DUPONT VAMAC ETHYLENE ACRYLIC ELASTOMER

Transcription

1 DUPONT VAMAC ETHYLENE ACRYLIC ELASTOMER 5000 SERIES PRE-COMPOUNDS Introduction 5000 Series Pre-Compounds for Improved Heat Resistance The 5000 series of Vamac pre-compounds offer superior performance for demanding applications requiring high heat resistance. Until the introduction of the 5000 series, AEM compounds relied on fillers like carbon black or silica to provide strength and stiffness for a finished article. These fillers, however, accelerated oxidative degradation series pre-compounds eliminate this problem by utilizing a novel filler system that actively extends the life of AEM articles exposed to hot air. Thus, finished parts based on 5000 series pre-compounds last up to three times longer at any given temperature compared to AEM compounds containing conventional fillers. Compounds based on the 5000 series are also lighter, with up to 15% lower specific gravity. The improved heat ageing performance of 5000 series pre-compounds benefits automotive applications such as turbocharger hose and molded air ducts, with specific advantages for seals and gaskets applications. Compounds made with 5000 grades exhibit significantly improved compressive stress relaxation properties in air, as well as in long term compression set measurements. While 5000 series pre-compounds may be extended with the addition of AEM elastomer, plasticizer or small amounts of conventional filler like carbon black, in some cases no additional filler may be required compounds also provide a route to bright colored finished articles having superior physical properties and heat ageing resistance compared to mineral filled AEM compounds Series Product Range As shown in Table 1, the 5000 series grades are available in a range of viscosities, suitable for molding, and extrusion applications and 5394 are preferred for steam autoclave cure low swell grade contains higher methyl acrylate content for better fluid resistance. Table 1 - Vamac Pre-Compounds for High Heat Resistance Grade ML (1+4) at 100 C Tg (by DSC) C 1 Density, g/cc Key Feature Compression molding pre-compound Injection molding pre-compound Extrusion, steam autoclave curable pre-compound Low swell, steam autoclave curable pre-compound 1 Tg of compounds with Vamac may be extended typically 10 C lower with the addition of plasticizer. 2 Not suitable for steam autoclave cure series products are available in bale form, and the natural color is opaque creamy white to light pink. Bales are packaged in 23kg units with a blue strippable wrap in individual boxes. The strippable wrap must be completely removed prior to using the product. A full pallet will hold thirty individual boxes with a net weight of 690kg.

2 Handling Precautions Because Vamac 5000 series pre-compounds may contain small amounts of residual methyl acrylate monomer, adequate ventilation should be provided during storage and processing to prevent worker exposure to methyl acrylate vapor. Additional information may be found in the respective Vamac 5000 product Safety Data Sheet (SDS), and bulletin, Safe Handling and Processing of Vamac (VME- A10628), available on the DuPont website. Improved Heat Resistance Vamac 5000 series pre-compounds offer significantly improved heat resistance over conventional carbon black filled AEM or HT-ACM. Characterization of temperature rating as a function of retention of properties in static heat ageing is shown in Figure 1. Stress-Strain property and Shore A hardness change are given as time versus temperature for the specified property retention criteria. Figure 1 Temperature Rating Comparing 5000 series to black filled AEM or HT-ACM, a significant increase in temperature rating is achieved. 6 weeks from 167 C to 182 C rating (+15 C) 3 weeks from 175 C up to 190 C rating (+15 C) 1 week from 185 C up to 205 C rating (+ 20 C)

