Cyanate Ester EP-BLEND
Matrix
Use when full CE performance is not needed — lower cost and lower cure temperature, at reduced Tg and higher dielectric loss.
Values for the EP-BLEND condition
Other Cyanate Ester grades and fills
Cyanate Ester is listed in 8 conditions; see the grade overview at Cyanate Ester.
Compare all 8 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Fused-silica / mineral-filled CE | Choose for chip encapsulation and low-CTE tooling where dimensional match to silicon/ceramic is required. | — | 70 | 0.8 | — |
Flame-retardant grade | For laminates and enclosures needing certified V-0 with low smoke; phosphorus modification slightly raises Df and lowers Tg. | — | 72 | 2 | 89 Shore D |
Toughened cyanate ester | Pick when microcracking resistance under thermal cycling matters (space structures, thick laminates); costs ~30–50 °C of Tg. | — | 78 | 4.5 | — |
NEATDefault Neat / unfilled cast cyanate ester | Baseline unmodified resin: highest Tg and lowest dielectric loss, but brittle — use for castings, adhesives and as a matrix reference. | — | 80 | 2.6 | 89 Shore D |
EP-BLENDThis page Epoxy-blended cyanate ester (cost-reduced, easier cure) | Use when full CE performance is not needed — lower cost and lower cure temperature, at reduced Tg and higher dielectric loss. | — | 82 | 3.2 | 88 Shore D |
BT resin | Workhorse blend for IC-substrate and high-Tg PCB laminates: better toughness and processability than neat CE at slightly higher loss. | — | 85 | 2 | 90 Shore D |
E-glass fabric / CE laminate | Standard form for high-speed copper-clad laminates and radomes needing stable Dk/Df to microwave frequencies. | — | 400 | 2 | — |
Carbon-fiber / CE composite | Primary space-structure form — near-zero CTE laminates, very low moisture-induced dimensional drift and low outgassing. | — | 1,900 | 1.4 | — |
What is Cyanate Ester EP-BLEND?
Cyanate Ester EP-BLEND is Cyanate Ester in the EP-BLEND condition — use when full CE performance is not needed — lower cost and lower cure temperature, at reduced Tg and higher dielectric loss. Cyanate Ester EP-BLEND has a tensile strength of 82 MPa (11.9 ksi), stronger than 84% of polymer grades. Elongation at break is 3.2% and the elastic modulus is 3.2 GPa (0.464 Msi). Cyanate Ester EP-BLEND has a density of 1.21 g/cm³ (0.0437 lb/in³), heavier than 60% of polymer grades. Its glass-transition temperature is 195°C (383 °F). NEAT is the default condition FabDigit quotes; EP-BLEND is available on request or by drawing note.
Advantages
- High service temperature — 165°C (329 °F), better than 81% of polymer grades
- Stiff — 3.2 GPa (0.464 Msi), better than 77% of polymer grades
Limitations
- Difficult to weld — 0/100, worse than 98% of polymer grades
- Limited formability — 5/100, worse than 95% of polymer grades
- Low fracture toughness — 0.8 MPa·√m (0.728 ksi·√in), worse than 92% of polymer grades
- High embodied carbon — 9.5 kg CO₂/kg, worse than 89% of polymer grades
- Limited ductility — 3.2%, worse than 81% of polymer grades
Cyanate Ester EP-BLEND properties
Typical room-temperature values for Cyanate Ester EP-BLEND; 26 are specific to this condition. Other listed values are Cyanate Ester reference data and may not represent this condition. Bars are the position among polymer grades.
Physical5
Cyanate Ester EP-BLEND has a density of 1.21 g/cm³ (0.0437 lb/in³), heavier than 60% of polymer grades. Its glass-transition temperature is 195°C (383 °F).
Mechanical15
Cyanate Ester EP-BLEND has a tensile strength of 82 MPa (11.9 ksi), stronger than 84% of polymer grades. Elongation at break is 3.2% and the elastic modulus is 3.2 GPa (0.464 Msi).
Thermal10
Cyanate Ester EP-BLEND is rated for continuous service to 165°C (329 °F). It conducts heat at 0.22 W/m·K (0.127 BTU/hr·ft·°F), better than 60% of polymer grades. Thermal expansion is 63 µm/m·K (35 µin/in·°F).
Electrical7
Cyanate Ester EP-BLEND is an electrical insulator with a dielectric strength of 22 kV/mm (558.8 V/mil) and a resistivity of 5×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (78/100), worse than 61% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of Cyanate Ester EP-BLEND takes about 185 MJ of energy and emits 9.5 kg of CO₂ — more than 88% of polymer grades. Typical recycled content is 0%.
