Synthesis, Characterization, and Gas Permeation Properties

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78 Dendronization of Ethyl Cellulose structures and organosolubility of ethyl cellulose carrying hydroxy (anchor) groups available for derivatization, it would be interesting to synthesize novel dendron-functionalized macromolecular architectures based on cellulose and to investigate the structural characteristics and functions of this new emerging class of ‘hybrid architectures’ derived from dendrimers and the most sustainable linear polymers. The present episode narrates the synthesis and characterization of G1 and G2 of various amide-containing dendrons and dendronized derivatives (2a–c, 3a–c) of ethyl cellulose (1) (Schemes 1 and 2). The solubility characteristics and thermal properties of the resulting polymers were elucidated. Free-standing membranes of the dendronized polymers (2a–c) were fabricated and their density, fractional free volume, and gas permeation parameters were determined. Moreover, the diffusion and solubility coefficients of polymer membranes for O2, N2, CO2, and CH4 were also revealed. Experimental Section Measurements. 1 H and 13 C NMR spectra were recorded on a JEOL EX-400 spectrometer and the residual proton or carbon signal of the deutrated solvent was used as internal standard. The samples for the NMR measurements were prepared at a concentration of approximately 10 mg/mL and chemical shifts are reported in parts per million (ppm). The 1 H NMR spectra of ethyl cellulose and dendronized polymers were recorded for 192 scans with a pulse delay of 37 s in order to obtain reliable integrations. Infrared spectra were recorded on a Jasco FTIR-4100 spectrophotometer and 68 spectra were accumulated at a resolution of 4 cm -1 , for each measurement. The FAB-MS analyses were conducted using the JEOL JMS-HX110A and JMS-SX102A spectrometers while 3-nitrobenzyl alcohol (MNBA) was used as a matrix. Melting points (mp) were determined with a Yanaco micro melting point apparatus and elemental analyses were conducted with a Yanaco-CHN corder at the Microanalytical Center of Kyoto University. The number- and weight-average
79 Chapter 3 molecular weights (Mn and Mw, respectively) and polydispersity indices (Mw/Mn) of polymers were determined by gel permeation chromatography (GPC) on a JASCO Gulliver system (PU-980, CO-965, RI-930, and UV-2075). All of the measurements were carried out at 40 ºC using two TSK-Gel columns [α-M (bead size, 13 μm; molecular weight range > 1×10 7 ) and GMHXL (bead size 9 μm; molecular weight range up to 4×10 8 )] in series and LiBr solution (0.01 M) in N,N-dimethylformamide as an eluent at a flow rate of 1.0 mL/min. The elution times were converted into molecular weights using a calibration curve based on polystyrene standards in combination with the information obtained from the refractive index detector. Thermogravimetric analyses (TGA) were conducted in air with a Shimadzu TGA–50 thermal analyzer by heating the samples (3–5 mg) from 100–700 ºC at a scanning rate of 10 ºC min -1 . Differential scanning calorimetric (DSC) analyses were performed using a Seiko DSC6200/EXSTAR6000 apparatus and measurements were carried out by making use of 3–5 mg samples, under a nitrogen atmosphere, after calibration with an indium standard. The samples were first heated from ambient temperature (25 ºC) to 260 °C at a scanning rate of 20 ºC min -1 (first heating scan) and then immediately quenched to -100 °C at a rate of 100 ºC min -1 . The second heating scans were run from -100 to 260 °C at a scanning rate of 20 ºC min -1 to record stable thermograms. The data for glass transition temperature (Tg) were obtained from the second run and correspond to the midpoint of discontinuity in the heat flow. Membrane thickness was estimated by using a Mitutoyo micrometer. The gas permeability coefficients (P) were measured with a Rikaseiki K-315-N gas permeability apparatus using a constant volume/variable-pressure system. 14 All of the measurements were carried out at 25 ºC and a feed pressure of 0.1 MPa (1 atm) while the pressure difference across the membrane was ~107 kPa as the system was being evacuated on the downstream side of the membrane. Materials. Ethyl cellulose (1; ethoxy content, 49 wt%) and N-(3-aminopropyl)propane-1,3-diamine (98%) were purchased from Aldrich and used as received. 1,1′-Carbonyldiimidazole (Sigma-Aldrich), 2-ethylbutanoic acid (97%,
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Synthesis, Characterization, and Ga
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Table of Contents General Introduct
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General Introduction cellulose deri
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General Introduction biogenetically
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General Introduction chemistry offe
