Chemistry and technology of polyols for polyurethanes pdf
Reaction.13 is predominant at higher temperatures.
Sufcak in Proceedings of utech 2000 Conference, The Hague, The Netherlands, 2000, Coatings, Adhesives, Sealants and Elastomer Session, Paper.9.
The single polyol from this group that needs special attention is sorbitol, which is delivered in the form of an aqueous solution of around.
PO and EO are really excellent reaction media fm09 real time editor for alkoxylation of solid polyols, but only in the presence of tertiary amines and the resulting polyethers are of excellent quality.Hubin, inventors; Minnesota Mining and Mfg Co, assignee; US 3,824,220, 1974.The urethane linkages (and urea linkages because of the possibility of association by hydrogen bonds, generate the hard domain or hard segment of a polyurethane elastomer.No inventor; Upjohn, assignee; GB 1,042,220, 1966.(8.38) The catalysts of this ring opening polymerisation reactions are: pyridinium salts (for example N-benzyl pyridinium p-toluene sulfonate 75 p-toluene sulfonic acid 75, stannium or titanium compounds 68-74 etc.Of course the polymerisation reaction takes place in a liquid state, where the anionic catalyst is present.
Hickson, ACS Symposium Series.41, American Chemical Society, Washington, DC, USA, 1976,.41.
Stuber in Reactive Polymers,.,.
Table.1 Some characteristics of polyols used frequently as starters for polyether polyols for rigid PU foams.This polyol with a MW of around 7000 daltons, PO-EO copolyether (13- 15 EO) with polyEO as terminal block, was used successfully for making cold cure high resilience moulding fl exible PU foams.Rubber Age, 1975, 107, 6,.HB db 155HB db 155 27/10/05 1:55:26 pm27/10/05 1:55:26 pm 156 Chemistry and Technology of Polyols for Polyurethanes.A technological variant for pipa polyol fabrication, by reaction of teoa with TDI, is presented in Figure.12.Very interesting polyols for rigid PU foams are obtained by the simultaneous alkoxylation with PO (or EO) of a mixture from bisphenol A and a costarter, such as: bisphenol A - ortho toluene diamine 32, bisphenol A - diaminodiphenylmethane 32, bisphenol A - polyethylene glycol.