Study On Synthesis、Chiral Polymerization And Application Of Substituted Phenylacetylene Monomers

The Polyacetylenes showed especially high gas permeability.The chiral group isintroduced in polyacetylene monomer,Then under a chiral catalyst,the polymer obtained inpolymerization having alternating double bond structure in its main chain is easy to formhelical structure, which can inhibit the polymer main chain from bending movement and thesoft segment twining, so the free volume of polymer increase. Additionally, larger substituentgroups have a strong mutual repulsion, which makes a large free volume is formed betweensuch gas permeable beneficial. And different nature of the substituents can also have a goodselectivity of gas.In this study, the successful synthesis of three new phenylacetylene monomers,then((nbd)Rh+[η6-(C6H5)B-(C6H5)3])、[Rh(nbd)Cl]2] were used as catalyst,and (R)-PEA、(S)-PEA、TEA were used as cocatalyst. The phenylacetylene monomer VDHPA, PIDHPAand DoDHPA were polymerized and DoDHPA was used to copolymerize with VDHPA.Molecular weight of Obtained Polyphenylacetylene was0.3×104-11.5×104.The obtainedmonomer structure was characterized by nuclear magnetic resonance. Circular dichroism(CD)was used to study the secondary structure of the copolymers. At the wavelengths around290nm and430nm，there are different heights at the peak shape, indicating that the polymersshowed a different intensity Condon effect, which are monomers corresponding hand sidegroups on the main chain and the conjugated CD absorption position.They show that thepolymer has one-hand helical structure in its main chain. The main chain of the copolymer isan asymmetric-induced polymerization (AIP) and the self-helix-selectively-sense thepolymerization (SHSSP). Because High polarity of the monomer VDHPA and PIDHPA,they were hardly insoluble in THF and CHCl3and other non-polar solvent.In order to improvethe solubility of the polymers, the monomer phenylacetylene monomer DoDHPA have a longalkyl,which be used to copolymerize with monomer VDHPA. It was found that if there ishydrogen bonds present in the polymer, then monomer1and monomer PIDHPA may bepartially or entirely dissolved in a non-polar or weakly polar solvent. This is a very importantpoint because intramolecular hydrogen bonding is an important factor in the spiral formingthe polymer main chain, and hydrogen in a weak polar solvent can not be destroyed. This fact indicated that the chiral monomer DoDHPA is able to change the solubility of polar monomerVDHPA and PIDHPA.In this study, the membranes were made of copolymers by solvent casting method. Thesolvent capacity of the copolymer influence the conformation of the membrane. The solventcapacity of the copolymer is better, the film is more easily to form. The Poly(VDHPA-co-DoDHPA) displays excellent solubility and film-forming ability. Thepoly(VDHPA-co-DoDHPA) membrane’s permeability and selectivity for equalvolumeCO2/N2mixture gas were measured by gas permeability equipment G2/110X. Thepoly(VDHPA-co-DoDHPA) membrane showed the ability of the CO2permeabilitypreferentially.