High-performance liquid crystal thermosets: Resins for marine composite applications

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1 High-performance liquid crystal thermosets: Resins for marine composite applications Theo Dingemans, Alan Dow and Edward Samulski, Martino Marchetti (TU-Delft) E-LASS Seminar Finspång 2016

2 Polymer Additives Marine Defense ALLOTROPICA TECHNOLOGIES Commercial Aerospace Stock Shapes 3D Printing Extreme Materials for Extreme Applications

3 High-performance polymers Thermoplastic Thermoset ü Shelf life ü Thermal bonding ü Post forming possible High Temperature use Reactive Thermoplastic Polymers ü Ease of processing ü High temperature use Shelf life Post forming PEKK T g 156 ºC; T m 338 ºC bisphenol-a diglycidyl ether epoxy T g 190 ºC 3

4 Reactive Thermoplastic polymers Thermoplastic oligomer (5-10 K) Oligomer state makes low viscous melt processing possible (ideal for composites!) Reactive end-groups allow for post processing curing: both chain extension and crosslinking is possible 4

5 Reactive Thermoplastic polymers Oligomer is liquid crystalline (LC), which means the polymer chains are rod-like and closely packed High after cure Tg ( o C) and T d 5% (>480 o C) Low CTE (below Tg: 5.2 o C -1 ) low moisture uptake (< 0.05%) and fluid ingress stable Inherently flame ret. (com LCPs are typically UL94-V0) LCP have excellent track record in marine applications (stable in UV and salt water and wear resistant) 5

6 Thermal properties cured films When the LC oligomer is cured a Liquid Crystalline Thermoset or LCT is obtained Cured neat films: Ø20 x 5 x 0.25 mm ØHeating rate 2 o C/min ØFrequency 1 Hz! 6

7 Thermal properties cured films When the LC oligomer is cured a Liquid Crystalline Thermoset or LCT is obtained Cured neat films: Ø20 x 5 x 0.25 mm ØHeating rate 2 o C/min ØFrequency 1 Hz! 7

8 Thermal properties cured films LCT creep vs PPS and PEKK (neat resins only!) Ø20 x 5 x 0.25 mm ØHeating rate 2 o C/min ØFrequency 1 Hz ØForce: N E' [Pa] E' HBA/BP/TA(15)-NDA(5)-5k [Pa] PPS E' PEKK [Pa] PPS strain HBA/BP/TA(15)-NDA(5)-5k PEKK PPS P EKK s train T g = 270 C HBA /BP/TA( 15)-NDA(5)-5k strain Strain [%] Strain 5% Temperature [ C] 8

9 Applications LCT is typically in film, powder or granulate form (infinite shelf-life) and can be processed into machinable stock shapes, foams, coatings, adhesives and composites: 25,7 MPa Steel Adhesive 25 22,2 MPa Pull-off strenght (MPa) Coating Al 5 LCT-A LCT-A (salt-spray) (1000 h salt spray) (a) (b) 9

10 Composite processing Rheology Compressed powder pellets, 1% strain, 5 rad/sec, 5 o C/min Complex viscosity η * [Pa s] Time [min] 0 N 1 N 2.5 N 5 N LCT suitable for melt prepreging or pultrusion of fibres Temperature [ C] 10

11 Composite processing - Composite stack: 6 plies, 60/40 volume, glass fibre fabric - Type of yarn: EC9 68, 8 harness satin; Fabric thickness: 0.23 mm. 5 N 10k 5 N 5k 10 cm 10 cm LCT powder 11

12 Composite processing - C-scan inspection of panels 20 cm 5N-5k 5N-10k 20 cm 12

13 Flame exposure tests Initial flame exposure test (Peter Coppens, Airborne) 13

14 Cone calorimetry tests Heat release and smoke production according to ISO Per Blomqvist (SP) 14

15 Cone calorimetry tests Heat release and smoke production according to ISO

16 Cone calorimetry tests How to compare to a well-known epoxy resin? Bis F epoxy/glass (30/70). ASTM E at 50kW/m 2 Fire Mater 2009; 33:

17 Cone calorimetry tests Smoke production rate 17

18 Cone calorimetry tests Test results from ISO were used to predict the behaviour of glass/lct in a ISO 9705 room-corner test 300 kw 100 kw 18

19 Conclusions Cured LC thermosets (LCTs) offer high Tg s ( o C), low creep, low CTE s, low moisture absorption and fluid stability Reactive LC oligomers exhibit low melt viscosities, which makes them ideal candidates for (highly filled) short- and continuous fibre reinforced composites LCT can be processed into composite panels that can be thermally formed on-site (e.g. stampforming) LCT glass composites show good room temperature mechanical properties LCT-glass composites exhibit low flammability and hence show promise for marine structural (composite), coating, insulating foam and adhesive applications 19

20 Acknowledgements TU-Delft Martino Marchetti, Mazhar Iqbaland Alwin Knijnenberg Tencate Joris Markenstein and Hans Luinge Airborne Peter Coppens SP Group Per Blomqvist Industrial partners (M2i) Fokker, Tencate, SKF, TPRC and Promoulding 20

21 3D Printing Defense ALLOTROPICA TECHNOLOGIES Commercial Aerospace Stock Shapes Polymer Additives Extreme Materials for Extreme Applications