A Study on Rheological Properties for Preparing Flow Mark Free PP Compounds

흐름자국이 없는 PP 복합소재 제조를 위한 유변학적 특성 연구

  • Lee, Yong-Hee (Department of Applied Chemical Engineering, Korea University of Technology and Education) ;
  • Nam, Byeong-Uk (Department of Applied Chemical Engineering, Korea University of Technology and Education) ;
  • Lim, Jae-Gon (Samsung Total Petrochemical Co.) ;
  • Choi, Chi-Hoon (Hyundai-Kia Motor Co.)
  • Published : 2009.06.30

Abstract

Our objective is to increase the flowability of Polypropylene(PP) compounds and achieve flow mark free surface in injection molded specimen. We have investigated flowabilities of PP compounds which were composed of PP, rubber, talc, and trace amount of additives. Flowability measurement was performed with four types PPs of which molecular weight distributions(MWD) and melt indexes(MI) were different. Rheological properties of the PP compounding materials, such as spiral flow(SF) length, MI, and shear viscosity, were evaluated. When PP with the broad MWD was used, there were remarkable cases where the spiral flow length of low MI PP compound was longer than that of higher MI PP compound. The PP compound having low MI but broad MWD PP has more flowability than the compound with only high MI.

사출성형 시 흐름자국이 생기지 않는 흐름성이 향상된 PP(Polypropylene) 복합재료를 제조하기 위한 연구를 진행하였다. PP는 분자량 분포와 용융지수(MI)가 다른 4종류의 PP를 사용하였으며, PP, 탈크, 고무와 약간의 첨가제로 구성된 PP컴파운드의 유변학적 특성은 Spiral Flow(SF), MI, 전단점도를 측정함으로써 평가하였다. 분자량 분포가 넓은 PP를 사용한 경우 MI가 상대적으로 낮다 하더라도 SF는 MI가 높은 PP보다 높게 관찰되는 경우도 있었다. 사출성형시 표면에 흐름자국이 발생하지 않도록 하기 위해서는 분자량 분포가 넓은 PP를 사용하는 것이 바람직 함을 확인하였다.

Keywords

References

  1. Premphet K. and Horanont P., 'Phase structure of ternary polypropylene /elastomer/filler composites: effect of elastomer polarity', Polymer, 41, 9283 (2000) https://doi.org/10.1016/S0032-3861(00)00303-7
  2. Kansai Research Institute Multiclient Report, 'Advanced Materials-Phase Ⅷ', 11, 207 (1997)
  3. J. Karger-Kocsis, A. Kallo, and A. N. Kuleznev, 'Phase structure of impact-modified polypropylene blends', Polymer, 25, 279 (1984) https://doi.org/10.1016/0032-3861(84)90337-9
  4. Van der Wal A, Mulder JJ, and Gaymans RJ, 'Polypropylenerubber blends: 1. The effect of the matrix properties on the impact behaviour', Polymer, 39, 6781 (1998) https://doi.org/10.1016/S0032-3861(98)00170-0
  5. C. H. Hong, Y. B. Lee, J. Y. Jho, B. U. Nam, and T. W. Hwang, 'Polypropylene /Clay Nanocomposites for Automotive Applications', Int. J. Automotive Technol., 6, 665 (2005)
  6. S. G. Lyu, K. S. Bae, and G. S. Sur, 'Properties of Polypropylene/CaCO3 Composites from the Shape of Calcium Carbonate' J. Korean Ind., 8, 771 (1997)
  7. Denac M and Musil V, 'The influence of thermoplastic elastomers on morphological and mechanical properties of PP/talc composites' Acta. Chim. Sloven., 49, 55 (1999)
  8. Taranco J, Martinez JMG, Laguna O, and Collar EP, 'Polypropylene/talc composites: interfacial modifications by surface treatments on the solid particles' J. Poly. Eng., 13, 287 (1994)
  9. Wypych G., 'Handbook of fillers. 2nd ed.' Toronto, Chem Tec Publishing, 395 (1999)
  10. Naiki M, Fukui Y, Matsumura T, Nomura T, and Matsuda M, 'Effect of talc on the crystallization of isotactic polypropylene.' J. Appl. Polym Sci. 79, 1693 (2001) https://doi.org/10.1002/1097-4628(20010228)79:9<1693::AID-APP190>3.0.CO;2-P
  11. M. Denac and V. Musil, 'The Influence of Thermoplastic elastomers on Morphological and Mechanical Properties of PP/Talc Composites', Acta Chim. Slov. 46, 55 (1999)
  12. F. Martinatti and T. Ricco, 'High-rate J-testing of thoughened Polypropylene', J. Mat. Sci., 29, 442 (1994) https://doi.org/10.1007/BF01162504
  13. Pukanszky B and Maurer FHJ, 'Composition dependence of the fracture toughness of heterogeneus polymer systems', Polymer, 36, 1617 (1995) https://doi.org/10.1016/0032-3861(95)99007-H
  14. S. Maeda, K. Fukunaga, and E. Kamei, 'Flow Mark in the Injection Molding of Polypropylene/Rubber/Talc Blends', Nibon Reoroji Gakkaishi, 35, 293 (2007) https://doi.org/10.1678/rheology.35.293
  15. S. Maeda and E. Kamei, 'Relationship between Surface Appreance and Rheological Properties of Injection Molding of Polypropylene/Rubber/Talc Blends', Nibon Reoroji Gakkaishi, 35, 273 (2007) https://doi.org/10.1678/rheology.35.273
  16. J. O. Park, 'Rotational Rheometry for Polymeric Materials (Ⅰ):Basic Concepts in Rheology', Polym. Sci. Technol., 5, 275 (1994) https://doi.org/10.1002/pat.1994.220050506
  17. K. J. Kim and J. K. Jang, 'The Characteristics of Polypropylene Resins', Polym. Sci. Technol., 4, 89 (1993)
  18. H. K. Kim and H. J. Kang, 'The Characteristics of Poly(ethylene naphthalate) /Poly(butylene terephthalate) Blends', Polymer, 30, 23 (2006)
  19. K. S. Park and S. Y. Kim, 'Effect of Molecular Weight and Rheological Properties on the Cross-sectional Charateristics of Polypropylene Hollow Fiber', J. Korean Fiber Society, 37, 311 (2000)
  20. K. Hirano, Y. Suetsugu, and T. Kanai, 'Morphological Analysis of the Tiger Stripe on Injection Molding of Polypropylene/Ethylene-Propylene Rubber/Talc Blends Dependent on Based Polypropylene Design', J. Appl. Polym. Sci., 104, 192 (2007) https://doi.org/10.1002/app.25393
  21. K. Hirano, S. Tamura, Y. Obata, and T. Kanai, 'Striped-Pattern Deterioration and Morphological Analysis of Injection Molding Comprising Polypropylene/Ethylene–$\alpha$-Olefin Rubber Blends II. Influence of Heating', J. Appl. Polym. Sci., 108, 76 (2008) https://doi.org/10.1002/app.27403