Water transport, structure features and mechanical behavior of biodegradable PHB/PVA blends

Abstract

Stochastic programming is a typical method for addressing the uncertainties in capacity expansion planning problem. However, the corresponding deterministic equivalent model is often intractable with considerable number of uncertainty scenarios especially for stochastic integer programming (SIP) based formulations. In this article, a hybrid solution framework consisting of augmented Lagrangian optimization and scenario decomposition algorithm is proposed to solve the SIP problem. The method divides the solution procedure into two phases, where traditional linearization based decomposition strategy and global optimization technique are applied to solve the relaxation problem successively. Using the proposed solution framework, a feasible solution of the original problem can be obtained after the first solution phase whereas the optimal solution is obtained after the second solution phase. The effectiveness of the proposed strategy is verified through a numerical example of two stage stochastic integer program and the capacity expansion planning examples. © 2011 American Institute of Chemical Engineers AIChE J, 2012

Gas transport and thermal characterization of mono‐ and di‐polyethylene films used for food packaging

“…3 Previous studies have shown that the sorption and diffusion phenomena took place exclusively in the amorphous phase of a semicrystalline polymer and not in its crystalline zones. 4,5 The crystalline portion increases the effective path length of gas diffusion, and they seem to reduce the polymer chains mobility in the amorphous phase (because chain ends are trapped in the neighboring crystalline lamellae).…”

Application of Poly(hydroxyalkanoate) In Food Packaging: Improvements by Nanotechnology

“…As a rule, blending has been known as a strategy of tailoring the properties of PHAs while maintaining biodegradability 67 . Blending of PHB and PHBV with other biopolymers including starch [89][90][91] , thermoplastic starch, PLA 92 , PCL 13,93,94 , and polyvinyl alcohol (PVOH) 91 are reported. In addition, there are some reports on PLA blending with different polymers e.g.…”

“…Besides, solubility and diffusivity of water in PHAs is a key factor for their degradation via enzymatic or non-enzymatic hydrolysis [120][121][122] . The water transport properties of PHB and PHBV films and their blends with other biodegradable polymers in different process conditions are reported 65,94,[115][116][117]120,121,[123][124][125] . PHAs can decrease the water sensitivity of other biopolymers 94 .…”

“…The water transport properties of PHB and PHBV films and their blends with other biodegradable polymers in different process conditions are reported 65,94,[115][116][117]120,121,[123][124][125] . PHAs can decrease the water sensitivity of other biopolymers 94 . PHAs shows suitable barrier properties against different organic solvents 115,116,126 and possess low oxygen and CO 2 permeability 65,77,[126][127][128][129] .…”

Visualization of Sorption Dynamics: Application of Confocal Laser Scanning Microscope Technique

“…The first factor was the effect of additives mixed with perylene. With respect to the diffusion of penetrant in polymer materials, free volume theory was proposed in 1960s 39 and recently, it has been generally thought that amorphous portion in polymer material is dominating diffusion pathway [40][41][42][43][44][45][46] . It was considered that with the diffusion of TEGDA or GTA, amorphous portion, i.e.…”