Carboxymethyl chitins synthesized homogeneously in the green aqueous solution.
Less deacetylation and degradation and higher yield than heterogeneous method.
Simultaneous determination of DA, DS and carboxymethylation fraction at C3 and C6.
Carboxymethyl chitins with lower DS exhibited thermo- and pH-sensitive behaviors.
Potential bioapplications as injectable degradable hydrogels due to the nontoxicity.