New thermoplastic poly(carbonate-urethane)s based on chain extenders with sulfur atoms

Abstract

New thermoplastic segmented polyurethanes were obtained by a one-step melt polyaddition using 40, 50 and 60 mol% poly(hexane-1,6-diyl carbonate) diol of g mol−1, 1,1′-methanediylbis(4-isocyanatobenzene) and 2,2′-[sulfanediylbis(benzene-1,4-diyloxy)]diethanol, 2,2′-[oxybis(benzene-1,4-diylsulfanediyl)]diethanol or 2,2′-[sulfanediylbis(benzene-1,4-diylsulfanediyl)]diethanol as a chain extender. FTIR, atomic force microscopy, differential scanning calorimetry and thermogravimetry were used to examine the polyurethanes’ structure and thermal properties. Moreover, their Shore A/D hardness, tensile, adhesive and optical attributes were determined. They were transparent high-molar-mass materials showing good tensile strength (up to 51.9 MPa). The polyurethanes exhibited improved adhesion to copper taking into consideration that of conventional ones, and middle or high refractive index values (1.57–1.60), and both these parameters increased with an increase of the content of sulfur atoms in the polyurethane chain. The newly obtained polyurethanes can be considered as materials for numerous medical and optical appliances.

The effect of chain extender structure on the properties of new thermoplastic poly(carbonate–urethane)s derived from MDI

“…In this area, DTG curve of this polymer exhibited only a small shoulder. Similar trend could be observed in analogous PCURs based on PHCD of M n = 860 g mol -1 [18]. In the case of the polymers derived from diol ME, no distinct differences in the course of DTG curves were to be seen.…”

“…This paper is a continuation of our studies on the synthesis and characterization of new thermoplastic segmented polyurethanes, including TPUs, based on commercial diisocyanates and polymer diols as well as nonconventional aliphatic-aromatic chain extenders. These chain extenders are diols with sulfide linkages and dithiols, derivatives, among others, of diphenylmethane, diphenylethane, benzophenone, diphenyl ether and diphenyl sulfide [8][9][10][11][12][13][14][15][16][17][18]. Making use of ''bulky'' chain extenders, additionally introducing sulfur atoms to polymer chain can improve adhesive properties to metals [9,10,13,17,18] and refractive index [10,13] and enhance antimicrobial activity [10] of such polyurethanes in relation to conventional ones.…”

“…Moreover, because of their low melting temperatures (T m s), melt polyaddition could be used to produce high-molar-mass polymers at relatively low reaction temperatures. These chain extenders have already been applied by us for the synthesis of MDI-based PCURs by using poly(hexane-1,6-diyl carbonate) diol (PHCD) of M n = 860 g mol -1 [12,18]. Most of the obtained polymers showed high tensile strengths (42.0-55.8 MPa), but unfortunately were not elastomers (their glass transition temperatures (T g s) were in the range of 16.2-47.0°C).…”

Transparent sulfur-containing thermoplastic polyurethanes with polyether and polycarbonate soft segments

“…1). They did not turn yellow after a long exposure (6 months) to atmospheric conditions at room temperature in contrast to the earlier obtained MDIderived ones [21,25]. These materials showed various resistance against common organic solvents.…”

“…Using aliphatic isocyanate and the chain extender with specific structure (no possibility of forming colored benzenoid (quinonoid) structures) makes it possible to synthesize non-yellowing polymers [20]. These segmented polyurethanes (SPURs) in view of the presence of sulfur atoms may show improved adhesive properties to metals [20][21][22][23][24][25][26] and higher refractive index [20,[23][24][25][26] in comparison with the conventional polyurethanes derived from the butane-1,4-diol (BD) chain extender. To be able to make such a comparison, their analogs based on BD, PTMO or PHCD and HMDI were prepared in the same conditions as SPURs.…”