Polyether Polyols Polyether polyols can be used in coatings as modifier for high solids and waterborne industrial crosslinked coatings. Polyether  polyols decrease VOC, improve flexibility and raise the application solids. Polyether polyols can be used with melamine and with isocyanate crosslinked coatings. Polyether polyols can also introduce potential problems into coatings. Adhesion to metals surfaces and water resistance can suffer. Additive levels of 5-10 % are for many applications acceptable. Polyether polyols can be crosslinked with melamine formaldehyde, with polyisocyanates, blocked isocyanate or with other hydroxyl reactive crosslinker.
Amine Polyols Amine polyols can function as neutralize and emulsifier in a waterborne coating
Polyether Polyols Addition reaction products of propylene oxide, ethylene oxide on alcohols and phenols or THF polymer. Most polyether are soft and give low Tg films. For increased hardness and improved water resistance and corrosion resistance bisphenol A based polyether polyols can be used. 
  PPG homo polymer MW 400-700 Reactive diluent for high solids coatings and reactive co-solvent replacement for waterborne crosslinked coatings. General industrial single coat and primer crosslinked with HMMM melamine resin or with polyisocyanate. Addition levels as high as 30 % are possible.
PPG based triol, MW 400-1500 Similar applications as above but increased crosslink density.
THF polyol 400-1000 More hydrophobic than polypropylene glycol, improved water resistance and highly elastomeric properties. Higher cost than PPG polyols.
Bisphenol A EO or PO adduct Increased hardness and improved adhesion to metal surfaces. Modifier for cationic epoxy resins.
 Features Low viscosity PPG diols and triols with a MW <1000,   <500 cps at 25C
Solubility Soluble in all polar solvents and in water

Flexibility  Glass transition temperature (Tg) of -80C
Compatible Acrylic, polyester, alkyds,  
Hydrolytic stability Excellent stability at a pH of 3-14
Function Flexibility 5-10 % can increase flexibility, also low temperature flexibility can be improved
Hydrolytic stability Polyether resins have excellent hydrolytic stability under basic conditions
Reduction in cost Polyether polyols are lower in cost
Higher solids Low viscosity permits an increase in application solids
Reduction in VOC Can be used as reactive co solvent and diluent
Disadvantage Softer films The low Tg of the polyol can reduce film hardness
Exterior durability Polyether can reduce the exterior durability. 
Water sensitivity High levels of polyether can increase the water sensitivity. Use of higher functional polyols can reduce water sensitivity.
Adhesion Polyether have poorer adhesion to metal surfaces 
Gloss Higher levels of polyether can give pigment flocculation

Amine Polyether Polyols

Amine polyether polyols can be used in waterborne coatings to neutralize carboxyl functional resins. Amine Polyether Polyols improve flow and leveling and also aid pigment dispersion. Amine polyether polyols are very effective dispersants for carboxyl functional resins and  pigments. It is possible to disperse waterborne resins with only partial neutralization of the resin.
Applications High Solids Higher solids, improved flexibility
Waterborne  Higher solids, increased flexibility
Wood coatings Flexibility
General industrial Flexibility
  Features Nonvolatile Amine will co-react and be built into film
Gloss Reduction in wrinkling for HMMM crosslinked coatings
Solvent popping Increased film thickness without solvent popping. 
Catalyst Increase the rate of reaction of isocyanate crosslinked coatings.
Disadvantage Cure inhibition The presence of amine can inhibit amino resin crosslinked coatings. High imino or methylol functional melamine resins are less sensitive to cure inhibition.
Yellowing At very high cure temperature yellowing can be seen. Because the amine is tertiary, yellowing is usually not a problem.
Exterior durability Lower MW amine polyether have surprisingly good exterior durability.
Waterborne coatings
Polyether polyols to waterborne coatings do not necessarily have to be water-soluble, water-insoluble polyether resins can be solubilized in the presence of water-dispersible resins. Polyether resins show inverted water solubility, therefore, accelerate testing at higher temperatures can produce misleading results. Substantial improvements in properties can be obtained with the use of either bisphenol A EO or phenol formaldehyde EO or PO diols and polyols. The presence of the aromatic moiety improves the adhesion and corrosion resistance to metal surfaces, it increases hardness and still give excellent flexibility. Exterior durability is substantially impaired with these compounds. Short chain bisphenol A EO and PO adducts can substantially improve the water resistance and detergent resistance of coatings.
Water soluble polyether PPG diol polyether MW <700
PPG triol polyether MW <1000
PPG polyol functionality >3, MW <1000
Bisphenol A EO adducts 6-8 EO
Water insoluble polyether PPG diol with MW >700. 
THF diols
Bisphenol A adduct EO <6 EO
Bisphenol A adduct PO 
Water dispersible polyether PO-EO block polymers
Amine functional polyether Triethanolamine PO adducts
Ethylenediamine PO/EO adducts
High solids coatings
Polyether polyols due their low Tg give exceptional low viscous coatings. Modification of a polymer with a polyether is therefore one of the lowest cost methods to reduce VOC of a coating and to improve flexibility. The loss in hardness can be partially compensated by using higher functional polyether polyols.  
PPG diol with MW >700. 
THF diols
Bisphenol A adduct EO <6 EO
Bisphenol A adduct PO 

Last edited on:

November 20, 2006

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