Cyanate Ester
Cyanate ester is a triazine-forming high-temperature thermoset used neat, toughened, silica-filled, glass- or carbon-reinforced, blended with epoxy or bismaleimide (BT), and in space-qualified and flame-retardant formulations.
Reference datasheet — Cyanate Ester is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the NEAT condition
Cyanate Ester grades and fills
Cyanate Ester is supplied in 8 conditions, soft to hard. NEAT is the default FabDigit quotes; the values on this page are for it.
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 | |
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 |
Supply forms, finishes and certifications
Ways Cyanate Ester is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
SPACE | Space / low-outgassing qualified grade | Certification |
What is Cyanate Ester?
Cyanate ester is a triazine-forming high-temperature thermoset used neat, toughened, silica-filled, glass- or carbon-reinforced, blended with epoxy or bismaleimide (BT), and in space-qualified and flame-retardant formulations. Engineers select it for low dielectric loss, low moisture absorption and low outgassing at 200 °C service temperature and 270 °C Tg, with 80 MPa tensile strength and 2.6% elongation, typically as prepreg, copper-clad laminate or casting resin. Resin cost is high, the cure is moisture- and amine-sensitive, and the network yellows outdoors; BMI is the alternative when dielectric performance matters less. Cyanate Ester has a density of 1.21 g/cm³ (0.0437 lb/in³), heavier than 60% of polymer grades. Its glass-transition temperature is 270°C (518 °F). Cyanate Ester has a tensile strength of 80 MPa (11.6 ksi), stronger than 83% of polymer grades. Elongation at break is 2.6% and the elastic modulus is 3.1 GPa (0.45 Msi).
What is Cyanate Ester used for?
- Satellite composite structures
- High-frequency RF PCB substrates
- Radome composites
Advantages
- High service temperature — 200°C (392 °F), better than 87% of polymer grades
Limitations
- Difficult to weld — 0/100, worse than 98% of polymer grades
- Low fracture toughness — 0.6 MPa·√m (0.546 ksi·√in), worse than 96% of polymer grades
- Limited formability — 5/100, worse than 95% of polymer grades
- High embodied carbon — 9.5 kg CO₂/kg, worse than 89% of polymer grades
- Limited ductility — 2.6%, worse than 86% of polymer grades
Cyanate Ester properties
Typical room-temperature values for Cyanate Ester-NEAT; bars are the position among polymer grades.
Physical5
Cyanate Ester has a density of 1.21 g/cm³ (0.0437 lb/in³), heavier than 60% of polymer grades. Its glass-transition temperature is 270°C (518 °F).
Mechanical15
Cyanate Ester has a tensile strength of 80 MPa (11.6 ksi), stronger than 83% of polymer grades. Elongation at break is 2.6% and the elastic modulus is 3.1 GPa (0.45 Msi).
Thermal10
Cyanate Ester is rated for continuous service to 200°C (392 °F). It conducts heat at 0.24 W/m·K (0.139 BTU/hr·ft·°F), better than 67% of polymer grades. Thermal expansion is 63 µm/m·K (35 µin/in·°F).
Electrical7
Cyanate Ester is an electrical insulator with a dielectric strength of 22 kV/mm (558.8 V/mil) and a resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (82/100), better than 56% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of Cyanate Ester 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's machinability is good (55/100, worse than 64% of polymer grades); weldability not recommended (0/100); formability not recommended (5/100).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the polymer family
Yield strength against density for every polymer grade FabDigit runs. Cyanate Ester is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Cyanate Ester
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.
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) |
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.
Equivalent designations
Standards and trade names that resolve to Cyanate Ester in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- CE
How much does Cyanate Ester cost?
Cyanate Ester is a high-cost polymer ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Cyanate Ester — frequently asked
What is Cyanate Ester used for?
Cyanate Ester 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?
Cyanate Ester has a typical tensile strength of 80 MPa (11.6 ksi) — stronger than 83% of polymer grades. Strength varies by condition: see the 8 listed tempers.
Is Cyanate Ester easy to machine?
Reasonably — machinability is rated good (55/100, worse than 64% 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 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?
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 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?
Cyanate Ester is rated for continuous use to about 200°C (392 °F), and briefly to 300°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Cyanate Ester cost?
Cyanate Ester is a high-cost polymer ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.