Amino acid‐functionalized ethyl cellulose: Synthesis, characterization, and gas permeation properties

Abstract

Amino acid esters of ethyl cellulose [R 0 ¼ H (1), CH 3 (2), CH 2 CH(CH 3 ) 2 (3), CH 2 CONH 2 (4), CH 2 OCH 2 C 6 H 5 (5, 5 0 ), CH 2 CH 2 CH 2 CH 2 NHOCOC(CH 3 ) 3 (6)] were synthesized in moderate to quantitative yields (30-99%) by the reaction of t-butoxycarbonyl (t-Boc)-protected amino acids or an activated ester derivative with hydroxy groups of ethyl cellulose [EC; degree of substitution (DS Et ), 2.69]. The amino acid functionalities displaying varied chemical nature, shape, and bulk were used, and bulk of the substituent on the a-carbon of amino acids was elucidated to be of vital significance for the observed degree of incorporation (DS Est ). 1 H NMR spectra were used to determine the degree of incorporation of amino acid moiety (DS Est ), and almost complete substitution of the hydroxy protons was revealed in 1, 2, and 5 0 . The onset temperatures of weight loss of 1-6 were 198-218 C, indicating fair thermal stability. The glass transition temperatures of the derivatized polymers were 30-40 C lower than that of EC (T g 131 C; cf. T g of 1-6, 93.5-103 C). Free-standing membranes of EC and its amino acid esters (1, 2, 5, 5 0 , and 6) were fabricated, and enhanced permselectivity for CO 2 /N 2 and CO 2 /CH 4 gas pairs was discerned, when compared with EC. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: [3986][3987][3988][3989][3990][3991][3992][3993] 2010

Gas permeation behavior of CTA polymer inclusion membrane (PIM) containing an acidic carrier for metal recovery (DEHPA)

“…The gas permeability values obtained with CTA and CTA + NPOE membranes were comparables with those acquired by Ikeuchi et al [19] employing amino acid-functionalized ethyl cellulose (EC) derivatives for gas permeation study and higher of the values attained by Morita et al [18] using the silyl derivatives of cellulose acetate membranes for the permeation of the same gases. The PIM (CTA + NPOE À D2EHPA) exhibited higher gas permeability than that reached by the same authors.…”

“…However, as the value of gas permeability undergoes an increase, a decrease in permselectivity is observed. The most important feature of the gas permeability data of the polymer inclusion membranes is relatively high PCO 2 / PH 2 selectivity (= 5.6) compared with the permselectivities showed in the above studies [18,19] (PCO 2 /PH 2 selectivity 62.36 and 1.52 in the Refs. [18] and [19], respectively).…”

“…Derivatives of cellulose such as silyl derivatives of cellulose acetate [18] and amino acid-functionalized ethyl cellulose (EC) derivatives [19] were synthesized and their gas permeation characteristics were defined.…”

Ethanol organosolv lignin-based rigid polyurethane foam reinforced with cellulose nanowhiskers

“…1,2 Due to their renewable and biodegradable nature, extremely wide availability, non-agricultural based economy, and reactivity attributed to various functional groups, cellulose and lignin have been exploited in many applications. [3][4][5][6][7][8][9][10][11][12][13][14][15] Cellulose nanowhiskers (CNWs) are a group of needle-like nano particles hydrolyzed from cellulose fibers. It has a wide size range and is normally 100 to 300 nm in length and 3-15 nm in width for wood or cotton-based CNWs.…”

Amino acid modified cellulose whiskers

“…With regard to cellulose, some recent studies have described the successful modification of cellulose fibrous networks and hydroxypropyl and ethyl cellulose with amino acids having as an objective to develop cell-adhesive structures, hydrophobic drug carriers and gas separation membranes, respectively. 7,8,9,10 In fact, amino acids are the building blocks of proteins and peptides and are involved in the development of a wide range of biocompatible applications or architectures. 9 These include controlled drug delivery systems, 11 celladhesive structures, 7 chiral recognition materials 12 and polymers 13 to mention only a few.…”