Hot curing epoxy system based on Araldite LY 556 ...

1 February 1998 Ciba Specialty ChemicalsPerformancePolymersStructural CompositesMATRIX SYSTEMS FOR INDUSTRIAL COMPOSITESDATA SHEETHot curing epoxy system based onAraldite LY 556 / Hardener HY 917 / accelerator DY 070 Araldite LY 556 is an epoxy resinHardener HY 917 is an anhydride hardenerAccelerator DY 070 is an imidazole acceleratorApplicationsHigh performance composite partsPropertiesAnhydride-cured, low-viscosity standard matrix system with extremely long pot reactivity of the system is adjustable by variation of the accelerater system is easy to process, has good fibre impregnation properties and exhibitsexcellent mechanical, dynamic and thermal properties.

2 It has an excellent chemicalresistance especially to acids at temperatures up to 80 C. This epoxy systemfulfills MIL specifications R WindingPultrusionPressure MouldingKey dataAraldite LY 556 Aspect (visual)clear, pale yellow liquidColour (Gardner, ISO 4630) 2 epoxy content (ISO 3000) - [eq/kg]Viscosity at 25 C (ISO 9371B)10000 - 12000[mPa s]Density at 25 C (ISO 1675) - [g/cm3]Flash point (ISO 2719)> 200[ C]Storage temperature(see expiry date on original container)2 - 40 C[ C]Hardener HY 917 Aspect (visual)clear liquidColour (Gardner, ISO 4630) 2 Viscosity at 25 C (ISO 9371B)50 - 100[mPa s]Density at 25 C (ISO 1675) - [g/cm3]Flash point (ISO 2719)

3 195[ C]Storage temperature(see expiry date on original container)2 - 40 C[ C] accelerator DY 070 Aspect (visual)clear liquidColour (Gardner, ISO 4630) 9 Viscosity at 25 C (ISO 9371B) 50[mPa s]Density at 25 C (ISO 1675) - [g/cm3]Flash point (ISO 2719)92[ C]Storage temperature(see expiry date on original container)2 - 40 C[ C]February 1998 Hot curing epoxy system based on Araldite LY 556 / Hardener HY 917 / accelerator DY 0702/8 StorageProvided that Araldite LY 556, Hardener HY 917 and accelerator DY 070 arestored in a dry place in their original, properly closed containers at the abovementioned storage temperatures they will have the shelf lives indicated on emptied containers should be closed immediately after Hardener HY 917 is sensitive to moisture.

4 Storage containers should beventilated with dry air LY 556 which has crystallized and looks cloudy can be restored to itsoriginal state by heating to 60 - 80 1998 Hot curing epoxy system based on Araldite LY 556 / Hardener HY 917 / accelerator DY 0703/8 Processing dataMix ratioComponentsAraldite LY 556 Hardener HY 917 accelerator DY 070 Parts by - 2 Parts by - recommend that the components are weighed with an accurate balance toprevent mixing inaccuracies which can affect the properties of the matrix components should be mixed thoroughly to ensure homogeneity. It is importantthat the side and the bottom of the vessel are incorporated into the mixing processing large quantities of mixture the pot life will decrease due toexothermic reaction.

5 It is advisable to divide large mixes into several simplify the mixing process the resin can be preheated to about 30 C to 50 Cbefore adding the cold hardener. Hardener and accelerator can be premixed, thusallowing the use of two component mixing/metering equipment. The mix of hardenerand accelerator has a shelf life of several processing of the system at elevated temperatures of 30 C to 40 C shows thebest results. The gelation temperature should not be higher than absolutelynecessary. A high gelation temperature induces high shrinkage and generatesinternal 1998 Hot curing epoxy system based on Araldite LY 556 / Hardener HY 917 / accelerator DY 0704/8 Processing dataInitial mix viscosity(Hoeppler, ISO 9371B)[ C]at 25at 40at 60[mPa s]600 - 900200 - 300< 75 Viscosity build-up(Hoeppler, ISO 9371B)

6 Components [pbw] Araldite LY 556 Hardener HY 917 accelerator DY 070 system 2100901 system 3100902[ C]at 25at 40at 80at 90[mPa s]to 1500to 3000to 1500to 3000to 1500to 3000to 1500to 3000[h][h][h][h][min][min][min][min]10 - 1233 - 3719 - 2123 - 2695 - 105105 - - - 187 - 89 - 1052 - 5760 - - 26 - 73 - 44 - 532 - 3535 - 3814 - 1615 - 17 Pot life(Tecam, 65 % RH,100 g)10 kg metal container[ C]at 23at 40[h][h] system 1165 - 1755 - 7 system 295 - 1054 - 5 system 348 - 54-Gel time(Hot plate)[ C]at 80at 100at 120at 140at 160[min][min][min][min][min] system 1230 - 27065 - 7521 - 257 - 92 - 4 system 2140 - 16035 - 4510 - 123 - 51 - 2 system 365 - 7518 - 225 - 71 - 3-The values shown are for small amounts of pure resin/hardener mix.

