High performance resins for FRP composites in structural / construction applications

Transcription

1 High performance resins for FRP composites in structural / construction applications Arie van Buren - Ashland Performance Materials, Kehl, Germany Presented to the International Conference Composites - CIS September 2012 Sevastopol, Ukraine

2 Contents Use of VE and EP resins Basics of VE and EP resins Differentiation of VE and EP applications Material science aspects Representative case histories Conclusion and outlook Questions & Answers (Q&A) 2

3 Use of VE and EP resins The high industrial value of epoxy vinyl ester (VE) resins and epoxy (EP) resins are proven since 40 years for composite applications. A differentiated portfolio of epoxy vinyl ester resins and epoxy resin systems cover a broad application window from pressure pipes to severe chemical service. The global pioneers, who developed & patented the DERAKANE and HETRON Epoxy Vinyl Ester Resins technology, The Dow Chemical Company and Shell Chemical Company, were also the global leading epoxy producers. Before developing Vinyl Ester Resins, the end-users were limited to use less chemical resistant resins for composite applications. 3

4 Use of VE resins (1) The use of epoxy vinyl ester (VE) resins covers a broad range of industrial applications with an operating window of -40 to +200 C: Industrial / petrochemical Oil & gas Power plants Marine & offshore Utility e.g. Fire water lines Desalination (drinking water approved resin) Industrial sewers 4

5 Use of VE resins (2) Typical properties: Mechanical resistance Thermal resistance Similar to epoxy resins Viscosity Handling Cure Chemical resistance Similar to unsaturated polyester (UP) resins Better than epoxy or UP resins 5

6 Use of EP resins (1) The use of epoxy (EP) resins, covers a broad range of industrial applications with an operating window of -40 to +180 C: Aeronautic design (carbon fiber reinforced parts in airplanes) Industrial Coatings Industrial / petrochemical Oil & gas Power plants Marine & offshore Utility e.g. Fire water lines 6

7 Basics of VE resins (1) An epoxy vinyl ester (VE) resin refers to resin (without hardener ). The vinyl ester (epoxy acrylate) resin is a reaction product of epoxy resin with acrylic or methacrylic acid and dissolved in styrene monomer. Vinyl ester resins were developed by Dow (DERAKANE ) and Shell (HETRON ) specifically to shape a resin resistant to severe corrosion environments for applications where epoxy- and polyester resins did not meet the industrial requirements for life time, maintenance- and installed costs. When the resin is mixed with peroxide a radical polymerisation, called curing, is initiated (in most processes enhanced by accellerators). Typically an ambient temperature cure is adequate for most uses, however, an elevated temperature post cure e.g. 2 h@80 C may be added to reach optimum thermal properties (mechanical properties are fully developed after ambient temperature cure). 7

8 Basics of EP resins (1) An epoxy (EP) resin typically refers to an resin and hardener. The epoxy resin is a polymer with an epoxide group at either end and normally produced from a reaction between epichlorhydrin and bisphenol-a. For pipes the hardener is typically a polyamine or anhydride. When resin and hardener are mixed the reaction or polymerisation, called curing, is initiated (unless a latent hardener or homopolymerisation is applied). Depending on hardener type an ambient temperature cure or elevated temperature cure is possible and/or required (elevated temperature cure typically required to reach optimum properties). For fiberglass reinforced plasic (FRP) pressure pipe the use of an liquid epoxy resin and an amine (e.g. IPDA) hardener is most establised. The IPDA hardener type requires elevated temperature cure e.g. 1 h@80 C + 4 h@150 C. The use of aromatic amine hardeners is mostly banned in pipe production because of safety (EH&S) issues. 8

