邱文英臺灣大學：材料科學與工程學研究所李建裕Li, Chien-YuChien-YuLi2007-11-262018-06-282007-11-262018-06-282006http://ntur.lib.ntu.edu.tw//handle/246246/55295本論文中，首先利用兩步法迷你乳化聚合反應成功合成出高分子量且疏水性聚胺酯懸浮微粒。之後，再利用兩步法迷你乳化聚合製備聚胺酯/聚甲基丙烯酸甲酯混成微粒，並觀察其型態。此外，透過熱力學公式，利用介面張力值計算其可能的粒子型態分佈。最後，利用包覆導電高分子聚苯胺形成核殼型態複合粒子，並觀察其型態。In this thesis, first of all, the synthesis of high-molecular-weight polyurethane (PU) was prepared successfully by two-step miniemulsion polymerization. Second, PU/PMMA hybrid particles were synthesized and discussed with their morphologies. In addition, by consideration of thermodynamics, the analysis of free energy changes produced the prediction of the preferred-particle morphology. Finally, the conducting composites of PU/polyaniline and PU-PMMA/polyaniline particles were also prepared and characterized. Utilizing a two-step miniemulsion polymerization, hydrophobic polyurethane dispersions were prepared with co-surfactant, hexadecane (HD) hydrophobe in oil phase and sodium dodecyl sulfate (SDS) in water phase. The first step involved the formation of NCO-terminated prepolymers between isophorone diisocyanates (IPDI) and poly (propylene glycol) (PPG) oligomer in toluene. Next, polyurethane dispersions were produced by a miniemulsion method where an oil phase containing NCO-terminated prepolymers, HD, a chain extender 1,4-butanediol (BD), a cross-linking agent trimethylol propane (TMP), and a catalyst dibutyltin dilaurate (SnDBL) was dispersed in the water phase containing SDS. The influences of experimental parameters, such as ultrasonication time, concentration of SDS and HD, TMP/BD and NCO/OH equivalent ratios on the sizes of miniemulsion droplets and polymer particles, as well as the molecular weight and thermal properties of PU polymer were discussed. Chemical structure of the produced PU polymer was identified by Fourier-transform infrared spectrometer. Molecular weight distribution and average particle size were measured through gel permeation chromatography (GPC) and dynamic light scattering (DLS), respectively. Thermal properties of PU polymer was characterized through differential scanning calorietry (DSC) and thermal gravimetric analysis (TGA). The final morphology of PU particle was also characterized by transmission electron microscope (TEM). PU/PMMA hybrid particles were synthesized by using the method of two-step miniemulsion polymerization. In the first step, PU prepolymer was synthesized by isophorone diisocyanates (IPDI) and poly (propylene glycol) (PPG) with methyl methacrylate (MMA) as a solvent. Then the oil phase, including the NCO-terminated prepolymer, MMA, hexadecane (HD), a chain extender as 1,4-butanediol (BD) or bisphenol A (BisA), a cross-linking agent trimethylol propane (TMP), and a catalyst dibutyltin dilaurate (SnDBL) is dispersed in the water phase containing SDS. Then the mixtures turn into miniemulsion by ultrasonifying. Two kinds of initiators, BPO and KPS, were applied for the polymerization of MMA. The influences of chain extenders, initiators and PU/PMMA weight ratios on the morphology of PU/PMMA latex particles were investigated. Conversion of MMA was measured and discussed. Particle size and distribution were analyzed by dynamic lighting scattering (DLS) and transmission electron microscope (TEM). Thermal stability of the hybrid particle was characterized through thermal gravimetric analysis (TGA). The cross section morphology of the hybrid particles was also characterized TEM. For BD/BPO and BD/KPS systems, when increasing the load of PU component, PU-rich phase was moved to the outside of hybrid particles. A core-shell structure can be observed. However, for BisA/KPS system, while using hydrophobic bisphenol A as chain extender of PU, the boundary of PMMA and PU phases was not clear. A more homogeneous structure of hybrid particles can be obtained. In this chapter, the morphology of PU/PMMA hybrid particles prepared by miniemulsion polymerization was predicted through the consideration of their Gibbs free energy changes. Five morphological states of PU/PMMA hybrid particles were proposed and their Gibbs free energy changes were calculated. Before the formation of hybrid particles, the initial state included a monomer mixture of PU prepolymer, MMA, a chain extender, TMP and an initiator, which was in droplets suspended in water containing SDS. Two assumptions were made. First, the densities of all states were the same. Secondly, secondary nucleation of particles was negligible. Thus the size of initial droplet and final particle was unchanged through miniemulsion polymerization. The interfacial tensions were measured by a pendant drop method and were used for calculation. The preferred morphology of PU/PMMA hybrid particle had the minimum value of ΔGphase. Different NCO/OH ratios of PU and initiators of MMA were used to study the morphological change of