**6. Practice of adjusting the stiffness and toughness of iPP based on α/β compound NAs**

Here an example of adjusting the stiffness and toughness of isotactic polypropylene based on different of α/β compound NAs was employed. Shi et al. studied the different ratios α/β compounded NAs on mechanical properties of iPP (Shi & Xin, 2011). It was found that stiffness and toughness of iPP could be adjusted and enhanced simultaneously by changing the ratio of α and β nucleating agents, as shown in Fig.8. Comparing to the others, the absolute value of difference of crystallization peak temperature between two kinds of NAs at optimal compounded ratio was the smallest. It verifies that the key factor summarized before can also be applied to different ratios α/β compounded NAs. Then relying on the established method, the optimal compounded ratios of NA40/H-Ba and NA40/PA-03 (PA-03, Carboxylate β NA for iPP) were obtained, at which there appeared TC <sup>α</sup> = TC β as shown in Fig.9. Refer to Fig.10, the calculated results were proved to be valid by the investigation of the effect of NA40/H-Ba and NA40/PA-03 with different ratio on mechanical properties of iPP, which means the method is applicable for compounding any NAs. Furthermore compounded NAs could enhance stiffness and toughness of iPP simultaneously with these ratios, as can be seen from Tab.5.

Fig. 8. Effect of NA40/NABW compounded NAs with different ratio on mechanical properties of iPP (addition amount 0.2wt %) (Shi & Xin, 2011)

to this: First, we shall obtain Tc of iPP nucleated with different addition amounts of α and β NAs individually by DSC. Then list TC <sup>α</sup> and TC β at each ratio of compounded α/β with a fixed concentration. The ratio which contains TC <sup>α</sup> = TC <sup>β</sup> will be the optimal compounded ratio of these two α and β NAs at this concentration. In this context, competitive nucleation

**6. Practice of adjusting the stiffness and toughness of iPP based on α/β**

Fig. 8. Effect of NA40/NABW compounded NAs with different ratio on mechanical

properties of iPP (addition amount 0.2wt %) (Shi & Xin, 2011)

Here an example of adjusting the stiffness and toughness of isotactic polypropylene based on different of α/β compound NAs was employed. Shi et al. studied the different ratios α/β compounded NAs on mechanical properties of iPP (Shi & Xin, 2011). It was found that stiffness and toughness of iPP could be adjusted and enhanced simultaneously by changing the ratio of α and β nucleating agents, as shown in Fig.8. Comparing to the others, the absolute value of difference of crystallization peak temperature between two kinds of NAs at optimal compounded ratio was the smallest. It verifies that the key factor summarized before can also be applied to different ratios α/β compounded NAs. Then relying on the established method, the optimal compounded ratios of NA40/H-Ba and NA40/PA-03 (PA-03, Carboxylate β NA for iPP) were obtained, at which there appeared TC <sup>α</sup> = TC β as shown in Fig.9. Refer to Fig.10, the calculated results were proved to be valid by the investigation of the effect of NA40/H-Ba and NA40/PA-03 with different ratio on mechanical properties of iPP, which means the method is applicable for compounding any NAs. Furthermore compounded NAs could enhance stiffness and toughness of iPP simultaneously with these

will occur during crystallization.

ratios, as can be seen from Tab.5.

**compound NAs** 

Fig. 9. TC <sup>α</sup> and TC <sup>β</sup> at different ratio of NA40/H-Ba and NA40/PA-03 compounded NAs (addition amount 0.2 wt %)

Fig. 10. Effect of NA40/H-BA and NA40/PA-03 compounded NAs with different ratio on mechanical properties of iPP (addition amount 0.2wt %) (Shi & Xin, 2011)

Controlled Crystallization of Isotactic Polypropylene

central universities of China for financial support.

