Studying On Oxygen Barrier,Free Volume And Miscibility Properties Of Fully Bio-based Polyamide 1010/Poly (Vinyl Alcohol) Blends And Their Active Packaging Properties

Fully bio-based polyamide 1010(PA1010)was successfully melt-blended with poly(vinyl alcohol)(PVA⁰³,PVA⁰⁵,PVA⁰⁸ and PVA¹⁴)to prepare PA1010_xPVA_y^zblends.The PA1010_xPVA⁰³_y,PA1010_xPVA⁰⁵_y,PA1010_xPVA_y⁰⁸ and PA1010_xPVA_y¹⁴films demonstrated the lowest oxygen transmission rates(OTR),free volume fraction(F_v),mean volume of the free volume holes(V_f)and mean number of free volume holes per unit volume(I₃)values,when the PVA concentration in each PA1010_xPVA_y^zseries reached a corresponding critical value of 22.5,20,17.5 and 12.5wt%,respectively.OTR,F_v,V_f and I₃ values obtained for the best PA1010_87.5PVA¹⁴_12.5,PA1010_82.5PVA⁰⁸_17.5,PA1010₈₀PVA₂₀⁰⁵ and PA1010_77.5PVA⁰³_2.25 films reduced gradually as the degree of polymerization of PVA reduced.The results of dynamical mechanical and other experimental characterizations demonstrated that PA1010 and PVA are compatible to some extent,when the PVA are?the corresponding critical concentration.The significantly enhanced oxygen permeation resistance and free volume characteristics for optimal PA1010_xPVA_y^z films is at least partly due to the improved hydrogen-bonded molecular interactions between PA1010 C=O groups and PVA O-H groups.The OTR values detected for the optimum fully bio-based PA1010_77.5PVA⁰³_22.5 films are even lower than those of petroleum-based PA/PVA or partially bio-based PA/PVA films reported in the literatures.Novel oxygen scavenger compounds(MFe_xANC_yZeo_0.5)composed of modified iron powder(MFe),activated nanocarbon(ANC),zeolite(Zeo)and sodium alginate were successfully prepared and displayed considerably enhanced deoxidization efficienncy in PE,PA1010 and PA1010_77.5PVA⁰³_22.5 sealed packagings.Lipid oxidation experiments of modeled food samples was used to evaluate the deoxidization efficiency of these oxygen scavenger compounds.A remarkable reduction of oxygen concentration in airtight conical flask from 21.2%to?0.5%was found after 100 hours oxygen depletion experiment for the airtight conical flask incorporated with the best oxygen scavenger compounds.While after 100 hours oxygen depletion with traditional oxygen scavenger compounds(e.g.modified iron powder/calcium chloride/zeolite compound),the residual oxygen concentrations in the airtight conical flask reduced merely from 21.2%to?4%?After 100 hours of lipid oxidation experiments,the modelled food samples in air filled PE,PA1010 and PA1010_77.5PVA⁰³_22.5 packagings were significantly oxidized.In which,the peroxide value(POV)of modeled food samples in air filled PE package increased to?24 after50 hours of lipid oxidation experiment.In contrast,the POV of modeled food samples in air filled PE,PA1010 and PA1010_77.5PVA⁰³_22.5 packagings with the most proper oxygen scavenger compound were significantly lower than those without oxygen scavenger compound,and remained at an unchannged value at 6,2.5 and 1.5,respectively,after?70 hours of lipid oxidation experiments.In addition,POV of modelled food samples in these packagings reduced considerably with the oxygen permeation resistance of plastic films.For example,POV of the modelled food samples in air filled PE,PA1010,PA1010_77.5PVA⁰³_22.5 packagings with or without MFe_20/0.8ANC₅Zeo₂ are?2.3/?27.4,?1.9/?15.9,and?1.1/?12.3,respectively,after100 hours of lipid oxidation experiments.While the POV of modelled food samples in nitrogen purged PE,PA1010,PA1010_77.5PVA⁰³_22.5 packagings with MFe_20/0.8ANC₅Zeo₂ oxygen scavenger compound are only?0.21,?0.09,and?0.02,respectively,after 100 hours of lipid oxidation experiments.These results revealed that MFe_20/0.8ANC₅Zeo₂ could serve as an effective oxygen scavenger compounds to prevent lipid oxidation for modelled food samples and PA1010_77.5PVA⁰³_22.5packagings with excellent oxygen permeation resistance could further prolong the shelf life of the modelled food samples.