Data in support of dual-functionalized cellulose nanofibrils prepared through TEMPO-mediated oxidation and surface-initiated ATRP

Abstract

We previously studied a suitably 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibrils (TOCNs) that can be further functionalized with initiating sites and overcame the obstacle of performing atom transfer radical polymerization (ATRP) in the presence of neutral carboxylic acid sodium salt groups [1]. Herein, characterization of the modified TOCNs and of the products from surface-initiated (SI) ATRP of the (nano)celluloses with styrene (St) was performed using nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), and contact angle (CA) measurements. From the analysis of 1H NMR, a high purity of sacrificial initiator (i.e., 2-hydroxyethyl 2-bromoisobutyrate (HEBiB)) was confirmed. HEBiB was utilized to trace the SI ATRP with the generated free PSt. Gradually molecular weight evaluations were revealed from GPC analysis (ca. Mn=21,000 and Đ=1.10) using different TOCNs, implying the insignificant contribution to the kinetics from the grafted initiating sites. The TOCN-g-PSts were further characterized by contact angles and displayed an obvious reversibility between hydrophilicity and hydrophobicity in tens of minutes. These results illustrated a simple and facile approach for controlling the graft length and composition of TOCNs through SI ATRP.

Surface-Initiated Initiators for Continuous Activator Regeneration (SI ICAR) ATRP of MMA from 2,2,6,6–tetramethylpiperidine–1–oxy (TEMPO) Oxidized Cellulose Nanofibers for the Preparations of PMMA Nanocomposites

“…For an approach of SI RAFT polymerization, RAFT agents have generally a stinky problem to handle and a pinky problem for the products. To overcome these drawbacks, we [6,43] previously immobilized ATRP initiating site on the residual hydroxyl groups of TOCNs with 2–bromoisobutyryl bromide. The modified products (TOCN–Br) were subsequently grafted with polystyrene (PSt) by the surface-initiated (SI) normal ATRP method.…”

Preparations of Tough and Conductive PAMPS/PAA Double Network Hydrogels Containing Cellulose Nanofibers and Polypyrroles

“…Additionally, the repulsions among surface carboxylate groups promote TOCNs to disperse in aqueous or high-polar organic solvents. In recent studies, TOCNs were hybridized with the matrix to construct a porous 3D framework for fabricating TOCN/hydrogels [36][37][38][39] or TOCN/polymer composites [40][41][42][43][44] thermo-responsive hydrogels to efficiently inhibit post-surgical peritoneal adhesions [37]. Li et al incorporated TOCN into polyacrylamide-based shape memory hydrogels to improve the mechanical properties [45].…”