Polyether triols functionality

We observed in a previous investigation of PU s derived from a kraft lignin (KL)-polyether triol-diphenylmetane diisocyanate (MDI) system (Yoshida, H. Morck, R. Kringstad, K. P. Hatakeyama, H., submitted to J. Appl Polym. Set.) that KL fractions of low molecular weight yielded more flexible and less crosslinked PU s than the medium and high molecular weight KL fractions. This was attributed to the lower functionality of the low molecular weight KL fractions. 

Both KOH and water present in glycerol are sources of polyether diols which decrease the functionality of the polyether triol [2-13] ... 

The polyethers obtained by the anionic polymerisation of PO initiated by glycerol are not trifunctional, having a lower functionality than 3, but usually in the range 2 < f < 3. The diols and monols decrease the functionality. The functionality is lower for high MW polyethers and for the polyethers obtained at higher polymerisation temperatures. In Figure 4.6, one observes the strong polyether triol functionality decrease as the polyether MW increases. 

The polyether triol functionality as function of unsaturation and of diol content can be calculated using the following formula ... 

Figure 4.6 The real functionality of polyether triols, PO homopolymers, as function of...

In a polyether triol composition the following are present nj = mols of monols, of functionality = 1 n2 = mols of diols, of functionality f2 = 2 n3 = mols of triols, of functionality f3 = 3... 

The average functionality of a polyether triol can be calculated with the following formula (deduced from the previous formula) [48] ... 

Figure 4.23 Variation of primary hydroxyl content as a function of EO content in polyether triols block copolymers [PO-EO] with terminal poly[EO] block MW = 5000 daltons catalyst KOH - 0.0056 mol%...

Table 5.1 shows the double bond content and the functionality of polyether triols, with a MW of 6000 daltons, synthesised with different catalysts. 

A similar structure to the one in Figure 6.6 is obtained by using instead of epoxy resins diphenylmethane diisocyanate (MDI pure or crude ). For example by using crude MDI with the functionality of around 2.2-2.5 -NCO groups/mol, by the reaction with terminal groups of high molecular weight polyether triols (5000-6500 daltons), nonreactive NAD... 

Figure 21.1 shows the functionality decrease function of the poly ether diols MW while Figure 21.2 shows the variation of the functionality against the polyether triol MW. 

For the production of rigid polyurethane foams, polyether triols of lower molecular weight (about 500) are used so that the degree of cross-linking is increased. Alternatively, polyethers of higher functionality may be used these are prepared by polymerizing propylene oxide in the presence of hydroxy compounds such as pentaeryrthritol and sorbitol. 

Telechelic polymers rank among the oldest designed precursors. The position of reactive groups at the ends of a sequence of repeating units makes it possible to incorporate various chemical structures into the network (polyether, polyester, polyamide, aliphatic, cycloaliphatic or aromatic hydrocarbon, etc.). The cross-linking density can be controlled by the length of precursor chain and functionality of the crosslinker, by molar ratio of functional groups, or by addition of a monofunctional component. Formation of elastically inactive loops is usually weak. Typical polyurethane systems composed of a macromolecular triol and a diisocyanate are statistically simple and when different theories listed above are... 

The principal polymeric plasticizers are the polymer hydrocarbons and the polyesters. The condensation products of diols and dicarboxylic acids, belonging to the polyester group, are most important. Higher functional compounds, like triols and tricarboxylic acids, are less important as are polyethers, polyacetals, and polymeric acids. 

The one-shot methods used to produce flexible polyurethane foams employ quick mixing of a (usually) triol-based polyether of fairly high-molecular weight with toluene diisocyanate, catalyst, and water for gas production (Eq. 21.19). The reaction of water with the diisocyanate rapidly raises the average functionality in the polymerizing system by forming urea, as well as urethane links (Eq. 21.23). 

Reaction 11.4 is used to decrease the unsaturation of polyether polyols simultaneously with the functionality increase. Thus, by introducing a polyether polyol with high unsaturation (0.07-0.09 mequiv/g), a low molecular weight polysiloxane compound, having 2-3 Si-H groups/mol, together with a platinum catalyst, the polyether monol present in the polyether (in fact allyl ether based polyethers) is added to the polysiloxane compound and the monol is transformed into a diol or into a triol (reaction 11.5). 

Polyol, rigid Polyoxypropyleneamine Polyoxypropylene triol Uses Functional polyol for polyurethane industry for industrial/consumer RIM and structural polymers, dynamic elastomers, adhesives, binders, coatings, and sealants reactive diluent, dispersant for solvent coatings, etc. flexibilizer for PU PU curative and crossiinker Manuf./Distrib. Aiichem Ind. http //www.aiichem.com] BASF http //www.basf.com] Bayer http //www.bayerus.com] Huntsman Poiyurethanes http //www.icipu. com] http //www. rubinate. com Trade Name Synonyms Adeka Polyether PR-3007 [Asahi Denka Kogyo http //www.adk.co.jp]] Baycoll ND 1110 [Bayer/Fiber, Addits., Rubber http //www.bayerus.com]] Baycoll ND 2060 [Bayer/Fiber, Addits., Rubber http //www.bayerus.com]] Baycoll NT 1380 [Bayer/Fiber, Addits., Rubber http //www.bayerus.com]] Baycoll NT 5028 [Bayer/Fiber, Addits., Rubber http //WWW. bayerus. com]... 

Polyether Polyols. The polyether polyols used in the manufacture of polyurethanes are hydroxy-terminated macromolecules, with molecular weights ranging from 250 to 8000. Lyondell/Bayer has provided pilot plant diols/triols having molecular weights of 10,000 to 15,000 for lubricant and surfactant applications. The hydroxy functionality can range from 2 to 8. The economically attractive polyether polyols based on alkylene oxides are listed in Table 4. 

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