Organic–Inorganic Polyureas with POSS Cages in the Main Chains via Polycondensation of Diamines with Carbon Dioxide

Abstract

Linear organic–inorganic polyureas (PUreas) with polyhedral oligomeric silsesquioxane (POSS) cages in the main chains were synthesized via polycondensation of diamines with carbon dioxide (CO2). First, 3,13-dianilino double decker silsesquioxane (denoted 3,13-dianilino DDSQ) was synthesized. An α,ω-diamino-terminated poly­(propylene oxide) as well as the POSS diamine was exploited for polycondensation with CO2; PUrea and PUrea-DDSQ with sufficiently high molecular weights were obtained with various contents of POSS. The morphological investigation shows that the linear PUreas with POSS cages in the main chains were microphase-separated; the POSS cages were aggregated into spherical microdomains with the size of 50–120 nm in diameter. Owing to the introduction of POSS cages, PUrea was transformed from a viscous liquid into elastic solids in the ranges of composition investigated. At room temperature, linear organic–inorganic PUreas behaved as cross-linked elastomers. This behavior is ascribed to the generation of physical cross-linking with POSS microdomains as the cross-linking sites. In addition, the organic–inorganic PUreas displayed self-healing properties via the dynamic exchange of multiple hydrogen bonds. It was found that the self-healing properties were significantly affected by the content of 3,13-dianilino DDSQ.

Progress in the self-assembly of organic/inorganic polyhedral oligomeric silsesquioxane (POSS) hybrids

“…126 Several other organic-inorganic BCPs based on POSS cages have been studied during the last decade. [127][128][129][130][131] Pyun and Matyjaszewski prepared PMAPOSS from n-butyl acrylate monomers to form methacryloyl POSS BCPs. 132 133 We extended these BCPs with various volume fractions of each segment and then blended them with phenolic resin (Fig.…”

A Review on CO2‐Based Polyureas and Polyurea Hybrids

“…[67] A novel series of organic-inorganic siloxane-PUas with a M n ranging between 11200-21200 Da synthesized from 3,13dianilino double decker silsesquioxane (3,13-dianilino DDSQ, POSS), PPGda2000 and CO 2 , were reported by Zheng et al (Scheme 20). [68] When NaH was used as a water scavenger, the polycondensation was promoted remarkedly as the by-product water was removed efficiently and the resulted product NaOH could catalyse the polycondensation, leading to a higher molecular weight of the final product formed. The introduction of POSS turned the viscous liquid (homopolymer without POSS) into elastic solids (siloxane-PUas), suggesting the formation of physically cross-linked networks with the POSS microdomains as the cross-linking sites.…”

“…Moreover, the multiple hydrogen bonding interactions in siloxane-PUas endowed them with self-healing properties that were affected majorly by the amount of POSS. [68] Zhao et al synthesized a type of poly(urea-imine) thermosets (PUIs) via the reaction of CO 2 -based OUa and terephthalaldehyde (TA) with tris(2-aminoethyl)amine (TAEA) as crosslinker. The amino group and aldehyde group of the reactants was maintained equimolar at the start (Scheme 21).…”

“…Synthesis of organic-inorganic PUas. [68] Scheme 21. Synthesis of poly(urea-imine) (PUI) from CO 2 -based OUa, terephthalaldehyde (TA) and tris(2-aminoethyl)amine (TAEA).…”

“…As the POSS content increased, the T g , the modulus of rubbery plateaus and the Young's modulus increased while the elongation at break decreased. Moreover, the multiple hydrogen bonding interactions in siloxane‐PUas endowed them with self‐healing properties that were affected majorly by the amount of POSS [68] …”