posted on 2022-12-23, 20:35authored byPengcheng Miao, Ziyue Jiao, Jie Liu, Maomao He, Guanjun Song, Zhiyong Wei, Xuefei Leng, Yang Li
In the current context of sustainable chemistry development
and
new regulations, aminolysis of cyclic carbonate is one of the most
promising routes to nonisocyanate polyurethanes, also called polyhydroxyurethanes
(PHU). In this study, a new kind of shape memory PHU vitrimers with
outstanding mechanical properties and chemical recyclability is prepared.
The monomer employed for aminolysis to form the PHUs is bis(six-membered
cyclic carbonate) of 4,4′-biphenol (BCC-BP), which is synthesized
by bi(1,3-diol) precursors and CO2. The synthetic strategy,
isocyanate-free and employing CO2 as a building block,
is environmentally friendly and suits the concept of carbon neutrality.
The thermal properties, mechanical properties, and dynamic behaviors
of the PHUs are explored. The maximum breaking strength and elongation
at break of the resultant PHUs reach 65 MPa and 452%, respectively,
exceeding other reported PHU-based materials in combined performance.
Such a PHU material can also lift up a load 4700 times heavier than
its own weight by a shape recovery process. Finally, the bi(1,3-diol)
can be regenerated through the alcoholysis of PHUs to realize chemical
recycling. This work provides a feasibility study for a green synthetic
approach and for designing a novel PHU material with outstanding properties.