| In the field of C≡C and C≡N carbon-carbon and carbon-nitrogen triple bond monomer polymerizations,hydrothiolation and hydroamination polymerization of alkynes are efficient and convenient synthesis methods,which are usually used to prepare backbone heteroatomic polymers.Among them,“ester activated alkynes”and“carbonyl activated alkynes”obtained by replacing alkynyl hydrogen atoms with electron withdrawing groups have become important reaction monomers for the preparation of unsaturated heteroatom polymers.However,most of the polymerization based on alkynes usually employ catalysts containing transition metals,which results in the difficulty of removing metal residues.In synthetic chemistry,the hydroalkoxylation of alkynes with hydroxyl compounds is an important potential method for the preparation of poly(vinyl ether)s because of its simple and efficient synthesis process,but it has been rarely reported.Therefore,it is urgent to explore the hydroalkoxylation polymerization of alkynes without metal catalyst.1,4-diazabicyclo[2.2.2]octane(DABCO)is a kind of amine compound with low cost,environmentally friendly,highly reactive,easy treatment and nontoxic.It can be used in a variety of organic reactions as a kind of ideal base.In particular,it shows a unique advantage in the hydroalkoxylation of activated alkynes,which means polymers with high stereoregularity and excellent yield can be obtained.As a result,it has attracted extensive attention.This thesis is mainly engaged in the development and application of DABCO catalyzed hydroxyl-yne click polymerization.The specific research as follows:In Chapter 2,we successfully established the click polymerization of diols and diynes under mild conditions without metal catalysis.Poly(vinyl ether)s can be obtained with a yield of 99%and a weight-average molecular weight(M_w)of 71 000 by the polymerization of diols and diynes for 1 hour in the presence of DABCO.This click polymerization reaction has the advantages of easy availability of raw materials,mild reaction conditions and high polymerization efficiency.Based on this efficient click polymerization,two cross-linked semi-crystalline polycaprolactone networks were obtained by hydroxyl-yne click polymerization of diynes and tetraphenylethylene(TPE)groups with aggregation induced emission characteristics with polycaprolactone prepolymers with four terminal hydroxyl groups.These two polymer network structures show excellent reversible shape memory behavior when put into 0 ~oC and39 ~oC water,which is expected to be further applied in the fields of intelligent bionics and so on.In Chapter 3,we successfully developed the click polymerization of ester activated internal diynes and diphenols with DABCO.Poly(vinyl ether)s with the yields up to 88%and M_w up to 37 200 can be obtained by the click polymerization of diphenols and diynes under the40 ~oC for 24 hours.The reaction has excellent regioselectivity and stereoselectivity,and all the obtained poly(vinyl ether)s are E conformational isomer.In addition,the axial chiral binaphthol was introduced into the polymer backbone through click polymerization,and the resulting polymer showed obvious circular polarization luminescence(CPL)properties after mixing with PMMA.In Chapter 4,we successfully established the click polymerization reaction of ester activated diynes and dicarboxyl acids catalyzed by DABCO.Poly(carbonyl enol ester)with yields up to 96%and M_w up to 24 200 can be obtained by the click polymerization of ester-activated diyne with dicarboxylic acids at 40 ~oC for 4 hours.It was found that all the prepared aliphatic unsaturated poly(carbonyl enol esters)could show crystallization behavior.In Chapter 5,we successfully established the click polymerization of carbonyl-activated dikynes and dicarboxyl acids catalyzed by DABCO.When the polymerization was carried out at room temperature for 1 hour,poly(carbonyl enol ester)could be obtained with yields up to82%and M_w up to 22 800.Based on this click polymerization,TPE group was successfully introduced into the polymer main chain by using dicarboxylic acid containing TPE group.Therefore,a polymer with AIE characteristics was prepared,which can be applied to the sensitive detection of explosives.In addition,this click polymerization can obtain poly(carbonyl enol ester)with E structure of 95%,which has excellent regionalselectivity. |
