화학공학소재연구정보센터
Macromolecules, Vol.53, No.20, 9054-9064, 2020
Competing Molecular Packing of Blocks in a Lamella-Forming Carbohydrate-block-poly(3-hexylthiophene) Copolymer
A molecular packing model of poly(3-hexylthiophene)-block-peracetylated maltopheptaose (P3HT-b-AcMal(7)) was proposed based on the X-ray and electron diffraction measurements. The P3HT and AcMal(7) segments are confined in the lamellae in which the AcMal(7) segments are aligned side by-side. The extended P3HT chain segments are tilted with respect to the lamellar plane and strongly pi-stacked. This molecular arrangement results from a subtle balance between segregation strength of the P3HT and AcMal(7) blocks, strong pi-pi interactions of the P3HT backbones, geometrical mismatch between two blocks, space filling requirement, and entropic penalties. The small-angle X-ray scattering (SAXS) analysis above the melting temperature of P3HT block indicates strong segregation strength between P3HT and AcMal(7) blocks. Differential scanning calorimetry (DSC), Fourier-transform infrared (FT-IR) spectroscopy, and SAXS measurements underline the improved thermal stability of P3HT crystalline domains in the phase-separated P3HT-b-AcMal(7).