Synthesis, Structure, Crystallization and Mechanical Properties of Isodimorphic PBS-ran-PCL Copolyesters

Abstract

Isodimorphic behavior is determined by partial inclusion of comonomer segments within the crystalline structure and arises from the comparatively similar repeating chain units of the parental homopolymers. Isodimorphic random copolymers are able to crystallize irrespective of their composition and exhibit a pseudo-eutectic behavior when their melting point values are plotted as a function of comonomer content. At the pseudo-eutectic point or region, two crystalline phases can coexist. On the right-hand and the left-hand side of the pseudo-eutectic point or region, only one single crystalline phase can form which is very similar to the crystalline structures of the parent homopolymers. This article aims to study the synthesis method, structure, crystallization behavior and mechanical properties of isodimorphic random PBS-ran-PCL copolyesters. Moreover, this study provides a comprehensive analysis of our main recent results on PBS-ran-PCL random copolyesters with three different molecular weights. The results show that the comonomer composition and crystallization conditions are the major factors responsible for the crystalline morphology, crystallization kinetics and mechanical performance of isodimorphic random copolyesters. Our studies demonstrate that in the pseudo-eutectic region, where both crystalline phases can coexist, the crystallization conditions determine the crystalline phase or phases of the copolymer. The relationships between the comonomer composition and mechanical properties are also addressed in this work.

Poly(butylene succinate-co-ε-caprolactone) Copolyesters: Enzymatic Synthesis in Bulk and Thermal Properties

“…As can be observed, these parameters strongly depend on the copolymer composition. With respect to the pure homopolymers, the obtained values of T m and T g are close to the expected values found in the literature [29,32,33], with a deviation of at most 7%.…”

“…Copolymers show a typical Gordon-Taylor evolution with composition, where they have intermediate glass transition temperatures between the pure homopolymers (Figure S6 of Supplementary Information). A value of Gordon-Taylor parameter k = 0.46 is intermediate between the values of low molecular weights (k = 0.23) and high molecular weights (k = 0.63) PBSCL copolyesters are obtained [29]. Figure 9 shows the DSC traces of the copolyesters upon cooling (a) and heating (b).…”

“…One drawback is that the enzyme has to be removed from the final polymer in order to avoid its enzymatic degradation. In fact, CALB has been used for the synthesis of both polyesters (PBS and PCL) [24][25][26][27][28][29]. Although poly(butylene succinate-coε-caprolactone) (PBSCL) copolyesters have already been synthesized using organometallic catalyst [30][31][32], an attempt to produce them using enzymes by ring opening polymerization of CL and butylene succinate cyclic oligoesters provided low molecular weight copolymers, which could restrict their properties and consequently their applications [33].…”

A Review on Current Strategies for the Modulation of Thermomechanical, Barrier, and Biodegradation Properties of Poly (Butylene Succinate) (PBS) and Its Random Copolymers

“…It follows that a thorough investigation of the crystallinity behavior of PBS copolymers as a function of the comonomer composition is necessary to design PBS-based materials with the physical and biodegradation properties required for specific applications. In the current review, we summarize and quantitatively compare the results corresponding to PBS copolyesters synthesized in our group and other research groups to determine, on the one hand, the influence of different synthetic routes on the resulting molecular weight of PBS copolyesters and, on the other hand, the impact of the comonomer content on the crystallization behavior and resulting mechanical properties of the selected PBS copolyesters, including a series of biodegradable PBS-ran-PCL synthesized and characterized in our group [26]. Such analysis is extended to PBS composite films, for which the effect of the incorporation of the selected fillers on the mechanical and barrier properties is analyzed.…”

Rheology and Tack Properties of Biodegradable Isodimorphic Poly(butylene succinate)-Ran-Poly(ε-caprolactone) Random Copolyesters and Their Potential Use as Adhesives

“…Considering this, the combination of caprolactone and butyl succinate monomers to obtain random or block copolymers in the field of new materials has been contemplated in literature. In particular, our group has recently investigated the synthesis, thermal properties, and morphology of random PBS- ran -PCL copolyesters [ 19 , 20 , 21 , 22 , 23 , 24 ].…”