Chemistry Reference
In-Depth Information
(a)
OH
OH
OH
CH
2
HOCH
2
CH
2
OH
+ 2CH
2
O
(excess)
“Resole”-type
products
Alkaline conditions
Heat “Cure”
OH
OH
CH
2
CH
2
OCH
2
CH
2
HO
CH
2
CH
2
OH
OH
HOCH
2
CH
2
Network polymer
(b)
OH
OH
OH
OH
CH
2
CH
2
3
+ 2CH
2
O
“Novolac”-type
products
Acidic conditions
with added
hexamethylene
tetramine
“Cure”
OH
CH
2
OH
CH
2
CH
2
OH
CH
2
OH
Network polymer
FIGURE 7.1
Phenol-formaldehyde polymers. (a) Character of “resole”-type resins normally produced
with excess formaldehyde under alkaline conditions. (b) “Novolac”-type resins normally
made with excess phenol under acidic conditions.
