β-Crystal in the iPP melt encapsulated by transcrystallinity and spherulites: effect of molecular weight

详细信息    查看全文

• 作者：Yanyan Liang (1)
  Guoqiang Zheng (1)
  Shuangyang Liu (1)
  Kun Dai (1)
  Chuntai Liu (1)
  Jingbo Chen (1)
  Changyu Shen (1)
  
• 刊名：Journal of Materials Science
• 出版年：2013
• 出版时间：March 2013
• 年：2013
• 卷：48
• 期：6
• 页码：2326-2333
• 全文大小：1123KB
• 参考文献：1. Galeski A, Koenczoel L, Piorkowska E, Baer E (1987) Nature 325:40 CrossRef
  2. Piorkowska E, Galeski A (1993) J Polym Sci B Polym Phys 31:1285 CrossRef
  3. Thomann R, Wang C, Kressler J, Mülhaupt R (1996) Macromol Chem Phys 197:1085 CrossRef
  4. Nowacki R, Kolasinska J, Piorkowska E (2001) J Appl Polym Sci 79:2439 CrossRef
  5. Galeski A, Piorkowska E (1983) J Polym Sci Polym Phys Ed 21:1299 CrossRef
  6. Galeski A, Piorkowska E (1983) J Polym Sci Polym Phys Ed 21:1313 CrossRef
  7. Pawlak A, Piorkowska E (1999) J Appl Polym Sci 74:1380 CrossRef
  8. Pawlak A, Galeski A (1990) J Polym Sci B Polym Phys 28:1813 CrossRef
  9. Monasse B, Haudin JM (1985) Colloid Polym Sci 263:822 CrossRef
  10. Varga J, Ehrenstein GW (1996) Polymer 37:5959 CrossRef
  11. Vancso GJ, Liu G, Karger-Kocsis J, Varga J (1997) Colloid Polym Sci 275:181 CrossRef
  12. Varga J, Karger-Kocsis J (1996) J Polym Sci B Polym Phys 34:657 CrossRef
  13. Nowacki R, Monasse B, Piorkowska E, Galeski A, Haudin JM (2004) Polymer 45:4877 CrossRef
  14. Varga J, Menyhárd A (2007) Macromolecules 40:2422 CrossRef
  15. Nowacki R, Piorkowska E (2007) J Appl Polym Sci 105:1053 CrossRef
  16. Liang YY, Liu SY, Dai K, Wang B, Shao CG, Zhang QX et al (2012) Colloid Polym Sci 290:1157
  17. Sun XL, Li HH, Zhang XQ, Wang DJ, Schultz JM, Yan S (2010) Macromolecules 43:561 CrossRef
  18. Varga J (1992) J Mater Sci 27:2557. doi:10.1007/BF0054067 CrossRef
  19. Li QT, Zheng GQ, Dai K, Xie MC, Liu CT, Liu BC et al (2011) Mater Lett 65:2274 CrossRef
  20. Tadakazu M, Toru M (1998) Polymer 39:5515 CrossRef
  21. Lovinger AJ, Chua JO, Gryte CC (1977) J Poym Sci Polym Phys Ed 15:641 CrossRef
  22. Wang C, Liu FH, Huang WH (2011) Polymer 52:1326 CrossRef
  23. Kajioka H, Yoshimoto S, Taguchi K, Toda A (2010) Macromolecules 43:3837 CrossRef
  
• 作者单位：Yanyan Liang (1)
  Guoqiang Zheng (1)
  Shuangyang Liu (1)
  Kun Dai (1)
  Chuntai Liu (1)
  Jingbo Chen (1)
  Changyu Shen (1)
  
  1. College of Materials Science and Engineering, The Key Laboratory of Advanced Materials Processing and Mold of Ministry of Education, Zhengzhou University, Zhengzhou, People’s Republic of China
  
• ISSN：1573-4803

文摘

The crystallization in isotactic polypropylene (iPP) melt inclusions, encapsulated by transcrystallinity and spherulites, was investigated by polarized light microscope. Generally, owing to the proceeding of crystallization in melt inclusions, a negative pressure will be built up. Up to a critical value, the negative pressure is released by the formation of cavitation in melt. Unexpectedly, β-crystals with different morphologies emerge at different locations in the melt inclusions. For low molecular weight iPP, only smaller β-crystals around bubbles are discernable. Turn to higher molecular weight iPP, apart from the smaller β-crystals, fan-shaped ones can be developed under suitable conditions (e.g., lower than 131?°C) at the growth front of spherulites and transcrystallinity. Considering the characteristics of molecular weight and morphology, it is proposed that β-crystals are induced by different mechanisms. That is, smaller β-crystals are resulted from the stress caused by the appearance of bubbles while the fan-shaped ones are derived due to the temperature gradient during the release of negative pressure.