Miscibility of block copolymers of poly(ε‐caprolactone) and poly(ethylene glycol) with poly(3‐hydroxybutyrate) as well as the compatibilizing effect of these copolymers in blends of poly(ε‐caprolactone) and poly(3‐hydroxybutyrate)

Abstract

Atactic poly(3-hydroxybutyrate) (a-PHB) and block copolymers of poly(ethylene glycol) (PEG) with poly(-caprolactone) (PCL-b-PEG) were synthesized through anionic polymerization and coordination polymerization, respectively. As demonstrated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) measurements, both chemosynthesized a-PHB and biosynthesized isotactic PHB (i-PHB) are miscible with the PEG segment phase of PCL-b-PEGs. However, there is no evidence showing miscibility between both PHBs and the PCL segment phase of the copolymer even though PCL has been block-copolymerized with PEG. Based on these results, PCL-b-PEG was added, as a compatibilizer, to both the PCL/a-PHB blends and the PCL i-PHB blends. The blend films were obtained through the evaporation of chloroform solutions of mixed components. Excitingly, the improvement in mechanical properties of PCL/PHB blends was achieved as anticipated initially upon the addition of PCL-b-PEG.

Biodegradable toughened polymers from renewable resources: blends of polyhydroxybutyrate with epoxidized natural rubber and maleated polybutadiene

“…Since natural rubber is completely amorphous, the only explanation of this behavior is that some PHB crystallites were affected by the rubber to form a different type of crystal due to some interaction between them. 29 When there are two types of crystals, it is possible for them to have different melting points. The DSC curves were also used to obtain the melting enthalpies of the PHB phases in the virgin polymer and the blend.…”

Degradation characteristics of poly(ϵ‐caprolactone)‐based copolymers and blends

“…The compatibilized blend was more hydrophilic than the uncompatibilized one. Shuai et al25 reported that the PEG segments in PEG‐PCL or PCL‐PEG‐PCL were miscible with another aliphatic polyester, poly(3‐hydroxybutyrate) (PHB), while the PCL segments of the copolymers are immiscible with PHB. On the basis of these results, PCL/PEG block copolymers were added as a compatibilizer to PCL/PHB blends.…”

Biodegradable compatibilized polymer blends for packaging applications: A literature review

“…The compatiblization of PLA/PCL blend with PCL‐ b ‐PEG copolymer showed improvement in mechanical performances. Similarly, PCL‐ b ‐PEG copolymer has been used as a compatibilizer in PCL/PHB blends to improve the compatibility . Choi et al .…”