Spontaneously
Healable Thermoplastic Elastomers Achieved
through One-Pot Living Ring-Opening Metathesis Copolymerization of
Well-Designed Bulky Monomers
posted on 2016-05-02, 00:00authored byJi-Xing Yang, Ying-Yun Long, Li Pan, Yong-Feng Men, Yue-Sheng Li
We
report here a series of novel spontaneously healable thermoplastic
elastomers (TPEs) with a combination of improved mechanical and good
autonomic self-healing performances. Hard–soft diblock and
hard–soft–hard triblock copolymers with poly[exo-1,4,4a,9,9a,10-hexahydro-9,10(1′,2′)-benzeno-l,4-methanoanthracene]
(PHBM) as the hard block and secondary amide group containing norbornene
derivative polymer as the soft block were synthesized via living ring-opening
metathesis copolymerization by use of Grubbs third-generation catalyst
through sequential monomer addition. The microstructure, mechanical,
self-healing, and surface morphologies of the block copolymers were
thoroughly studied. Both excellent mechanical performance and self-healing
capability were achieved for the block copolymers because of the interplayed
physical cross-link of hard block and dynamic interaction formed by
soft block in the self-assembled network. Under an optimized hard
block (PHBM) weight ratio of 5%, a significant recovery of tensile
strength (up to 100%) and strain at break (ca. 85%) was achieved at
ambient temperature without any treatment even after complete rupture.
Moreover, the simple reaction operations and well-designed monomers
offer versatility in tuning the architectures and properties of the
resulting block copolymers.