3 Likewise, when the temperature is held constant, there is a significant increase in performance lifetime. 160 C from 1800 hours up to 3600 hours (2 x) 175 C from 504 hours up to 1680 hours (3.3 x) 185 C from 168 hours up to 750 hours (4.5 x) Improved Sealing Performance Industry standard tests for sealing performance include compression set (CS) and compressive stress relaxation (CSR). Results of these tests for many elastomers, including AEM, can depend on sample geometry. When tested in air, a test specimen with a high surface area to volume ratio (like a D214 o-ring) experiences greater oxidation, and therefor, greater degradation of sealing properties than large specimen like an ASTM D395 type 1 button. Because many seals have small sealing beads, CS and CSR tests using large specimens can mask performance issues that may arise from in-service oxidation. The improved heat ageing performance of 5000 pre-compounds therefore has significant benefit on long term compression set resistance, especially when tested using ISO buttons, or D214 o-rings. Figure 2 shows compression set results for 60 Shore A hardness compounds of 5020 / Vamac IP blends with either carbon black (15phr) or red pigment (for colored compound), compared to a conventional carbon black filled Vamac LS compound. While all the compounds perform about equally when testing ISO buttons at 168 hours/170 C, the 5000 compound outperforms the black-filled LS compound when the test time extends to 1008 hours, or when the specimen is switched to a D214 O-ring under conditions of 168 hours/180 C. Note the 5000 series compounds can tolerate small amounts of filler added for color or increasing hardness (typically by less than 10 points Shore A) without adversely affecting compression set or hot air aging properties. Figure 2 Long Term Compression Set Resistance , black 5000, red Vamac LS CS ISO815B, C CS ISO815B, C CS O-ring, C

4 Figure 3 shows compressive stress relaxation testing of ISO buttons in hot air for carbon black filled compounds of Vamac IP, HT-ACM, and a 5000 compound containing 2phr N550 carbon black for color. The superior oxidative stability of the 5000 compound results in dramatically improved CSR performance. Figure 3 CSR in Hot Air Compounding 5000 Series Pre-Compounds 5000 series compounds optimally contain about 20% lower Diak 1 levels than conventional AEM compounds, and use 4-aminodiphenylamine (ADPA) as the anti-oxidant. The preferred diarylamine antioxidants for carbon black or silica filled AEM compounds, like IPPD or Naugard 445, do not perform as well in the 5000 series. Table 2 shows starting point recipes where the amount of 5000 series pre-compound is set so that the compound comprise 100phr total AEM. As desired, additional AEM polymer may be added along with the 5000 pre-compound to adjust hardness or cure speed. Vamac HT, IP, and GXF are suitable diluents. Vamac IP provides faster curing. For compounds that may be steam autoclave cured, 5315 or 5394 are recommended.

5 Table 2 Starting Recipes for 5000 Ingredient (phr) 75 ShA hose 60 ShA gasket 5000 Grade AEM (diluent) 36 Diak to to 1.0 Vulcofac ACT to 2 Alcanpoudre DBU-70 0 to 2 Armeen 18D to 0.5 Stearic Acid 0 to to 0.5 ADPA* 0.5 to to 1.5 Plasticizer** 2 to 5 0 to 0.5 Vanfre VAM 1 1 Carbon Black 2 2 * 4-aminodiphenyl amine, is available from ChemSpec or Safic Alcan as ADPA ** Alcanplast PO80, TegMer 812, or similar Fatigue resistance is optimized at 0.55phr or less of Diak 1, and ISO compression set is optimized at 0.8phr. VW compression set improves up to and beyond 1.0phr, although heat resistance worsens at Diak 1 levels greater than 1.0phr. Use at least 1phr accelerator, noting that Vulcofac ACT-55 is a weaker accelerator than Alcanpoudre DBU-70. Better release and faster cure may be achieved for molded compounds using 1.5 to 2phr DBU- 70. ADPA is the preferred anti-oxidant for 5000 pre-compounds, and also provides added scorch protection along with Armeen 18D. For bright compounds, staining diaryl amine AO like ADPA or Naugard 445 are not desirable. Low volatile plasticizers may be used up to 10phr, depending on the low temperature requirements. Low levels of carbon black (any type) may be used as a colorant without negatively impacting properties. For compounds of Vamac with conventional non-black inorganic fillers such as silica, clay or calcium carbonate, physical properties and rheology are inferior to carbon black filled compounds in terms of processing, and compression set. The 5000 pre-compounds already contain a non-black filler system, and exhibits excellent properties for heat ageing, and compression set. This makes the 5000 series suitable for use of AEM in colored compounds for differentiation of parts and optical control. While non-staining anti-oxidants, like Irganox 1010 and nox 626, may be used with 5000, ADPA is preferred for the best heat resistance. The ADPA will darken with oxidation.

