Polyester Polyol Reactors

For over 20 years Özköseoğlu Polyester Production / Pilot Reactor systems have been chosen by leading producers in Rigid, Flexible, TPU, and CASE industries in dozens of countries around the world. 

Polyester Polyol Resin Process Technology

The synthesis of polyester polyols takes place under an inert gas atmosphere (Nitrogen) in batch-type reactors at higher temperatures of 200-250 °C . 
 Depending on the vessel volume and application, reaction time may vary between 12 to 20hrs. 
The most preferred vessel sizes of Özköseoğlu Polyester Polyol Reactors are 12, 18, 24, and 30m3 orderly intermediate sizes are also available upon request. 
Alternatively, Polyester Polyol Process may be in 3(three) steps 
1) Pre-Blending of Diacids and Glycols at a certain temperature prior to polyesterification.
2) Polyesterification Process in a Batch Reactor with fully equipped with separation column, reflux system, overhead condenser. 
3) Post Blending process for cooling and treatment with additives.

The heating of Polyol Reactors is assured with high thermoresistant fluids by Thermal Oil Heaters. Özköseoğlu Heaters are designed to operate with optimum Delta T heat transfer efficiency to insure final Polyol resin suits TDS parameters as well as a market. 

The polyesterification reaction in Polyester Polyol Reactor is an equilibrium reaction, the equilibrium is pushed to the polyester formation by continuous removal of water.


The water is eliminated from the reaction system through a separation column, which assures a separation of water from the glycols, Özköseoğlu separation columns are equipped with all necessary packing materials and a reflux system to ensure the minimal fouling effect.

Glycols are returned back into the polyol reactor and water is condensed and discharged for a post-treatment. Özköseoğlu Polyol Reactor system designed for an optimum Glycol reflux ratio to assure a cost-effective production.


Polyester Polyol resin reaction may require catalysts during full vacuuming to lower the acid value between 0-2 mg KOH/g by measuring the quantity of water distilled and as well as a determination of the acid number, hydroxyl number, and viscosity. 
Özköseoğlu Polyol Reactor system technology offers such analysis to be monitored continuously (by in-line instruments) and recorded over operator panels. All critical stages of the process are automated with a default interlock system for optimum efficiency.


Typical values and characteristics of some polyester polyols for elastic polyurethanes

Characteristic AA-DEG  AA-EG  AA-DEG/TMP
Structure linear linear branched
Functionality, f  2 2 2.4 - 3.0 
MW, daltons  2900 2000 2700-3000 
Hydroxyl number, mg KOH/g  35-45  52-58  50-60 
Acidity, mg KOH/g  <2  <1  <2 
Water content, %  < 0.15  < 0.15  < 0.15 
Density at 20 °C, g/cm3  1.19  1.27 1.2
Viscosity at 70 °C, mPa-s 1100 450 1000-1500 
Applications Flexible foams, elastomers Elastomer, prepolymers, synthetic leather  Flexible foams, lacquers, coatings 


Depending on the application raw materials for a Polyester Polyol Resin process maybe ed among the chemicals below.

  • Phthalic acid anhydride (PA) / Polyethylene terephthalate (PET)
  •  Adipic acid / Monoethylene glycol / Di Ethylene Glycol
  •  Glycerol / Catalysts / Natural oil