The known Ca-acetate method (Tan, 2005), based on the formation of acetic acid, was used for determining the total number of carboxylic groups
Several functional groups were generated, such as carboxylic group
(COOH), carbonyl group (C=O), and hydroxyl group (O-H) as per their reference spectra .
In the eucalyptus samples, however, the greatest amount of carboxylic groups
was generated with the diluted tannery slurry treatment (L-EU, 0.
All polymerizations and analyses of carboxylic group
concentration were carried out with deionized water.
With screw configuration A1, the free radical grafting of GMA onto PP is disturbed by the presence of PBT: this latter dilutes the concentrations of GMA and PP reducing the grafting rate; more importantly, aside from the desired free radical grafting of GMA onto PP with the subsequent reaction with PBT, the free GMA monomer also reacts with PBT (mostly with the carboxylic group
at its chain end).
in MAA become ionized above its [pK.
The neutralizer of the carboxylic groups
, needed to get a stable dispersion, plays a key role in both the polymerization kinetics and in the hydrophilic character of the UV-cured polymer, the best performance being achieved by using a volatile tertiary amine.
Specific surface area, density of carboxylic group
, and the recovery rate after HN[O.
The carboxylic groups
and oxygen containing groups were introduced onto MWCNT surface facilitating further modification (8-10).
The unreacted carboxylic groups
were potentiometrically titrated in tetrahydrofuran solution with 0.
Since the carboxylate group is electronegative in water, higher carboxylate concentrations will lead to repulsion among these groups and a decrease of water absorbency, although carboxylate group have better water absorbency than carboxylic group
75), and according to the lower content of carboxylic groups
in the source sample (0.
Itaconic acid is stable at room temperature; however, due to the presence of two carboxylic groups
, it effectively takes part in the co-polymerization reaction.
PBMAD was selected as the bioadhesive coating because it has a large number of carboxylic groups
exposed on each side group and it exhibits pH-dependent solubility; the polymer is stable at a low pH, but dissolves at a pH > 8.
This positive shift was due to attachment of polar carboxylic groups