Page 61 - Template Tesis UTM v2.0

formation of an ester, and as shown in Figure 2.14, linear polyester is produced by

using a di-functional acid and a di-functional alcohol (glycol).

Figure 2.14 Linear polyester structure

The properties of polyester will be determined by the types of diacids and

glycols used. Polyester resin composites are cost effective because they require
minimal setup costs and their physical properties can be tailored to specific

applications. Another advantage of polyester resin composite is that they can be cured

in a variety of ways without altering the physical properties of the finished part.
Polyester resins have a certain shelf life and inhibitor is added during manufacturing

process to slow the gelation action on their own. Styrene monomers play a vital role
by cross-linking the molecular chains and assist to cure resin from liquid to solid state.

Typically, liquid polyester is pale in colour and viscous. Polyesters resins could be
divided into several classes depending on the structure of the basic building block.

These are orthophthalic, isophthalic, terephthalic, bisphenol-fumarate, chlorendic and

dicyclopentadiene. Table 2.10 shows the orthophthalic and isophthalic mechanical
properties of the polyester resin.

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