A method for preparing an aromatic di-ester includes combining an aromatic di-acid and a linear or branched C4-C13 alcohol to form a mixture. The method also includes heating the mixture from a first temperature (T1) to a second temperature (T2) without a catalyst present in the mixture. The method further includes combining a titanium catalyst with the mixture after the mixture is at the second temperature (T2). The method further includes increasing pressure from a first pressure (P1) to a second pressure (P2) after the mixture is at the second temperature (T2). The method further includes increasing the temperature of the mixture from the second temperature (T2) to a third temperature (T3) while maintaining the second pressure (P2).