Synergistic enhancement of mechanical properties and impact resistance of polyurethane elastomers by composite fillers containing quadruple hydrogen bonds and nano-CaCO3

Inorganic filler-filled polyurethane elastomer (PUE) is faced with problems such as cracking and functional structure failure under high-speed impact, which limits its application in the field of protection. Inspired by the secondary electrostatic effect of quadruple hydrogen bonds, a polymer containing quadruple hydrogen bonds (PHI) was composited with nano-CaCO3 to prepare a nano-reinforced filler (PUE-QHB@CaCO3). The composition, morphology and microstructure of the nano-reinforced filler were systemly characterized, and it was used to improve impact resistance and energy absorption of PUE. Compared with pure PUE, 4 wt% PUE-QHB@CaCO3 composite PUE simultaneously improves the maximum compressive modulus (190.70%), elastic modulus (186.81%), dynamic strength (24.32%) and energy absorption (23.33%) and reduces thermal weight loss rate (137.58%). The excellent mechanical properties exhibited by PUE-QHB@CaCO3 are not only attributed to the rigidity provided by nano-CaCO3 and the flexibility of PHI, but to the synergistic enhancement effect of the two in PUE.