Synthesis, Characterization, and Gas Permeation Properties

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110 Dendronization of Ethyl Cellulose 28. (a) Yampolskii, Yu.; Pinnau, I.; Freeman, B. D. Materials Science of Membranes for Gas and Vapor Separation; Wiley: Chichester, 2006. (b) Pinnau, I.; Freeman, B. D. Advanced Materials for Membrane Separations; ACS Symposium Series 876; American Chemical Society: Washington, DC, 2004. (c) Baker, R. W. Membrane Technology and Applications, 2nd ed.; Wiley: New York, 2004. (d) Graham, T. Philos. Mag. 1866, 32, 401–420. 29. Ghosal, K.; Freeman, B. D. Polym. Adv. Technol. 1994, 5, 673–697.
Chapter 4 111 Chapter 4 Synthesis, Characterization, and Gas Permeation Properties of t-Butylcarbamates of Cellulose Derivatives Abstract t-Butylcarbamates of ethyl cellulose (1; DSEt, 2.69 and 2; DSEt, 2.50) and cellulose acetate (3; DSAc, 2.46 and 4; DSAc, 1.80) were synthesized by the reaction of residual hydroxy groups of cellulose derivatives with t-butylisocyanate. The 1 H NMR spectra and elemental analysis were employed to determine the degree of incorporation of carbamoyl moiety (DSCarb) and almost complete substitution of the residual hydroxy protons was observed. The presence of the peaks characteristic of the carbamate linkage in the FTIR spectra furnished further evidence for the successful carbamoylation of ethyl cellulose and cellulose acetate. The resulting polymers (1a–4a) were soluble in common organic solvents. The onset temperatures of weight loss of 1a–4a were 177–204 °C, indicating fair thermal stability. The free-standing membranes of 1–4 and 1a–4a were fabricated, and derivatized polymers exhibited enhanced gas permeability, especially the gas permeability of cellulose acetate (3; DSAc, 2.46 and 4; DSAc, 1.80) underwent a significant increment. 4a exhibited a remarkable increase in CO2 permeability, i.e., 22 times higher than that of 4 (PCO2 38 barrers; cf. PCO2 of 4, 1.7 barrers). Quite interestingly, a more or less retainment of CO2/N2 permselectivity was revealed.
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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
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General Introduction 15. (a) Goetma
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General Introduction American Chemi
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General Introduction Macromolecules
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Silylation of Ethyl Cellulose Intro
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Silylation of Ethyl Cellulose milli
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Silylation of Ethyl Cellulose chlor
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Silylation of Ethyl Cellulose Resul
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Silylation of Ethyl Cellulose Solub
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Silylation of Ethyl Cellulose 1.034
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Silylation of Ethyl Cellulose poly(
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Silylation of Ethyl Cellulose the r
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Silylation of Ethyl Cellulose D.; Y
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Chapter 2 51 Chapter 2 Synthesis, C
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53 Chapter 2 are few and far betwee
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55 Chapter 2 constant volume/variab
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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.
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: 109 Chapter 3 17. van Krevelen, D.
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
Page 131 and 132: 129 Chapter 4 augmentation in eithe
Page 133 and 134: 131 Chapter 4 indicate the signific
Page 135 and 136: 133 Chapter 4 M.-R. J. Appl. Polym.
Page 137 and 138: Chapter 5 135 Chapter5 Synthesis an
Page 139 and 140: 137 Chapter5 acid- and peptide-cont
Page 141 and 142: 139 Chapter5 Specific rotations ([
Page 143 and 144: 141 Chapter5 1.66 (brs, 1.1H, NHCH(
Page 145 and 146: 143 Chapter5 as shown in Scheme 1,
Page 147 and 148: 145 Chapter5 in Table 1. The molecu
Page 149 and 150: 147 Chapter5 almost same pattern of
Page 151 and 152: Conclusions Table 3. Thermal Proper
Page 153 and 154: 151 Chapter5 W.; Jing, X. J. Polym.
Page 155 and 156: Chapter 5 Synthesis and Properties
Page 157 and 158: Acknowledgments While submitting th
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