PU/PMMA hybrid particles. When BD was used as the chain extender of PU, the hybrid particles showed the PU-rich phase as the shell and PMMA-rich as the core. When incorporating bisphenol A into PU polymer, the homogeneous structure of hybrid particle was preferred. Polyurethane/polyaniline (PU/PANI) and polyurethane-poly(methyl methacrylate)/polyaniline (PU-PMMA/PANI) conductive core-shell particles were synthesized by a two-stage polymerization process. The first stage was to produce a core of PU or PU-PMMA via miniemulsion polymerization using sodium dodecyl sulfate (SDS) as the surfactant. The second stage was to synthesize the shell of polyaniline over the surface of core particles. Hydrogen chloride (HCl) and dodecyl benzenesulfonic acid (DBSA) were used as the dopant agents. APS was used as the oxidant for the polymerization of ANI. Different concentrations of HCl, DBSA and SDS would cause different conformations of PANI chains and thus different morphologies of PANI particles. UV-visible spectra revealed that the polaron band was blue-shifted due to the more coiled conformation of PANI chains by increasing the concentration of DBSA. Besides, with a high concentration of DBSA, both spherical- and rod-shape PANI particles were observed by transmission electron microscope (TEM) and the coverage of PANI particles onto the core surfaces was improved. The key point of formation of rod-type PANI particles was that DBSA was served with a high concentration accompanied with the existence of HCl or SDS. The better coverage of PANI particles over the core surfaces by charging higher DBSA concentrations resulted in a higher conductivity of hybrid particles.Contents Contents I List of Tables V List of Figures VI Chapter 1 Introduction 1 1.1 Introduction of miniemulsion polymerization 1 1.2 Synthesis of polyurethanes (PU) by two-step miniemulsion polymerization 4 1.3 Preparation of PU/PMMA hybrid particles by miniemulsion polymerization 6 1.4 Thermodynamic considerations of PU/PMMA morphology 7 1.5 PU/PANI and PU-PMMA/PANI conducting particles 8 1.6 References 10 Chapter 2 Preparation of Polyurethanes Dispersions by Miniemulsion Polymerization 14 2.1 Introduction 15 2.2 Experimental 21 2.2.1 Materials 21 2.2.2 Synthesis of prepolymer 21 2.2.3 Preparation of polyurethane latex 22 2.2.4 Analysis 23 2.3 Results and discussion 25 2.3.1 Influences of different ultrasonication times 25 2.3.2 Influences of different concentrations of SDS 26 2.3.3 Influences of different concentrations of hexadecane 28 2.3.4 Influences of different TMP/BD equivalent ratios 29 2.3.5 Influences of different excess amounts of IPDI 29 2.3.6 Influences of different agitation speed 30 2.3.7 Thermal property of PU films 31 2.3.8 PU Latex morphology 33 2.4 Conclusion 35 2.5 References 36 Chapter 3 Preparation of PU/PMMA hybrid latex by Miniemulsion Polymerization 63 3.1 Introduction 64 3.2 Experimental 67 3.2.1 Materials 67 3.2.2 Synthesis of PU prepolymer 67 3.2.3 Preparation of PU/PMMA hybrid latex 68 3.2.4 Analysis 69 3.3 Results and discussion 71 3.3.1 BD/BPO system 71 3.3.2 BD/ KPS system 73 3.3.3 BisA/KPS system 75 3.3.4 Thermal decomposition analysis 76 3.3.5 Cross-section morphology of the PU/PMMA latex particles 77 3.4 Conclusion 79 3.5 References 81 Chapter 4 Morphology of PU/PMMA hybrid particles from thermodynamic consideration 110 4.1 Introduction 111 4.2 Thermodynamic considerations of the particle morphology 114 4.3 Experimental 121 4.3.1 Materials 121 4.3.2 Synthesis of PU prepolymer 121 4.3.3 Synthesis of PU latex 122 4.3.4 Synthesis of PMMA latex 122 4.3.5 Synthesis of PU/PMMA hybrid latex 123 4.3.6 Analysis 124 4.4 Results and discussion 128 4.4.1 Contact angles and surface tension components of polymer films 128 4.4.2 Interfacial tensions of monomer/water, PU/water, PMMA/water, and PU/PMMA 128 4.4.3 Particle size with different conversions of MMA 130 4.4.4 Consideration of four PU/PMMA systems 130 4.4.5 Comparison of TEM observation and the predicted morphology from thermodynamic consideration 132 4.5 Conclusion 135 4.6 References 136 Chapter 5 PU/Polyaniline and (PU-PMMA)/Polyaniline Conductive Core-Shell Particles: Preparation, Morphology and Conductivity 149 5.1 Introduction 151 5.2 Experimental 154 5.2.1 Materials 154 5.2.2 Preparation of PU and PU/PMMA core latex 154 5.2.3 Synthesis of PU/PANI and PU-PMMA/PANI latex 154 5.3 Analysis 156 5.4 Results and discussion 157 5.4.1 UV-Visible spectra of PU/PANI and PU-PMMA/PANI Latex 157 5.4.2 Morphology of PU/PANI and PU-PMMA/PANI Latex 159 5.4.3 Conductivity of PU/PANI and PU-PMMA/PANI disk pellets 163 5.5 Conclusion 165 5.6 References 167 Introduction to Author 185 List of Publication 18611917348 bytesapplication/pdfen-US迷你乳化聚合聚胺酯聚苯胺miniemulsion polymerizationPUPANIthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/55295/1/ntu-95-D91527014-1.pdf