S. Haseebuddin et al., INFLUENCE OF DIBASIC ACIDS ON THE PROPERTIES OF MODIFIED POLYURETHANECOATINGS, Surface coatings international, 78(2), 1995, pp. 68-70
In recent years, High Solids coatings have gained importance because t
hey are environmentally friendly. In their formulations, it is especia
lly difficult to balance the need;or high solids and low application v
iscosity without sacrificing the properties. For the purpose of develo
ping high solids formulations five polyester-polyols were synthesized
at 210-230 degrees C. Conversion of the polyester polyols was monitore
d by determining the acid number with respect to time The hydroxyl num
ber of the polyester polyols was determined practically and also calcu
lated theoretically. The number, weight and Z-average molecular weight
and polydispersity of the polyester polyols were obtained from GPC. T
he viscosity of polyester polyols in tetrahydrofurane (THF) and methyl
isobutyl ketone (MIEK) was determined by using Emila Rotational Visco
meter. Polyurethane resins prepared by adding the required amount of d
iphenyl methyle diisocyanate (MDI) to polyester polyol solution in MIB
K were applied to different substrates for determining properties such
as drying time scratch hardness. tensile strength, flexibility, resis
tance to impact and chemicals. The results indicate that the neopentyl
glycol polyester polyol prepared by using 1:1 adipic acid and isophth
alic acid have better properties This is probably because of the fact
that isophthalic acid constitutents improve the rigidity and the adipi
c acid component adds to the flexibility of polyurethane coatings.