Tailoring the Structure, Morphology, and Crystallization of Isodimorphic Poly(butylene succinate-ran-butylene adipate) Random Copolymers by Changing Composition and Thermal History

Abstract

Poly(butylene succinate-ran-butylene adipate) random copolymers (PBSA) were prepared by melt polycondensation in a wide composition range. Polarized light optical microscopy (PLOM) was employed to observe their superstructural morphology while their thermal and structural properties were studied by differential scanning calorimetry (DSC) and in situ synchrotron Xray diffraction at wide and small angles (WAXS and SAXS). The morphological study revealed negative spherulitic superstructures with (PBS-rich) and without (PBA-rich) ring band patterns depending on composition. The crystallization temperature, melting temperature, and related enthalpies display a pseudoeutectic behavior as a function of composition. WAXS studies demonstrated that these random copolymers are isodimorphic, as their unit cell parameters are composition dependent and switch from PBS-like unit cells to β-PBA-like unit cells around the pseudoeutectic point. For PBA-rich compositions, the inclusion of butylene succinate units in the copolymer selectively promotes the formation of the orthorhombic β-polymorph, instead of the commonly observed monoclinic α-structure. The pseudoeutectic point is located around the 50:50 and 40:60 compositions and is characterized by a remarkable rate-dependent cocrystallization. Parallel DSC, SAXS, and WAXS results for these intermediate compositions show that depending on the cooling rate employed, the materials can exhibit single-or double-crystalline character either upon cooling or during subsequent heating. The structure, morphology, and properties of these versatile random copolymers can be tailored by composition and thermal history.

Crystallization of isodimorphic aliphatic random copolyesters: Pseudo-eutectic behavior and double-crystalline materials

“…Deviations from the linear dependence [19,23,25,28] are typically described according to Fox [29] and Gordon-Taylor [30] equations.…”

Influence of soft block crystallization on microstructural variation of double crystalline poly(ether‐ mb ‐amide) multiblock copolymers

“…The crystallization behavior of poly(butylene succinate‐ ran ‐butylene adipate) (PBSA) random copolymer shows a similar composition‐dependent behavior with PBS‐ ran ‐PBAz. PBSA samples can display single or double crystalline character depending not only on the composition but also on the thermal treatment …”

“…PBSA samples can display single or double crystalline character depending not only on the composition but also on the thermal treatment. [69] Meanwhile, in-situ SAXS characterization was applied to a PA1012 homopolymer under the same protocol, and the FIGURE 4 A, In-situ FTIR spectra for sample A 960 G 3000 during the cooling process and B, the integral area ratio of the four characteristic bands during cooling (data normalized by the band at 2860 cm −1 )…”

Biotic and Abiotic Synthesis of Renewable Aliphatic Polyesters from Short Building Blocks Obtained from Biotechnology

“…[57,76] Interestingly,P BSA degrades faster than PBS due to the lower crystallinity of PBSA and the adipate moieties, which degrade faster than those of succinate. [57,76] Interestingly,P BSA degrades faster than PBS due to the lower crystallinity of PBSA and the adipate moieties, which degrade faster than those of succinate.…”

“…PBSA is aw ell-known copolyester of PBS,w hich is prepared through the addition of AA to the source materials of PBS. [57,76] Interestingly,P BSA degrades faster than PBS due to the lower crystallinity of PBSA and the adipate moieties, which degrade faster than those of succinate. [77,78] Comparedw ith PBS, PBSA has al ower crystallinity and is thus better suited for film applications.…”