Journal of Chemical and Engineering Data, Vol. 51, No. 2, 2006 751
shows good linearity. Therefore, they were correlated as a
function of temperature by
ln x ) a/(T/K) + b
(2)
The regressed parameters a and b for the solubilities (mole
fraction) of ODOPM in the selected solvents are listed in Table
2
1
. The smoothed data calculated from eq 2 are listed in Table
. The relative standard deviation (RSD) of the measured
solubilities from the smoothed data is defined as
exp
xi
cal
- xi
2 1/2
N
1
RSD )
∑
[
N
(
exp
)
]
i)1
xi
where the superscript exp stands for experimental values, the
superscript cal stands for calculated values, and N stands for
the total number of experimental data. The RSD of the measured
solubilities from the smoothed data in the selected solvents are
listed in Table 2.
Figure 1. Solubilities (mole fraction) of ODOPM in the selected solvents:
s, caculated data from eq 2; 0, measured data in acetone; 4, measured
data in ethyl acetate; 2, measured data in benzene; 9, measured data in
toluene; ×, measured data in water; *, in water and in p-xylene.
Conclusion
Table 2. Regressed Parameters a and b, Relative Standard
Deviation (RSD) of the Measured Solubility from Calculated Results
of Equation 2, and Experimental Uncertainties for the Different
Binary Mixtures
In this paper the synthesis method of ODOPM was improved,
and the ODOPM was directly prepared from HBP and paraform-
aldehyde. In the purification process, water was used as solvent
instead of xylene; therefore, a contaminate factor to environment
is eliminated. From Figure 1 it can be seen that the order of the
weight fraction solubility in the selected solvents is acetone >
ethyl acetate > benzene > toluene > water > xylene.
solvent
water
p-xylene
acetone
ethyl acetate
benzene
toluene
temperature range/K
a
b
RSD
303.57 to 361.63
302.95 to 360.65
302.25 to 327.78
303.45 to 350.26
300.68 to 352.65
300.95 to 362.35
-5076.5
-4313.3
-3711.3
-4693.9
-5398.0
-4034.1
7.0111
1.8973
6.4236
8.9241
10.437
5.9129
0.048
0.048
0.018
0.036
0.044
0.031
The solubility in mole fraction of ODOPM in water increased
-
5
-4
from 6.700‚10 at 303.57 K to 8.712‚10 at 361.03 K, while
the solubility in mole fraction of ODOPM in xylene increased
-
6
-5
from 4.880‚10 at 302.95 K to 4.712‚10 at 360.65 K. It has
been found that solubility of ODOPM in water is higher than
in xylene, and using water as a solvent hardly influences the
yield of product. Within the temperature range of the measure-
ments, the solubilities of ODOPM in water showed an increased
trend based on the increased temperature. Owing to solubilities
of paraformaldehyde and HBP, much higher than solubilities
of ODOPM in water at about 343.15 K, ODOPM can be purified
by warm water and satisfactory purity can be achieved.
of the solvent. The vial was covered with a piece of filter paper
to prevent dust contamination. After the solvent in the vial was
completely evaporated, the vial was weighed again (m2) to
determine the mass of the constant residue solid (m2 - m0).
Thus the solid concentration of the sample solution in mole
fraction x could be determined from eq 1:12
(
m - m )/M
2 0 1
x )
(1)
(
m - m )/M + (m - m )/M
2 0 1 1 2 2
Literature Cited
(
1) Wang, C.-S.; Shieh, J.-Y.; Sun, Y.-M. Synthesis and properties of
phosphorus containing PET and PEN (I). J. Appl. Polym. Sci. 1998,
70, 1959-1964.
where the M1 is the molecular weight of ODOPM and M2 is
the molecular weight of the solvent.
Different dissolution times were tested to determine the
suitable equilibrium time. It was found that 3 h was enough to
reach equilibrium. For convenience, the solubilities of ODOPM
in acetone, ethyl acetate, benzene, and toluene were measured
in a similar method.
During our experiments, three parallel measurements were
performed at each temperature, and an average value is given.
The maximum standard deviation of each triplicate data is 0.27
(2) Wang, C.-S.; Lin, C.-H. Synthesis and properties of phosphorus
containing PET and PEN co-polyesters. Polymer 1999, 40, 747-757.
(
3) Liu, Y.-L.; Wu, C.-S.; Hsu, K.-Y.; Chang, T.-C. Flame-retardant epoxy
resins from o-cresol novolac epoxy cured with a phosphorus-containing
aralkyl novolac. J. Polym. Sci., Part A: Polym. Chem. 2002, 40 (14),
2329-2339.
(
4) Liu, Y.-L.; Chiu, Y.-C. Novel approach to the chemical modification
of poly(vinyl alcohol): phosphorylation. J. Polym. Sci., Part A: Polym.
Chem. 2003, 41 (8), 1107-1113
(5) Wang, C.-S.; Shieh, J.-Y. Synthesis and properties of epoxy resins
containing 2-(6-oxido-6H-dibenz[c,e][1,2]oxaphosphorin-6-yl)-1,4-
benzenediol. Polymer 1998, 39 (23), 5819-5826.
%, and the minimum is 0.12 %.
The solubilities of ODOPM in some solvents determined in
(
(
(
(
6) Buysch, H. J.; Glock, V.; Griehsel, B. Process for preparing 6-oxo-
(6H)-dibenz[c,e][1,2]oxaphosphorins (ODOPS). U.S. Patent 5,650,530,
1997.
7) Saito, T.; Hirayama, T.; Kohguchi, Y. Process for producing 2-(2-
hydroxyphenyl) phenylphosphinic acid and derivatives. U.S. Patent
this work are summarized in Table 1 and plotted in Figure 1.
The estimated uncertainty of the solubility values based on error
analysis and repeated observations was within 2 %.
6,107,506, 2000.
Data Correlation
8) Shieh, J.-Y.; Wang, C.-S. Synthesis of novel flame retardant epoxy
hardeners and properties of cured products. Polymer 2001, 42, 7617-
Upon comparison the experimental Figure 1, a trend of
increasing solubility with temperature is observed. The logarithm
of the mole fraction solubilities determined that the temperature
7625.
9) Wang, S.-B.; Wang, L.-S. Solubilities of 2-(2-hydroxyphenyl)-
phenylphosphonic acid in chlorobenzene and in water and partition