Structural Effects upon Enzymatic Hydrolysis of Poly(butylene succinate-co-ethylene succinate)s

Abstract

High molecular weight poly(butylene succinate-co-ethylene succinate)s, P(BS-co-ES)s, were obtained from succinic acid, 1,4-butanediol, and/or ethylene glycol through a polycondensation process. Enzymatic hydrolysis of hot-pressed copolyester films was carried out by utilizing lipases derived from a wide variety of microorganisms. The formation of water-soluble total organic carbon (TOC) was monitored to determine the effect of structure upon enzymatic degradability. The P(BS-co-ES) copolyester containing approximately 53 mol % ES exhibited a minimum in systemic crystallinity and a maximum in enzymatic degradation. These results suggest that the degree of crystallinity may be the dominant influence upon the rate of degradation. Furthermore, it appears that the sequence distribution of BS and ES subunits has little effect upon lipase activity.

Preferential Incorporation of Azelaic Acid Units into the Crystalline Phase of the Copoly(Alkylene Dicarboxylate) Derived from 1,9-Nonanediol and an Equimolar Mixture of Pimelic and Azelaic Acids

“…Although melt crystallization of random poly(alkylene dicarboxylate)s have been extensively studied in recent years [16][17][18][19][20][21][22], this is the first time to our knowledge that single crystal morphology of such random copolymers has been evaluated. Figure 4a clearly shows pseudohexagonal lamellae of COPES 9,7/9 with identical morphology and dimensions to those crystals corresponding to the two homopolyesters that are shown in Figures 2c and 3a.…”

“…Incorporation of comonomers has a great influence on the thermal and mechanical properties, sample crystallinity, and both hydrolitic and enzymatic degradability [14][15][16]. Noticeable studies refer to random copoly(alkylene dicarboxylate)s constituted by even units, and specifically representative examples are poly(butylene succinate-co-ethylene succinate) [17], poly(hexamethylene succinate-co-hexamethylene adipate) [18], poly(hexamethylene sebacate-co-hexamethylene adipate) [19,20], and poly(hexamethylene suberate-co-hexamethylene adipate) [21].…”

Effects of Geometrical Difference of Unsaturated Aliphatic Polyesters on Their Biodegradability II. Isomerization of Poly(maleic anhydride-co-propylene oxide) inthe Presence of Morpholine

“…There are many articles in which the effect of crystallinity of the sample on its biodegradability was pointed out. 17,18 Generally speaking, highly crystalline polyester samples tend to inhibit their smooth degradation by microorganisms, regardless of its chemical structure. It was already noted that rising-up of T g was observed as increasing of the E-configuration fraction (Table I).…”

Study on the crystallization of poly(alkylene dicarboxylate)s derived from 1,9-nonanediol and mixtures with different ratios of azelaic acid and pimelic acid units

“…This could occur in the isomorphic co-crystallization where only one crystalline phase containing both crystalline units is developed and in the isodimorphic crystallization when at least one of the two crystalline phases incorporates the corresponding minor component in its crystalline lattice. Several works have recently addressed the isomorphic crystallization of copoly(alkylene dicarboxylate)s, which were mainly constituted by even units, such as poly(butylene succinate-co-ethylene succinate) [28], poly(butylene succinate-copropylene succinate) [29], poly(hexamethylene succinate-co-hexamethylene adipate) [30], poly(hexamethylene sebacate-co-hexamethylene adipate) [31,32], poly(hexamethylene sebacate-co-hexamethylene suberate) [33] and poly(hexamethylene suberate-co-hexamethylene adipate) [33]. Results pointed out that isomorphism was feasible and that a smaller difference between the chemical structure of comonomer units led to less free energy to incorporate foreign units and to a higher extent of comonomer unit inclusion in the host crystalline lattice [33].…”