Calcium dicarboxylates nucleation of ?-polypropylene
Autor: | Mingrong Ji, Yun-lan Huang, Xiao-jun Li, Gui-en Zhou, Keliang Hu |
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Rok vydání: | 2002 |
Předmět: |
Polypropylene
Morphology (linguistics) Polymers and Plastics Stereochemistry Nucleation chemistry.chemical_element General Chemistry Calcium Surfaces Coatings and Films law.invention chemistry.chemical_compound Crystallinity chemistry Chemical engineering law Adipate Materials Chemistry Particle size Crystallization |
Zdroj: | Journal of Applied Polymer Science. 86:633-638 |
ISSN: | 1097-4628 0021-8995 |
Popis: | Seven dicarboxylates of calcium were synthesized. The effect of dicarboxylate on the formation of β-form polypropylene was investigated by X-ray diffraction. Calcium pimelate, calcium suberate, calcium phthalate, and calcium terephthalate have been found to be an effective β-nucleator. The Kx values of the isotatic propylene samples with 0.5 wt % of the nucleators above are 0.95, 0.96, 0.93, and 0.62, respectively. Calcium succinate, calcium adipate, and calcium sebacate behave invalidly on the nucleating of the β-phase. We conducted an investigation on the affect of particle shape, crystal form, and crystallinity upon the level of the β-form. The X-ray diffraction of the effective nucleators reveals a common character that their first reflection locate at the d-spacing between 10 to 13 A, indicating structural similarity of the nucleators with β-polypropylene. The nucleation mechanism is explained by the cooperative effect of the nonpolar and polar part of nucleating agents in the crystallization of polypropylene. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 633–638, 2002 |
Databáze: | OpenAIRE |
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