Selecting Medical Grade Polymers

Making the grade—selecting the right medical grade polymer

Eastman understands that the stakes are high when selecting the material for your next fluid management component, blood contact device, or electronic medical device housing. That’s why we want to help make this complicated process simpler when you consider Eastman Tritan copolyester, beginning with two criteria:
•  Making the grade. Selecting medical grade polymers helps ensure your device complies with quality and biocompatibility standards—and that you have reliable support for regulatory approvals.   
•  Matching the application. Each medical grade of Tritan offers a different combination of desirable strengths that help ensure performance in specific medical applications.  

Matching a medical grade of Eastman Tritan copolyester to your needs

Different medical applications have different performance priorities. For example, clear applications, such as fluid management and IV components and dialyzer housings, place a high value on:
•  Clarity (for unobstructed viewing of fluid levels and foreign substances)
•  Durability and toughness (to withstand the applied stress of handling, connecting, and fabricating)
•  Chemical resistance (compatibility with cleaning and bonding agents as well as harsh drugs and their carriers)
•  Color stability after sterilization
•  No black specks
•  Biocompatibility (compliance with FDA/ISO 10993 and USP Class VI biological evaluation)
•  Heat resistance—Some devices require a higher level of heat resistance to deliver their intended performance or for accelerated aging validation.
•  Specific rigidity requirements to comply with ISO 80369 (required in some connectors)
On the other hand, opaque medical housings demand a durable combination of chemical resistance and impact strength to resist cracking, breaking, and premature device failure during rigorous daily use and disinfection. They also may require color stability and even true matching of a brand’s color palette.
Starting with your specific needs, Eastman provides a range of medical grades of Tritan as well as technical expertise and support to help determine your best material option. Eastman is a reliable partner in problem solving to help bring your product to market as seamlessly as possible.
Here is an overview of each of our medical grade polymers and a table with more details of the properties of each polymer. 
Eastman Tritan copolyester MX711 is our most commonly preferred medical grade. It sets the standard for most products that require: 
•  Impact strength and toughness
•  Excellent clarity
•  Chemical resistance
•  Good color stability upon sterilization by gamma irradiation or EtO

MX711 is also made without bisphenol A (BPA), BPS, or ortho-phthalates and offers improved processability compared with traditional copolyesters.
Eastman Tritan copolyester MX731 offers many of the same advantages as MX711 but with 40% to 50% lower viscosity. Its exceptional flowability is ideally suited for high-cavitation molds or designs with long plastic flow lengths.
Eastman Tritan copolyester MX811 offers similar properties to MX711 but adds greater value for products requiring higher Tg or higher heat deflection temperatures (see Table 1) for downstream product-validation testing.
For opaque electronic medical device housings, Eastman Tritan copolyester MXF121 offers good impact strength and significantly better chemical resistance than polycarbonate (PC) or PC alloys.  

Table 1. Eastman Tritan copolyesters—property overview
Physical properties MX711 (clear) MX731 (clear) MX811 (clear) MXF121 (opaque)
Suggested application IV components Medical devices Medical devices and housings Electronic medical device housings
Specific gravity (ASTM D792) 1.18 1.18 1.17 1.19
Izod impact strength, notched @ 23°C (73°F), J/m (ft-lbf/in) 980 (18.4) 860 (16.1) 650 (12.2) 416 (7.5)
Flexural modulus, MPa (105 psi) 1550 (2.25) 1575 (2.28) 1585 (2.28) 1748 (2.53)
Elongation @ break (%) 210 210 140 133
Tensile stress @ break, MPa (psi) 53 (7700) 52 (7500) 53 (7700) 47 (6780)
Tensile stress @ yield, MPa (psi) 43 (6200) 43 (6200) 44 (6400) 43 (6200)
Heat deflection temp @ 0.455 MPa (66 psi), °C (°F) 99 (210) 94 (201) 109 (228) 94 (201)
Heat deflection temp @ 1.82 MPa (264 psi), °C (°F) 85 (185) 81 (178) 92 (198) 83 (181)
Specific gravity 1.18 1.18 1.17 1.19
Thermal glass transition temp, Tg, °C (°F) 110 (230) 110 (230) 120 (248) 106 (223)
Clarity—haze % <1 <1 <1
Clarity— transmittance %  


NOTE: MX710, MX730, and MX810 offer properties similar to MX711, MX731, and MX811, respectively,
but without a mold release. Learn more

 TMI Tip