Enhanced porosity and degradation behavior of porous KNN/PLA piezoelectric composites with C2H5OH addition

The porous 0.3K 0.48 Na 0.52 NbO 3 /polylactic acid (KNN/PLA-P i , i = 0, 1, 2, 3, 4) composites were prepared using a nonsolvent-induced phase separation method. The effects of C 2 H 5 OH content on the porosity, degradation behavior and electroactivity of the composites were investigated. The addition of C 2 H 5 OH did not alter the phase composition of the obtained porous KNN/PLA-P i composites. However, it significantly increased the porosity and notably enhanced the degradation rate. Especially by adding 30 wt% C 2 H 5 OH, the obtained KNN/PLA-P 3 composite exhibited the optimal performance with a porosity of 69.5 %, a degradation weight loss rate (WLR) in water of 16.4 % after 28 d, a piezoelectric constant ( d 33 ) of 1.0 pC/N, a relative dielectric constant ( ε r ) of 5.5, and a water contact angle (CA) of 75.3° after polarization. These results give the underlying enlightenments needed for design and fabrication of electroactive bone repair composite, which match human bones well in terms of porosity and degradation rate.