Thermal and Structural Properties of Biologically Derived Monodisperse Hairy-Rod Polymers
- Creators
- Yu, Seung M.
- Tirrell, David A.
Abstract
Monodisperse derivatives of poly(γ-4-(hexadecyloxy)benzyl α,l-glutamate) (PHBG-X, X = 3 or 4) with backbone sequence GluAsp(Glu_(17)Asp)_xGluGlu were prepared by reaction of 4-(hexadecyloxy)phenyldiazomethane with the corresponding monodisperse poly(α,l-glutamate) (PLGA) derivatives (PLGA-X, X = 3 or 4). PHBG-3 and -4 exhibited strong endotherms near 45 °C and weak endotherms near 86 °C when analyzed by differential scanning calorimetry. X-ray diffraction suggested that these polymers aggregate to form layerlike solid structures at room temperature, with extended alkyl side chains forming paraffinlike crystallites. Most of the side chain order disappears at the first melting transition; however, the layerlike structure remains. Both polymers are isotropic above the second melting transition; no ordered melts were observed at higher temperatures, possibly due to the small aspect ratios of PHBG-3 and -4. In contrast, polydisperse poly(γ-4-(hexadecyloxy)benzyl α,l-glutamate) (PDI = 1.2, DP = 98) (PHBG-P1), prepared from commercial PLGA, formed liquid crystalline (LC) phases between 97 and 105 °C.
Additional Information
Copyright © 2000 American Chemical Society. Published In Issue September 12, 2000. Publication Date (Web): August 18, 2000. Received May 10, 2000. Acknowledgment. This work was supported by the National Science Foundation Materials Research Science and Engineering Center at the University of Massachusetts. Supporting Information Available. Text giving experimental details of the synthesis of PHBG and figures showing X-ray powder diffraction patterns for PHBG-4.Attached Files
Supplemental Material - bm000039w_s.pdf
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Additional details
- Eprint ID
- 53716
- DOI
- 10.1021/bm000039w
- Resolver ID
- CaltechAUTHORS:20150114-121449953
- National Science Foundation Materials Research Science and Engineering Center at the University of Massachusetts
- Created
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2015-01-15Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field