Polyisobutylene-based polyurethanes. VIII. Polyurethanes with -O-S-PIB-S-O- soft segments

Abstract

We describe the synthesis, characterization, and select properties of a novel polyurethane (PU) prepared using a new polyisobutylene diol, HO‐CH2CH2‐S‐PIB‐S‐CH2CH2‐OH, soft segment and conventional hard segments. The diol is synthesized by terminal functionalization of ally‐telechelic PIB followed by low‐cost thiol‐ene click chemistry. Properties of ‐S‐ containing PU (PIBS‐PU) containing 72.5% PIB were investigated and compared to similar PUs made with HO‐PIB‐OH (PIBO‐PU). Hydrolytic resistance was studied by contact with phosphate‐buffered saline, oxidative resistance by immersing in concentrated HNO3, and metal ion oxidation resistance by exposure to CoCl2/H2O2. Hydrolytic and oxidative resistances of PIBS‐PU and PIBO‐PU are similar and superior to a commercial PDMS‐based PU, Elast‐Eon™ E2A. According to 1H NMR spectroscopy the ‐S‐ in PIBS‐PUs remained unchanged upon treatment with HNO3, however, oxidized mainly to ‐SO2‐ by CoCl2/H2O2. Static mechanical properties of PIBS‐PU and PIBO‐PU are similar, except creep resistance of PIBS‐PU is surprisingly superior. The thermal stability of PIBS‐PUs is ∼15 °C higher than that of PIBO‐PU. FTIR spectroscopy indicates H bonded S atoms (N‐H…S) between soft and hard segments, which noticeably affect properties. DSC and XRD studies suggest random low‐periodicity crystals dispersed within a soft matrix. Energy dispersive X‐ray spectroscopy–scanning electron microscopy indicates homogeneous distribution of S atoms on PIBS‐PU surfaces. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1119–1131

Morphology and tensile properties of model thermoplastic polyurethanes with MDI/butanediol based monodisperse hard segments

“…Functional groups such as NH and CO may participate in hydrogen bonding in TPUs. In TPUs with strong hydrogen bonding, the frequencies of bonded NH and CO vibrations shift to 3320 cm −1 and 1705 cm −1 , respectively, in contrast to the free NH at 3450 cm −1 and the free CO at 1732 cm −1 . The frequency of ether bonded NH further decreases to 3250 cm −1 .…”

“…In TPUs with strong hydrogen bonding, the frequencies of bonded NH and CO vibrations shift to 3320 cm −1 and 1705 cm −1 , respectively, in contrast to the free NH at 3450 cm −1 and the free CO at 1732 cm −1 . The frequency of ether bonded NH further decreases to 3250 cm −1 . The inter‐urethane bonded HSs reside in the interior of the hard domains, while the HSs possessing free CO groups are present in the mixed soft phase or at the interface.…”

Calcification resistance of polyisobutylene and polyisobutylene‐based materials

“…The synthesis and characterization of PIB‐PU, PIB S ‐PU, PIB‐PU/nc, PIB S ‐PU/nc, and PIB‐PUU have been described . All PUs contained 72.5‐wt% PIB, a quantity that was shown to cover the surfaces .…”

“…We designed, prepared, and studied the mechanical properties and oxidative‐hydrolytic stability of PIB‐PUs and PU derivatives whose surfaces are covered with PIB . The exceptional biological stability for long‐term implant applications of these PIB‐PUs has been demonstrated .…”

Polyisobutylene-based polyurethanes. IX. synthesis, characterization, and properties of polyisobutylene-based poly(urethane-ureas)

“…This series of publications concern new polyurethanes (PUs) containing polyisobutylene (PIB) soft segments and conventional hard segments . These PIB‐PU thermoplastic elastomers have unparalleled chemical/biological resistance due to highly inert PIB chains enveloping/shielding the vulnerable hard segments.…”