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

Abstract

New thermoplastic polyether-and polycarbonate-based segmented polyurethanes were synthesized by a catalyzed one-step melt polyaddition from diphenyl sulfide-derivative diol, i.e., 2,2 0 -[sulfanediylbis(benzene-1,4-diyloxy)]diethanol as a nonconventional chain extender, 1,1 0 -methanediylbis(4-isocyanatocyclohexane), and 40, 50, and 60 mol% poly(hexane-1,6-diyl carbonate) diol (PHCD) of M n ¼ 860 g=mol or poly(oxytetramethylene) diol (PTMO) of M n ¼ 1000g=mol as soft segments. The structures and thermal properties of the polymers were examined by FTIR, elemental analysis, differential scanning calorimetry, thermogravimetry (TG), and TG-FTIR. Moreover, their Shore A/D hardness, tensile, physicochemical, adhesive, and optical properties were determined. The obtained colorless, transparent, amorphous materials exhibited elastomeric or plastic properties. The PTMO-based polymers showed lower glass-transition temperatures than those based on PHCD (from -29 to 5°C vs. from 11 to 43°C) as well as a higher degree of microphase separation. On the other hand, the polymers with the polycarbonate soft segments revealed better transparency (transmittance at 800 nm: 84-89% vs. 75-82%), higher tensile strength (up to 48.6 MPa vs. up to 28.3 MPa), and hardness in comparison with those with the polyether soft segments. The polymers decomposed in two (in helium) or three (in air) stages and possessed a relatively good thermal stability. Their temperatures of 1% mass loss were contained within the range of 255-274°C. In inert atmosphere, the values shown by polymers from PTMO were higher than those from PHCD, whereas in oxidative atmosphere, the situation was reversed. The newly synthesized sulfur-containing polymers showed a higher refractive index and adhesive strength to copper than analogous polymers based on butane-1,4-diol as a chain extender.

New thermoplastic poly(carbonate-urethane)s based on diphenylethane derivative chain extender

“…Thus, it can be supposed that carbon monoxide and carbonyl compounds are the products of the PHCD soft-segment decomposition. Moreover, a greater intensity of the bands characteristic of carbon dioxide indicates that carbon dioxide originates from the decomposition of soft segments, which is confirmed by the spectrum obtained for the PHCD [28]. In the second decomposition stage of this polymer (Fig.…”

“…The aromatic and aliphatic-aromatic diols are also advantageous when the aim is to prepare materials of higher modulus of elasticity and hardness, enhanced thermal stability or liquid crystalline properties [7,[17][18][19][20][21]. The investigation interests of co-workers and myself include aliphatic-aromatic diols with sulfur atoms, being the derivatives, among others, of diphenylmethane [22][23][24], diphenyl ether [25,26], and diphenyl sulfide [25][26][27][28][29]. They enable preparation of thermoplastic polyurethanes of good thermal stability and mechanical properties and simultaneously of higher adhesive strength to metals and refractive index compared with the aliphatic ones [23,[26][27][28].…”

New thermoplastic poly(carbonate-urethane)s based on diphenylethane-derivative chain extenders—the effect of chain extender structure on thermal and mechanical properties

“…It can therefore be supposed that carbon monoxide and ethers are the products of the soft-segment decomposition. Similarly, a much greater intensity of the bands characteristic of carbon dioxide indicates that also carbon dioxide originates from the decomposition of soft segments, which the spectrum obtained for the PHCD [20] confirmed.…”

“…My co-workers' and my own scientific interests cover aliphatic-aromatic diols with sulfur atoms being the derivatives, among others, of diphenylmethane [13][14][15], diphenyl ether and diphenyl sulfide [16][17][18]. They allow to obtain thermoplastic polyurethanes with good thermal stability and mechanical properties, but at the same time with higher adhesive strength to metals and refractive index in comparison with a conventional aliphatic diol [18][19][20][21]. Although it is possible to prepare thermoplastic PCURs from the abovementioned sulfur-containing chain extenders with good performance characteristics, it is interesting to check whether the use of the chain extenders with symmetric and linear structure instead of those with an angled one [17,18] will improve the properties of obtained PCURs.…”

Polycarbonate-based thermoplastic polyurethane elastomers modified by DMPA

“…Recently, I and my colleagues presented TPUs modified in the main chain [15][16][17][18]. They were obtained from non-conventional chain extenders, i.e., 2,2′-[sulfanediylbis(benzene-1,4-diyloxy)]diethanol (diol OSOE), 2,2′-[oxybis(benzene-1,4-diylsulfanediyl)]diethanol or 2,2′-[sulfanediylbis(benzene-1,4-diylsulfanediyl)]diethanol, commercial diisocyanates, such as MDI, HMDI and 1,6-diisocyanatohexane (HDI), and commercial polymer diols, such as aliphatic polyether diol of M n = 1000 g∕mol and aliphatic polycarbonate diol of M n = 2000 g/ mol (PCD).…”