Research Of Thiirane Ring-Opening-Polymerization To Synthesize Sequence Ordered Polymers And Cyclic Polymers

The relationship between the sequence and topological structure of polymer and its various physical and chemical properties has always been an important subject in the field of polymer chemistry research,and it is worthy of theoretical research and practical application.Polymers with advanced topologies,such as cyclic polymers,star polymers,and hyperbranched polymers,are promising materials.Polymers with controllable synthetic sequences and controllable topologies have important implications for polymer chemistry.Therefore,we conducted the study of the ring-opening polymerization of epithiopyrifid to synthesize sequence-regulating polymers and cyclic polymers.This article will introduce the following two aspects.In the first part,we synthesized a sequence-structured sulfur-containing polymer through the selective control of the insertion of an epithiopropane analogue.Using a mercapto-isocyanate click reaction,the resulting bis-indenyl compound was reacted with a diisocyanate compound to obtain sulfur.The sequence of the carbamate structure was sequenced and the polymer was then reacted with 2-(phenoxymethyl)cyclothiopropane to investigate the insertion of 2-(phenoxymethyl)isothiopropane in the structure.And finally,the sequence regularity of the polymer was obtained.Under the catalysis of quaternary phosphonium salt,the insertion efficiency of 2-(phenoxymethyl)cyclothiopropane(POMT)in the thiourethane structure is relatively high,and no ring-opening and self-polymerization of the ring sulfur monomer occurs.The reaction is applied for synthesizing polysulfides.As a result of the comparative reaction,it can be seen that the greater the steric hindrance of the substituent of the thiourethane structure,the lower the molecular weight of the resulting polymer,the narrower the distribution,and the greater controllability.The specific laws need further verification.In general,we have obtained a sequence of polymers,and the specific insertion of POMT in the polymer remains to be studied more systematically.In the second part,ring-opening polymerization of thiocyclopropane anion by quaternary phosphonium salt-catalyzed anions and N-substituted derivatives as initiators was used to successfully synthesize cyclic polymers.The cyclic block polymers and ring-brush polymers were synthesized by stepwise feeding and click reaction,respectively.First,thiirane structures with different pendant groups were synthesized separately:2-methylthiacyclopropane(MT),2-(phenoxymethyl)thietane(POMT)and 2-((propane-2-Alkyn-1-yloxy)methyl)thieam(PYMT)monomers reacted successfully by tetrabutylammonium chloride catalyzed ring-opening polymerization initiated by rhodanine and rhodanine derivatives.The cyclic polymer chain was synthesized by stepwise addition of cyclic polymers of different blocks.Through the click reaction of alkynyl-hydroxyl-azido,we successfully grafted the polymer chain of PEG2000 to the cyclic polymer.A specific ring polymer was synthesized.