Preparation And Properties Of Poly (Arylene Ether) Containing Tetraphenyl-Bipyrimidine For Gas Separation Membranes

Microporous polymer now has been widely studied as gas storage materials. However, theapplication of gas separation is quite limited. Gas separation membranes have becoming therecent research for microporous polymers.Through improving the gas separation performance;rigidity of the entire polymer structure has been enhanced.Primarily through designingmonomerof microporous polymer structure, internal conformation can be changed to enhance therigidity.For gas separation and storage materials, rigid structural reinforce the performance anddurability of membrane.So far there are hundreds of polymers were studied as potential film materials, but there areonly a few practical applications in industrial gas separation in reality. Polymer films applied inindustry need to display a combination of permeability and good selectivity，which is a verylong process. Producing high performance gas separation membrane requires not only goodmechanical properties and good film-forming properties, but also good selectivity andpermeability. However, if only through changing free volume of the polymer chain to improveseparation property, it is very difficult to improve both permeability and selectivity. Usuallytheenhancementof permeability usually results in reduced selectivity. Monomers with non-coplanar display distorting structure, but the application of existing non-coplanar monomerpolyarylethers is rare. Development of such monomers is effective way to promote thediversityof poly (arylene ether) materials. Therefore, in order to obtain optimum results, we did thefollowing works:in the molecular design aspect, we designed a monomer containing N-linkedpyrimidine heterocycle; this monomer has a twist center, a non-coplanar monomer. First,the N-containing heterocyclic bisphenol monomer is introduced into very rigid polyaryletherketonespolymers. Then we had a series of structural characterization, thermal stability and mechanicaltests. Testing results show that N-containing heterocyclic polyaryletherketonehas higher thermalstability and mechanical strength. Through gas separation test, it shows that with theenhancement of the rigidity of the polymer main chain groups, moving segments were increased,thus making the chain entanglement weakened, thus it easier for the gas pass through themembrane material. Secondly,we introducedthe monomer into the polyether sulfone polymers,synthesized a series of N-containing and trifluoromethyl heterocyclic polymers and characterizedtheir structure, thermal stability, mechanical and gas separation properties. These polymersmaintained excellent thermal stability and chemical stability as polyether sulfone-basedpolymers, and increased the free volume. With the increase of gas permeability agents, gas permeability and selectivity of the polymer filmare improved;ultimately achieving a balancedand effective state.In short, in this dissertation, we synthesizedtypes of gas separation membrane materialsbased on poly (aryl ether) and polyaryletherketones, and studied structural characterization,mechanical properties, thermal stability, and gas separation, which verify the potentialapplication in gas separation materials.