反应详情

温度

220 °C

A standard esterification apparatus, consisting of a 1-liter, 3 neck flask fitted with heating mantle, thermometer, nitrogen inlet tube and modified Dean-Stark separator topped with a total reflux condenser connected to a vacuum system, was charged with 148 g (1 mol) of phthalic anhydride, 312 g (2.4 mol) of 2-ethyl hexyl alcohol and 0.2 g (0.135% of PA charge) of tetrabutyl titanate (Tyzor TBT) catalyst. Heat was applied at a standardized setting and water of esterification began to form at a kettle temperature of 165° C. Heating was continued to reflux at 220° C. while removing water of reaction as fast as it is formed by azeotrope with toluene. Progress of reaction was monitored by rate of water formation until about 98% conversion of acid, at which time the reaction was sampled and the acid number determined by titration with 0.05N alcoholic KOH using bromthymol blue indicator. After 3.0 hours reaction time, the AN was reduced to 0.1 mg KOH/g, at which time the excess alcohol was removed by reducing the pressure of the system and removing alcohol distillate through the modified separator. Vacuum distillation was continued to 20 torr/200° C. at which time conditions were adjusted to 75 torr/150° C. and removal of alcohol continued by steam distillation, accomplished by dropwise addition of water to the bottom of the flask at a rate of about 1 ml/minute while maintaining the kettle at 150°-160° C. The kettle became cloudy after about 10 minutes. Distillation was continued for 30 minutes, at which time heat was removed and the system dried at full vacuum (12 torr) for 10 minutes. After cooling to 90° C. the cloudy residue was filtered through a No. 1 Whatman paper with a Buchner vacuum filter. The filtrate is cloudy and plugs the filter quickly. Refiltering with filter aid gives low odor di-octyl phthalate with AN=0.14 and color of 20 APHA.

1. customfitted
2. temperaturewith heating mantle
3. customthermometer, nitrogen inlet tube and modified
4. customDean-Stark separator topped with a total reflux condenser
5. temperatureHeat
6. customto form at a kettle temperature of 165° C
7. temperatureHeating
8. customwhile removing
9. customwater of reaction as fast as it
10. customProgress of reaction
11. aliquotwas sampled
12. customAfter 3.0 hours reaction time
13. customwas removed
14. customremoving alcohol distillate through the modified separator
15. distillationVacuum distillation
16. customwas continued to 20 torr/200° C. at which time conditions
17. customwere adjusted to 75 torr/150° C. and removal of alcohol
18. distillationcontinued by steam distillation
19. additionaccomplished by dropwise addition of water to the bottom of the flask at a rate of about 1 ml/minute
20. temperaturewhile maintaining the kettle at 150°-160° C
21. distillationDistillation
22. waitwas continued for 30 minutes, at which time
23. temperatureheat
24. customwas removed
25. customthe system dried at full vacuum (12 torr) for 10 minutes
26. temperatureAfter cooling to 90° C. the cloudy residue
27. filtrationwas filtered through a No
28. filtration1 Whatman paper with a Buchner vacuum filter
29. filtrationplugs the filter quickly
30. filtrationwith filter aid