While most, if not all, epoxies will yellow over time, especially upon exposure to heat and intense UV light, EP21LSCL-2Med is expected to resist yellowing to a greater extent than conventional systems. This feature makes it ideal for imaging applications or other medical devices where optical clarity is needed.
EP21LSCL-2Med is an optically clear compound with a refractive index of 1.57. It has a high glass transition temperature of 110-120°C and a service temperature range of -60°F to +350°F (-52°C to +177°C). This system has a 100:20 mix ratio by weight and a low mixed viscosity of 600-900 cps at room temperature. It is a moderate heat cured epoxy which features a gel time of six to eight hours at room temperature for a 100-gram batch. EP21LSCL-2Med cures at room temperature followed by a post cure of 3-5 hours at 140-175°F (60-80°C).
EP21LSCL-2Med is said to adhere well to many substrates, including but not limited to metals, composites, glass, ceramics, and plastics. It offers a tensile strength of 8,000-9,000 psi and a tensile modulus of 325,000-375,000 psi. This epoxy is claimed to resist many sterilisation methods, such as steam sterilisation, liquid sterilants, anti-bacterial agents, and Ethylene Oxide.
The shelf life of EP21LSCL-2Med is six months in its original, unopened containers, and it is available in kits ranging from ½ pints to five gallon pails, as well as specialty packaging in pre-mixed and frozen syringes requiring storage at –40°C.
In August, Master Bond launched EP21ARHTND-2, a two part epoxy adhesive that is designed to withstand prolonged exposure to a wide range of chemicals.
“The system’s chemical resistance was successfully tested in chemicals such as 98% sulfuric acid, 25% hydrochloric acid, 20% phosphoric acid, and 15% nitric acid, by soaking cured samples for more than 12 months”, said senior product engineer Rohit Ramnath. “The product also passes the damp heat reliability testing by withstanding 1000 hours of 85°C and 85% Relative Humidity (RH).”
