Effect of molecular weight and degree of chitosan deacetylation on the preparation and characteristics of chitosan thermosensitive hydrogel as a delivery system

Optimization of shrimp shell waste deacetylation for chitosan production

“…Between 1250 and 1080 cm -1 which represents the free amino group (-NH2) at C2 position of glucosamine indicates a major group that present in chitosan. FTIR spectra obtained for the chitosan produced showed the absorption bands for the free amino group between 1086 and 1254 cm -1 and also some bands which is also reported by Zhou et al (2008) where same strong characteristic amino peaks of chitosan at 3420, 1655, and 1325 cm -1 . Some of the bands were also observed by Puvvada et al (2002), 2911 (symmetric CH3 and asymmetric CH2 stretching), 1584 (-C=O secondary amide), and 1421 (-CN secondary amide).…”

“…Previous study done by Wan et al (2003) reported that the chitosan obtained highest DDA value 95.1% when performing deacetylation twice but the process was performed in a reactor at 100 o C using 50 % NaOH for 1 hour treatment. Another study which also conducted deacetylation twice is done by Zhou et al (2008) and managed to produce chitosan with DDA value 90.3 % by performing with 50% NaOH at 100 o C for 30 minutes. This explains that the DDA values can be different due to series of parameters used or conditions during the deacetylation process.…”

Hydrogels: Methods of Preparation, Characterisation and Applications

“…Wound care polyurethane, poly(ethylene glycol), poly(propylene glycol), (Rosiak & Yoshii, 1999) poly(vinylpyrrolidone), polyethylene glycol and agar (Benamer et al, 2006;Lugao & Malmonge, 2001;Rosiak et al, 1995) Xanthan, methyl cellulose (2006) carboxymethyl cellulose, alginate, hyaluronan and other hydrocolloids Rosiak et al, 1995;Rosiak & Yoshii, 1999;Walker et al, 2003) Drug delivery, pharmaceutical poly(vinylpyrrolidone) (Benamer et al, 2006;Rosiak et al, 1995) starch, poly(vinylpyrrolidone), poly(acrylic acid) (Kumar et al, 2008;Spinelli et al, 2008) carboxymethyl cellulose, hydroxypropyl methyl cellulose (Barbucci et al, 2004;Porsch & Wittgren, 2005) polyvinyl alcohol, acrylic acid, methacrylic acid chitosan, -glycerophosphate (Zhou et al, 2008) -carrageenan, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid (Campo et al, 2009;Pourjavadi & Zohuriaan-Mehr, 2002) acrylic acid, carboxymethyl cellulose (Rosiak et al, 1995) hyaluronan Shu et al, 2004) collagen (Drury & Mooney, 2003) Injectable polymeric system polyesters, polyphosphazenes, polypeptides, chitosan…”

Advanced microgel-functionalized polyester textiles adaptive to ambient conditions

“…On the other hand, CS also absorbs at 1632 cm -1 (C=O stretching, N-H bending) and 1550 cm -1 (N-H bending). These absorptions correlated with the broad peak that appears centered at 3300 cm -1 (O-H and N-H stretching) are attributed to its primary amine groups (-NH 2 ), residual acetylated units (-NHCOCH 3 ), and alcohol groups (Brugnerotto et al 2001;Zhou et al 2008). The bands at 1378 cm -1 and 1403 cm -1 (C-H bending) are assigned to the -CH 2 -groups.…”

“…The bands at 1378 cm -1 and 1403 cm -1 (C-H bending) are assigned to the -CH 2 -groups. Furthermore, the characteristic saccharide units of CS absorb at 1031 cm -1 and 1072 cm -1 (-C-O-C-bridge stretching), and at 1148 cm -1 (-C-O-C-bridge anti-symmetric stretching) (Zhou et al 2008;Kumirska et al 2010 With many of the FTIR-ATR bands of PNIAA and CS overlapping, it was difficult to distinguish the differences among the various microgel-treated polyesters. Another hindrance was that, due to the strong absorbance of the polyester substrate itself, any microgel bands that would appear close to the polyester bands (e.g.…”