7 In compositestructures the gel time can differ significantly from the given values depending onthe fibre content and the laminate cure cyclesGelation eitherorPost-cure eitheroror2 - 4 h at 80 C1 - 3 h at 90 C4 - 8 h at 120 C2 - 8 h at 140 C2 - 8 h at 160 CCure temperatures in excess of about 130 C cause brown discolouration but do notimpair the properties of the 1998 Hot curing epoxy system based on Araldite LY 556 / Hardener HY 917 / accelerator DY 0705/8 Properties of the cured, neat formulationUnless otherwise stated, the processing schedule for the samples tested wasgelation for 4 hours at 80 C and post-cure for 8 hours at 140 transitiontemperature (TG)(IEC 1006,10 K/min)Cure.

8 4 h 80 C + 4 h 120 C4 h 80 C + 8 h 120 C4 h 80 C + 4 h 140 C4 h 80 C + 8 h 140 C4 h 80 C + 4 h 160 C4 h 80 C + 8 h 160 CTG DSC [ C]140 - 144144 - 148145 - 150148 - 153150 - 155150 - 155TG TMA [ C]125 - 128125 - 128130 - 135135 - 145140 - 145140 - 145 Tensile test(ISO 527)Tensile strengthElongation at tensile strengthUltimate strengthUltimate elongationTensile modulus[MPa][%][MPa][%][MPa]83 - - - - - 3300 Flexural test(ISO 178)Flexural strengthDeflection at maximum load10 days in H2O 23 CFlexural strengthDeflection at maximum load60 min in H2O/100 CFlexural strengthDeflection at maximum load[MPa][mm][MPa][mm][MPa][mm]125 - 13510 - 18110 - 1208 - 18125 - 13510 - 18 Fracture propertiesBend notch test(PM 258-0/90)Fracture toughness K1 CFracture energy G1C[MPa m][J/m2] - - 96 Water absorption(ISO 62)Immersion:1 day H2O 23 C10 days H2O 23 C30 min H2O 100 C60 min H2O 100 C[%][%][%][%] - - - - of linearthermal expansion(DIN 53 752)Mean value.

9 From 20 - 100 C from 100 - 130 C[10-6/K][10-6/K]55 - 5767 - 70 Poison s ratio[ ] 1998 Hot curing epoxy system based on Araldite LY 556 / Hardener HY 917 / accelerator DY 0706/8 Properties of the cured, reinforced formulationUnless otherwise stated, the figures given are for pressed laminate samplescomprising 16 layers (4 mm) of E-glass fabric 1:1, 280 - 300 g/m2, fibre volume content 42 - 47 %.Flexural test(ISO 178)Flexural strengthDeflection at maximum loadFlexural modulus10 days inH2O 23 CFlexural strengthDeflection at maximum load60 min in H2O/100 CFlexural strengthDeflection at maximum load[MPa][mm][MPa][MPa][mm][MPa][mm]520 - 5505 - 616500 - 16700390 - 4104 - 5460 - 4805 - 6 Tensile test(ISO 3268 - 1978)Tensile strengthUltimate elongationTensile modulus[MPa][%][MPa]345 - 3751 - 225500 - 26000 Interlaminar shearstrength(ASTM D 2344)Short beam: E-glass unidirectional specimenLaminate thickness t = mmFibre volume content: 60 %Shear strength:[MPa]75 - 77 Water absorption(ISO 62)Immersion.

10 1 day H2O 23 C10 days H2O 23 C30 min H2O 100 C60 min H2O 100 C[%][%][%][%] - - - - ,Compressive andTorsional test (TCT)E-glassRovingE-glass roving, 1200 tex, silane finishFibre volume content67 %Gelation temperature90 CPost-cure8 h at 140 CCarbon HTRovingCarbon fibre high tensile,Torayca T 300 B - 6000 - 50 BFibre volume content64 %Gelation temperature90 CPost-cure8 h at 140 CTransverse tensile testTensile strengthTensile strainElastic modulus[MPa][%][MPa]E-Glass48 - - - 20000 Carbon HT77 - - - 9900 Transverse compressive testCompressive strengthCompressive strain at brakElastic modulus[MPa][%][MPa]165 - - - 22000190 - - - 9900 Torsional testShear strengthShear angleShear modulus[MPa][%][MPa]