Biomedical Engineering Reference
In-Depth Information
25
20
15
10
5
0
−
5
4
5
6
7
8
9
10
11
12
13
14
Number of methylene groups in diol
Figure 4.4
Effect of diol chain length on the glass transition temperature of polymers
prepared from 3,9 - diethylidene - 2,4,8,10 - tetraoxaspiro [5.5] undecane and
α
,
ω
- diols. Reprinted
from [19], p. 47, with permission from Harwood Academic Publishers.
10
5
0
−
5
−
10
−
15
−
20
Polymer
Figure 4.5
Glass transition temperatures for
poly(ortho ester) prepared from
3,9 - diethylidene - 2,4,8,10 - tetraoxaspiro [5.5]
undecane and
n
- octanediol,
n
- decanediol, and
n
-dodecanediol, each with 5, 10, and 20 mol%
of the corresponding lactide. Reprinted from
[17], p. 1025, with permission from Elsevier.
in Figure 4.5 [17]. Thus, both the diol structures, the latent acid diol structure and
their ratios must be considered when designing polymers having desired thermal
and mechanical characteristics.
The ability to vary mechanical properties by proper choice of diols allows the
synthesis of a wide range of materials, but the two most useful ones are solid
polymers and gel - like materials.
