POLYESTERS CONTAINING SULFUR, X: THE USE OF NEW HYDROXYL-TERMINATED THIOPOLYESTERS WITH DIPHENYLMETHANE UNIT IN THEIR STRUCTURE FOR POLYURETHANE PREPARATION
Title:
POLYESTERS CONTAINING SULFUR, X: THE USE OF NEW HYDROXYL-TERMINATED THIOPOLYESTERS WITH DIPHENYLMETHANE UNIT IN THEIR STRUCTURE FOR POLYURETHANE PREPARATION
Author:
Kultys, Anna
Appeared in:
International journal of polymeric materials
Paging:
Volume 52 (2003) nr. 9 pages 773-783
Year:
2003-09
Contents:
The new linear hydroxyl-terminated thiopolyesters (PEs) containing thioether linkages in the main chain were prepared by melt polymerization of newly obtained diphenylmethane-4,4'-bis(methylthioacetic acid) with excess of 1,4-butanediol, 1,5-pentanediol (PD), and 1,6-hexanediol. All these PEs ( {\bar M}_n of ~1900-2500) were converted to thiopoly(ester-urethane)s (PEUs) by addition reaction with hexamethylene diisocyanate (HDI) or 4,4'-diphenylmethane diisocyanate (MDI) which was carried out in melt at the ratio of NCO/OH=1.05. The PEUs obtained were elastomeric products, completely amorphous from MDI or with a little tendency to crystallize from HDI. Their characteristics were -red =0.65-0.93 dL/g, glass transition temperatures ranging from -12.7 to -0.9°C, tensile strength of 0.4 -2.3 MPa, elongation at break of 650-2000%, and thermal stabilities of up to 230-260°C. Segmented PEUs (hard segment content ~50 wt.%) prepared by using the PD-based PE, HDI or MDI, and bis[4-(6-hydroxyhexylthio)phenyl] ether as a chain extender were elastomeric materials, particularly those from MDI, with tensile strength of 10.6 or 13.8 MPa and elongation at break of 120 or 250%, respectively. The structures of the polymers were determined by Fourier transform infrared and H 1 -NMR.
Journal description