Preparation and characterization of lactitol-based poly(ether polyol)s for rigid polyurethane foam

✍ Scribed by Mark E. Wilson; Ming Hu; Mark J. Kurth; You-Lo Hsieh; John M. Krochta

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 754 KB
• Volume: 59
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19960314)59:11<1759::aid-app12>3.0.co;2-p

✦ Synopsis

SYNOPSIS

Propoxylation of lactitol [4-O-~-D-galactopyranosyl-D-g~ucito~]

under alkaline conditions afforded poly(ether polyo1)s (PEP) which have been characterized by their unsaturation content, alpha color, hydroxyl number, viscosity, hygroscopicity, and molecular weight distribution. The analogous sucrose-based PEP were prepared for comparison. Lactitol was found to require shorter reaction times and produced lighter-colored polyols than did sucrose. Polyols produced from lactitol displayed similar physical properties to sucrosebased PEP. Molecular weight analysis by GPC using the universal calibration method showed lactitol P E P to have polydispersities between 1.04 and 1.07. Negligible decomposition of lactitol during propoxylation was confirmed by 13C-NMR and GPC. 'H-NMR of trifluoroacetyl derivatives of lactitol P E P afforded secondary determination of M,. In addition, rigid polyurethane foams (PURF) formulated with lactitol-, sucrose-, or commercial sucroseglycerin-based polyols and PAP1 27 were prepared and characterized. Lactitol-based PURF were found to compare favorably with sucrose-based foams, displaying a density and compressive strength of 28.9 kg/m3 and 1.213 X lo5 N/M2, respectively.