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The goal of this study was to investigate the role of ethanol and temperature on the hydroxyl and carbonyl groups in biopolyol produced from hydrothermal liquefaction of loblolly pine (Pinus spp.) carried out at 250, 300, 350 and 390°C for 30min. Water and water/ethanol mixture (1/1, wt/wt) were used as liquefying solvent in the HTL experiments. HTL in water and water/ethanol is donated as W-HTL and W/E-HTL, respectively. It was found that 300°C and water/ethanol solvent was the optimum liquefaction temperature and solvent, yielding up to 68.1wt.% bio-oil and 2.4wt.% solid residue. (31)P-NMR analysis showed that biopolyol produced by W-HTL was rich in phenolic OH while W/E-HTL produced more aliphatic OH rich biopolyols. Moreover, biopolyols with higher hydroxyl concentration were produced by W/E-HTL. Carbonyl groups were analyzed by (19)F-NMR, which showed that ethanol reduced the concentration of carbonyl groups., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Chitosan is a natural polymer, which has similar structure and bioactivity with glycosaminoglycan, and is a potential material for use as injectable hydrogels. Authors elucidate structure-property relationship with particular focus on chitosan-based injectable hydrogels, and their application as biomaterials. The different gelation approach, including physical cross-link, chemical cross-link, ionic cross-link and supramolecular interaction, enable a variety of chitosan-based injectable hydrogels to be formed. These gelation methods have significant impact on the structure and properties of hydrogels, which governs their use as tissue engineering scaffold and drug delivery vehicle. [ABSTRACT FROM AUTHOR]