Syntheses And Applications Of Novel Helical Poly(N-Propargylamides) And Poly(N-Propargylthioureas)

Helical polymers are receiving wide attention because of their unique structures and properties. Polyacetylene derivatives, as an important type of helical polymers, include poly(N-propargylamides) and poly(N-propargylureas). For them, the previous studies focused on pursuing the pendent groups with appropriate steric hindrance to take conformation of stable helices. However, these polymers lack functionality, which greatly limit their application. In this dissertation, some functional groups were introduced for the first time in polyacetylene backbones as side chains. The obtained functional polymers are of great potential applications.The main contents are as follows:1. A novel N-propargylamide monomer (Ml) containing catechol moieties was synthesized and polymerized with monomer2 in the presence of [(nbd)Rh+B-(C6H5)4] as catalyst, providing a series of helical N-propargylamide copolymers containing functional catechol groups in side chains. It was found that poly(10.1-co-2o.9) exhibited different adsorption capacities towards Cr(Ⅲ), Fe(Ⅲ), Ni(Ⅱ), Cu(Ⅱ), Cu(Ⅰ) and Zn(Ⅱ), and the maximum adsorption of Fe(Ⅲ) was 186 mg·g-1. All the adsorption behaviours of poly(10.1-co-2o.9) towards Fe(Ⅲ), Cu(Ⅱ) and Ni(Ⅱ) followed Langmuir and Freundlich adsorption isotherms. Monodisperse layer adsorption played key roles in the absorption. The adsorption kinetics process of the poly(1x-co-2y)s towards Fe(Ⅲ) followed the pseudo first-order kinetic model. Besides, the secondary structure of poly(10.1-co-20.9) in Fe(III) complex varied with the amount of Fe(Ⅲ) adsorbed by poly(10.1-co-20.9), and there was a qualitative relationship between them. The coordination and hydrogen bonding were the main driving force for the formation of organometallic complexes.2. With [(nbd)Rh+B-(C6H5)4] as catalyst, M1, M3 and M4 were polymerized, providing helical copolymer (copolyl-copoly3) bearing interesting catechol groups. In the presence of PEG as pore-forming agent, optically active macroporous PNIPAM hydrogels were synthesized via free radical copolymerization of NIPAM, in which copolyl acted as macromonomer. The yields of the hydrogels were nearly 100%. The average pore size of the hydrogels increased from 10 to 50μm with an increase in molecular weight of PEGs (from 1000 to 6000), and the LCSTs of the hydrogels tend to decrease with increasing molecular weight of PEG. At temperatures below the LCST, the equilibrium swelling ratio (SR) of the hydrogels increased from Gel-0 to Gel-6000. Chiral recognition of amino acid tests was carried out by using Gel-1500, and it was found that Gel-1500 showed stronger ability of chiral recognition towards D-amino acids than towards L-amino acids. In addition, chiral resolution was further investigated by following the optical rotation of the rac-tryptophan solution. The results indicated that Gel-1500 adsorbed more D-tryptophan than L-tryptophan. It implied that Gel-1500 had enantioselectivity to preferentially adsorb D-tryptophan, and the enantiomeric excess of the residual L-tryptophan was about 30%.3. A novel series of N-propargylthiourea monomers (M5-M11) were designed and synthesized, among which M9 (S) and M10 (R) were chiral N-propargylthiourea. The monomers were polymerized in the presence of [(nbd)Rh+B-(C6H5)4], yielding the corresponding polymers, i.e. poly5-polyll. When DMF was utilized as the solvent instead of CHC13, the polymerizations occurred more smoothly and the polymer yields were higher. The solubility of the resulting polymers was tested in common solvents. Poly8-polyll showed good solubility and high cis contents in the polymer backbones. Poly9 and poly 10 adopted helical structure and thus showed optical activity under the examined conditions. The influences of solvent and temperature on the secondary structure of the polymers were investigated. Poly9 and poly10 kept stable helical structures at varied temperature from 0-60℃, and adopted stable helices or disordered states depending on the solvent. The addition of DMF destroyed the hydrogen bonds which formed between the neighboring thiourea groups. In addition, poly8-poly10 had strong complexing ability towards Fe(Ⅲ) ions. The Fe(Ⅲ) complex which formed between chiral polymers and Fe(Ⅲ) could not take helical structure since the intramolecular hydrogen bonds were destroyed by the coordination between Fe(III) and thiourea groups in polymer pendent chains. Finally, poly9 and poly 10 were used as macrocatalyst to catalyze asymmetric Baylis-Hillam reaction between p-nitrobenzaldehyde and 2-cyclohexen-1-one. The preliminary results suggested that chiral poly(N-propargylthioureas) had a promising application in asymmetric catalytic reaction.4. A novel N-propargylamide monomer (M12) containing 4-nitrobenzene groups was synthesized. With [(nbd)Rh+B-(C6H5)4] as catalyst, M12 was copolymerized with achiral monomer2 and chiral monomer4, respectively. We obtained a series of helical N-propargylamide copolymers containing 4-nitrobenzene moieties in the pendent groups. Anion recognition studies were carried out by using UV-vis and CD spectra, revealing that poly(120.2-co-20.8) and poly(120.2-co-40.8) exhibited the considerable recognition capability towards I-, but hardly showed binding ability with Br-, AcO- and H2PO4-...