Assessment of Ball Milling as a Compounding Technique to Develop Nanocomposites of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) and Bacterial Cellulose Nanowhiskers

Abstract

The aim of this study was the assessment of high energy ball milling technique to develop poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanocomposites containing bacterial cellulose nanowhiskers (BCNW). Crystallization behaviour of PHBV/BCNW nanocomposites was studied under non-isothermal and isothermal conditions using differential scanning calorimetry (DSC). The changes in PHBV crystalline structure were also studied using X-ray diffraction. The results confirmed that BCNW acted as nucleating agents and, hence, favored the crystallization of the PHBV. The oxygen permeability of the nanocomposites was reduced by ~22% when compared to that of the neat PHBV. This work provides a new insight into the development of polyhydroxyalkanoate (PHA) composites by means of the high energy ball milling technique.

Antimicrobial nanocomposites and electrospun coatings based on poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) and copper oxide nanoparticles for active packaging and coating applications

“…Thus, when CuO nanoparticles were directly added in the melt‐mixing process, the DSC curves of the first heating scan showed two distinguishable melting peaks, which occurred between 165 and 172 °C. Multiple melting peaks occurring during the DSC first heating scan of PHBV and PHBV containing metal nanoparticles have been previously interpreted as a result of a melting‐recrystallization process during the thermal run . Nevertheless, compared to the neat PHBVs, the active films prepared by melt compounding, that is, 0.1% and 0.05% films, did not present any significant difference in their melting enthalpy (Δ H m ) or crystallization temperature ( T c ) suggesting that the nanoparticles did not interfere with crystallization.…”

Biotechnological routes for the development of antimicrobial nano-metal based polyhydroxyalkanoates for active food packaging applications.

“…Table 1). These results are in good agreement with the existing literature [28,29,38,39]. In this regard, it is worth noting that some authors reported the appearance of Braggs reflections of the face-centered cubic crystal structure of silver located at 2θ= 37°, 44°, 64°, 78° and 82° and corresponding to the (111), (200), (220), (311) and (222) lattice plane [28,40].…”

“…followed by a melting shoulder (~ 183°C) during the first heating run, which was consistent with results published earlier [6,41]. Some authors hypothesized that the first melting peak corresponds to more defective or smaller crystals which are able to recrystallize during the run, thus forming more perfect crystals which subsequently melt at higher temperatures (second melting peak) [42].…”

“…5). The fringe spacing corresponds well with that of the (1 1 1) and (2 0 0) lattice spacing of Ag and suggests a face centered cubic structure (FCC) as (a=4.086Å) and in line with previous experimental reports [38,39]. For instance, Theivasanthi and Alagar reported similar crystalline structures using silver nanopowder made by electrolytic synthesis [40].…”

“…It is worth mentioning that crystallinity was seen to decrease in the silver loaded sample while a heat of fusion drop was not observed by DSC. Both techniques seldom match one another, since DSC is a dynamic measurement and it is well known that PHAs develop crystallinity during the actual DSC run [34,38,39]. …”