Synchrotron X-ray scattering studies on the structural evolution of microbial poly(3-hydroxybutyrate)

• Published in: Journal of applied crystallography Vol. 40; no. s1; pp. s594 - s598
• Main Authors: Heo, Kyuyoung, Yoon, Jinhwan, Jin, Kyeong Sik, Jin, Sangwoo, Kim, Gahee, Sato, Harumi, Ozaki, Yukihiro, Satkowski, Michael M., Noda, Isao, Ree, Moonhor
• Format: Journal Article
• Language: English
• Published: 5 Abbey Square, Chester, Cheshire CH1 2HU, England Blackwell Publishing Ltd 01.04.2007
• Subjects: amorphous layer; Crystal structure; Crystallization; isothermal crystallization; lamellar crystal; long period; microbial polyester; Microbiology; Polyesters; primary crystal; Scattering; secondary crystal; X-ray scattering; X-rays
• ISSN: 1600-5767; 0021-8898; 1600-5767
• DOI: 10.1107/S0021889807000878

The crystallization behavior of microbially synthesized poly(3‐hydroxybutyrate) was studied in detail using time‐resolved small‐angle X‐ray scattering. This polyester was found to undergo primary crystallization as well as secondary crystallization. In the primary crystallization, the thicknesses of the lamellar crystals were sensitive to the crystallization temperature, but no thickening was observed throughout the entire crystallization at a given temperature. The thickness of the lamellar crystals in the polyester was always larger than that of the amorphous layers. Secondary crystallization favorably occurred during the later stage of isothermal crystallization in competition with the continuous primary crystallization, forming secondary crystals in amorphous regions, in particular in the amorphous layers between the primarily formed lamellar crystal stacks. Compared to the primarily formed lamellar crystals, the secondary crystals had short‐range‐ordered structures of smaller size, a broader size distribution, and a lower electron density.