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INDUSTRY NEWS

An amorphous polymer demonstrates high performance without the disadvantages associated with semicrystalline materials and imidized thermosets.

Inventing a polymer isn’t a feat accomplished overnight. Or, in some cases, even in a decade. For GE Plastics (Pittsfield, MA, USA), it’s been nearly 20 years since the company last released a new family of polymers. However, patience has paid off for the firm now that a 13-year development cycle has yielded an amorphous thermoplastic polyimide that is able to withstand extremely high temperatures.

GE’s Extem high-performance polymer platform achieves high temperature and chemical resistance without the drawbacks of semicrystalline materials, imidized thermosets, and competitive amorphous thermoplastics, according to the company.

Potential medical applications for the polymer include haemocompatible membranes and noninvasive surgical and laboratory products.

“Until now, customers needing an ultra-high-performance plastic were forced to choose between expensive imidized thermosets with high processing costs, or high-performance semicrystalline resins,” says Brian Herington, general manager, high-performance polymers, GE Plastics. “Extem resins help solve these challenges through top-of-the-line extreme performance, cost-effective processing, and the elimination of such secondary operations as postmould curing or crystallization.”

While the resin’s properties eliminate the need for some secondary operations, they offer the benefits of flexible melt processability for other common operations. The resin retains its properties following injection moulding, extrusion, welding, machining, or thermoforming. Moreover, Extem is melt processable on traditional extrusion and moulding equipment.

The product has dimensional stability across temperatures ranging from subzero to more than 200°C and is inherently flame retardant without the use of halogen additives, which are viewed as potentially unsafe. In addition, the resin boasts a glass transition temperature up to 310°C and extreme amorphous chemical resistance to chlorinated solvents. Stiffness and creep resistance under load and elevated temperatures are additional benefits of the polymer.

New molecules using proprietary monomers serve as the foundation for the Extem thermoplastic polyimide. Upon inventing these monomers, the firm realized that it would need a facility dedicated to the manufacture of the Extem resin. To accommodate the new polymerization process required for producing the resin, the company has invested US$30 million to expand its Indiana-based plant. The firm is also completing construction of a new facility in Cartagena, Spain, to handle Extem operations.

For more information, contact GE Plastics at One Plastics Ave., Pittsfield, MA 01201, USA; phone: +1 413 4487110; fax: +1 413 4487501; e-mail: gelit@ge.com; Internet: www.geplastics.com.