Table II. Structure and properties of some members of three
new families of thermoplastic silicone-urethane copolymers (TSPUs)
compared with related biomedical polyurethanes.
|
Polymer
|
Hard Seg.
|
Organic Soft Segment
|
Wt. % PSX
|
Tensile Strength (psi)
|
Ult. Elong. (%)
|
Initial Modulus (psi)
|
Mw (Daltons)
|
|
Pellethane 80A
|
MDI-BD
|
PTMO
|
0
|
5700
|
815
|
2785
|
194660
|
|
PurSil-10 TSPU
|
MDI-BD
|
PTMO
|
10
|
6515
|
760
|
2880
|
182130
|
|
PurSil-10 TSPU
|
MDI-BD
|
PTMO
|
10
|
6515
|
760
|
2880
|
182130
|
|
PurSil-20 TSPU
|
MDI-BD
|
PTMO
|
20
|
5710
|
665
|
2930
|
185950
|
|
PurSil-40 TSPU
|
MDI-BD
|
PTMO
|
40
|
3930
|
580
|
3510
|
145260
|
|
MDI-BD-PSX
|
MDI-BD
|
None
|
60
|
2275
|
410
|
4920
|
98000
|
|
Tecoflex 80A
|
HMDI-BD
|
PTMO
|
0
|
5570
|
715
|
1240
|
185000
|
|
PurSil Al-5 TSPU
|
HMDI-BD
|
PTMO
|
5
|
6225
|
810
|
465
|
243000
|
|
PurSil Al-10 TSPU
|
HMDI-BD
|
PTMO
|
10
|
6255
|
835
|
370
|
217450
|
|
Bionate 80A
|
MDI-BD
|
PC
|
0
|
7270
|
580
|
1170
|
330060
|
|
CarboSil-10 TSPU
|
MDI-BD
|
PC
|
10
|
7140
|
500
|
6260
|
289650
|
|
CarboSil-20 TSPU
|
MDI-BD
|
PC
|
20
|
5720
|
480
|
4125
|
NA
|
|
CarboSil-40 TSPU
|
MDI-BD
|
PC
|
40
|
3250
|
305
|
6402
|
216360
|
Table II. Structure and properties of some members of three
new families of thermoplastic silicone-urethane copolymers (TSPUs)
compared with related biomedical polyurethanes. (CarboSil AL
TSPU series is currently being characterized.) The aromatic
PurSil and CarboSil TSPUs have initial modulus values higher
than comparable silicone-free polyurethanes. The rubbery, aliphatic
PurSil AL TSPUs (center) have high toughness combined with very
low tensile modules. Note that typical filled silicone rubber
has a tensile strength of ~ 1000 psi and ultimate elongation
of ~ 400%. (MDI = diphenylmethane diisocyanate, BD = butane
diol, PTMO = polytetramethyleneoxide, PSX = polydimethylsiloxane,
Mw = weight-average molecular weight via gel-permeation chromatography.)