Rapidly, block 53, less than 30 minutes synthesis! \”Angew\”: using a Lewis acid-base synthetic sequence depressed controllable polymer

Determine the nature of the structure of matter, and for the molecular weight copolymers, their nature is not only the structure of the monomer has a great influence, the structure of the monomer sequence affects its nature is also very significant. Professor Frank S. Bates person in their review article ( Science 2012, 336, 434-440) on the current situation and future of the sequence controlled polymer was evaluated and prospects: composed of a single polymer chain the kinds and properties of impact ( k ), block number ( n ) and a degree of polymerization ( dp n) of the resultant block polymer structure is very huge. Small changes in these factors may be regulated to the exponential of the polymer structure. If arbitrary regulation of these factors, a controlled molecular sequence can solve almost any problem among synthetic polymer. DHDM (double high (molecular weight and dpn However, in terms of the current method of polymer synthesis, a particularly efficient means yet meet the high molecular weight can be synthesized, multiple cell, the number of multi-block and each block having a high degree of polymerization value) and double multiple (monomers and block numbers)) multiblock copolymer. ​神速,53嵌段,不到30分钟合成!《Angew》:利用沮丧Lewis酸碱对合成序列可控高分子 Professor Zhang Yuetao Jilin University research group has been researching frustrated Lewis acid-base applications in polymer synthesis, and made a series of groundbreaking achievements (see review Acta Polym Sinica.2019, 50, 233-246..; Sci. Bull.2019, 64, 1830-1840). Recently, they are frustrated by using Lewis acid-base pair (the FLP) active in the polymerization system can be quickly and one hundred grams stage polymerization of methyl methacrylate (MMA), ethyl methacrylate (EMA), 2- methoxyethyl methacrylate ester (MEMA), methyl acrylate, 2-ethoxyethyl different (EEMA) Hydropathy four kinds of monomers, to achieve a controlled polymer synthesis DHDM sequence. Synthesis of a polymer having a controlled sequence of 53 blocks world record class (FIG. 1), the recording than before is improved by about 2.5 times. Moreover, each block dpn also from 10 to 50.True to double high and more than double (DHDM). Fig. 1 Synthesis of Tripentacontablock Copolymer through Sequential Addition of Monomer The block polymer of the work is not high, but the reaction system is also very easy. The reaction at room temperature can be rapidly polymerize the monomer, the polymerization of each segment only takes 30 seconds to complete (100% conversion of monomer to polymer), so that the entire polymerization period only 53 minutes to less than 30 synthesized. The reaction process is very simple, can be in a flask, in addition to the initial stage of the reaction system requires the addition of FLP, the other block simply added to the monomer continuously, controlled polymer synthesis sequence is completed does not require additional catalyst or initiator . The resulting series of sequences controllable molecular weight polymer having a controlled and narrow molecular weight distribution (FIG. 2A, B). In addition, the system may also be implemented amplification experiments, more than one hundred grams level of aggregation can be completed quickly, while the isolated yield of 98% can be achieved (FIG. 2C). These features are sufficient to show the prospects for industrial application of this sequence FLP catalytic system controlled polymer synthesis. ​神速,53嵌段,不到30分钟合成!《Angew》:利用沮丧Lewis酸碱对合成序列可控高分子 Finally, also by changing the sequence order of the sequence found in the initial polymer in either order or sequence number of the block polymer changes will have an impact on the thermal properties of the polymer. This discovery let people see the advantage of this system to the polymerization of monomers with different properties to achieve the desired polymer properties comprehensive regulation. By extension of the monomers, using a Lewis acid of the multi-block polymeric depressed ability of an active polymerization system, the polymeric elastomer is expected, since the field assembly, and the shape memory biochemistry be applied, will greatly expand the depressed Lewis the scope of application of the acid-base. The work was published as a full text in Angew. Chem. Int. On Ed., First author of the study group for doctoral clouds. References: Bai, Y .; Wang, H .; He, J .; Zhang, Y., Rapid and Scalable Access to Sequence-Controlled DHDM Multiblock Copolymers by FLP Polymerization Angew Chem Int Ed 2020, 10.1002anie….. .202004013