**8. Acknowledgment** 

ISSN 00218995

ISSN 00218995

1407-1425, ISSN 08876266

1273, ISSN 00218995

4992, ISSN 00323861

(January 1999), pp. 195-200, ISSN 00218995

ISSN 00249297

**9. References**

Based on α/βCompounded Nucleating Agents: From Theory to Practice 139

The authors thank the National Natural Science Funds of China (20876042), the Program of Shanghai Subject Chief Scientist (XD1401500) and the Fundamental Research Funds for the

Awaya, H. (1988). Morphology of different types of isotactic polypropylene spherulites

Bai, H. W.; Wang, Y. & Liu, L . et al. (2008). Nonisothermal Crystallization Behaviors of

Bai, H. W. & Wang, Y. (2009). A comparative study of polypropylene nucleated by

Busse, K. ; Kressler, J. & Maier, R, D., et al. (2000). Tailoring of the α-, β-, and γ-modification

Fillon, B. ; Thierry, A. & Wittmann, J, C., et al. (1993). Self-nucleation and recrystallization of

Gui, Q. D. ; Xin, Z. & Zhu, W. P., et al. (2003). Effects of an organic phosphorus nucleating

Ismail, A. & Al-Raheil. (1998). Isotactic polypropylene crystallization from the melt.1.

Kristiansen, M. ; Werner, M. & Tervoort, T., et al. (2003). The binary system isotactic

Labour, T. ; Ferry, L. & Gauthier, C., et al. (1999). α- and β-crystalline forms of isotactic

Lotz, B. ; Wittmann, J, C. & Lovinger, A, J. (1996). Structure and morphology of poly

*Appl. Polym. Sci.*, Vol.88, No.2, (April 2003), pp. 297-301, ISSN 00218995 Huang, Y. P. ; Chen, G. M. & Yao, Z., et al. (2005). Non-isothermal crystallization behavior of

Vol.41, No.11, (November 2005), pp. 2753-2760, ISSN 00143057

Vol.17, No.46, (September 2008), pp. 1853-1867, ISSN 08876266

crystallized from melt. *Polymer,* Vol.29, No.3, (April 1988), pp. 591-596, ISSN 00323861

Polypropylene with α/β Nucleating Agents. *J. Polym. Sci. Part B: Polym. Phys.*,

individual and compounding nucleating agents. I. Melting and Isothermal Crystallization. *J. Appl. Polym. Sci*., Vol.111, No.3, (February 2009), pp. 1624-1637,

in isotactic polypropylene and propene/ethene random copolymers. *Macromolecules*, Vol.33, No.23, (November 2000), pp. 8775-8780, ISSN 00249297 Cai, Z. ; Zhao, S, C. & Shen, B, X., et al. (2010). The Effect of Bicyclo[2.2.1]hept-5-ene-2,3-

dicarboxylate on the Mechanical Properties and Crystallization Behaviors of Isotactic Polypropylene. *J. Appl. Polym. Sci*., Vol.116, No.2, (April 2010), pp. 792-800,

polymers. Isotactic polypropylene, β phase: β-α conversion and β-α growth transitions. *J. Polym. Sci., Part B: Polym. Phys.*, Vol.31, No.10, (September 1993), pp.

agent on crystallization behaviors and mechanical properties of polypropylene. *J.* 

polypropylene with nucleating agents and nano-calcium carbonate. *Eur. Polym. J*.,

Morphological study. *J. Appl. Polym. Sci.*, Vol.67, No.7, (February 1998), pp. 1259-

polypropylene/bis (3, 4-dimethylbenzylidene) sorbitol: phase behavior, nucleation, and optical properties. *Macromolecules*, Vol.36, No.14, (July 2003), pp. 5150-5156,

polypropylene investigated by nanoindentation. *J. Appl. Polym. Sci.*, Vol.74, No.1,

(propylenes): a molecular analysis. *Polymer,* Vol.37, No.22, (October 1996), pp. 4979-


Table 5. Mechanical Properties of iPP Nucleated with different NAs (addition amount 0.2 wt %) (Shi & Xin, 2011)
