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N. G. Bazarnova V. I. Markin I. B. Katrakov P. V. Kolosov E. V. Kalyuta M. Yu. Cheprasova 《Russian Journal of General Chemistry》2012,82(5):947-954
Chemical modification of plant raw materials aimed at obtaining new valuable products and materials is described. Methods of preliminary treatment and modification of biopolymers (cavitation, microwave irradiation, and application of cross-linking and delignification reagents) making it possible to reduce decomposition of all major components are considered. Modified products can be used as sorbents of heavy metal salts, additives to drilling fluids in drilling of oil and gas wells, in the construction industry etc. 相似文献
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A convenient and efficient method for the preparation of unsymmetrical and symmetrical diacetylenic ketones bearing a carboxylate group. 相似文献
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Reactivity Ratios and Sequence Distribution Characterization by Quantitative 13C NMR for RAFT Synthesis of Styrene‐Acrylonitrile Copolymers
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Md. Mahbub Alam Hui Peng Kevin S. Jack David J. T. Hill Andrew K. Whittaker 《Journal of polymer science. Part A, Polymer chemistry》2017,55(5):919-927
The kinetics and reactivity ratios of styrene‐acrylonitrile (SA) copolymerization have been studied extensively in bulk and in a variety of solution media using conventional free radical polymerizations (FRPs). Due to the significant difference in the two reactivity ratios for this monomer pair, at certain feed ratios the copolymers display composition drift with conversion due to monomer depletion. In this study, the kinetics of SA copolymerization using Reversible Addition‐Fragmentation Chain Transfer (RAFT) has been studied in bulk at 80 °C. The reactivity ratios for the terminal model were calculated from the comonomer sequence distributions for the RAFT process at low conversion for nine different compositions and found to be in the same range as those reported for conventional FRP of SA. The changes in the composition and sequence distribution with conversion were studied for three feed compositions. The copolymers show compositional drift with conversion, except at the azeotropic composition, and match the predictions from the reactivity ratios obtained at low conversion. From quantitative 13C NMR the triad distributions of these copolymers were estimated and found to match the predicted triad distributions as conversion increased. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 919–927 相似文献
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