Correlation between crystallization and mechanical stress revealed by chain scission of segmented amide copolymer

Abstract

By tuning hydrolysis duration of a segmented ether-amide copolymer (PEBA), a range of specimens presenting various macromolecular structures has been produced. Knowing that scissions occur predominantly at the bond between hard and soft blocks, for a given hard phase structure we study the impact of phase interconnection changes on strain-induced crystallization (SIC) occurring during tensile loading. The consequences of chain scissions on the structural reorganization involving SIC measured with in situ X-ray diffraction is considered here for the first time. A close correlation between stress and crystallinity induced under strain is highlighted whatever the chain scission number, i.e. the number of phase interconnections. As a result, the stress decrease observed at a given elongation can be interpreted as a consequence of a SIC weakening with the chain scission process.