Evaluation of beta-phase formation in the failure of PVDF-based solar module backsheets

There are concerns about the potential for polyvinylidene fluoride (PVDF)-based backsheets to crack and fail prematurely. Several studies have suggested that polymer phase change may play a role in the failure mechanism. Here we utilize wide-angle X-ray scattering maps to show that alpha- to beta-phase transformations occurs at cracks tips in aged PVDF-based backsheets. In addition, our work demonstrates that beta-phase formation is not required for crack growth and only occurs at crack tips when plastic deformation of the PVDF polymer has occurred.