✦ LIBER ✦

Conformational analysis of the polymorphic forms of syndiotactic polypropylene in the crystalline field

✍ Scribed by Beniamino Pirozzi; Roberto Napolitano

Publisher: Elsevier Science
Year: 1992
Tongue: English
Weight: 361 KB
Volume: 28
Category: Article
ISSN: 0014-3057
DOI: 10.1016/0014-3057(92)90047-6

No coin nor oath required. For personal study only.

✦ Synopsis

Abstraet~Conformational energy calculations have been performed on two crystalline polymorphic forms of syndiotactic polypropylene. A chain conformation having the helicoidal s(2/1)2 symmetry has been obtained for the form of the polymer having chain axis c = 7.40 A.. A chain conformation having the tcm symmetry has been obtained for the form having chain axis c = 5.06 A. Results obtained by calculations of the packing energy and of the structure factors for the latter form are compared with the experimental crystal structure recently proposed.

📜 SIMILAR VOLUMES

Valence force calculation of the vibrati

Valence force calculation of the vibrational frequencies of two forms of crystalline syndiotactic polypropylene

✍ J.H. Schachtschneider; R.G. Snyder 📂 Article 📅 1965 🏛 Elsevier Science ⚖ 759 KB

On the form IV of syndiotactic polypropy

On the form IV of syndiotactic polypropylene

✍ Finizia Auriemma; Claudio De Rosa; Odda Ruiz De Ballesteros; Valeria Vinti; Paol 📂 Article 📅 1998 🏛 John Wiley and Sons 🌐 English ⚖ 195 KB 👁 2 views

The packing of the chains in (T 6 G 2 T 2 G 2 ) n conformation of the form IV of s-PP is revisited on the basis of packing energy and structure factor calculations. According to this analysis, an alternative mode of packing has been suggested. A monoclinic structural model, with the unit cell center

Chain Conformations in the Crystalline F

Chain Conformations in the Crystalline Field of Syndiotactic Vinyl Polymers Deriving from 1,3-Diene Monomers. Analysis by Molecular Mechanics

✍ Beniamino Pirozzi; Roberto Napolitano; Simona Esposito 📂 Article 📅 2004 🏛 John Wiley and Sons 🌐 English ⚖ 147 KB

## Abstract **Summary:** Conformational energy calculations on the chain conformation in the crystalline field have been performed for various syndiotactic vinyl polymers deriving from 1,3‐diene monomers. Energy maps as a function of the independent torsion angles have evidenced for all the polymer

The β-crystalline form of wollastonite-f

The β-crystalline form of wollastonite-filled polypropylene

✍ Liu Jingjiang; Wei Xiufen; Guo Qipeng 📂 Article 📅 1990 🏛 John Wiley and Sons 🌐 English ⚖ 352 KB 👁 1 views

Conformational and packing energy of the

Conformational and packing energy of the crystalline α modification of syndiotactic polystyrene

✍ Paolo Corradini; Claudio De Rosa; Gaetano Guerra; Roberto Napolitano; Vittorio P 📂 Article 📅 1994 🏛 Elsevier Science 🌐 English ⚖ 296 KB

Conformational and packing energy calculations have been performed on the ~t modification of syndiotactic polystyrene. The conformational energy has been optimized as a function of the internal parameters of the chain. The packing energy has been calculated considering at first the best packing of c

In situ FTIR spectroscopic study of the

In situ FTIR spectroscopic study of the conformational change of syndiotactic polypropylene during the isothermal crystallization

✍ Kai Zheng; Ruigang Liu; Haibo Chang; Deyan Shen; Yong Huang 📂 Article 📅 2009 🏛 Elsevier Science 🌐 English ⚖ 349 KB

The isothermal crystallization of syndiotactic polypropylene (sPP) was investigated by in situ Fourier transform infrared spectroscopy (FTIR) and wide angle X-ray diffraction (WAXD). It was found that the ordered helical structure developed during the induction period of the isothermally crystalliza