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HYDROLYSIS RESISTANT COMPOSITES

IP.com Disclosure Number: IPCOM000239166D
Publication Date: 2014-Oct-17

Publishing Venue

The IP.com Prior Art Database

Abstract

The present invention is a severe water environment resistant composite using a hydrolysis resistant thermosetting matrix resin composition and an alkali resistant structural reinforcement fiber system characterized by reduced degradation in severe water environments especially at high pH or high temperature. In particular, the hydrolysis resistant thermosetting resin composition is a non-anhydride cured epoxy, benzoxazine, hindered bismaleimide or a hindered cyanate thermosetting resin composition and the alkali resistant structural reinforcement fiber is selected from carbon, quartz, AR-glass, silicon carbide and silica fibers.

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HYDROLYSIS RESISTANT COMPOSITES

ABSTRACT

The present invention is a severe water environment resistant composite using a hydrolysis resistant thermosetting matrix resin composition and an alkali resistant structural reinforcement fiber system characterized by reduced degradation in severe water environments especially at high pH or high temperature. In particular, the hydrolysis resistant thermosetting resin composition is a non-anhydride cured epoxy, benzoxazine, hindered bismaleimide or a hindered cyanate thermosetting resin composition and the alkali resistant structural reinforcement fiber is selected from carbon, quartz, AR-glass, silicon carbide and silica fibers.

FIELD OF THE INVENTION


[0001] The present invention relates to thermosetting composites that are resistant to degradation by water in severe environments. In particular, the present invention relates to composites formed from non-anhydride cured epoxy, benzoxazine, hindered bismaleimide or hindered cyanate thermosetting resin compositions and alkali resistant structural reinforcement fibers such as fibers of carbon, quartz, AR-fiberglass, silicon carbide, or specially formulated silica.

BACKGROUND


[0002] Fiber reinforced, polymer matrix composites (PMCs) are widely used in a number of applications and increasing amounts of PMCs are being used in severe environments. A variety of PMC materials and parts are being incorporated into a vast number of applications for the marine industry and the aerospace industry to other applications where the PMC is used in a severe environment. Severe environments are those applications where PMC parts and materials may come into direct contact with high temperatures or high alkali environments which often cause significant degradation of composite components. For the purpose of this patent hydrolysis resistance means resistance to extreme water environments: water over about 100°C,

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pH greater than 9 or both or a moisturized coupon, part or structure exposed to temperature greater than about 100°C.


[0003] For many PMC applications, epoxy resins are utilized because of epoxy's good combination of mechanical properties, wide service temperature range, and ease of part manufacture. Some epoxies may perform satisfactorily in high temperature water or high alkaline water as long as the water or working environment is not substantially above the epoxy's maximum working temperature or wet Tg. Composites that are used at less than about 150°C can use epoxy based matrix resins. However, epoxies with structural reinforcements may fail in high alkali environments and some composite applications require higher thermal durability (higher wet Tg or oxidation resistance at elevated temperature) of the finished composite than traditional epoxy resin systems can provide. Epoxy PMCs cannot be used in high temperature applications, above about 180°C, because they lack adequate wet Tg and can be oxidized by oxygen in the air.


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