bousmina, M., Utracki, L.A., 2004. Role of organically modified layered silicate as an active interfacial modifier in immiscible polystyrene/polypropylene blends. Polymer, 45(25):8403-8413.

[22] Sinha Ray, S., Bandyopadhyay, J., Bousmina, M., 2007. Effect of organoclay on the morphology and properties of poly(propylene)/poly[(butylenes succinate)-co-adipate] blends. Macromolecular Materials and Engineering, 209: 729-747.

[23] Su, Q.S., Feng, M., Zhang, S.M., Jiang, J.M., Yang, M.S., 2007. Melt blending of polypropylene-blend-polyamide 6-blend-organoclay systems. Polymer International, 56(1): 50-56.

[24] Wang, Y., Zhang, Q., Fu, Q., 2003. Compatibilization of immiscible poly(propylene)/polystyrene blends using clay. Macromolecular Rapid Communications, 24(3):231-235.

[25] Yoo, Y., Park, C., Lee, S.G., Choi, K.Y., Kim, D.S., Lee, J.H., 2005. Influence of addition of organoclays on morphologies in nylon 6/LLDPE blends. Macromolecular Chemistry and Physics, 206(8):878-884.

[26] Zou, H., Zhang, Q., Tan, H., Wang, K., Du, R.N., Fu, Q., 2006. Clay locked phase morphology in the PPS/PA66/clay blends during compounding in an internal mixer. Polymer, 47(1):6-11.