6 Hardness, Shore A (3s) Formulating for Different Hardness Level 5000 series pre-compounds contain filler level for a hardness of approximately 75 Shore A after vulcanization. To achieve lower hardness levels, unfilled Vamac AEM polymer must be added to dilute and reduce the overall filler level. Figure 4 exhibits a profile of hardness range between 55 to 75 Shore A (3 sec) for 5015 / Vamac IP blends in a compound formulation and curative package typical for a sealing application. Further modification can be achieved by changing curative, supplemental filler, and plasticizer level. Dilution of 5000 pre-compounds may be extended to provide compounds of low hardness level (37 to 47 Shore A) with relatively good properties, and processing, which is difficult to achieve with conventional black filled compounds. Figure 4 AEM Blends with 5000 Series for Lower Hardness Compounds Example (%): 5015 = 73%, Vamac IP = 27%, ADAP = 0.93%, Stearic Acid = 0.33%, Vanfre VAM = 0.67%, Diak 1 = 0.67%, Alcanpoudre DBU-70 =1.33% for a hardness (3s) of 62 Shore A Content (% of total polymer) Higher hardness compounds (>75 Sh A) may be achieve with addition of supplemental filler.

7 Compound Comparison of Four 5000 Grades (65-70 Shore A) The following tables compare the four 5000 grades versus a black filled Vamac LS compound. Two variations of red colored compounds with 5020 are included. The later compound is a blend of and Vamac LS with higher Diak 1 level. Table 3 Compound Formulation for Comparison of All Four 5000 Grades Compound Ingredient (phr) Vamac LS Reference red 5020 / LS, red Vamac IP Vamac LS 17.5 Vamac Vamac Vamac Vamac Alcanpoudre ADPA Naugard Armeen 18D PRILLS 0.5 Stearic Acid Vanfre VAM sil VN Alcanpoudre A Ferroxide 214 M Spheron SOA (N550) 20 Corax N MT Thermax Floform N Alcanplast PO Diak Vulcofac ACT

8 Mooney viscosity of the 5020 injection molding compound is the lowest among the 5000 series. MDR MH is relatively lower, and cure times are longer generally for the lower swell, higher methyl acrylate containing 5394 grade. Table 4 Comparison Study Rheology Rheology Vamac LS Reference red 5020 / LS, red Mooney Viscosity ML 1+4 at 100 C (ISO 289-1:2005) Initial Mooney [MU] Final Mooney [MU] Slope [lg M/g s] Intercept Mooney [MU] MDR cure rate 15 minutes at 180 C, arc 0.5 (ISO 6502:1999) ML [dnm] MH [dnm] Ts1 [min] Ts2 [min] T10 [min] T50 [min] T90 [min] T95 [min] Tan delta at ML Tan delta at MH Peak rate [dnm/min] Mooney Scorch 45 min at 121 C (ISO 289-2:1994) Initial Mooney [MU] Minimum Mooney [MU] Ts1 [min] Ts2 [min] T5 [min] T10 [min] T35 [min] Point rise at 30 min

9 Table 5 Comparison Study Original Properties Original Properties Vamac LS Reference red 5020 / LS, red Compression molding 10 minutes at 180 C / Post-cure 4 hours at 175 C Hardness (ISO :2004) Hardness Shore A, 3s Hardness Shore A, 1s Tensile Properties (type 2) at 23 C Tensile Strength [MPa] Elongation at Break [%] Modulus at 10 % [MPa] Modulus at 25 % [MPa] Modulus at 50 % [MPa] Modulus at 100 % [MPa] Modulus at 200 % [MPa] Trouser Tear, Propagation Direction: Mill (ISO 34-1:2004) Tear Strength - type A Tg [ C] Tensile Properties T2 at 150 C (ISO 37:2005, Cor ) Tensile Strength [MPa] Elongation at Break [%] Modulus at 10 % [MPa] Modulus at 25 % [MPa] Modulus at 50 % [MPa] Modulus at 100 % [MPa]

