Image courtesy of SABIC
At MD&M West 2020 SABIC debuted its new family of LNP ELCRES CRX polycarbonate (PC) copolymers to offer medical device manufacturers a new approach to chemical resistance. Using the new materials could allow medical device manufacturers to lengthen product lifecycles to meet warranty expectations and could reduce replacement claims, Darpan Parikh, global product management leader, LNP Specialty Compounds at SABIC, told MD+DI.
“Aggressive cleaners are being used in hospitals to prevent healthcare-associated infections,” Parikh explained. The risks for medical devices, however, are material cracking and discoloration, he explained. Consequently, “customers have been asking us what we can do to improve chemical resistance.”
SABIC’s answer is a new family of “drop-in” polycarbonate copolymers that could be used in place of traditional PC homopolymers, acrylonitrile-butadiene-styrene (ABS), and polyester and co-polyester resins and blends. The new materials are “robust as offerings against the incumbent materials,” he said.
For instance, “polycarbonate is an amorphous material designed as a high-impact material, but if you put aggressive chemicals on it, it could crack, craze, or discolor.” Parikh said. “For instance, peroxides and other disinfectants can attack PC over time.” Most durable device housings and handheld diagnostics are made of PC-based materials, he added.
For the LNP ELCRES CRX copolymers, SABIC “utilizes a proprietary process to modify the polymer backbone of our existing copolymer resin” to achieve the chemical resistance, Parikh said. “We then compound this modified copolymer with other polymers or additives to achieve the desired properties,” he added.
To help medical device manufacturers process these new amorphous and semi-crystalline blends, SABIC provides processing guidelines for use in existing injection mold tools. “It is not too different, but there are processing rules,” Parikh said. “Similar shrinkage allows the PC copolymers to be dropped into existing tools and infrastructure.” The LNP line also supports specialty compounding, and the company can also help with developing the right design.
SABIC tested the new family LNP ELCRES CRX polycarbonate (PC) copolymers according to ASTM D543, applying more stringent criteria than outlined in the test method, Parikh said. In addition, “customers often have their own set of tests,” he said. “We’ve engaged existing customers to test according to theirs, and we’ve seen strong interest based on the results.”
In terms of addressing medical device manufacturers’ concerns about warranty claims, Parikh said that “cracking and discoloration can be attributed to the frequency of cleaning with chemicals. But if the cracking and discoloration occur within the warranty period, companies basically have to replace these parts.” By using family LNP ELCRES CRX polycarbonate (PC) copolymers, companies shouldn’t see “crazing or cracking within the warranty period,” he said.
Also at MD&M West, SABIC experts discussed material solutions for healthcare disinfectant exposure February 11 in the Tech Theater. Manish Nandi, SABIC business development manager for Specialties in the Americas, and Nithin Raikar, SABIC senior business manager for LNP Resins and Compounds, presented “Keeping Medical Equipment Clean and Durable: PC Copolymer Technology Innovations that Improve Chemical Resistance against Hospital Disinfectants.”
Testing the family of LNP ELCRES CRX polycarbonate (PC) copolymers according to ISO 10993 is in process, Parikh said. The material building blocks of these grades have been pre-screened for limited biocompatibility (e.g., cytotoxicity).
Their chemistry is also applicable to other healthcare segments interested in upgrading their resistance, such as medical devices used at home and consumer electronics, he added. The new materials can also withstand sunscreens, lotions, and other intense chemicals, he said.