Phosphorylation of polysaccharides: New results on synthesis and characterisation of phosphorylated cellulose

Characterisation and properties of homo- and heterogenously phosphorylated nanocellulose

“…Despite that we could observe a new small adsorption band at 1740 cm −1 but only for heterogeneously phosphorylated p-NCC, which can be attributed to the carboxyl or aldehyde vibration modes arising from the opened terminal glycopyranose rings or oxidation of the C OH groups during the phosphorylation process. On the other hand, the homogeneously phosphorylated p-NFC as well as p-NCC samples showed the appearance of several new bands; a band at ∼2360 cm −1 corresponding to the P H stretching vibration mode (Suflet et al, 2006), a band at ∼1240 cm −1 corresponding to the P O stretching mode (Aoki & Nishio, 2010) (only detectable for the p-NFC) and the peaks between 920 and 1000 cm −1 attributable to the P OH stretching vibration mode of the phosphoric group (Suflet et al, 2006). For homogenously phosphorylated p-NFC a highly increased band between 1500 and 1700 cm −1 was observed with the three maxima appearing at 1600, 1625 and 1660 cm −1 .…”

“…The creating of negatively charged phosphoric groups (such as cellulose phosphate or cellulose phosphite) on cellulose is a well-known strategy when producing materials applicable in orthopaedics (Petreus et al, 2014), biomedical (Granja et al, 2001a(Granja et al, , 2001bLi, Wang, Liu, Xiong, & Liu, 2012;Mucalo, Kato, & Yokogawa, 2009), textile (Aoki & Nishio, 2010;Tzanov, Stamenova, & Cavaco-Paulo, 2002), plastics (as flame-retardants' fillers) (Gérard, Fontaine, & Bourbigot, 2010), fuel cell (Ma & Sahai, 2013) bio-chemical separation (as cation exchangers) (Suflet, Chitanu, & Popa, 2006), and other applications (such as protein adsorbents) (Oshima, Taguchi, Ohe, & Baba, 2011).…”

“…The synthesis of phosphorus cellulose derivatives has thus been performed in various solvents [dimethyl sulphoxide (DMSO)-methylamine, DMAc-LiCl, SO 3 -triethylamine, formic acid, trifluoroacetic acid, N,N-dimethylformamide (DMF)-N 2 O 4 , paraformaldehyde, trimethylchlorosilane-DMF, urea in melt or aqueous-NaOH], with many variants of phosphorous compounds (phosphoric and phosphinic acids, phosphorus oxoacids, phosphorus pentoxide, amidophosphates, alkyl or aryl derivatives of phosphorous acids) (Granja et al, 2001a(Granja et al, , 2001bIsogai & Atalla, 1998;McCormick, Callais, & Hutchinson, 1985;Nifant'ev, 1965;Oshima et al, 2011;Petreus, Bubulac, Petreus, & Cazacu, 2003;Ramos, Assaf, El Seoud, & Frollini, 2005). The highest substitution degree (DS between 1 and 2.8) of water soluble phosphorylated cellulose was obtained from the reaction of MCC with phosphorous acid/urea, either in melt (Inagaki, Nakamura, Asai, & Katsuura, 1976;Suflet et al, 2006) or subsequently to microwave activation (Gospodinova et al, 2002). Phosphorylation of different cellulose derivates (i.e.…”

An ionic liquid as reaction media for radiation-induced grafting of thermosensitive poly (N-isopropylacrylamide) onto microcrystalline cellulose

“…The following characteristic bands in the IR spectrum of original MCC (Fig. 3a) were observed: a large absorption band at 3300-3500 cm À1 corresponding to the vibration of valence for OH groups; a band at 2700-2900 cm À1 attributed to CH 2 groups; characteristic bands at 1161 and 1109 cm À1 for CAOAC from the glucosidic units (Suflet, Chitanu, & Popa, 2006). The sharp bands at 1387 and 1367 cm À1 in cellulose-g-PNIPAAm (Fig.…”

Cationic curdlan: Synthesis, characterization and application of quaternary ammonium salts of curdlan

“…A solution of 0.1 N KOH was used in order to estimate DS by conductometric titration, according to the method already verified (Suflet, Chitanu, & Popa, 2006). Viscometric measurements were performed with an Ubbelohde viscometer with type 0a capillary, at 25 ± 0.01 • C using an AVS 350 Schott (Germany) automatic viscosity measuring system.…”