|
篇目详细内容 |
【篇名】 |
Synthesis and characterization of calixarene-based poly(蔚-caprolactone) stars catalyzed by yttrium complex |
【刊名】 |
Frontiers of Chemistry in China |
【刊名缩写】 |
Front. Chem. China |
【ISSN】 |
1673-3495 |
【EISSN】 |
1673-3614 |
【DOI】 |
10.1007/s11458-008-0070-8 |
【出版社】 |
Higher Education Press and Springer-Verlag |
【出版年】 |
2008 |
【卷期】 |
3
卷3期 |
【页码】 |
330-337
页,共
8
页 |
【作者】 |
GOU Pengfei;
ZHU Weipu;
SHEN Zhiquan;
|
【关键词】 |
star polymers; calixarene; poly(蔚-caprolactone); rare earth catalyst; ring-opening polymerization |
【摘要】 |
Two calixarene derivatives (2a, 2b) have been synthesized and used as macro-initiators to prepare star-shaped poly(蔚-caprolactone)s (SPCLs) via controlled ring-opening polymerization of 蔚-caprolactone in the presence of yttrium tris(2,6-di-tert-butyl-4-methylphenolate) [Y(DBMP)3]. The molecular weight of SPCLs was characterized by end group 1H-NMR analyses and size-exclusion chromatography (SEC). The results indicate that SPCLs based on a calix[4]arene derivative (2a) are well-defined four-arm star polymers with reasonably narrow molecular weight distributions in the given molecular weight range, while SPCLs based on a calix[6]arene derivative (2b) are star polymers with not so defined structures. Differential scanning calorimetry (DSC) analyses suggest that the maximal melting point, the crystallization temperature and the degree of crystallinity of SPCLs increases with the increasing molecular weight and are lower than those of the liner poly(蔚-caprolactone) (LPCL) counterpart. Furthermore, polarized optical microscopy (POM) indicates that SPCL exhibits irregular spherulites with poor morphology and slower crystallization rate, whereas LPCL shows fast crystallization rate and good spherulitic morphology. |
|