Synthesis And Properties Of Polymers Containing Bithiazole And Poly (Ionic Liquid)s

The dissertation comprises two parts. The first part is about synthesis and properties of conjugated polymers containing bithiazole and their metal complexes. The second part is about synthesis and CO₂ separation properties of poly(ionic liquid)s.In the first part, the background and progress of organic and polymeric magnetic materials are reviewed. Organic and polymeric magnetic material has been becoming a hot research area due to its significant scientific value and wide potential application. Polymeric metal complex could be a new kind of designable magnetic material through controlling the electronic interaction between the metal ions in the polymer by molecular design. The goal of this part is to design and synthesize polymeric magnetic materials, to understand the relationship between the structure and properties of polymeric magnetic materials, to improve the theory of magnetism for polymeric metal complexes. The results in this part are summarized as follows:4. A novel conjugated polymer poly[(4, 4'-bithiazole)-2, 2'-diyl](PTz) and its complexes with iron and lanthanide ions (PTz-Fe²⁺, PTz-Nd³⁺, PTz-Gd³⁺, PTz-Pr³⁺ and PTz-Sm³⁺) were synthesized, and their structure were characterized by FT-IR, ¹H-NMR, XRD and elemental analysis.5. The magnetization as a functional of the temperature for the polymeric complexes was investigated, indicating that magnetization of PTz complexes increase with the decrease of temperature. There is a transition from paramagnet to ferromagnet for PTz-Fe²⁺, PTz-Nd³⁺and PTz-Gd³⁺, with Curie temperature at 9.5 K, 254 K and 28 K, respectively. PTz-Pr³⁺ and PTz-Sm³⁺ have a transition from anti-magnet to ferromagnet with the transition temperature at 239.5 K and 31.8 K, respectively. The hysteresis loops at 5 K for PTz complexes were determined, indicating that the remanence magnetization for PTz-Fe²⁺, PTz-Nd³⁺, PTz-Gd³⁺, PTz-Pr³⁺and PTz-Sm³⁺are 0.0022. O.O033. 0.018. 0.0075 and 0.001 emu/g, respectively, and the coercive field for PTz-Fe2+, PTz-Nd3+, PTz-Gd3+ and PTz-Pr3+ are 5.6. 51.4. 26.1. 197.0 and 119.3 Oe. They are soft ferromagnets at low temperature.6. A novel bithiazole diethyl phosphate monomer was synthesized, which can be used for constructing a new class of ^-conjugated polymers containing bithiazole. Two novel conjugated PPV derivatives containing bithiazole (p-VBVP and m-VBVP) were synthesized from this monomer using Wittig-Horner reaction.*H NMR and FT-IR were used to characterize their structure. The photoluminescene spectra indicated that the photoluminescene in CF3COOH are green for both p-VBVP ((^ax=508 nm) and m-VBVP (Xmax=501nm). The conductivities of bulk and I2 doped p-VBVP and m-VBVP were studied, which indicated p-VBVP and m-VBVP are insulators, while after I2 doped, p-VBVP become a semiconductor.In the second part, the background and progress of CO2 separation, ionic liquid and poly(ionic liquid), especially CO2 sorption in ionic liquid, are reviewed. CO2 separation is an important process for CO2 sequestration and natural gas industry. It is important to develop new materials for CO2 separation due to its environmental significance and economic value. Recently, many reports indicated that CO2 has significant solubility in ionic liquids for the special interaction between them. Poly(ionic liquid)s should have similar interaction with CO2 because they have the same functional group with ionic liquids. With the processability of polymer, poly(ionic liquid)s are possible to be a new kind of materials for CO2 separation. However, to my best knowledge, there is no report about poly(ionic liquid)s for CO2 separation so far. The goal of the second part is to design and synthesize novel poly(ionic liquid)s, to investigate their CO2 sorption and membrane separation property, to develop new materials for CO2 separation. The results in this part are summarized as follows:1. Fifteen novel ionic liquid monomers and their corresponding polymers including imidazolium, pyridinium, ammonium and phosphonium were synthesized and characterized by 'H-NMR and elemental analysis. DSC and XRD indicated that the polymers are amorphous, and the glass transition temperature (Tg) ranges from 3-255 °C.2. The CO2 sorption in poly(ionic liquid)s was studied for the first time. We found that poly(ionic liquid)s have higher sorption capacity than their corresponding monomers and ionic liquid [bmim][BF4]. The sorption is very fast and desorptin is very easy by changing pressure. The sorption and desorption are reversible. There was no change with the capacity and kinetics for CO2 sorption in poly(ionic liquid)s after four sorption and desorption cycles. With high CO2 sorption, there is no measurable N2 and O2 sorption in poly(ionic liquid)s. The gas sorption in poly(ionic liquid)s is selective.3. The study of the relationship between the sorption of CO2 in poly(ionic liquid)s and their structure indicated that all cation, anion, substituent, backbone can affect CO2 sorption in poly(ionic liquid). P[VBTMA][BF4] with ammonium cation, BF4" anion has the highest CO2 sorption capacity of 10.67 cc(STP)/cc polymer (at 22 °C,1 atm). Dual —Mode model was applied to study CO2 sorption in poly(ionic liquid)s with different structure. The CO2 sorption in poly(ionic liquid)s can be fitted to the Dual — Mode model very well. The capacity of CO2 sorption in poly(ionic liquid)s increases with increasing of pressure. The rate of capacity increase decreases with increasing of pressure, gradually closing to linearly increase. According to Dual—Mode model, CO2 sorption in poly(ionic liquid) can be divided into two parts: Henry sorption and Langmuir sorption.4. The mechanism of CO2 sorption in poly(ionic liquid) was investigated, indicating that CO2 sorption in poly(ionic liquid) is mainly bulk absorption, not surface adsorption.The size and surface area of poly(ionic liquid) sample does not affect CO2 sorption capacity in it, but affect the sorption rate. The CO2 sorption capacity in poly(ionic liquid) is determined by two parameters: interaction between CO2 and poly(ionic liquid), and void /unrelaxed volume in poly(ionic liquid).5. PEG grafted poly(ionic liquid)s were prepared by copolymerization of ionic liquid monomers and PEG macromonomers. Membranes were prepared from these PEG grafted poly(ionic liquid)s (P[VBTMA][BF4]-g-PEG2000, P[MATMA][BF4]-g-PEG2000, P[VBTMA][BF4]-g-PEG475 and P[MATMA][BF4]-g-PEG475) and their gas separation (CO2/N2, CCVCtLO properties were investigated. We found that P[VBTMA][BF4]-g-PEG2000 and especially P[MATMA][BF4]-g-PEG2000 are above Robeson line for CO2/N2 separation. They are better than the previous polymeric membranes for CO2/N2 separation. The P[VBTMA][BF4]-g-PEG2000 and P[MATMA][BF4]-g-PEG2000 are close to Robeson line for CCVCI-Lt separation. They are close to the previous polymeric membranes for CO2/CH4 separation. The effect of molecular weight of PEG macromonomer and the type of ionic liquid monomer on gas separation was investigated and the mechanism of gas separation for PEG grafted poly(ionic liquid) was also studied. The high solubility selectivity of PEG grafted poly(ionic liquid)s is the main reason for their high CO2 separation ability.