| abstract |
Provided is a process for producing a polymeric piezoelectric material including a first step of heating a sheet in an amorphous state containing the helical chiral polymer to obtain a pre-crystallized sheet, and a second step of stretching the pre-crystallized sheet in biaxial directions, wherein the polymeric piezoelectric material includes a helical chiral polymer having a weight-average molecular weight of from 50,000 to 1,000,000 and having optical activity, wherein a crystallinity of the material measured by a DSC method is from 20% to 80%, and a product of a standardized molecular orientation MORc measured by a microwave transmission type molecular orientation meter based on a reference thickness of 50 μm and the crystallinity is from 25 to 250. |