Chemistry Reference
In-Depth Information
The first step (a) was completed by esterification of the carboxyl groups of the
condensed resins with EC, followed by dehydrohalogenation with sodium hydroxide
.
The second step (b), the etherification of the hydroxyl group of the condensed
resins with EC in the presence of sodium hydroxide ,was completed as described in
Scheme 2.4
.
a) Epoxy binder produced from condensation of rosin acid and formaldehyde at temperature 150
o
C.
HOOC
CH
2
O-CH
2
- CH - CH
2
CH
2
O-CH
2
- CH - CH
2
O
CH
2
- CH - CH
2
- O-CH
2
b) Epoxy binder produced from condensation of rosin acid and formaldehyde at temperature 240
o
C.
COOH
HOOC
CH
2
O-CH
2
-CH-CH
2
CH
2
O
CH
2
CH
2
-CH-CH
2
OCH
2
CH
2
O
CH
2
Scheme 2.4
Epoxy binders produced from condensation products of rosin acid
with FA at different temperatures
2.3 Modification of Rosin Epoxy Binders
A major derivative of epoxy resins is the epoxy vinyl ester resin. Vinyl ester resins
have been widely recognised as materials with excellent resistance to a wide variety
of commonly encountered chemical environments and are used to fabricate a variety
of reinforced structures including pipes, tanks, scrubbers and ducts. They are prime
candidates for use in composites for transportation and/or infrastructure applications
,
such as fabrication of parts for automobiles and other surface transportation vehicles,