9 VE and EP resins in composites applications 9

10 Differentiation of VE and EP applications (1) The differentiation between an epoxy vinyl ester (VE) resin and epoxy (EP) resin application, illustrated by of an industrial pressure pipe, can be summarized to: Typically epoxy (EP) pressure pipes are used in services neither with requirements for high media resistance nor special design requirements of the chemical resistance barrier (CBL) layer but typically a liner of 0.1 to 0.5 mm is considered adequate. Typically epoxy vinyl ester (VE) pipes are used for a broad range of services, which demand higher media resistance and/or special design requirements for both of the chemical resistance barrier (CBL) layer as well as the structural laminate. Hence, special designs of the CBL may be required. Most case histories for DERAKANE epoxy vinyl ester resin pipe are with operating pressures < 35 bar, while representative for most industrial processes. However, also applications (CNG tanks) for 200 bar were developed. 10

11 Differentiation VE resins (2) Chemical resistant layer mm thick wt% resin Inside / Media side Pure resin layer Surfacing veils Chopped glass strand mats Structural laminate layer wt% resin Filament winding or alternate layers of chopped strand mat and woven roving Outside /Coating and/or surface veil 11

12 Differentiation EP resins (3) 12

13 Material Science aspects (1) Physical properties of epoxy vinyl ester (VE) and epoxy (EP) based Fiber Reinforced Plastic (FRP) composites e.g. industrial pipe are comparable when: - equal content of glass fiber is used - equal fiber orientation (winding angle) is used - equal laminate composition (layers) is used Hence the mechanical properties of neat resins and fiberglass pipe are comparable in static and dynamic (fatigue) mode resulting in equal: - laminate strength, modulus (stiffness), toughness and strain. The thermal properties # of epoxy / amine (IPDA) and epoxy vinyl ester resin are typically equal up to 85 C. # i.e. retention of mechanical properties at elevated temperature 13

14 Material Science aspects (2) Material properties of epoxy vinyl ester (VE) resin and epoxy (EP) based fiberglass reinforced plastic (FRP) pipe are comparable i.e. result in equal: - strength, modulus, toughness and allowable strain 14

15 Material Science aspects (3) Stress corrosion tests (under load) partly or fully immersed in media. Tests at elevated temperature to acquire data for long life time (e.g. 50 yrs). 15

16 Representative case histories (1) Summary of representative case histories for high performance DERAKANE epoxy vinyl ester resins in Fiber Reinforced Plastic (FRP) composites and structural / constuction applications. 16

17 Case history (2) Scrubber, duct and stack for fertiliser industry made in DERAKANE 411 resin, installed in Spain. 17

18 Case history (3) Pultruded structural profiles made in DERAKANE 411 resin, used a chemical plant, installed in Germany 18

19 Case history (4) Translucent => liquid level Light weight Resist high pressure Gas cylinders for Liquefied Petroleum Gas (LPG) made in DERAKANE 8090 resin and globally used (Europe, US, South America, Korea, Vietnam) 19

20 Case history (5) Blades for wind turbines made in DERAKANE 601 epoxy vinyl ester resin installed at diverse wind parks globally 20

21 Case history (6A) Duct from flue gas scrubber to chimney made in DERAKANE 411 epoxy vinyl ester resin, installed in Germany 21

22 Case history (6B) Duct from flue gas scrubber to chimney made in DERAKANE 411 epoxy vinyl ester resin, installed in Germany 22

23 Conclusion and Outlook The comparison of fiberglass pressure pipe made of epoxy (EP) and epoxy vinyl ester (VE) resin allows following conclusion: - There is an overlap in material properties between an epoxy / amine (IPDA) and epoxy / anhydride (MTHPA) resin systems and the DERAKANE epoxy vinyl ester (VE) resin and therefore equal performance of the pipes. - The suitabilty of each resin type (VE & EP) vs. media and operating temperature needs verification and backed by chemical resistance data. - The broad experience with DERAKANE epoxy vinyl ester (VE) resin for a wide range of media gives security on expected life time, anticipated maintenance etc. - A good outlook for new applications is the back-up of over 40 years case histories & industrial experience of DERAKANE epoxy vinyl ester (VE) resin. 23