Soft-segment Free Polyurethanes and their Self-healable Films

[Display omitted] •H-bonding strength and sites are tuned by synthesizing functionalized (FPU) and un-functionalized (NFPU) PUs.•Temperature dependent FTIR and NMR provided clear evidence of H-bonding and recognized sites in FPU and NFPU.•The H-bonding strength and sites are identified by computational modelling of polymeric chains.•Microparticles of PUs are achieved by solution polymerization method. The formation of spherical particles is associated with the H-bonding units in PUs.•FPU is less transparent due to increased polymer chain interaction via H-bonding. FPU is more elastomeric whereas NFPU is highly brittle.•The FPU films are transformed into a self-healable by incorporating a flexible polyurethane. The film self-healed at ambient temperature with a healing efficiency of 80-85 %.•Glycerol embedded SH8020 PU film displayed healing in a shorter time compared to the original self-healing film, which is ascribed to the availability of abundant H-bonding sites at the healing location. Introducing non-covalent interactions into polymeric chains can result in supramolecular polymers with interesting properties and dynamic features. In this work, a functional polyurethane (FPU) and non-functional polyurethane (NFPU) were synthesised from phloroglucinol and hexamethylene diisocyanate monomers by tuning their stoichiometry. Both the PUs featured spherical morphology as observed in FESEM images and exhibited surface dynamics with time. The PUs led to self-standing films but their properties are significantly different. Temperature dependent FTIR and NMR gave strong evidence for the presence of multiple H-bonding. Computational studies (B3 LYP/6-31G** level DFT method) highlighted considerable interaction for FPU than NFPU due to enhanced H-bonding between chains. The FPU was further made into self-healable film by incorporating another polyurethane (MPU) (self-healing efficiency >80%). The mechanism of self-healing lies on the gradual growth of H-bonding between FPU and MPU at ambient conditions which is corroborated with glycerol-embedded self-healing film.