Poly ether polyols functionality

For poly ether polyols an NMR method was elaborated for functionality determination [20]. The most usual and practical method for functionality determination is based on the assessment of the MW of an oligo-polyol, by a method applicable to low MW compounds (MW < 10,000 daltons), such as vapour pressure osmometry (VPO) or gel permeation chromatography (GPC), together with hydroxyl number determination. The functionality is calculated by using the fundamental equation 3.4 ... 

In Chapter 3, the chemistry and technology of the most important oligo-polyols used for elastic polyurethanes fabrication, in fact high MW oligomers (2000-12000 daltons) with terminal hydroxyl groups and low functionality (2-4 hydroxyl groups/mol) were discussed. Polyalkylene oxide polyols (homopolymers of PO or copolymers PO - EO, random or block copolymers), polytetrahydrofuran polyols, filled polyols (graft poly ether polyols, poly Harnstoff dispersion - polyurea dispersions (PHD) and polyisocyanate poly addition (PIPA) polyols), polybutadiene polyols and polysiloxane polyols were all discussed. The elastic polyurethanes represent around 72% of the total polyurethanes produced worldwide. 

Polyureas. Polyureas involve the combination of novel MDI polymers and either amine or imino-functional poly ether polyols. The resin systems can be reinforced with milled glass fibers, flaked glass, Wollastanite, or treated mica, depending on the compound requirements as too processability or final product. 

In view of the functionality thus created, it is interesting to consider possible applications for the epoxldlzed oils mentioned as epoxy monomers per se. Indeed, some epoxldlzed oils are commonly used as reactive diluents for other epoxy prepolymers in order to reduce cost or Improve processability (10,11) examples claimed in reference 11 Include epoxldlzed linseed, butylated linseed, soybean, and tall oils. However, although some fundfimental studies of the effects of monofunctional reactive diluents on the viscoelastic and other properties of epoxy resins have been published (see, for example, reference 12), little or no analogous Information on the effects of multifunctional reactive diluents appears to exist. At the same time, some reactive additives such as polyols (13), poly(ether esters) (14) and carboxy-terminated elastomers (15) have been used to provide an elastomeric toughening phase for epoxies. 

Second, these catalysts are not only useful for preparing high molecular weight poly(propylene oxide) rubber (2), but they are equally effective when used with certain low molecular weight hydroxyl containing compounds (initiators) to form poly(propylene ether) polyols having good hydroxyl functionality. The latter feature of these catalysts is the topic of this paper. 

Poly(tetramethylene oxide) polyols (see Scheme 4.4) are a special class of polyethers syndiesized via acid-catalyzed ring-opening polymerization of tetrahy-drofuran. Although less susceptible to side reactions, the synthesis of these C4 ethers is less flexible in terms of product composition and structure. Thus, because of diis syndietic route, only two-functional glycols are available and copolymers are not readily available. Molecular weights of commercial C4 glycols range up to about 3000 g/m. 

Aliphatic Glycidyl Ethers. Aliphatic epoxy resins have been synthesized by glycidylation of difunclional or poly functional polyols such as a 1.4-butanediul. 2.2-dimethyl-1.3-propanediol (neopentyl glycol), polypropylene glycols, glycerol, irimethylolpropane. and pentaerythritol. 

Carboxylic functional polyols can be prepared by reacting hydroxyl terminated polyethers with unsaturated acids and a free radical initiator. Also carboxylic groups can be added to poly(ester/ethers) or other hydroxy terminated polymers by reacting with dianhydrides. 

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