10 The conventional carbon black reference AEM compound exhibits more hardening, and greater loss of properties than the 5000 compounds. Table 6 Comparison Study Heat Ageing Heat Ageing Vamac LS Reference red 5020 / LS, red Heat Ageing 1008 hours at 150 C Hardness Shore A, 3s Delta Hardness Tensile Strength [MPa] Delta TS [%] Elongation at Break [%] Delta Elong. [%] Modulus at 50 % [MPa] Delta 50% [%] Modulus at 100 % [MPa] Delta 100% [%] Modulus at 200 % [MPa] Delta 200% [%] Heat Ageing 1008 hours at 175 C Hardness Shore A, 3s Delta Hardness Tensile Strength [MPa] Delta TS [%] Elongation at Break [%] Delta Elong. [%] Modulus at 50 % [MPa] Delta 50% [%] Modulus at 100 % [MPa] Delta 100% [%]

11 Long term compression set at 160 to 170 C are lower for the 5000 compounds, and is less impacted over time when cooled in the clamps compared to the black reference AEM compound. Compression set for the lower swell 5394 (higher methyl acrylate) pre-compound is highest among the 5000 series. VW compression set can be made lower than what is shown for this study using higher Diak , and 5315 are shown best among the 5000 series in VW compression set. Table 7 Comparison Study Compression Set Compression Set Vamac LS Reference red 5020 / LS, red Compression Set type B (ISO 815-1:2008) 70 hours / 150 C [%] hours / 160 C [%] hours / 160 C [%] hours / 170 C [%] hours / 180 C [%] Compression Set type B (ISO 815-1:2008), cooled in clamps for 2h 24h / 150 C [%] h / 150 C [%] Compression Set VW (PV 3307: ), 72 hours at 23 C at 5 seconds [%] at 30 minutes [%] Compression Set VW (PV 3307: ), 22 hours at 150 C at 5 seconds [%] at 30 minutes [%] Deflection [%] Table 8 Comparison Study Fluid Ageing with Oil

12 Fluid Ageing: Reference and Engine Oil Vamac LS Reference red 5020 / LS, red Ageing 1008 hours at 150 C, Aeroshell Oil Diesel, 5W-30 Compression Set type B (ISO 815-1:2008), cooled in clamps for 2h CSet, 1008h / 150 C [%] Hardness Shore A, 3s Delta Hardness Tensile Strength [MPa] Delta TS [%] Elongation at Break [%] Delta Elong. [%] Modulus at 25 % [MPa] Delta 25% [%] Modulus at 50 % [MPa] Delta 50% [%] Modulus at 100 % [MPa] Delta 100% [%] Weight Change [%] Volume Change [%] Ageing 1008 h, 150 C, Lubrizol OS Compression Set type B (ISO 815-1:2008), cooled in clamps for 2h CSet, 1008h / 150 C [%] Hardness Shore A, 3s Delta Hardness Tensile Strength [MPa] Delta TS [%] Elongation at Break [%] Delta Elong. [%] Modulus at 25 % [MPa] Delta 25% [%] Modulus at 50 % [MPa] Delta 50% [%]

13 Modulus at 100 % [MPa] Delta 100% [%] Weight Change [%] Volume Change [%] Table 9 Comparison Study Fluid Ageing with 10% FAM-B Fluid Ageing: Reference Oil + 10% FAM-B Vamac LS Reference red 5020 / LS, red Fluid ageing 168 hours at 150 C in Lubrizol OS % FAM-B (ISO 1817:2011) in Autoclave Hardness Shore A, 3s Delta Hardness Tensile Strength [MPa] Delta TS [%] Elongation at Break [%] Delta Elong. [%] Modulus at 10 % [MPa] Delta 10% [%] Modulus at 25 % [MPa] Delta 25% [%] Modulus at 50 % [MPa] Delta 50% [%] Modulus at 100 % [MPa] Delta 100% [%] Modulus at 200 % [MPa] Delta 200% [%] Weight Change [%] Volume Change [%] Table 10 Comparison Study Fluid Ageing with Blow-By Condensate

