What is the monomer from Dacron

Epoxy resins
Formaldehyde resins
Cellulose acetate
Polyvinyl chloride

Plastics to get to know:


Polyesters are versatile plastics that we come across all the time in everyday life. You can make all sorts of things from polyesters, in addition to textile fibers (including Trevira®, Dacron®, Diolen®) e.g. the well-known plastic drinks bottles made from PET (short for the tongue-twisting name PolyE.ethyleneTerephthalate) and other food packaging. CDs are also made of a polyester, namely polycarbonate, an ester of carbonic acid.
In general, all substances that contain ester bonds are referred to as polyester, their different properties and possible uses depend on the monomers from which they are made.

Polyesters are formed by polycondensation, either from hydroxycarboxylic acids or from dicarboxylic acids and dialcohols, so - as with polyamides - two types can be distinguished: Type I monomers are hydroxycarboxylic acids, type II polyesters are made from dicarboxylic acids and dialcohols.

If dicarboxylic acids and polyhydric alcohols (e.g. glycerine) are used as monomers, cross-linked polyesters are obtained. These are often fiberglass-reinforced for boats, balcony cladding and body parts.

Polyethylene terephthalate (PET)

One of the most important and quantitatively most important polyesters is the above-mentioned polyethylene terephthalate (PET for short), from which not only bottles but also man-made fibers are made.
PET is one of the type II polyesters, its monomers are terephthalic acid (1,4-benzene dicarboxylic acid) and glycol (1,2-dihydroxyethane):

The structural formula shows that PET is polar: The oxygen atoms are negatively polarized, the neighboring carbon atoms are correspondingly positively polarized, which creates strong intermolecular forces. In addition, the molecule is linear, there are no branches, so all the requirements for crystalline areas and thus for the formation of fibers are given.
Since PET is also not cross-linked, it is a thermoplastic (the latter can be seen very clearly when you pour hot tea into a PET bottle - the glass transition temperature of PET is 74 ° C).
As a textile fiber, PET has various useful properties: It is barely stretchable and therefore very dimensionally stable, wrinkle-free, tear-resistant, and it also absorbs very little water, which makes it well-suited for sportswear, for example, which should dry quickly on the body in order to cool down prevent.

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