SleepTech July - August 2018

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one with four is a tetrol and so on.
The polyols used in polyurethane
production are predominantly
hydroxy- polyethers, rather than
hydroxy-polyesters. They are produced
by alkoxylation. Depending
on the degree of cross-linking
required, the starting alcohols
used for hydroxy-polyethers may
be divalent glycols (ethylene,
propylene and other glycols) or
multivalent alcohols (e.g. glycerol,
sucrose). The epoxides used are
generally propylene oxide and
ethylene oxide.
Monomeric polyols such as glycerin,
pentaerythritol, ethylene
glycol and sucrose often serve as
the starting point for polymeric
polyols. These materials are often
referred to as the “initiators” and
reacted with propylene oxide
or ethylene oxide to produce
polymeric polyols. However, they
should not be confused with
free radical “initiators” used to
promote other polymerization reactions.
The functional group used
as the starting point for a polymeric
polyol need not be a hydroxyl
group; there are a number of
important polyols which are built
up from amines. A primary amino
group (-NH2) often functions as
the starting point for two polymeric
chains, especially in the case of
polyether polyols.