LCh and LChA dissolved in their respective HCl solution were titrated with 0.5 mol dm-3 NaOH solutions under magnetic stirring and the volume of added NaOH was recorded.
Degree of acylation (DA) and degree of substitution (DS) of LChA were then calculated based on the average of triplicates:
Approximately 2 - 3 mg of LCh and LChA were placed in a ceramic pan and heated at a rate of 10 AdegC min-1 from 35 to 900AdegC using Perkin Elmer Pyris 6 Thermogravimetric Analyzer (USA) under a nitrogen purge at 50 mL min-1.
DSC was carried out by weighing approximately 5 mg of LCh and LChA in hermetic aluminium pans with covered lids and heated at a rate of 5 AdegC min-1 from 30 to 300AdegC in a nitrogen atmosphere of 50 AdegC min-1 by using TA Instruments model Q20 calorimeter (Perkin-Elmer, USA).
The kinematic viscosity of LCh and LChA was measured at 20, 30, 40, 50, 60, 70 and 80AdegC using a Cannon Ubbelohde Capillary No 1c and Lauda S5 measuring stand in Lauda E200 water bath (Lauda Scientific GmbH, Germany).
LCh and LChA were spray dried at an inlet temperature of 130AdegC using a Mini Spray Dryer Model 290 (Buchi Labortechnik AG, Flawil, Switzerland).
3, it can be observed that increasing of acid anhydrides caused a higher DS value of the LChA. The increase of the DS of short chains acylated chitosans such as LChC4 and LChC6 (8.0 - 18.0%) was higher than those with longer chains LChC8 and LChC10 (1.5 - 12.0%).
There were three main weight losses showed in TGA thermograms for LCh and LChA, the first was the elimination of adsorbed water moisture (W1) from the beginning of the heating process until a temperature of 140 - 150AdegC was reached.
The LCHA, representing 53 homes in Liverpool, says it needs between pounds 61-88 more per resident each week but councillors voted an increase of just pounds 6 -11.
Len Collins, president of the LCHA, said: ``If the High Court fails to support us then I think we will see meltdown within a month.
But that argument cuts little ice with the LCHA who point to the 3pc cut in council tax in Liverpool this year.