PHA/Clay Nano-Biocomposites

Abstract

Polyhydroxyalkanoates or PHAs were first observed in a laboratory in France in the 1920s and, since then, their creation as a form of energy storage in bacteria as well as their practical uses have been much studied. There has been increased interest in commercial production of PHAs in recent times and, over the past 10 years in particular, there have been various reports on solution-cast or melt-processed PHA/clay nano-biocomposites and their properties. In most studies, these nano-biocomposites exhibit intercalated or mixed exfoliated/intercalated morphologies. The use of plate-like clays as additives can lead to some enhancement in the mechanical and gas barrier properties of PHAs as well as increased thermal stability, although the effects depend significantly on clay type, clay organomodifer and process conditions. The influence of clay addition on PHA biodegradability has been either positive or negative according to the particular study. There has been very little research to date on the migration properties of PHA in the context of use in packaging and none yet in which PHA/clay nano-biocomposites have been the focus. If economic and technical challenges can be solved, PHAs should have a promising future in various uses ranging from packaging through to medicine and PHA/clay nano-biocomposites may also play a role in the future by providing a way for PHA material properties to be tuned according to the particular need.

Birch Tar Introduced into Polylactide and Its Influence on the Barrier, Thermal, Functional and Biological Properties of the Film Obtained by Industrial Extrusion

“…For PLA samples, the values were two times higher than those obtained in the present study. Plackett [ 35 ] analyzed the water vapor permeability of PLA (at 23 °C and 0–50% RH), as well as the oxygen and carbon dioxide permeabilities (at 23–38 °C and 50–90% RH) [ 35 ]. The obtained results differed from those presented in this paper, but all the results were expressed in a unit other than that indicated by the standard [ 26 , 27 , 28 , 29 ], i.e., the documents according to which the water vapor permeability analyses were conducted and presented in the present study.…”

“…This difference could also be the result of the thickness of the tested films. Moreover, Plackett [ 35 ] clearly indicated that the obtained P V , P O and P D values should be treated only as indicative, pointing out that the results of water vapor or gas permeability depend on various factors, such as the molecular weight of the polymer, crystallinity and test conditions.…”

Incorporation of Active Components in Biopolymer-Based Films for Food Use

“…In order to compare the effect of the film processing and storage conditions, and the effect of the active compounds incorporation on the matrices, the results have been bring together taking into account the different chapters of the thesis, as described in Table 1. (Cho et al, 1998;Shudesh et al, 2000;Plackett, 2012). Chapter 1.I and 1.II (dark blue for CH-based films), Chapter 2.IV, Chapter 2.V.…”

“…On the other hand, pea starch-based films obtained by casting and thermo-processed starch-based films showed similar TS and EM values than some commercial LDPE plastic, as can be observed in Figure 1. (Cho et al, 1998;Shudesh et al, 2000;Plackett, 2012). Chapter 1.I and 1.II (dark blue for CH-based films), Chapter 2.IV, Chapter 2.V.…”

“…In the casted starch films, the water barrier effect was influenced by the hydrophilic/hydrophobic ratio of the film (and microparticles) constituents. (Plackett, 2012). Chapter 1.I and 1.II (dark blue for CH-based films), Chapter 2.V, Chapter 2.IV.…”