Preparation Of Novel Conjugated Microporous Polymer And Study On Thermal Insulation And Flame Retardancy Of Its Composites

With the promotion of global energy-saving concept,thermal insulation materials have been widely used in construction,aerospace,petrochemical and other fields.However,most of the traditional thermal insulation materials are flammable polymers,which often lead to frequent fire accidents.Therefore,it is of great significance to develop thermal insulation materials with flame-retardancy.Conjugated microporous polymers(CMPs)have excellent porosity,high specific surface area,low density and other characteristics.The control of their structure,morphology and chemical composition can be achieved by adjusting the structure and chemical composition of monomer molecules.Based on this,a new type of CMPs material and its composites with hollow nanostructure were designed and prepared in this thesis,which started from CMPs block units,and their thermal insulation and flame retardant properties were systematically studied.The main research contents of this paper are as follows:(1)1,3,5-triethynylbenzene and 2,4,6-tribromoaniline were used as monomers,the molar ratio of terminal alkynes and bromine was adjusted to 2:1,and a hollow tubular CMPs aerogel(M-CMPN0)was prepared through Sonogashira-Hagihara cross-coupling reaction.M-CMPN0has excellent mechanical strength,good processability and thermal insulation performance(thermal conductivity is 0.03 W m^-1k^-1).Two CMPs-based composite flame retardant materials(M-CMPN1 and M-CMPN2)were prepared by using M-CMPN0 as carrier,Mg(OH)₂ and ionic liquid(IL)as additives.The peak heat release rate(pHRR)value of M-CMPN1 is 7.2 W g^-1,and its flame retardancy is better than that of M-CMPN0.(2)Two CMPs hollow microspheres(CMP1-HS and CMP2-HS)were prepared by using1,3,5-triacetylenebenzene as alkynyl monomer,1,4-dibromobenzene and 2,4,6-tribromidine as brominated monomers,respectively,SiO₂ nanoparticles as hard template,and the molar ratio of terminal alkynes and bromine was adjusted to 1:1.The hollow structure enables CMPs to provide more cavities for volatile flame retardants,which is conducive to the improvement of their flame retardancy.It was found that the CMPs-HS composite flame retardant(CMPs-HS-DMMP)prepared with dimethyl-methyl-phosphonate(DMMP)as an additive can effectively improve the flame retardant performance of epoxy resin(EP)matrix.When the addition amount of CMPs-HS-DMMP is 0.2%,the pHRR value and total heat release(THR)value of EP are650.9 k W m^-2 and 79.4 MJ m^-2,respectively,which are 19.6±2%and 19.1±5%lower than that of pure EP samples.