Synthesis, Characterization, and Gas Permeation Properties

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37 Chapter 1 where MA is the weight of membrane in air and ML is that in the auxiliary liquid. Aqueous NaNO3 solution was used as an auxiliary liquid. Fractional Free Volume (FFV) of Polymer Membranes. FFV (cm 3 of free volume/cm 3 of polymer) is commonly used to estimate the efficiency of chain packing and the amount of space (free volume) available for gas permeation in the polymer matrix. FFV is calculated by the following equation: 10 FFV = (υsp – υ0)/ υsp ≈ (υsp – 1.3 υw)/ υsp where υsp and υ0 are the specific volume and occupied volume (or zero-point volume at 0 K) of the polymer, respectively. Typically, occupied volume (υ0) is estimated as 1.3 times the van der Waals volume (υw), which is calculated by the group contribution method. 11 Measurement of Gas Permeation Parameters. The P values were calculated from the slopes of time-pressure curves in the steady state where Fick’s law holds. 12 The D values were determined by the time lag method using the following equation: D = l 2 /6θ here, l is the membrane thickness and θ is the time lag, which is given by the intercept of the asymptotic line of the time-pressure curve to the time axis. The membrane thickness was controlled so that the time lag would be in the range of 10–300 s, preferably 30–150 s. When the time lag was < 10 s, the error of measurement became relatively large. If the time lag was, on the contrary, > 300 s, the error arising from the baseline drift became serious. The gas solubility coefficients (S) were calculated by using the equation, S = P/D.
Silylation of Ethyl Cellulose Results and Discussion Silylation of Ethyl Cellulose. Silylation of ethyl cellulose was carried out by employing various chlorosilanes as silylating agents, THF as a solvent, and imidazole as a base as shown in Scheme 1, and the results are summarized in Table 1. Table 1. Degree of Substitution and Molecular Weight of Polymers 1 and 2a–f polymer DSSi a DStotal a Mw b Mw/Mn b 1 0.00 2.69 195 000 3.46 2a 0.32 3.01 187 000 2.26 2b 0.31 3.00 237 000 2.90 2c 0.33 3.02 289 000 4.24 2d 0.31 3.00 206 000 3.11 2e 0.34 3.03 264 000 2.20 2f 0.38 3.07 168 000 2.59 a DSSi: Degree of silylation, DStotal: Total degree of substitution. Calculated from 1 H NMR. b Determined by GPC (THF, PSt). Figure 1. 1 H NMR spectra of polymers 1 and 2a–f in CDCl3 at 25 ºC. 38
Page 1 and 2: Synthesis, Characterization, and Ga
Page 3 and 4: Table of Contents General Introduct
Page 5 and 6: General Introduction cellulose deri
Page 7 and 8: General Introduction biogenetically
Page 9 and 10: General Introduction chemistry offe
Page 11 and 12: General Introduction solution-diffu
Page 13 and 14: General Introduction A simplified t
Page 15 and 16: General Introduction been observed
Page 17 and 18: polymers. 41,46 General Introductio
Page 19 and 20: General Introduction Keeping in vie
Page 21 and 22: General Introduction the derivatize
Page 23 and 24: General Introduction strategy (G1-a
Page 25 and 26: General Introduction In conclusion,
Page 27 and 28: 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: Silylation of Ethyl Cellulose chlor
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 and 80: 77 Chapter 3 cost, and above all ap
Page 81 and 82: 79 Chapter 3 molecular weights (Mn
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.
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89 Chapter 3 1091, 1053, 853, 806,
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91 Chapter 3 dendrons (G1-a-ІІ-G1
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93 Chapter 3 (DMAP) as a base, as s
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Figure 3. FTIR spectra of 1, 2c, an
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97 Chapter 3 (partly soluble) and 3
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99 Chapter 3 increased polarity of
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101 Chapter 3 that of 1, and approx
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103 Chapter 3 derivatization per th
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105 Chapter 3 (2a-c) were in the or
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107 Chapter 3 2709-2719. (b) Schenn
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109 Chapter 3 17. van Krevelen, D.
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Chapter 4 111 Chapter 4 Synthesis,
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113 Chapter 4 Since, no significant
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115 Chapter 4 Materials. Ethyl cell
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DStotal = DSEt + DSCarb (for 1a and
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119 Chapter 4 Figure 2. 1 H NMR spe
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121 Chapter 4 ruling out the possib
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123 Chapter 4 t-butyl moiety. A str
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125 Chapter 4 reported to lead to t
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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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