ChronoFlex®
C: Biodurable Medical Grade Polyurethane
[In pdf
format]
Product Definition
ChronoFlex® C is a family of premium polycarbonate
aromatic biodurable thermoplastic polyurethane elastomers developed
by us. ChronoFlex® C medical-grade elastomers are manufactured
under strict GMP conditions. Polycarbonate polyurethanes have been
shown to minimize surface degradation such as stress induced microfissures.
Aromatic materials have good solvent resistance and limited softening
in the body.
Product Advantages
ChronoFlex® C elastomers are custom synthesized from the reactive
monomers. We tailor polymers to specific customer applications. ChronoFlex® C
polymers can be compounded for radiopacity. This family of polymers is
offered in hardness ranging from a soft 80A Shore hardness to a very
hard 75D.
Technical Data Sheet
| Properties |
ASTM
Procedure |
Typical
Values |
| Hardness (Shore Durometer) |
ASTM D-2240 |
80A |
55D |
75D |
| Appearance |
Visual |
Clear to slightly cloudy |
Clear to slightly cloudy |
Clear to slightly cloudy |
| Ultimate Tensile Strength (psi) |
ASTM D-638* |
5500-6500 |
6000-7500 |
7000-8000 |
| Ultimate Tensile Strain (%) |
ASTM D-638* |
400-490 |
365-440 |
255-320 |
| 100% Secant Modulus (psi) |
ASTM D-638* |
770-1250 |
1850-2200 |
5300-5700 |
| 300% Secant Modulus (psi) |
ASTM D-638* |
700-1400 |
1700-2000 |
2700-3200 |
| Flexural Strength (psi) |
ASTM D-790 |
350 |
550 |
10,000 |
| Flexural Modulus (psi) |
ASTM D-790 |
5500 |
9300 |
300,000 |
| Melt Index (g/10 min) 210°C; 2.17
Kg |
ASTM D-1238 |
8 |
5 |
3 |
| Vicat Softening Point (°F/°C) |
ASTM D-1525 |
160/70 |
180/80 |
------ |
| Water Absorption |
ASTM D-5170 |
1.2 |
1.0 |
0.8 |
| Dielectric Strength (volts/Mil) |
ASTM D-149 |
360 |
520 |
420 |
| Specific Gravity |
ASTM D-792 |
1.2 |
1.2 |
1.2 |
| Coefficient of Friction (Kinetic) |
ASTM D- 1894 |
1.5 |
0.8 |
0.64 |
| Abrasion Resistance (% loss at 1000 cycles) |
ASTM D-1044 |
0.008 |
0.035 |
0.053 |
| Melt Processing Temp. (0°F/0°C) |
|
375-430 / 190-220 |
| Recommended Sterilization Method |
|
Gamma; E-Beam; ethylene oxide |
| Class VI Biocompatibility Test |
U.S.P. XXII |
Pass |
Pass |
Pass |
* Specimens conditioned for 7 days at room temperature
and 50% R.H.
Physical Properties
| Shore Hardness |
80A |
55D |
65D |
| Appearance |
Slightly cloudy |
Slightly cloudy |
Slightly cloudy |
| Modulus at 100% |
775 |
1900 |
5500 |
| Modulus at 300% |
600 |
---- |
---- |
| Tensile Strength (psi) |
6600 |
7500 |
9000 |
| Elongation (%) |
475 |
325 |
250 |
Drying Recommendations
ChronoFlex® C pellets should be dried to a moisture
content equal to or less than 0.01% by weight prior to melt processing.
Most extrusion problems can be traced to improperly dried pellets.
We recommend a desiccant-type hopper dryer capable of reaching and
mantaining a dew point of minus 40°F. Typically, the pellets should
be dried for at least 3-4 hours with a dryer inlet temperature of 180°-200°F
for 80A durometers and 205°-240°F for 75D durometer materials.
Since ChronoFlex® C elastomers are highly hygroscopic,
the pellets must be dried well before extrusion. Unless pellets are properly
dried, ChronoFlex® C tubing will exhibit haze, surface craters and
under extreme moisture conditions, will appear "foamy".
Melt Processing
Process Equipment Used: Killion Extruder, with a 2:24/1
(L/D) screw.
| (°F) |
Zone 1 |
Zone 2 |
Zone 3 |
Die |
Melt Temperature |
| Low Durometers |
320 |
330 |
340 |
345 |
345 |
| High Durometers |
420 |
435 |
450 |
460 |
460 |
Handling Extruded Tubing
Following extrusion, lower durometers of tubing will remain somewhat
sticky for about 10-15 minutes. The tubing should be protected during
this time frame. Afterwards, the tubing surface will become tack-free.
Surface tack will diminish as surface crystallization of the hard segments
takes place.
FDA Status
The use of ChronoFlex® C in medical devices
is not covered by any specific FDA regulation. It is the responsibility
of the user to establish safety with the FDA through submission of an
individual application. We have submitted an MAF to the FDA and will
approve FDA access as required in processing a customer's application.
The MAF contains proprietary information on the base polymers, the manufacturing
process, product release specifications, and other relevant data to assist
FDA personnel in the approval process.
Technical Service
Our personnel stand ready to assist you with processing, product availability,
or pricing.
This information has been gathered from standard reference
sources and is believed to be accurate and reliable. CardioTech makes
no other warranty, express or implied, that the results obtained from
the use of this product or information contained herein shall be merchantable
or fit for any particular purpose, or that the use of this product will
not infringe any patent. It is offered solely for your consideration,
investigation, and verification.
[In pdf
format]
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