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681.
R.P. Drake F.W. Doss R.G. McClarren M.L. Adams N. Amato D. Bingham C.C. Chou C. DiStefano K. Fidkowski B. Fryxell T.I. Gombosi M.J. Grosskopf J.P. Holloway B. van der Holst C.M. Huntington S. Karni C.M. Krauland C.C. Kuranz E. Larsen B. van Leer B. Mallick D. Marion W. Martin J.E. Morel E.S. Myra V. Nair K.G. Powell L. Rauchwerger P. Roe E. Rutter I.V. Sokolov Q. Stout B.R. Torralva G. Toth K. Thornton A.J. Visco 《High Energy Density Physics》2011,7(3):130-140
682.
683.
Marion Pommet Andréas Redl Marie-Hélène Morel Sandra Domenek Stéphane Guilbert 《Macromolecular Symposia》2003,197(1):207-218
Proteins, as heteropolymers, offer a large range of possible interactions and chemical reactions. The thermoplastic behavior of proteins has been studied in order to produce bioplastics by thermal or thermomechanical processes such as mixing, extrusion or hot molding. The extrusion trials were performed by using a co-rotating twin-screw extruder, recording torque, temperature and die pressure. Batch mixing was done in a two blade counter-rotating mixer, with continuous recording of torque and product temperature. Proteins were alternatively extruded, mixed or hot molded under a large range of processing conditions. Protein aggregation during each process was estimated from the accumulation of SDS-insoluble protein fraction. Protein aggregation evidences a cross-linking reaction the activation energy of which was dependent on the thermoplastic process used. The increase in network density appears to be induced by the severity of the treatment: temperature and shear strongly affect the structural characteristics of the protein-based bioplastics. 相似文献
684.
Colorless lath-shaped single crystals of the title compound are obtained from a melt of Y2O3, YF3, and SiO2 (2:5:3 molar ratio) using CsCl as a flux (evacuated silica tube, 973 K, 9 d, 10 K/h cooling rate). 相似文献
685.
686.
Marion Helou Olivier Miserque Jean‐Michel Brusson Jean‐Franois Carpentier Sophie M. Guillaume 《Macromolecular rapid communications》2009,30(24):2128-2135
α,ω‐Dihydroxy‐telechelic poly(trimethylenecarbonate), HO‐PTMC‐OH, is synthesized from the controlled “immortal” ring‐opening polymerization (ROP) of trimethylene carbonate under mild conditions (bulk, 60 °C), using ZnEt2 or, more efficiently, [(BDI)Zn(N(SiMe3)2)] (BDI = CH(CMeNC6H3‐2,6‐iPr2)2) as catalyst precursor, in the presence of a diol HO‐R‐OH (R = (CH2)2 or CH2C6H4CH2; 0.5–10 equiv. vs Zn) acting both as co‐initiator and chain transfer agent. Alternatively, HO‐PTMC‐OH is prepared upon hydrogenolysis of HO‐PTMC‐OCH2Ph, initially prepared from the ROP of TMC using the [(BDI)Zn(N(SiMe3)2)]/PhCH2OH system, under smooth operating conditions using Pd/charcoal. Well‐defined dihydroxy‐functionalized PTMCs of molar mass ranging from = 2 000 to 109 500 g · mol−1 were thus quantitatively obtained and fully characterized by NMR, MALDI‐TOF‐MS and SEC analyses. The versatility of this “immortal” ROP allows the preparation of alike α,ω‐functional polyester such as linear HO‐poly(lactide)‐OH, as well as star polymers such as the glycerol‐based PTM‐OH3.