Epon epoxy resins, structure

Epoxidised allyl soyate resin (a mixture of epoxidised fatty acid esters) copolymerised with the base Shell Epon epoxy resin is used as matrix for glass fibre reinforced composite, which is prepared using a Durapul 6000 Labstar Pultrusion machine. The lubricating quality of soybean oil-based resin significantly reduces the pulling force which improves the structural performance characteristics of the composites. Curing is carried out in an oven at 80°C for one hour, followed by heating to 177 C for 1.5 h. 

Glycidyl Ether of Tetraphenolethane. A large number of polyhydric phenols have been used to prepare diglycidyl ethers. The polyphenol, l l,2 2-(p-hydroxyphenol)ethane, is used to prepare a tetrafunctional epoxy resin, tetraglycidyl ether of tetraphenolethane. The functionality of commercial resins (e.g., EPON Resin 1031, Resolution Performance Products, LLC) is about 3.5. This forms a solid resin (melting point of 80°C) with a structure as shown in Fig. 2.6. Commercial products are solid resins and solutions. 

Tetraglycidyl ether of tetraphenolethane is an epoxy resin that is noted for high-temperature and high-humidity resistance. It has a functionality of 3.5 and thus exhibits a very dense crosslink structure. It is useful in the preparation of high-temperature adhesives. The resin is commercially available as a solid (e.g., EPON Resin 1031, Resolution Performance Polymers). It can be crosslinked with an aromatic amine or a catalytic curing agent to induce epoxy-to-epoxy homopolymerization. High temperatures are required for these reactions to occur. 

Shell Chemical has produced EPON HPT epoxy resins, which are used in large parts made of graphite-7 reinforced prepreg material for primary aircraft structures. EPON 9000 series of epoxy resins produced by the same company have been used for fabricating, by wet filament winding process, fuselages and other large components that have been used in the prototype of Beech Aircraft s experimental small business aircraft, the Starship 1. 

Figure 1. Chemical structures of used model molecules a) Cycloaliphatic epoxy resin (Araldite CY179), b) Methylcyclohexyl cyclohexanecarboxylate (Ester), c) Dicyclohexyl ketone d) cyclohexane oxide e) Bisphenol F epoxy resin (Epon 862), f) Bisphenol A epoxy resin (DER 331), g) Ethyl acetate, h) acetone, i) Phenol, j) 1,1,1,3,3,3 Hexafluoro-2-propanol (HFIP)...

Two types of epoxy resins were used in this study. They were bisphenol A type epoxy resins (EPON 828 fiom Shell Chemicals), and cycloaliphatic qwxy resins (ERL 4221 from Union Carbide). The epoxy equivalent weight (EEl of ERL 4221 was 134 g/mol, and the EEW of EPON 828 was 188 g/mol. The curing agent used in this study was hexahydro-4-meth)dphthalic anhydride (HMPA), purchased from Lindau Chonicals. The molecular weight of HMPA was 168.2 g/mol. The chemical structures of the epoxy resins and HMPA are shown in Figure 1. 

The FM 123-2, supplied as a supported film on a knitted mlcro-fllament nylon carrier, was applied directly to one pretreated (SAA or FPL) A1 panel (15 cm x 15 cm x 0.3 cm). A second panel was then pressed onto the exposed adhesive side and the "sandwich structure was subsequently cured at 120°C under 40 psi for 1 hr. A 1 1 1 mixture of the epoxy-polyamide formulation (EPON resin Versamld curing agent thinner, MIL-T-81772) was sprayed onto prepared 7075-T6 specimens to a thickness (dry) of 0.015 - 0.023 cm. 

DBA and TBA, a secondary and tertiary amine respectively, when used as curing agents at 1.0 1.0 stoichiometries, showed no noticeable reaction with Epon 828 over a period of five hours. After two days, however, the DBA-resin mixture turned into a clear glassy solid. Hydroxyl groups were calculated from the structure of epoxy given in Structure 1 with n = 0.2. For each epoxy consumed one hydroxyl was produced. 

Epon HPT . [Shell] Epoxy matrix resin used for advanced composites with glass, carbon, aramid or b n fibers, high-performance structural laminates and adhesives, preptegs. 

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