Aramid FRPs with thermoset matrices

In general, polyester, vinyl ester and epoxy resins are the most common matrices used for the preparation of fiber-reinforced composites. 

Unsaturated polyesters (UP) are by far the most widely used resins in the composite industry [49]. UP resins are used in the highest volume due to their relatively low cost and good combination of thermo-mechanical properties and environmental durability. Typical properties of a cast UP resin are reported in Table 8.2. A UP resin is usually obtained from unsaturated polyesters dissolved in a reactive monomer. Unsaturated polyesters are linear polymers obtained by a condensation reaction between three chemical species saturated aromatic acids, unsaturated acids (maleic anhydride, fumaric acid), and glycols 

Property Unsaturated polyester Vinyl ester Epoxy resin 

The FRPs for demanding structural applications comprising continuous p-aramid fiber reinforcements are most frequently based on epoxy matrices [54-56]. The main reasons 

A significant number of studies on p-aramid/epoxy systems are related with surface treatments of the reinforcing fibers. The purpose of these treatments is threefold (i) roughening of the fiber surface in order to enlarge the physical interface with the matrix resin allowing also for mechanical anchoring, (ii) chemical activation of the fiber surface, and (iii) creating chemical bonds across the fiber/matrix interface. 

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