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

Extreme Materials for Extreme Applications

ALLOTROPICATECHNOLOGIES

3D Printing

Defense

CommercialAerospace

StockShapes

PolymerAdditives

Marine

High-performance polymers

3

ü Shelf life

ü Thermal bonding

ü Post forming possible

– High Temperature use

PEKKTg 156 ºC; Tm 338 ºC

Thermoplastic

ü Ease of processing

ü High temperature use

– Shelf life

– Post forming

Thermoset

ReactiveThermoplastic

Polymers

bisphenol-A diglycidyl ether epoxyTg 190 ºC

Reactive Thermoplastic polymers

4

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

Reactive Thermoplastic polymers

5

• High after cure Tg (250–350 oC) and Td5% (>480 oC)

• Low CTE (below Tg: 5.2 oC-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)

Oligomer is liquid crystalline (LC), which means the polymer chains are rod-like and closely packed

Thermal properties cured films

6

!

When the LC oligomer is cured a Liquid Crystalline Thermoset or LCT is obtained

Cured neat films:

Ø20 x 5 x 0.25 mmØHeating rate 2 oC/minØFrequency 1 Hz

Thermal properties cured films

7

!

When the LC oligomer is cured a Liquid Crystalline Thermoset or LCT is obtained

Cured neat films:

Ø20 x 5 x 0.25 mmØHeating rate 2 oC/minØFrequency 1 Hz

Thermal properties cured films

8

LCT creep vs PPS and PEKK (neat resins only!)

Ø20 x 5 x 0.25 mmØHeating rate 2 oC/minØFrequency 1 HzØForce: 1–1.2 N

50 100 150 200 250 300 350 400 450106

107

108

109

101 0

Strain [%

]

E' P

PS [P

a]

Temperature [°C]

HBA/BP/TA(15)-NDA(5)-5k PEKK PPS

E' P

EKK

[Pa]

E'

HBA

/BP

/TA(

15)

-ND

A(5

)-5k [P

a]

0102030405060708090100110

P EKK s train

P PS s tr ain

HBA /BP/TA( 15)-NDA(5)-5k stra in

Stra in 5%

Tg = 270 °C

Applications

9

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:

LCT-A LCT-A (salt-spray)5

10

15

20

25

Pull-

off s

tren

ght (

MPa

)

25,7 MPa

22,2 MPa

(a) (b)

Coating

Adhesive

Al

Steel

(1000 h salt spray)

10

RheologyCompressed powder pellets, 1% strain, 5 rad/sec, 5 oC/min

20 40 60 80100

101

102

103

104

105

106

Com

plex

vis

cosit

y |η

|* [P

a s]

Time [min]

240

260

280

300

320

340

360

380Tem

perature [°C]

20 40 60 80100

101

102

103

104

105

106

Com

plex

vis

cosit

y |η

|* [P

a s]

Time [min]

0 N

240

260

280

300

320

340

360

380Tem

perature [°C]

20 40 60 80100

101

102

103

104

105

106

Com

plex

vis

cosit

y |η

|* [P

a s]

Time [min]

0 N 1 N

240

260

280

300

320

340

360

380Tem

perature [°C]

20 40 60 80100

101

102

103

104

105

106

Com

plex

vis

cosit

y |η

|* [P

a s]

Time [min]

0 N 1 N 2.5 N

240

260

280

300

320

340

360

380Tem

perature [°C]

20 40 60 80100

101

102

103

104

105

106

Com

plex

vis

cosit

y |η

|* [P

a s]

Time [min]

0 N 1 N 2.5 N 5 N 240

260

280

300

320

340

360

380Tem

perature [°C]

Composite processing

LCT suitable for melt prepreging or pultrusion of fibres

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 – 5k

10 c

m

10 c

m

5 N – 10k

LCT powder

12

Composite processing

- C-scan inspection of panels

5N-5k 5N-10k20 c

m

20 cm

Flame exposure tests

13

Initial flame exposure test (Peter Coppens, Airborne)

Cone calorimetry tests

14

Heat release and smoke production according to ISO 5660-1

Per Blomqvist (SP)

Cone calorimetry tests

15

Heat release and smoke production according to ISO 5660-1

Cone calorimetry tests

16

How to compare to a well-known epoxy resin?

Bis F epoxy/glass (30/70). ASTM E-1354-04 at 50kW/m2

Fire Mater 2009; 33:323–344.

Cone calorimetry tests

17

Smoke production rate

Cone calorimetry tests

18

Test results from ISO 5660-1 were used to predict the behaviour of glass/LCT in a ISO 9705 room-corner test

100 kW

300 kW

19

• Cured LC thermosets (LCTs) offer high Tg’s (200–350 oC), lowcreep, low CTE’s, low moisture absorption and fluid stability

• Reactive LC oligomers exhibit low melt viscosities, which makesthem ideal candidates for (highly filled) short- and continuousfibre reinforced composites

• LCT can be processed into composite panels that can bethermally formed on-site (e.g. stamp forming)

• LCT–glass composites show good room temperature mechanicalproperties

• LCT-glass composites exhibit low flammability and hence showpromise for marine structural (composite), coating, insulatingfoam and adhesive applications

Conclusions

Acknowledgements

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TU-DelftMartino Marchetti, Mazhar Iqbal and Alwin Knijnenberg

TencateJoris Markenstein and Hans Luinge

AirbornePeter Coppens

SP GroupPer Blomqvist

Industrial partners (M2i)Fokker, Tencate, SKF, TPRCand Promoulding

Extreme Materials for Extreme Applications

ALLOTROPICATECHNOLOGIES

3D Printing

Defense

CommercialAerospace

StockShapes

PolymerAdditives