14 Fluid Ageing: Blow-By Condensate Vamac LS Reference red 5020 / LS, red Fluid ageing 24 hours at 120 C in Blow-By Condensate (ISO 1817:2011), in Autoclave Hardness Shore A, 3s Delta Hardness Tensile Strength [MPa] Elongation at Break [%] Modulus at 50 % [MPa] Modulus at 100 % [MPa] Weight Change [%] NaN NaN Volume Change [%] NaN NaN Drying - Blow-By Condensate, BMW - GS Hardness Shore A, 3s Delta Hardness Tensile Strength [MPa] Elongation at Break [%] Modulus at 50 % [MPa] Modulus at 100 % [MPa] Weight Change [%] Volume Change [%] Table 11 Comparison Study of Fluid Ageing with AdBlue Fluid Ageing: AdBlue (32% Urea Solution in Water) Vamac LS Reference Fluid ageing 168 hours at 130 C in Adblue (registered trademark of BASF) ISO 1817:2011, in Autoclave 5315 Hardness Shore A, 3s Delta Hardness Tensile Strength [MPa] Delta TS [%] Elongation at Break [%] Delta Elong. [%]

15 Modulus at 50 % [MPa] Delta 50% [%] Modulus at 100 % [MPa] Delta 100% [%] Weight Change [%] Volume Change [%] Higher Hardness Compounds 70 to 80 Shore A Formulating 5000 pre-compounds with additional filler allows for producing higher hardness compounds. The following study is made to further show the effect of carbon black filler type and level on 5015, and 5020 compounds, and compared with conventional black-filled AEM compounds for applications like bonded piston seals. Table 12 Compound Formulations with Added Carbon Black Compound Formulation G G / Vamac G GXF Vamac LS Vamac IP Vamac GXF 50 Vamac LS , Vamac SRF MT Vamac Alcanpoudre ADPA Naugard Armeen 18D PRILLS Stearic Acid Reagent Vanfre VAM Spheron SOA (N550) Corax N MT Thermax N Alcanplast PO low MT, high DIAK Diak no

16 No scorch retarder was added to the 5000 compounds for this study. The addition of Armeen 18D would reduce viscosity, lower scorch times, and slow cure speed. Table 13 Higher Hardness Compounds, Rheology Rheology G G / GXF LS 5015, SRF MT low MT, high DIAK Mooney, ML 1+4 at 100 C Initial Mooney [MU] Final Mooney [MU] MDR, 12 min, 180 C, arc 0.5 ML [dnm] MH [dnm] Ts1 [min] Ts2 [min] T10 [min] T50 [min] T90 [min] Tan delta at MH Peak rate [dnm/min] Mooney Scorch 45 min at 121 C Initial Mooney [MU] Minimum Mooney [MU] Ts1 [min] Ts2 [min] T5 [min] T10 [min]

17 Hardness of 5000 compounds may be adjusted by varying the addition of carbon black, and carbon black type. The 5000 series exhibit significantly lower IRHD hardness than conventional carbon black filled AEM compounds, especially Table 14 Higher Hardness Compounds, Original Properties Original Properties G G / GXF LS 5015, Compression Molding 10 minutes at 180 C, Post-cure 4 hours at 175 C SRF MT low MT, high DIAK Initial Specific Gravity [g/cm³] Hardness Sh A, 1s Hardness Sh A, 3s Hardness IRHD (Method N, ISO48:2007) Tensile properties (type 2) at 23 C, ISO 37:2005 Cor Tensile Strength [MPa] Elong at Break [%] Mod at 10 % [MPa] Mod at 25 % [MPa] Mod at 50 % [MPa] Mod at 100 % [MPa] Tear strength type A - Trouser test pieces (Tear propagation direction: mill), ISO 34-1:2004 Tear strength [kn/m] Table 15 Higher Hardness Compounds, Compression Set Compression Set G G / GXF LS 5015, SRF MT low MT, high DIAK Compression Set, ISO 815-1, type B 70 h at 150 C [%] h at 160 C [%] h at 170 C [%] h at 180 C [%]

