Structural Change in the Topochemical Solid-State Polymerization Process of Diethyl cis,cis-Muconate Crystal. 1. Investigation of Polymerization Process by Means of X-ray Diffraction, Infrared/Raman Spectra, and DSC

• Published in: Macromolecules Vol. 32; no. 8; pp. 2449 - 2454
• Main Authors: Tashiro, Kohji, Kamae, Toshiya, Kobayashi, Masamichi, Matsumoto, Akikazu, Yokoi, Katsutaka, Aoki, Shuzo
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 20.04.1999
• Subjects: Applied sciences; Exact sciences and technology; Physicochemistry of polymers; Polymerization; Polymers and radiations; Diene polymer; Topochemical polymerization; Photopolymerization; Time curve; Structure modification; Unsaturated polymer; Solid polymerization; Experimental study; Functional polymer; Crystalline structure
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma981327b

Structural change occurring in the light-induced solid-state polymerization of diethyl cis,cis-muconate crystal has been investigated by means of the X-ray diffraction, infrared and Raman spectra, and DSC. The infrared and Raman spectral changes during this polymerization reaction could be interpreted on the basis of a simple two-component system consisting of monomer and polymer molecules. This apparent observation may originate from the high sensitivity of the vibrational spectra to the local structure. The time-resolved X-ray diffraction measurement, however, showed that the lattice spacings changed continuously in the process of polymerization, indicating that the strain to the crystal lattice, due to the coexistence of the different chemical species of monomer and polymer with various lengths or volumes, changed in this reaction. But this strain was quite small, and the crystal lattice could be maintained more or less during the polymerization reaction. It was also found that the polymerization did not occur at a low temperature below −40 °C, where the phase transition occurred and the packing structure of monomer molecules changed, as indicated by the large change in the X-ray diffraction pattern. This good correlation between the reactivity and the crystal structure indicates that the polymerization reaction is governed sensitively by the packing structure of monomer molecules; i.e., this reaction is just the lattice-controlled polymerization.