In Situ Copolyesters Containing Poly(l-lactide) and Poly(hydroxyalkanoate) Units

Abstract

In situ copolyesters containing polylactide (PLA) and polyhydroxyalkanoate (PHA) segments were obtained via ring-opening polymerization of L-lactide using PHA as a macroinitiator with stannous octoate as catalyst. Incorporation of PHA (20 wt %) into PLA affords a novel copolymer with Mn values ranging from 25 to 50 KDa and low polydispersities of 1.8-2.3. DSC analysis of the copolymer indicates well-defined crystallization and melting transitions different from the homopolymers and corresponding blend. The polymers were characterized by FT-IR, GPC, DSC, optical microscopy, NMR, and TGA. The results show successful reactivity of PHA as a macroinitiator for the ring-opening polymerization of lactide.

Lactate fraction dependent mechanical properties of semitransparent poly(lactate-co-3-hydroxybutyrate)s produced by control of lactyl-CoA monomer fluxes in recombinant Escherichia coli

“…However, the relatively poor impact and heat resistance of the material are considered to be a crucial weak point blocking a wider range of applications. Thus, PLAs are an active area of research into improving their properties, for example, by the addition of plasticizers, blending with other polymers, copolymerizations and various chemical modifications, as may be seen in the large number of reports and patents (Haynes et al, 2007;Noda et al, 2004;Ozkoc and Kemaloglu, 2009;Pillin et al, 2006;Younes and Cohn, 1988).…”

In vitro synthesis of polyhydroxyalkanoates using thermostable acetyl-CoA synthetase, CoA transferase, and PHA synthase from thermotorelant bacteria

“…Previous studies reported the synthesis of copolymers, containing LA and 3HA units, by the ring-opening copolymerization of (S,S)-lactide and (R)-b-butyrolactone and the ring-opening copolymerization of (S,S)-lactide using PHA as a macroinitiator. The synthesized copolymers have better properties than those of PLA homopolymer (16,17).…”

In vitro synthesis of polyhydroxyalkanoate (PHA) incorporating lactate (LA) with a block sequence by using a newly engineered thermostable PHA synthase from Pseudomonas sp. SG4502 with acquired LA-polymerizing activity

“…It is a very attractive material, but its application is limited in part due to its brittle properties, such as poor elongation, slow crystallization rate, and so on. One of the methods to improve the properties of PLA is copolymerization (Abe et al 1997;Haynes et al 2007) with another repeating unit. For example, Abe et al and Haynes et al (Abe et al 1997;Haynes et al 2007) reported the synthesis of copolymers containing LA and 3HA units by the ring-opening copolymerization of (S, S)-lactide with (R)--butyrolactone and by the ring-opening copolymerization of (S, S)-lactide using PHA as a macroinitiator.…”

“…One of the methods to improve the properties of PLA is copolymerization (Abe et al 1997;Haynes et al 2007) with another repeating unit. For example, Abe et al and Haynes et al (Abe et al 1997;Haynes et al 2007) reported the synthesis of copolymers containing LA and 3HA units by the ring-opening copolymerization of (S, S)-lactide with (R)--butyrolactone and by the ring-opening copolymerization of (S, S)-lactide using PHA as a macroinitiator. The synthesized copolymers had better properties than those of the PLA homopolymer (Abe et al 1997;Haynes et al 2007).…”