18 504 h at 190 C [%] Compression Set, ISO 815-1:2008 (DBL 6038), plied cooled in the clamps 2h 1008 h at 150 C [%] Compression Set VW (PV 3307: ), 22h at 150 C after 5 sec. [%] after 30 min [%] Compression Set VW (PV 3307: ), 72h at 23 C after 5 sec. [%] after 30 min [%] Six week air oven ageing of 5000 compounds show significantly less change in hardness, and loss in elongation than carbon blacked filled AEM compounds. Table 16 Higher Hardness Compounds, Ageing Heat Ageing G G / GXF Heat Ageing 1008 h at 150 C (ISO 188:2007) LS 5015, SRF MT low MT, high DIAK Hardness Shore A, 1s Delta Hardness Tensile Strength [MPa] Delta TS [%] Elong at Break [%] Delta Elong. [%] Mod at 25 % [MPa] Delta 25% [%] Mod at 100 % [MPa] Delta 100% [%] Heat Ageing 1008 h at 175 C (ISO 188:2007) Hardness Shore A, 1s Delta Hardness Tensile Strength [MPa] Delta TS [%]

19 Elong at Break [%] Delta Elong. [%] Mod at 25 % [MPa] Delta 25% [%] Mod at 100 % [MPa] Delta 100% [%] Table 17 Higher Hardness Compounds, Fluid Ageing Fluid Ageing G G / GXF LS 5015, SRF MT low MT, high DIAK Fluid Ageing, 1008 h at 150 C in Petro Dexron VI RDL 3434 Hardness Shore A, 1s Delta Hardness Tensile Strength [MPa] Delta TS [%] Elongation at Break [%] Delta Elong. [%] Mod at 10 % [MPa] Delta 10% [%] Mod at 100 % [MPa] Delta 100% [%] Weight Change [%] Volume Change [%] Fluid Ageing, 1008 h at 150 C in Pentosin FFL-5 LV Hardness, Shore A, 1 s Delta Hardness Tensile Strength [MPa] Delta TS [%] Elongation at Break [%] Delta Elong. [%] Mod at 10 % [MPa] Delta 10% [%]

20 Mod at 100 % [MPa] Delta 100% [%] Weight Change [%] Volume Change [%] Visit us at vamac.dupont.com Contact DuPont at the following regional locations: North America Latin America Europe, Middle East, Africa Greater China Japan ASEAN The information provided in this data sheet corresponds to DuPont knowledge on the subject at the date of its publication. This information may be subject to revision as new knowledge and experience becomes available. The data provided fall within the normal range of product properties and relate only to the specific material designated; these data may not be valid for such material used in combination with any other materials, additives or pigments or in any process, unless expressly indicated otherwise. The data provided should not be used to establish specification limits or used alone as the basis of design; they are not intended to substitute for any testing you may need to conduct to determine for yourself the suitability of a specific material for your particular purposes. Since DuPont cannot anticipate all variations in actual end-use and disposal conditions, DuPont does not guarantee results, makes no warranties and assumes no liability in connection with any use of this information. All such information is given and accepted at the buyer s risk. It is intended for use by persons having technical skill, at their own discretion and risk. Nothing in this publication is to be considered as a license to operate under or a recommendation to infringe any patent. CAUTION: Do not use DuPont materials in medical applications involving implantation in the human body or contact with internal body fluids or tissues unless the material has been provided from DuPont under a written contract that is consistent with DuPont policy regarding medical applications and expressly acknowledges the contemplated use. For further information, please contact your DuPont representative. You may also request a copy of DuPont POLICY Regarding Medical Applications H and DuPont CAUTION Regarding Medical Applications H Copyright 2018 DuPont. The DuPont Oval Logo, DuPont and Vamac are trademarks or registered trademarks of E.I. du Pont de Nemours and Company or its affiliates.