Knowde Enhanced TDS
Identification & Functionality
- Polymer Name
- Composite Materials Functions
- Technologies
Features & Benefits
- Materials Features
- Product Highlights
- Good resistance to galvanic corrosion
- Low outgassing
- Low dielectric performance
Applications & Uses
- Markets
- Composites Processing Methods
- Recommended Applications
- Radome
- Aircraft
- Spacecraft
- High temperature radomes and antennae
- Radar transparent structures
- Low outgassing Applicationss
- BMI replacement
- High performance electronic substrates
- Processing Method
Cyanate esters can be processed using an Autoclave, Press, Pressclave, or Oven Cure/Vacuum Bag. For any Applications where the optimum properties are needed, Toray Advanced Composites recommends the use of an autoclave, or press especially for its BTCy–1 & BTCy-2 resin systems. This is due to the fact that air voids caused by vacuum bag/oven cure processing may darken upon post cure and create unsightly dark specs in the laminate. Although the structural deficit caused by these voids has not been assessed, it can most probably be assumed that the detriment would be no more than that caused by the voids themselves created via vacuum bag processing.
Properties
- Physical Form
- Mechanical Properties
- Typical Properties
- Thermal Properties
| Value | Units | Test Method / Conditions | |
| Poisson’s Ratio | 0.48 | — | — |
| Shear Modulus | 6.10 (0.885) | Gpa (Msi) | — |
| Tensile Modulus | 3.93 (0.57) | Gpa (Msi) | — |
| Value | Units | Test Method / Conditions | |
| Density | 1.17 | g/cc | — |
| Dielectric Constant at 10 GHz | 2.7 | — | — |
| GIC Value | 1.2 | inlb/in2 | — |
| Loss Tangent at 10 GHz | 0.003 | — | — |
| Moisture Absorption at 100°C (212°F) saturation | 1 | % | — |
| Outgassing (CVCM) | 0 | % | — |
| Outgassing (TML) | 0.36 | % | — |
| Outgassing (WVR) | 0.33 | % | — |
| Value | Units | Test Method / Conditions | |
| Polymer Tg after post cure | 238 (461) | °C (°F) | — |
| Polymer Tg cured at 177°C (350°F) | 190 (374) | °C (°F) | — |
Technical Details & Test Data
- Recommended Cure Cycle
- Bagging For Cure
Toray Advanced Composites recommends that CE composite parts bagged for cure should be performed as follows:
- Release the tool surface
- Layup part using standard debulking procedures
- Dam the edges of the part for cure
- Place one ply of porous Teflon® or perforated Teflon® onto the bag surface of the part
- Place bleeder layers over porous Teflon® material and trim to the part periphery
- Place a non-porous layer of Teflon® over the part
- Utilize a breather cloth to facilitate vacuum draw
- Install vacuum bag on the tool for cure
- Follow the provided Toray Advanced Composites cure cycle for the particular resin system
Storage & Handling
- Shelf Life
- Out Life*: 14 days at ≤ 21°C (70°F) and ≤ 60% RH
- Frozen Storage Life: 12 months at ≤-18°C (0°F)
Out life is the maximum time allowed at 21°C (70°F) or below and 60% or less RH before cure, after a single frozen storage cycle in the original unopened packaging at -18°C (≤ 0°F) or below for a period not exceeding the frozen storage life noted above. *Out life tested by SBS on a 15 cm x 15 cm (6 in x 6 in) laminate, cured in an autoclave. Users may need to evaluate out life limits for their own Applicationss due to differing thickness, configuration, and complexity.
- Product Handling
The following guidelines are provided to our customers for one specific purpose: to assure that all customers are aware of the manner by which to attain the best possible results from Toray Advanced Composites cyanate ester products. These resin systems will provide sound composite hardware and structures if some simple procedures are followed. Keep in mind that these procedures are good practice for all composite prepreg and adhesive materials and should be used whenever possible.
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FREEZER STORAGE: Cyanate Esters (CE’s) should always be sealed in an airtight bag and kept frozen below -12°C (10°F) when not being used. A good safety measure is to have a bag of desiccant (Silica Moisture Absorber) in the core of the prepreg roll just in case a pin-hole in the bag or other problem occurs
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MOISTURE ABSORPTION AND SENSITIVITY: While very resistant to moisture absorption after cure, CE’s can be adversely affected by moisture uptake prior to cure. For this reason, all materials must be “Thoroughly Thawed” to room temperature prior to opening the sealed bag to avoid condensation on the material. Also, it is good practice to keep prepreg and in-process hardware in a sealed bag or vacuum bag if to be exposed to atmosphere for long periods of time.
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HANDLING OF MATERIALS: When handling any prepreg materials, one should always be wearing clean, powder-free latex gloves. This will assure that no hand oils are transferred to the prepreg and/or composite during processing. The presence of oils in the part could lead to problems in both mechanical and electrical performance. This also guards against any dermatitis that could occur with certain users.
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NON-METALLIC HONEYCOMB AND FOAM CORE USE: When using Non-Metallic honeycomb and foam core materials for sandwich structures, the materials should always be dried in an oven prior to layup to drive off any moisture that may be in the core. The material should then be cooled in the presence of a desiccant, to avoid any moisture uptake. Following this procedure, it is always a good idea to use the material as soon as possible to avoid re-hydration. Recommended Core Dry Time/Temp: 121°C (250°F) for 3–4 Hours.
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SELF ADHESIVE PROPERTIES AND FILM ADHESIVE USE: Toray Advanced Composites cyanate ester resins have been formulated to have good self-adhesive properties to core materials. However, this should not be taken as a green light to eliminate a film adhesive from a cored, structural piece of hardware. This option has been given by Toray Advanced Composites for customers who are looking for the best electrical properties available by not using a film adhesive. Toray Advanced Composites recommends that the structural integrity be verified your specification prior to end item usage and takes no responsibility otherwise.
If this option is exercised, the following modified cure cycle has been found to work well.
- Ramp the part to 66–71°C (150–160°F) (Keep Pressure <15 Psi)
- Dwell for approximately 1 hour
- Ramp the part to the dictated cure temperature for the resin and cure per the provided standard cure cycle.
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LAY-UP AREA ENVIRONMENTAL CONTROLS: Toray Advanced Composites recommends that any composite or adhesive lay-up be performed in a clean area visibly free from dust. Any work surfaces should likewise be free of residue, dust or debris. No eating or smoking shall be allowed in the shop area. For radome materials, conductive materials shall not be allowed in the process area. The processing shop area should be maintained between 16°C to 32°C (60°F to 90°F) with a relative humidity of no greater than 70% rH.
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