Nanostructured Composites Obtained by ATRP Sleeving of Bacterial Cellulose Nanofibers with Acrylate Polymers

Abstract

Novel nanostructured composite materials based on bacterial cellulose membranes (BC) and acrylate polymers were prepared by in situ atom transfer radical polymerization (ATRP). BC membranes were functionalized with initiating sites, by reaction with 2-bromoisobutyryl bromide (BiBBr), followed by atom transfer radical polymerization of methyl methacrylate (MMA) and n-butyl acrylate (BA), catalyzed by copper(I) bromide and N,N,N',N″,N″-pentamethyldiethylenetriamine (PMDETA), using two distinct initiator amounts and monomer feeds. The living characteristic of the system was proven by the growth of PBA block from the BC-g-PMMA membrane. The BC nanofiber sleeving was clearly demonstrated by SEM imaging, and its extent can be tuned by controlling the amount of initiating sites and the monomer feed. The ensuing nanocomposites showed high hydrophobicity (contact angles with water up to 134°), good thermal stability (initial degradation temperature in the range 241-275 °C), and were more flexible that the unmodified BC membranes.

Poly(bis[2-(methacryloyloxy)ethyl] phosphate)/Bacterial Cellulose Nanocomposites: Preparation, Characterization and Application as Polymer Electrolyte Membranes

“…The solid-state 13 C CP/MAS NMR spectroscopy also validated the composition of the nanocomposites through the presence of the representative resonances of both P(bisMEP) and BC, as depicted in Figure 3. Nanocomposites P(bisMEP)/BC_1 and P(bisMEP)/BC_2 exhibit the resonances of the BC at δ 65.2 ppm (C6), 71.7-74.5 ppm (C2, C3, C5), 89.0 ppm (C4) and 105.1 ppm (C1) [35], jointly with those of P(bisMEP) at δ 16.5 ppm (CH3 of polymer backbone, C3′), 45.0 ppm (quaternary C of polymer backbone, C2′), 54.4 ppm (CH2 of polymer backbone, C1′), 65.1 ppm (OCH2CH2O, C5′) and 177.2 ppm (C=O, C4′). The comparison between the spectra of P(bisMEP)/BC_1 and P(bisMEP)/BC_2 ) shows an increase of the intensity of the resonances allocated to P(bisMEP) with the increasing polymer content and are in accord with the WP(bisMEP)/Wtotal ratio ( Table 1).…”

Immobilization of α-amylase onto poly(glycidyl methacrylate) grafted electrospun fibers by ATRP

“…Then, 148 μL (0.0011 mol) of BiBBr in 1 mL DMF was added dropwise to the ice-cold reaction mixture. The reaction proceeded at room temperature for 24 h. The brominated nanofiber was thoroughly washed with fresh DMF to remove residual reactants and byproducts [18].…”

Reinforcement of bacterial cellulose aerogels with biocompatible polymers

“…BC- g -PMMA, BC- g -PBA, BC- g -PMMA- co -PBA; Lacerda, Barros-Timmons, Freire, Silvestre, & Neto, 2013). Further techniques are in situ generation of the interpenetrating network by loading and subsequent chain-growth polymerization of a suitable monomer such as methacrylic acid (Hobzova, Duskova-Smrckova, Michalek, Karpushkin, & Gatenholm, 2012) or precipitation of the reinforcing polymer from a compatible solvent, filling the voids of the cellulosic network, as it has been described in our previous work for BC/cellulose acetate composites (Liebner, Aigner, Schimper, Potthast, & Rosenau, 2012).…”