Deformation Mechanism of Poly(3-alkylthiophene) Studied by in Situ X-ray Scattering and Texture Analysis

• DOI: 10.1021/acs.macromol.8b01223
• Publication Date: 2018-10-12T16:30:08Z
• Authors: Haiming Chen; Cui Su; Guangyu Shi; Xiaolu Li; Xiuqin Zhang; Guoming Liu; Dujin Wang
• Keywords: 02 engineering and technology; 0210 nano-technology

Understanding the deformation mechanism of conjugated polymers is essential for developing flexible or stretchable electronic devices. In this work, the mechanical properties of poly(3-dodecylthiophene) (P3DDT) and poly(3-hexylthiophene) (P3HT) are measured at different temperatures, and the underlying deformation mechanism is explored by using in situ X-ray scattering and pole figure. It is observed that the modulus and fracture strength of P3DDT decrease with increasing stretching temperature. The elongation at break of P3DDT exhibits a sharp increase when the stretching temperature reaches 45 °C. The general deformation process of the two polymers is in line with the traditional deformation mechanism established for flexible crystalline polymers with several special features. Well-defined yielding is not detected even at temperatures below the main-chain glass transition temperature, which corresponds to the microscopic observation of the absence of a well-defined lamellar–fibrillar transition. By anal...