MACROMOLECULAR PIEZOELECTRIC MATERIAL AND MANUFACTURING METHOD THEREFOR

摘要

The present invention provides a macromolecular piezoelectric material that contains optically active helical chiral macromolecules, which have a weight-average molecular weight of 50,000-1,000,000, and exhibits: a crystallinity of 40-80% as measured by DSC; a transmission haze of 0.0-40% with respect to visible light; and a normalized molecular orientation (MORc) of 3.5-15.0, using 50 µm as the reference thickness, as measured by a microwave-transmission molecular-orientation analyzer. The product of said MORc value and the aforementioned crystallinity is 100-700. The present invention also provides a macromolecular piezoelectric material that contains polylactic acid macromolecules and polyvinylidene fluoride, with the mass content of said polyvinylidene fluoride being more than 0% and no more than 5% of the total mass of the polylactic acid macromolecules and the piezoelectric constant (d14) of said macromolecular piezoelectric material being 10 pC/N or higher, as measured by the resonance method at 25°C. The present invention provides: a macromolecular piezoelectric material with a high piezoelectric constant (d14), a high degree of transparency, and excellent dimensional stability; and a manufacturing method therefor.