Interplay of Structural Factors in Formation of Microphase-Separated or Microphase-Mixed Structures of Polyurethanes Revealed by Solid-State NMR and Dielectric Spectroscopy

Stepan A Ostanin; Maxim V Mokeev; Dmitry V Pikhurov; Aleksandr S Sakhatskii; Vjacheslav V Zuev

doi:10.3390/polym13121967

Interplay of Structural Factors in Formation of Microphase-Separated or Microphase-Mixed Structures of Polyurethanes Revealed by Solid-State NMR and Dielectric Spectroscopy

Polymers (Basel). 2021 Jun 14;13(12):1967. doi: 10.3390/polym13121967.

Authors

Stepan A Ostanin¹, Maxim V Mokeev², Dmitry V Pikhurov³, Aleksandr S Sakhatskii⁴, Vjacheslav V Zuev^{1

2}

Affiliations

¹ ITMO University, Kronverkskiy pr. 49, 197101 Saint-Petersburg, Russia.
² Institute of Macromolecular Compounds of the Russian Academy of Sciences, Bolshoi pr. 31, 199004 Saint Petersburg, Russia.
³ Varnish-Paint Plant "CRONOS SPb", Polevaya Sabirovskaya 42, 197183 Saint Petersburg, Russia.
⁴ Saint-Petersburg State University, 7/9 Universitetskaya nab., 199034 Saint Petersburg, Russia.

Abstract

A set of aromatic-oxyaliphatic polyurethanes (PUs) with different mass fractions of components also containing fluorinated fragments was synthesized and studied using various solid-state NMR techniques and dielectric spectroscopy. In contrast to the common model suggested by Cooper and Tobolsky in 1966, the rigid domains of microphase separated PUs are formed, not only by units containing urethane bonds, but also by oxyethylene fragments that form a common rigid phase. The urethane bonds and oxyethylene fragments are incorporated into both rigid and soft phases. Good agreement with the Cooper and Tobolsky model is observed only when solubility parameters are significantly different for the hard and soft segments, such as hydrocarbon aromatics and perfluoroaliphatic blocks.

Keywords: FTIR; dielectric spectroscopy; domain size; microphase separation; polyurethane; solid-state NMR.

Abstract

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