Thermal processing influence on mechanical, thermal, and biodegradation behavior in poly(β‐hydroxybutyrate)/poly(ε‐caprolactone) blends: A descriptive model

Abstract

Poly(β‐hydroxybutyrate) [PHB] is a biodegradable and biocompatible polymer produced by some bacteria genders. To improve mechanical properties, PHB has been blended with other polymers. Compression‐molded blends of PHB and poly(ε‐caprolactone) [PCL] (70/30 mass ratio) were cooled to room temperature following five different thermal treatments after molding at 180 °C. Blends processed with higher cooling rates were easier to biodegrade, nevertheless elongation at break and tensile strength decreased. Slower cooling kinetics and isothermal treatments increased perfection of crystals, as seen in differential scanning calorimetry and X‐ray diffraction and spherulites size. A descriptive model is proposed herein where thermal, biodegradation, tensile properties, and crystal features were related to cooling kinetics applied. It is proposed that properties of 70/30 (PHB/PCL) blends can be predetermined by an adequate control of thermal conditions during processing. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43569.

Reinforcing capability of cellulose nanocrystals obtained from pine cones in a biodegradable poly(3-hydroxybutyrate)/poly(ε-caprolactone) (PHB/PCL) thermoplastic blend

“…Therefore, the CNCs addition on the PHB75/PCL25 decreases the PHB crystallinity values as shown in DSC analysis. [54,56]. In general, after the addition of CNCs, no significant changes can be detected, being all the XRD spectra similar to those of the PHB75/PCL25 blend.…”

Plasticized poly(3‐hydroxybutyrate) with improved melt processing and balanced properties

“…Their verified biodegradability and biocompatibility, lack of immunogenic and carcinogenic effects, and lack of toxicity promote the use of PHAs in the biomedical field . Abundant literature has been published on new methods for improving the synthesis and characteristics of PHAs for the biomedical field and food packaging …”

“…PHB shows a high stiffness and crystallinity, similar to those of petroleum‐based polymers . Strong barriers for the wide application of PHB are its high brittleness, low crystallization rate, poor thermal stability, and narrow processing window . The thermal degradation of PHB during melt processing and the poor melt strength have been targeted as the main unsolved problems for the fabrication of biomedical devices or packages from PHB by injection or blow molding .…”

“…Copolymerization and the addition of polymeric or low‐molecular‐weight modifiers, plasticizers, nucleating agents, and various microfillers, and nanofillers have been tested in efforts to overcome these drawbacks . For example, poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) copolymer shows a better flexibility and lower melt‐processing temperature but poorer mechanical properties and lower thermal stability than PHB.…”

Recent Advances on Fabrication of Polymeric Composites Based on Multicomponent Reactions for Bioimaging and Environmental Pollutant Removal

“…The AIE‐active polymer based on the block copolymer PEG‐PCL prepared by microwave‐assisted KF reaction not only exhibits excellent biocompatibility but also exhibits high degradability due to the degradation of PCL into small molecules by lipases hydrolysis and further assimilated by microorganisms. [ 124–126 ] Therefore, PCL was selected as optimal reagent to be copolymerized with PEG through ring‐opening reaction. It is worth mentioning that, compared with RAFT polymerization, the strategy that combines ring‐opening polymerization and esterification reaction can create various fluorescent polymers with excellent structures and performances.…”