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Phase behavior of poly(gama-alkyl-L-glutamate)s

The polyglutamate which grafts with flexible alkyl side-chain by ester exchange reaction is like rod-hairy molecule. The numbers of methylene group of side-chain and the graft-density affect the molecular packing of poly(gama-alkyl-L-glutamate)s. To be sure the correct chemical structure of poly(gama-alkyl-L-glutamate)s by Fourier transform infrared spectrometer (FTIR), and find out the graft-density of each sample by proton nuclear resonance spectrometer (1H-NMR). Phase behavior of poly(gama-alkyl-L-glutamate)s were studied via differential scanning calorimetry (DSC) and variable temperature x-ray diffraction (XRD).We combine the results from C. C. Hsu(24). When the side-chain length is long enough (m>10), side-chains will crystallize into a 3D hexagonal lattice. The results of DSC and XRD analyses show that the side-chain crystalline phase will melt at Tm1, where as a liquid crystalline (LC) phase transition exists at Tm2. Poly(gama-alkyl-L-glutamate)s with shorter side-chain (m<8) tend to form 2D hexagonal LC structure. On the other hand, longer side-chains (m>10) tend to give lamellar structure. The critical number of methylene group of side-chain between hexagonal and lamellar structure is between 8 and 10.

Identiferoai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0612103-060541
Date12 June 2003
CreatorsLee, Yu-Hsien
Contributors¢Ûing Chen, Rong-Ming Ho, Jung-hsien Lin, An-Chung Su
PublisherNSYSU
Source SetsNSYSU Electronic Thesis and Dissertation Archive
LanguageEnglish
Detected LanguageEnglish
Typetext
Formatapplication/pdf
Sourcehttp://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0612103-060541
Rightscampus_withheld, Copyright information available at source archive

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