In coating compositions above 1:5 mol ratio, the unreacted HMMM reduces the solvent resistance of the coating films by leaching from the coating.
Anticorrosive properties of WH-HP and HMMM mixture coating were evaluated by following two methods.
Coating prepared using WH-HP resin and HMMM in the mole ratio of 1:5 showed good adhesion, mechanical, and anticorrosive properties compared to the rest of the compositions.
Therefore, coatings with more than 20 wt% HMMM are considered to have an excess of HMMM.
The coatings with excess of HMMM (>20 wt%) showed a substantial resistance to high-radiation doses (Fig.
The decrease in the concentration of methoxy groups in HMMM was attributed to self and cocondensation reactions due to absorption of UV energy equivalent to thermal curing.
1] (corresponding to ether crosslinks), that no significant change in the concentration of ether links between HMMM and hydroxy functional polymer was observed with increasing UV dose; thus, an increase in UV radiation dose does not increase the rate of degradation.
This is particularly noted for the coatings with lower HMMM concentrations.
At a given HMMM concentration, it can be assumed that coatings baked under cure condition B have less free volume than those under cure condition D, since condition B produces coatings with higher [T.
For coatings with greater than 20 wt% HMMM, the intensity of peak II (HMMM self-condensation) is markedly reduced, and the temperature at which this decomposition occurs increases until the peak merges with peak I (cocondensation) due to an increase in radiation induced crosslinking.