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Novel Aromatic Polyether Polyols for Polyurethane Applications

published on August 5, 2022

Aromatic polyether polyols offer significant potential product improvements to formulators in the coatings, adhesives, sealants, and elastomers (CASE) arena. These polyols have many attributes, as they improve flammability resistance, thermal performance, hydrolytic stability, and mechanical properties of polyurethanes and polyureas. 

At Gantrade, we work with chemical manufacturers worldwide to bring new solutions to our clients, helping them improve both product performance and processability. For more than 40 years, we’ve developed an extensive portfolio of products through working with like-minded partners centered on customer needs. 

Bakelite Synthetics has commercialized a family of aromatic polyether polyols that provide substantial advantages in both polyurethane and polyisocyanurate (PIR) foam. These aromatic polyether polyols contain primary aliphatic hydroxyl functionality and have an aromatic content of 33 percent. The team at Gantrade has joined with Bakelite Synthetics to translate the performance attributes of the Resonance® aromatic polyether polyols identified in foam applications into the CASE marketplace.

General Attributes of the Resonance™ Aromatic Polyether Polyols

Resonance™ Aromatic Polyether Polyols feature several attributes relevant to performance and processing capabilities in the CASE market.  These attributes include the following: 

  • Significantly higher aromaticity than traditional polyols, 33 percent aromaticity
  • Potential to improved flammability characteristics of PURs 
  • Good compatibility with other commonly used polyols 
  • Primary hydroxyl end functionality with good isocyanate reactivity 
  • Low acid values, < 0.15 mg KOH/g  
  • Low color 
  • Liquids at room temperatures 
  • Hydroxyl functionalities of 2.4 - 3.6.  

In polyurethane and polyisocyanurate foam, Resonance™ Aromatic Polyether Polyols exhibit the following benefits when used at replacement levels of 10-40% in standard PUR and PIR formulations: 

  • Improved flammability resistance.   
    • UL94 V-0 rating achieved 
    • ASTM E84 Class A smoke and flame spread classifications 
    • Significant improvements in ASTM vertical burn performance 
  • Improved mechanical properties 
  • Higher thermal performance 
  • Increased dimensional stability 
  • Hydrolytic stability 
  • Decreased k value (under laboratory conditions) 

Physical Properties of Resonance™ Aromatic Polyether Polyols 

Gantrade and Bakelite Synthetics has selected two Resonance® Aromatic Polyether Polyol grades with primary hydroxyl functionality as the starting grades for translation into CASE applications, while lower functionality grades are under development. The typical properties of these grades are summarized below. A version of PL91-205 with a viscosity of 6,000 cps at 25°C is available.


Hydroxyl Functionality 


Viscosity (cps, 25°C) 

Hydroxy (mg KOH/g)

Molecular Weight 

Moisture Content (%) 

Acid Number (Mg KOH/g)



Pale yellow Liquid 




< 0.2 

< 0.15 



Pale Yellow Liquid 




< 0.2 

< 0.15 


The sample bottles below illustrate the typical color characteristics of the above two grades. 

Resonance PL91-203         Resonance PL91-205


Flammability Improvements in PUR Foam Products using Resonance™ Polyols 

Resonance™ Aromatic Polyether Polyols are compatible with standard polyether polyols used in spray form and chemically blown foam applications. Substituting sucrose polyols from 15 – 100 parts with Resonance™ polyols afforded a significant improvement in vertical burn performance when compared with a control without the aromatic polyether ether polyol. The spider diagram below demonstrates the improvements in vertical burn performance. This includes the Peak Heat Release Rate (HRR), Average Heat Release Rate (Avg. HRR), B2 Vertical Burn (DIN 4102) and Flame-out Time (after the flame is removed). Polyol PL91-203 based foams displayed a substantial improvement in the B2 vertical burn test as well as in cone calorimetric data while maintaining dimensional stability and compressive strength. The reference foam, based on a sucrose polyol (f = 4.5) shows a reduced volume change (-1.5% vs. -3.25%).

vertical burn performance spider diagram

The chart below shows the results in the UL 94 Vertical Burn test, when a sucrose base polyol in a reference formulation was replaced with 10-40 % of the Aromatic Polyether Polyol PL91-203. The reference foam was normalized to a 100 reference point. The % vertical burn (RtF – Reaction to Fire) of the substituted foams are shown relative to the reference sample, i.e. zero (0) burn time after ignition with a 40% replacement with the Resonance® polyol. 

Vertical Burn Test


Recommended End-uses in CASE 

The hydroxyl functionality of these two Aromatic Polyether Polyol grades suggests the following end uses. 

  • Polyol blend component with other polyols in cast elastomers.  The blend content which has shown substantial performance enhancements in foam applications start at 10 weight % of the Aromatic Polyether Polyol. These Aromatic Polyether Polyols are compatible with PPG type polyether polyols and polyester polyols. 
  • Prepolymer blends. 
  • Primary polyol is coating applications where abrasion, chemical and moisture resistance are the drivers. 
  • Chain extenders for MDI systems as alternatives to HQEE, HER and other multifunctional crosslinking agents.  
  • Replacement for TDI/MOCA systems based on MDI/Resonance® Aromatic Polyether Polyols systems.

Gantrade Has the Resources You Need to Meet Your Performance Goals

The attributes of Resonance™ Aromatics Polyether Polyols in PUR and PIR foam suggest considerable potential in polyurethane CASE applications as a formulating intermediate. The aromaticity of these polyols is anticipated to contribute to improvements in fire resistance, hydrolytic and chemical resistance, thermal performance, and mechanical properties. 

The Resonance™ Aromatic Polyether Polyols are currently being produced on a commercial scale in NA and Europe. Sample quantities are available to support evaluations and developmental programs. 

For aromatic polyether polyols and other intermediates that will enhance your CASE products, look to the Gantrade expert team for assistance. We will work with you to meet your performance goals whether you require greater performance in a particular set of properties or you’re looking to drive greater efficiency and competitiveness. Contact us today!

Topics: Polyols