Influences of aldehyde type and p-substituent type on structural characteristics of p-alkylphenol aldehyde resins using a molecular simulation

Structural characteristics of isotactic p-alkylphenol acetaldehyde novolak resins with methyl, t-butyl, and t-octyl as the p-substituent and p-t-butyl phenol aldehyde novolak resins with methylene, ethylidene, and propylidene as the linkage were calculated using molecular mechanics and molecular dyna mics. The five p-alkylphenol aldehyde resins were found to have common stru ctural characteristics that hydroxyl groups of the p-alkylphenols cluster i n the center of the molecule by intramolecular hydrogen bonds of hydroxyl g roups of the adjacent p-alkylphenols and the alkyl groups are extended out. Distances between oxygen atoms and between p-carbon atoms of the adjacent p-alkylphenols become longer as the size of the p-substituent increases fro m methyl to t-octyl. Bond angles of the linkage built between the adjacent p-alkylphenols become wider by increasing the p-substituent size and by dec reasing the linkage size.