Preparation And Actuating Properties Of Shape Memory Poly (Arylene Ether Ketone) Materials

Shape memory polymers（SMPs）are able to percept the external stimuli and make the corresponding response,which possess the deformation and programmable shape recovery abilities.Poly（arylene ether ketone）（PAEK）,exhibiting the excellent mechanical performances and thermal stability,possesses the wide utilizations in the fields of aerospace,engineering,and electronic devices.In this paper,based on the design of molecular chains,we have prepared the novel shape memory PAEK materials through the chemical synthesis and investigated the actuat ing performances.We synthesized a series of novel shape memory PAEK materials through the condensation polymerization（shape recovery ratio over 91%,and fixity ratio over98%）.The regulation of programmable glass transition temperature（T_g）,which ranged from 121.9 to 159.3°C,of PAEKs was achieved through tuning the proportion of bisphenol monomers.Besides,we used SAXS to investigate the synthesized PAEKs during the heating process.As the increasing of temperature,the phase transition（the glass state was transformed into rubber state）occurred in PAEK matrix,promoting the orientation of internal molecular chains,which released the internal stress stored before,resulting in the shape recovery behaviors.We fabricated the shape memory PAEK material with multi-T_g through mixing the PAEKs with different T_g.Meanwhile,Fe₃O₄ nanoparticles and CNTs were integrated into PAEK matrix for the achievement of magnetic-triggered and electric-triggered shape memory behaviors.Through integrating the multi-responsive ability into the multi-shape memory PAEK system,we fabricated the region-selective responsive multi-shape memory PAEK composite materials.The photosensitive shape momery PAEKs were synthesized by the grafting of azobenzene（ABZ）groups（sensitive to UV withλof 365 nm）onto shape memory PAEK main chains.Meanwhile,we fabricated the PAEK/cinnamic acid（CA）composites（sensitive to UV withλof 254 nm）via physical blending.Due to the photosensitivity for different wavenumbers of ultraviolent of ABZ and CA groups,we constructed the wavenumber（365nm and 254 nm）selective-responsive shape memory composites through combining the PAEK/ABZ,PAEK,with PAEK/CA components.We grafted the zwitterionic groups（ZPs）onto PAEK chains,improving the hydrophilicity and tuning the shape memory behaviors.The synthesized ZPAEK exhibited the water-actuating behaviors at room temperature,in addition to the reshaping-reconfiguration ability and triple-shape memory effect due to the interaction between carboxylic acid pyridine zwitterionic groups and water molecules.Additionally,the conductive（thermal and electrical）CNTs were integrated into shape memory PAEK matrix,and the aligned orientation were achieved.As the increasing of CNTs content,the CNTs conductive path was fabricated in PAEK matrix,promoting the conduction of heat and charge,and the achievement of the efficient thermal/electrical-triggered shape memory behaviors.Meanwhile,based on the composites,we prepared the voltage actuators,which could be controlled through the angle-and time-modes.Furthermore,we integrated the dynamic metal-coordination bonds into the shape memory PAEK system,and fabricated the metal-coordinated shape memory PAEK materials.The synergistic effect between the intrinsic motion ability of PAEK chains and the cracking-recombination of metal-coordination bonds enhanced the shape memory effect（shape recovery ratio over 98%and fixity ratio over 98%）.Besides,the gradient shape memory PAEK materials were fabricated through combining the different PAEK materials with diverse species and contents of metal ions.In PAEK matrix,the gradient distribution of Cu²⁺and Fe²⁺imparted the gradient shape recovery behaviors.Additionally,due to the dynamic cracking-recombination of metal-coordination bonds,these metal-coordinated PAEK materials exhibited the excellent self-healing and re-processing abilities.