New Functional Polymer Materials via Click Chemistry-Based Modification of Cellulose Acetate

Abstract

Cellulose acetate (CA) was partially acrylated, and the resulting cellulose acetate acrylate (acryl-substitution degree of 0.2) underwent quantitative thio-Michael click reactions with various thiols. A toolbox of functional CA polymers was obtained in this way, and their properties were studied. The modification with fatty alkyl thiols led to hydrophobic materials with large water drop contact angles. Octadecylthio-, butoxycarbonylpropylthio-, and furanylthio-modifications formed highly transparent materials. The new derivative CAASFur disintegrated completely under industrial composting conditions. Films of modified CA polymers were cast and investigated in terms of barrier properties. The nanocomposite of CAAS18 compounded with a synthetic layered silicate (hectorite) of a large aspect ratio showed permeabilities as low as 0.09 g mm m −2 day −1 for water vapor and 0.16 cm 3 mm m −2 day −1 atm −1 for oxygen. This portfolio of functional CA polymers opens the door to new applications.

Modification of Cellulose Ether with Organic Carbonate for Enhanced Thermal and Rheological Properties: Characterization and Analysis

“…29 Therefore, in recent years, there has been a search for less polluting, simpler, and more efficient energy methods to improve thermal stability and enhance the properties of solutions. 22,28,30 Propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), and dimethyl carbonate (DMC) are nonpolymeric cyclic and acyclic organic carbonate solvents that are minimally toxic and biodegradable. 31 These solvents have been investigated as green cosolvents for modification and are considered viable alternatives to conventional ionic liquids regarding safety and environmental impact.…”

“…Ionic liquids and solvents are being used for modification and regeneration to enhance the properties of polymers . However, the current regeneration methods are considered highly problematic due to toxic ionic solvents and reagents requiring multiple derivatization steps and high-temperature reactions . These processes are associated with substantial environmental pollution and pose economic and environmental challenges .…”

“…These processes are associated with substantial environmental pollution and pose economic and environmental challenges . Therefore, in recent years, there has been a search for less polluting, simpler, and more efficient energy methods to improve thermal stability and enhance the properties of solutions. ,, …”

Revisiting the Synthesis of Cellulose Acrylate and Its Modification via Michael Addition Reactions

“…17 Very recently, modification of cellulose acetate acrylate having only partial acryloyl group by thiol-ene reactions was reported. 18 However, these methods using methacrylated and acrylated cellulose derivatives are not applicable to the synthesis of highly functionalized cellulose derivatives with high values of degree of substitution (DS) because the DS values of Michael acceptors are typically low (DS < 0.2). 15,16,18 We envisioned that simple cellulose acrylate 1 could be used as a good precursor to directly synthesize highly modified cellulose 2 by Michael addition with easily available function- alized nucleophiles such as amines if 1 with a high DS value could be synthesized from cellulose by acylation with acryloyl chloride (Scheme 1a).…”

“…18 However, these methods using methacrylated and acrylated cellulose derivatives are not applicable to the synthesis of highly functionalized cellulose derivatives with high values of degree of substitution (DS) because the DS values of Michael acceptors are typically low (DS < 0.2). 15,16,18 We envisioned that simple cellulose acrylate 1 could be used as a good precursor to directly synthesize highly modified cellulose 2 by Michael addition with easily available function- alized nucleophiles such as amines if 1 with a high DS value could be synthesized from cellulose by acylation with acryloyl chloride (Scheme 1a). 19,20 Although there are few reports of the application of 1 to the precursor for versatile modification of cellulose, cellulose acrylate 1 is known as a precursor of radical polymerization.…”