Effect of Reaction Conditions on Production of Catechinone Hair Dyestuff in Water/Alcohol Mixed Solution ()
ABSTRACT
Catechinone hair dyestuff was produced
chemically from (+)-catechin by the oxidation with O2 in basic
water/alcohol mixed solution. The effects of reaction conditions such as
basicity, sorts of added base, temperature, alcohol molar fraction of solvent
and sorts of added alcohols on the catechinone formation were studied in order
to increase the efficiency of the dyestuff production. The amount of obtained
catechinone increases with increasing basicity of the reaction solution. The
dyestuff is obtained by adding monoethanol amine, diethanol amine, triethanol
amine, l-arginine, Na2CO3,
K2CO3, Na3PO4 or NaOH into the
solution as a base and the most preferable base is monoethanol amine. The
optimum temperature for the production in water/ethanol solution is 30°C.
It was found that water-soluble alcohols such as methanol, ethanol, 2-propanol,
1-propanol and tert-butyl alcohol are
available for preparing the dyestuff. The optimum alcohol molar fraction of the
mixed solvent used for the dye formation is 0.45 for methanol, 0.25 for ethanol
and 0.20 for 2-propanol, 0.15 for 1-propanol
and 0.10 for tert-butyl alcohol. The
amount of the obtained dyestuff reaches
a maximum at 1) 0.35 and 0.59, 2) 0.35 or 3) 0.35 mol·kg¨1 of the concentration of (+)-catechin for the 1) water/methanol, 2) water/ethanol or
3) water/1-propanol system, respectively.
Share and Cite:
Matsubara, T. , Wataoka, I. , Urakawa, H. and Yasunaga, H. (2014) Effect of Reaction Conditions on Production of Catechinone Hair Dyestuff in Water/Alcohol Mixed Solution.
Advances in Chemical Engineering and Science,
4, 292-299. doi:
10.4236/aces.2014.43032.