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General Introduction solution-diffu
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General Introduction A simplified t
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General Introduction been observed
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polymers. 41,46 General Introductio
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General Introduction Keeping in vie
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General Introduction the derivatize
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General Introduction strategy (G1-a
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General Introduction In conclusion,
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General Introduction 5. (a) Kobayas
Page 29 and 30: General Introduction 15. (a) Goetma
Page 31 and 32: General Introduction American Chemi
Page 33 and 34: General Introduction Macromolecules
Page 35 and 36: Silylation of Ethyl Cellulose Intro
Page 37 and 38: Silylation of Ethyl Cellulose milli
Page 39 and 40: Silylation of Ethyl Cellulose chlor
Page 41 and 42: Silylation of Ethyl Cellulose Resul
Page 43 and 44: Silylation of Ethyl Cellulose Solub
Page 45 and 46: Silylation of Ethyl Cellulose 1.034
Page 47 and 48: Silylation of Ethyl Cellulose poly(
Page 49 and 50: Silylation of Ethyl Cellulose the r
Page 51 and 52: Silylation of Ethyl Cellulose D.; Y
Page 53 and 54: Chapter 2 51 Chapter 2 Synthesis, C
Page 55 and 56: 53 Chapter 2 are few and far betwee
Page 57 and 58: 55 Chapter 2 constant volume/variab
Page 59 and 60: 57 Chapter 2 Membrane Density. Memb
Page 61 and 62: 59 Chapter 2 IR spectrum of 1 (Figu
Page 63 and 64: 61 Chapter 2 1,3-bis(trifluoromethy
Page 65 and 66: 63 Chapter 2 The increase in the po
Page 67 and 68: 65 Chapter 2 other fluorinated poly
Page 69 and 70: 67 Chapter 2 of the gas permeabilit
Page 71 and 72: 69 Chapter 2 Gas Diffusivity and So
Page 73 and 74: 71 Chapter 2 mobility of the perflu
Page 75 and 76: 73 Chapter 2 1325-1329. (b) Hamza,
Page 77 and 78: Chapter 3 75 Chapter 3 Synthesis an
Page 79: 77 Chapter 3 cost, and above all ap
Page 83 and 84: 81 Chapter 3 1.99-2.07 (m, 2H, (CH3
Page 85 and 86: 83 Chapter 3 25 °C, ppm): 11.9, 13
Page 87 and 88: 85 Chapter 3 38.1, 44.7, 46.8, 47.9
Page 89 and 90: 87 Chapter 3 CH2CH2C(=O)O), 2.50-4.
Page 91 and 92: 89 Chapter 3 1091, 1053, 853, 806,
Page 93 and 94: 91 Chapter 3 dendrons (G1-a-ІІ-G1
Page 95 and 96: 93 Chapter 3 (DMAP) as a base, as s
Page 97 and 98: Figure 3. FTIR spectra of 1, 2c, an
Page 99 and 100: 97 Chapter 3 (partly soluble) and 3
Page 101 and 102: 99 Chapter 3 increased polarity of
Page 103 and 104: 101 Chapter 3 that of 1, and approx
Page 105 and 106: 103 Chapter 3 derivatization per th
Page 107 and 108: 105 Chapter 3 (2a-c) were in the or
Page 109 and 110: 107 Chapter 3 2709-2719. (b) Schenn
Page 111 and 112: 109 Chapter 3 17. van Krevelen, D.
Page 113 and 114: Chapter 4 111 Chapter 4 Synthesis,
Page 115 and 116: 113 Chapter 4 Since, no significant
Page 117 and 118: 115 Chapter 4 Materials. Ethyl cell
Page 119 and 120: DStotal = DSEt + DSCarb (for 1a and
Page 121 and 122: 119 Chapter 4 Figure 2. 1 H NMR spe
Page 123 and 124: 121 Chapter 4 ruling out the possib
Page 125 and 126: 123 Chapter 4 t-butyl moiety. A str
Page 127 and 128: 125 Chapter 4 reported to lead to t
Page 129 and 130: 127 Chapter 4 Table 4. Gas Permeabi
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129 Chapter 4 augmentation in eithe
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131 Chapter 4 indicate the signific
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133 Chapter 4 M.-R. J. Appl. Polym.
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Chapter 5 135 Chapter5 Synthesis an
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137 Chapter5 acid- and peptide-cont
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139 Chapter5 Specific rotations ([
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141 Chapter5 1.66 (brs, 1.1H, NHCH(
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143 Chapter5 as shown in Scheme 1,
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145 Chapter5 in Table 1. The molecu
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147 Chapter5 almost same pattern of
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Conclusions Table 3. Thermal Proper
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151 Chapter5 W.; Jing, X. J. Polym.
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Chapter 5 Synthesis and Properties
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Acknowledgments While submitting th
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Synthesis, Characterization, and Ga
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Synthesis, Characterization, and Gas Permeation Properties

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