Optimization of mechanical and color properties of polystyrene/nanoclay/nano ZnO based nanocomposite packaging sheet using response surface methodology

The Combined Effect of Nanoclay and alpha-tocopherol on Mechanical and Physical Properties of Polyethylene Active Packaging

“…In order to show the relationship effect of factors, i.e., nanoclay and α-TOC concentrations on color properties (L*, a*, b*) and OP, the 3D response surface plot were introduced as the function of two variables concentrations ( Figure 3). By increasing of C15A and α-TOC, the L* value decreases, while the L* value increases at high levels of α-TOC by increasing C15A (Figure 3a), similarly, a decrease in L* value with addition of nanoclays [32] was already reported in the literature. Based on the Duncan test (Table 4), increasing of α-TOC had an insignificant effect on a* value at all level of C15A.…”

Poly(ethylene terephthalate), Poly(butylene terephthalate), and Polystyrene Oligomers: Occurrence and Analysis in Food Contact Materials and Food

“…Nevertheless, even within a specific oligomeric series difference between oligomers exists, with a dimer or a trimer presenting different physical characteristics than their decamer counterparts. Not much data is available in the literature, but there are some works in the FCM field that reported significant differences in solubility, chemical behavior, intermolecular forces, and physical-chemical properties, among oligomers. − ,,, These differences may have implications for their chemical analysis. Different solubility properties make it difficult to find a common solvent to be used for simultaneous extraction of all the oligomers in a material (dimer and trimer vs heptamers and octamers, linear chain vs cyclic, etc. ). Different solubility also makes it difficult to find a solvent to prepare stock and working solutions with all oligomers (dimers soluble in common organic solvents, tetramers and hexamers requiring harsh solvents such as 1,1,1,3,3,3-hexafluoro-2-propanol). Precipitation during analysis with liquid chromatographic methods may occur due to different solubility behaviors. Response in detectors (such as a Mass Spectrometer; MS) varies immensely from oligomer to oligomer (low chain compared with high chain length). Some smaller and semi-volatile oligomers can be analyzed with gas chromatographic (GC) methods (PS oligomers, PET dimer and trimer), but bigger ones (less volatile) cannot (PET oligomers higher than trimer, PBT oligomers). Migration experiments need to be properly planned, as precipitation may occur after oligomers migrate to aqueous/ethanolic official food simulants. Migration and extraction experiments involving temperature also need to be carefully planned, as its use may have implications on the oligomers’ stability (conversion of oligomers, chain opening for the cyclic ones, hydrolysis, etc.…”

“…It possesses adequate durability and considerable mechanical strength during processing, which ended up promoting its use as packaging. Other advantages include its relatively low moisture absorption and transparency, and a relatively low production cost, which gave PS an advantage over other polymers for some applications (e.g., disposable ware). − …”

The Emergence of Edible and Food-Application Coatings for Food Packaging: A Review

“…The aromatic polymer synthesizes each styrene monomer to form a long polymer [ 18 ]. PS has become one of the most sought-after packaging materials in the food industry [ 19 ] due to its high thermal resistance, excellent moisture-barrier properties, low density, ease of production, and high affordability. The use of PS began to decline when the public realized that the toxic substances released during degradation could harm humans and the environment [ 20 , 21 ].…”