Effect of main-chain rigidity on the phase transitional behavior of comblike polymers

Haifeng Shi, Ying Zhao, Shichun Jiang, Joerg Rottstegge, John Haozhong Xin, Dujin Wang, Duanfu Xu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

31 Citations (Scopus)

Abstract

The influence of the rigidity of polymer backbones on the side-chain crystallization and phase transition behavior was systematically investigated by a combination of differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), Fourier transform infrared spectroscopy (FTIR), and high-resolution solid-state nuclear magnetic resonance spectroscopy (NMR). DSC investigation indicated that the crystallization number of alkyl carbon atoms of the side chains grafted onto the rigid polymer backbone, poly(p-benzamide) (PBA), is much lower than that of the alkyl carbon atoms of the side chains grafted onto the flexible polymer backbone, poly(ethyleneimine) (PEI), implying that the conformational state of the polymer backbones has a strong effect on the side-chain crystallization behavior in comblike polymers. WAXD and FTIR results proved that these two comblike polymers pack into hexagonal (PBA18C) and orthorhombic (PEI18C) crystals, respectively, depending on the adjusting ability of the polymer backbones for particular conformational states. It was also found that the presence of the crystalline-amorphous interphase (δ = 31.6 ppm) in PBA18C detected by solid-state13C NMR spectroscopy can be attributed to the rigid PBA backbone, which restricts the mobility of the alkyl side chains. The conformation effect of the polymer backbones and the packing mode variation of alkyl side chains are explicitly discussed in terms of molecular chain mobility and theory of macromolecular chain conformation.
Original languageEnglish
Pages (from-to)3198-3203
Number of pages6
JournalMacromolecules
Volume40
Issue number9
DOIs
Publication statusPublished - 1 May 2007

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

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