Thermosets and some Thermoset Composites

1 Amino and Phenolic Thermoset Polymers, and their Composites 

There are two basic types of amino plastics - urea formaldehyde (UF) and melamine formaldehyde (MF). Both are hard, rigid materials with good abrasion resistance and mechanical characteristics for their continuous use at moderate temperatures (up 

MF plastics have lower water absorption and better durability, and they are preferentially used for tableware, laminated worktops and electrical fittings. Due to high contents of nitrogen in melamine, MF are non-flammable and can provide fire retardant properties. It releases nitrogen and formaldehyde when burned (or charred) [67]. MF foams were mainly used for fire resistant, soundproofing applications. 

Phenol-formaldehyde (PF, Bakelite) is one of the oldest synthetic materials available. It is strong, hard and brittle with good creep resistance and excellent electrical properties, but it is susceptible to attack by alkalis and oxidising agents. Typical applications are domestic electrical fittings, handles, fan blades, smoothing iron and pump parts. 

Most amino and phenolic thermosets are used in the production of composites, mainly prepared with wood (wood-plastic composites, WPC) [68]. Particleboard, or the chipboard is a kind of WPC, which is produced from wood particles, such as wood chips or saw dusts, through their glueing together with synthetic resins or other suitable binders, by pressing and extruding afterwards. In most particleboards, the resin used is formaldehyde-based. 

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