Manufacturability7
Cyanate Ester EP-BLEND's machinability is good (58/100, worse than 55% of polymer grades); weldability not recommended (0/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Cyanate Ester EP-BLEND
Is Cyanate Ester easy to machine?
Machine fully post-cured parts with sharp PCD/diamond tooling, light feed and dust extraction — the neat resin is brittle and glass/carbon-filled laminates are highly abrasive.
Can Cyanate Ester be welded?
Thermoset — cannot be welded; join by co-cure, secondary CE/epoxy film adhesive bonding or mechanical fasteners.
Can Cyanate Ester be formed, bent or molded?
Processed as prepreg (autoclave/oven, 177–200 °C cure with 220–250 °C free-standing post-cure), RTM/VARTM or casting; keep resin and reinforcement dry — moisture and amine/phenol contamination form carbamates that depress Tg and cause voids.
What surface finishes work on Cyanate Ester?
Post-cure before machining, seal or paint/UV-coat exposed surfaces since aromatic triazine networks yellow and chalk in sunlight; copper foil bonds well in laminate pressing without an adhesive tie layer.
Cyanate Ester chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| transition-metal catalyst (Cu/Zn/Mn carbcyclotrimerization catalyst package | 0.05 – 2 | 0.4 |
| toughener (thermoplastic or core-shell rtoughened variants only | 0 – 20 | 0 |
| filler / reinforcement (fused silica, E-filled and composite variants only | 0 – 70 | 0 |
| bisphenol-A dicyanate ester monomer/prepmay be replaced/blended with novolac (PT-type), dicyclopentadiene (XU-71787) or bisphenol-E (LECy) dicyanates | ≥ 95 (balance) | — |
Cyanate Ester EP-BLEND — frequently asked
What is Cyanate Ester EP-BLEND used for?
Cyanate Ester EP-BLEND is typically used for satellite composite structures, high-frequency RF PCB substrates and radome composites. In short: lowest dielectric loss thermoset; space-grade low outgassing; costlier than BMI.
What is the tensile strength of Cyanate Ester EP-BLEND?
Cyanate Ester EP-BLEND has a typical tensile strength of 82 MPa (11.9 ksi) — stronger than 84% of polymer grades. Strength varies by condition: see the 8 listed tempers.
Is Cyanate Ester EP-BLEND easy to machine?
Reasonably — machinability is rated good (58/100, worse than 55% of polymer grades). Machine fully post-cured parts with sharp PCD/diamond tooling, light feed and dust extraction — the neat resin is brittle and glass/carbon-filled laminates are highly abrasive.
Can Cyanate Ester EP-BLEND be welded?
Not readily — weldability is rated not recommended (0/100). Thermoset — cannot be welded; join by co-cure, secondary CE/epoxy film adhesive bonding or mechanical fasteners.
What surface finishes work on Cyanate Ester EP-BLEND?
Post-cure before machining, seal or paint/UV-coat exposed surfaces since aromatic triazine networks yellow and chalk in sunlight; copper foil bonds well in laminate pressing without an adhesive tie layer.
Can Cyanate Ester EP-BLEND be formed, bent or molded?
Processed as prepreg (autoclave/oven, 177–200 °C cure with 220–250 °C free-standing post-cure), RTM/VARTM or casting; keep resin and reinforcement dry — moisture and amine/phenol contamination form carbamates that depress Tg and cause voids.
What is the maximum service temperature of Cyanate Ester EP-BLEND?
Cyanate Ester EP-BLEND is rated for continuous use to about 165°C (329 °F), and briefly to 300°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Primaset cyanate ester monomers technical data — Lonza (2019)
- AroCy cyanate ester resin data sheets (B-10, L-10, XU-71787) — Huntsman / Ciba (2005)
- Cyanate ester prepreg systems (EX-1515, RS-3, CE toughened grades) — Solvay / Tencate Advanced Composites (2021)
- Engineered Materials Handbook Vol.3: Adhesives and Sealants / Vol.1 Composites — cyanate ester chemistry — ASM International (1990)
- Chemistry and Technology of Cyanate Ester Resins — Blackie / Springer (I. Hamerton, ed.) (1994)
- Outgassing Data for Selecting Spacecraft Materials (ASTM E595 results) — NASA GSFC (2023)
- IPC-4101 laminate specification sheets (BT/CE high-Tg, low-loss classes) — IPC (2021)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.