Metal complexed-enzymatic hydrolyzed chitosan improves moisture retention of fiber papers by migrating immobilized water to bound state

Publication date: Available online 9 February 2020Source: Carbohydrate PolymersAuthor(s): Huijuan Wang, Heping Cui, Xuejiao Wang, Chao Lin, Shuqin Xia, Khizar Hayat, Shahzad Hussain, Muhammad Usman Tahir, Xiaoming ZhangAbstractTo obtain chitosan (CTS) with narrower molecular weight distribution, CTS with weight-average molecular weight (MW) of 197.30 kDa was first metal complexed and then degraded into five CTSs with MW of 107.90, 56.48, 10.40, 5.67 (CTS-4) and 3.66 kDa. Decrease of MW did not cause a significant change in chemical structure of the residue CTS, but the crystal structure was transformed significantly. The moisture retention increased firstly and then decreased as the MW of CTS decreased. CTS-4 was superior to CTSs with other MW and propylene glycol in terms of the moisture retention. The lower water activity and increase of net isosteric heat were observed in CTS-4, which was due to the migration of immobilized water to a bound-state caused by mounting newly formed chain-end hydrophilic groups per unit weight. CTS-4 could effectively improve moisture retention, showing a potential to substitute commonly used humectant such as propylene glycol.Graphical abstract
Source: Carbohydrate Polymers - Category: Biomedical Science Source Type: research