Chemistry Reference
In-Depth Information
100.0
90.0
80.0
70.0
60.0
50.0
40.0
30.0
20.0
Methanol:Toluene
Neat methanol
On water
10.0
0.0
0
10 0 0 0 0 0 0 0 0 00
110
Temperature (°C)
Fig. 6.8
The enzymatic hydrolysis/methanolysis of 3AcO-TMDS. Each data point is the average
of triplicate trials. The standard deviation is shown
Seeking to understand the role of catalyst loading and time, two model studies
were carried out to examine the effect of increasing the enzyme loading and the
reaction time frame. At room temperature, hydrolysis of 3AcO-TMDS was pro-
portional to the amount of N435 included in the reaction mixture (Fig.
6.9
). The
smallest amount of N435 that was used, 5 mg, afforded only 11 % hydrolysis, while
increasing to 10 and 15 mg gave 24 and 33 % hydrolysis. This trend was mirrored
when the time frame for the reaction was doubled to 48 h affording an increase from
11 to 22 % hydrolysis.
6.10 Conclusions
Lipases have been employed as a mild method for affecting many chemical trans-
formations in organic and polymer chemistry. Many reports in the polymer chemis-
try literature have described the molecular weight build-up of the resulting polymer
using N435. N435 has been shown to accept substrates of varying size, and under
a diverse range of reaction conditions. A few of these reports have incorporated
silicone-derived monomers to a small extent, but an extensive study of the interac-
tion between the biocatalyst and siloxane-containing monomers has not been seen.
