Top Menu - Main

General Qualities of Rexolite

Rexolite® is a unique cross-linked polystyrene, microwave plastic manufactured by C-Lec Plastics Inc. This material’s most notable properties are it’s stable electrical properties into the Giga-hertz frequency range. It is also optically clear, with a slight yellow cast, when polished (approximately the same as Acrylic), dimensionally stable, and has excellent sound transmission characteristics.

As a result, Rexolite® is often used for high-frequency circuit substrates, microwave components, and lenses with acoustic, optical and radio-frequency applications.

Outstanding Dielectric Properties

Dielectric constant of 2.53 (through 500GHz) with extremely low dissipation factors.

Valuable for microwave lenses, microwave circuitry, antennae, coaxial cable connectors, sound transducers, TV satellite dishes and sonar lenses.

Other uses include non-destructive material testing devices, surveillance equipment, radar windows, radomes and missile guidance system housings. One interesting application is for radar lenses which are used for mapping the earth’s surface from fast high-flying aircraft.

High Voltage Insulators

Ability to withstand high voltage is important for producing gap switch houses, capacitors and other components. Rexolite® is proven superior over Acrylics, Epoxies, Urethanes and other plastics for dendriting resistance (failure caused by electron bombardment).

Radiation Resistance

Superior to most plastics. Little change in dielectric loss over a wide range of exposures up to 1000M rads. It has superior resistance to mechanical deterioration by ionizing radiation.

Rigidity and Dimensional Stability

Rexolite® exhibits no permanent deformation or plastic flow under loads of 10 psi to 2000 psi at temperatures of 20°C to 200°C. In addition, all castings are stress-free, not requiring any stress relieving prior to, during or after machining.

Temperature Range

Recommended operating temperature is 100°C; Glass transition at 114°C; maintains excellent dielectric properties from -270°C to 176°C (no load-short time).


Optical transmission approximately equals Acrylic – (87% visible light @ 1″ thick). Refraction index 1.59 @ 589 nanometers, 1.604 @ 486 nanometers and 1.585 @ 656 nanometers. Used in combination with acrylic lenses for color correction.

Sound Transmitting

Excellent acoustic impedance close to water. Velocity 93×10³ inches per second. Ideal for sonar lenses.

Out Gassing

Negligible at elevated temperatures.

ASTM-E-595 Total Mass Loss (TML) .04% Collected Volatile Condensable Materials (CVCM) .01%

Water Absorption

Less than .08% Rexolite 1422 has been immersed in boiling water for 1000 hours without change in dielectric constant.


Handles well in all machining operations. Tool configuration is similar to those used on Acrylic. Because of it’s high resistance to cold flow and freedom from stress, it is easily machined by water jet or laser beam. Accuracy of .0001 can be obtained in grinding. Crazing can be avoided by using sharp tools and avoid excessive heat when polishing. Stress relieving of Rexolite is not required before, during or after machining. Always maintain sharp tooling.

Chemical Resistance

Alkalies, Alcohols, Aliphatic Hydrocarbons and mineral acids have no effect. Contact with Aromatic hydrocarbons cause swelling and should be avoided.

Light Weight

Specific gravity of 1.05. Approximately 15% lighter than Acrylic and less than half of TFE (Teflon).

Sub-zero Properties

Maintains a Dielectric Constant of 2.55. At -270°C the dissipation factor is .00019.


Burn rate is less than 1 inch per minute.


Rexolite® Adhesive #12517 has been developed especially for bonding Rexolite® to itself.

Environmentally Friendly

Non-hazardous, contains no ingredients harmful to the environment.

Military Specification

Rexolite® 1422 conforms to military specification LP-516A, type E2, formerly known as MIL-P-77C-E2.

Standard Shapes and Sizes

Rexolite® 1422 rod from 1/16″diameter to 9″diameter.

Rexolite® 1422 sheet from .010″ to 6″ thick.

Rexolite® Adhesive #12517 supplied in 2 – 1/2 pint containers.

Rexolite®-1422-Standard-Sheet-Sizes              Rexolite®-1422-Standard-Rod-Sizes

Background of Cross Linked Polystyrene

Cross linked polystyrene was originally developed for the U.S. Military during World War II for use in coaxial cable connectors. There were two manufacturers sharing the market, Dow Chemical and General Electric. After the war, Dow Chemical passed their manufacturing rights of Q200.5 to the Polymer Corporation and General Electric sold their Texolite 1422 production facility to the Rex Corporation. The Rex Corporation changed the name Texolite to Rexolite® and registered the trade name. It then passed in succession to Brand Rex, Dodge Industries, Oak Materials, and Norplex Oak. With all these manufacturers, the production of Rexolite® was limited to sheets up to two inches thick and rods up to four inches in diameter. During the early 1960’s, C-Lec Plastics developed a process to produce stress free sheets up to 6 inches thick and rods up to 8 inches in diameter, creating a new market for cross linked polystyrene. C-Lec marketed this material as Dielco 100. In the mid 1970’s, Norplex Oak terminated production of Rexolite® and passed the Trade Name rights to C-Lec Plastics . Additionally,in the mid 1990’s the Polymer Corporation ceased the production of their Q200.5. C-Lec has continued to improve production techniques through research and development and with computer control. Stress free castings more than 10 inches thick and 6 feet in diameter have been produced.