Polyether triols Structures

All the oligo-polyols are used to build the polyurethane high MW structure in a reactive process, as a consequence of the oligo-polyols terminal hydroxyl group reaction with polyisocyanates. The reactivity of oligo-polyols in polyurethane fabrication is a very important practical characteristic. Reactivity is a measure of the reaction rate of an oligo-polyol with an isocyanate in order to make the final polyurethane polymer. One practical method is the measurement of viscosity, in time, by Brookfield Viscosity Test (BVT), especially used to determine the reactivity of ethylene oxide capped polyether polyols. Figure 3.12 shows the effect of the primary hydroxyl content upon the reactivity of ethylene-oxide capped polyether triols of MW of 5,000 daltons. 

Figure 4.5 shows some structural possibilities for polyether diols and polyether triols [1-13]. 

The PO homopolymers (MW of 3000) initiated by glycerol are some of the most popular polyols for flexible PO slabstock. This structure is one of the oldest structures of a polyether used for flexible PU foams. In essence these polyether triols are obtained by the anionic polymerisation of PO initiated by glycerol and catalysed by KOH. 

This polyether triol hybrid structure block [PO] - random [PO - EO]- block EO, with a MW of 3000 daltons, was used successfully for hot moulded flexible PU foams with... 

Figure 4.28 The structures of polyether triol block copolymers PO-EO a) terminal poly[EO)] block b) poly[EO] block linked to the starter c) internal poly[EO] block...

During the radical polymerisation of vinylic monomers in liquid polyether media, graft species (carbocatenary vinylic polymer chemically linked on the polyether) are formed, by chain transfer reactions, which play the role of a true NAD. For grafting reactions on polyether triols, the graft species have the following idealised structure (Figure 6.3). 

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... 

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... 

Figure 4.5 Various structures of polyether diols and triols...

The preferred polyether used in this reaction is a higher molecular weight triol of 5000-6000 daltons (preferred MW is 6000 daltons). By copolymerisation of the macromer (structure 6.12) with ACN and styrene, a NAD is obtained in situ, which is in fact a graft copolymer ... 

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]... 

Polyol ligands (ethylene glycol, propane-1,2-diol, propane-1,3-diol and propane-1,2,3-triol) were used as models for the interaction of carbohydrates with Li, Na and K+. Multidentate effects are the rule with these ligands, but the existence of intramolecular hydrogen bonds is a complicating factor in the determination of structures, as compared with polyethers [76],... 

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