Graft Copolymer Elastomers with Polar Polyacrylonitrile as Semicrystalline Side Chains: Excellent Toughness and Healability
writer：Deli Xu, Wenwen Wang,* Y Zheng, S Tian, Y Chen, Z Lu, Y Wang, K Liu, D Wan
keywords：Graft Copolymer, elastomer, self-healing
source：期刊
specific source：Macromolecules
Issue time：2020年
Elastomers with optimal mechanical performance and
healability are indispensable for applications such as wearable
electronics, automotive, and future robotics. Herein, an infrequent
strategy was developed to build graft copolymer elastomers with
polar polyacrylonitrile (PAN) as semicrystalline side chains and
poly(methyl acrylate) (PMA) as amorphous backbones, in which the
fraction of PAN segments and junction points was designed.
Miniemulsion polymerization was utilized to increase the incorpo-
ration of semicrystalline macromonomers into amorphous back-
bones. The resultant graft copolymer elastomers (PMA-g-PAN)
presented that the maximum toughness could reach 19.3 MJ/m3. For PMA-g-PAN with a PAN content of 10.6 wt % and appropriate
graft density (junction points of 10.1), the minimum residual strain was approximately 20% after the tenth stretch to 200% strain.
The maximum residual strain runs up to approximately 70% after the tenth stretch to 400% strain. Results indicated that high
toughness and excellent elasticity after cyclic stretching were assigned to the high molecular weight, optimized polar interaction
between cyano groups, and crystallinity of side chains (PAN, 10.6 wt %) as well as the numerous junction points (10.1) of the graft
copolymer. Additionally, elastomers in this work possessed excellent healability, and the healing efficiency was 82% under 50 °C only
by interaction between cyano groups in side chains. In this work, we report a superior and convenient strategy for improving
mechanical properties and prolonging the lifetime of polymeric elastomers only by importing polar and semicrystalline segments into
the graft copolymer elastomer.