scholarly journals WATER SORPTION AND WATER VAPOR PERMEABILITY OF NYLON 4

1973 ◽  
Vol 29 (7) ◽  
pp. T285-T289
Author(s):  
Hiroski Okada ◽  
Kazuyoshi Ueno ◽  
Akira Takizawa
LWT ◽  
2006 ◽  
Vol 39 (3) ◽  
pp. 292-301 ◽  
Author(s):  
Sílvia Maria Martelli ◽  
Geovana Moore ◽  
Sabrina Silva Paes ◽  
Cristhiane Gandolfo ◽  
João Borges Laurindo

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2279
Author(s):  
Darrel S. Naidu ◽  
Maya J. John

In this study, xylan–alginate-based films were reinforced with nanoclays (bentonite or halloysite) by the solvent casting technique. The effect of the nanoclay loadings (1–5 wt %) on various properties—mechanical, optical, thermal, solubility, water sorption, and water vapor permeability (WVP)—of the xylan–alginate films were examined for their application as food packaging materials. A 5 wt % loading of either bentonite or halloysite resulted in a 49% decrease of the WVP due to the impermeable nature of the silicate layers that make up both bentonite and halloysite. Thermal stability and solubility of the nanocomposite films were not significantly influenced by the presence of the nanoclays, whereas the optical properties were significantly improved when compared to neat xylan–alginate blend. In general, films reinforced with bentonite exhibited superior mechanical and optical properties when compared to both halloysite-based nanocomposite and neat films.


Author(s):  
Miguel Salvador- Figueroa ◽  
Dafne Castillo- López ◽  
Lourdes Adriano- Anaya ◽  
Didiana Gálvez- López ◽  
Raymundo Rosas- Quijano ◽  
...  

The main objectives of this study were; first formulate and evaluate some properties of chitosan composite films enriched with essential oils of cinnamon, thyme, clove, and lime alone or in combination; and second select the most appropriate formulation and evaluate their effect on physiological properties and fungal incidence of papaya Maradol stored at environmental tropical conditions. Breaking strength, thickness, color, moisture, water vapor permeability, solubility and water sorption of films were measured. Furthermore, in vitro activity was evaluated against Colletotrichum gloeosporioides Penz. Using multivariate analysis and based on the most desirable characteristics (low water sorption values, water vapor permeability, solubility, and greater inhibition of C. gloeosporioides), three formulations of films were used lately for coated fruit of papaya Maradol and stored at 28 ± 2 °C and 85 % RH. Two control treatments were included: one uncoated and other treated with Mancozeb® fungicide. At six days of storage, the fruit of both control treatments showed evident signs of ripening; contrary to the treatments wherein fruit were coated, and had low respiration, other attributes as firmness, little change in the external color of the fruit were manifested. Similarly, the use of composite films reduced the fungus C. gloeosporioides by 30-50 %. The use of film enriched with essential oil of 1 % cinnamon- 1 % thyme improved the characteristics of fruit quality, increased shelf life and reduced by 50 % the incidence of fungus in papaya Maradol stored under humid tropic environmental conditions. This coating can be an alternative to potentially reduce the need for cold storage during postharvest handling.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jinshu Liu ◽  
Xiaoyan Ma ◽  
Wenzhao Shi ◽  
Jianwei Xing ◽  
Chaoqun Ma ◽  
...  

Abstract Baicalin, an active flavonoid ingredient of Scutellaria baicalensis Georgi, was extracted by heat reflux extraction and showed the same significance UV absorption property with standard baicalin. Active films were prepared from polyvinyl alcohol (PVA) containing baicalin extract by casting method. The effect of baicalin extracts on the UV-blocking, optical, antioxidant property, water vapor permeability, swelling and mechanical properties of the films were studied. UV–vis transmittance spectra showed that PVA films incorporated with baicalin extract blocked ultraviolet light range from 280–400 nm even with low concentration of baicalin (0.5 wt%) and maintain the high transparency in visible spectrum. The outstanding UV-blocking properties of PVA films incorporated with baicalin extract were also confirmed by Rhodamine B degradation. Baicalin conferred antioxidant properties to PVA films as determined by DPPH radical scavenging activity. Due to the interaction between hydroxy groups of baicalin and PVA molecule, water vapor permeability, swelling and elongation at break of the films were decreased accompanied with the increasing in tensile strength and Young’s modulus. FTIR reveal that the interaction between PVA molecules was significant changed by the introduction of baicalin. These results suggest that PVA film incorporated with baicalin extract can be used for the development of functional protective film.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 602
Author(s):  
Carmen Rodica Pop ◽  
Teodora Emilia Coldea ◽  
Liana Claudia Salanţă ◽  
Alina Lăcrămioara Nistor ◽  
Andrei Borşa ◽  
...  

Kefiran is an exopolysaccharide classified as a heteropolysaccharide comprising glucose and galactose in equimolar quantities, and it is classified as a water-soluble glucogalactan. This work aimed to investigate the effect of different extraction conditions of kefiran on the structural and physical properties of the edible films obtained. Fourier-transform infrared spectroscopy and scanning electron microscopy were performed, together with a determinations of moisture content, solubility, water vapor permeability and degree of swelling. The kefiran films presented values of the water vapor permeability between 0.93 and 4.38 × 10−11 g/m.s.Pa. These results can be attributed to the development of a more compact structure, where glycerol had no power to increase the free volume and the water vapor diffusion through their structure. The possible conformational changes in the kefiran film structure, due to the interspersing of the plasticizers and water molecules that they absorb, could be the reason for producing flexible kefiran films in the case of using glycerol as a plasticizer at 7.5% w/w. Moreover, it was observed that the extraction conditions are a significant factor in the properties of these films and their food technology applications.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3090
Author(s):  
Anita Ptiček Siročić ◽  
Ana Rešček ◽  
Zvonimir Katančić ◽  
Zlata Hrnjak-Murgić

The studied samples were prepared from polyethylene (PE) polymer which was coated with modified polycaprolactone (PCL) film in order to obtain bilayer films. Thin PCL film was modified with casein/aluminum oxide compound to enhance vapor permeability as well as mechanical and thermal properties of PE/PCL films. Casein/aluminum oxide modifiers were used in order to achieve some functional properties of polymer film that can be used in various applications, e.g., reduction of water vapor permeability (WVTR) and good mechanical and thermal properties. Significant improvement was observed in mechanical properties, especially in tensile strength as well as in water vapor values. Samples prepared with aluminum oxide particles indicated significantly lower values up to 60%, and samples that were prepared with casein and 5% Al2O3 showed the lowest WVTR value.


Author(s):  
Grégoire David ◽  
Laurent Heux ◽  
Stéphanie Pradeau ◽  
Nathalie Gontard ◽  
Hélène Angellier-Coussy

Abstract This paper aims at investigating the potential of vine shoots (ViSh) upcycling as fillers in novel poly(3-hydroxybutyrate-3-hydroxyvalerate) (PHBV) based biocomposites. ViSh particles of around 50 µm (apparent median diameter) were obtained combining dry grinding processes, and mixed with PHBV using melt extrusion. Thermal stability and elongation at break of biocomposites were reduced with increasing contents of ViSh particles (10, 20 and 30 wt%), while Young’s modulus and water vapor permeability were increased. It was shown that a surface gas-phase esterification allowed to significantly increase the hydrophobicity of ViSh particles (increase of water contact angles from 59° to 114°), leading to a reduction of 27% in the water vapor permeability of the biocomposite filled with 30 wt% of ViSh. The overall mechanical performance was not impacted by gas-phase esterification, demonstrating that the interfacial adhesion between the virgin ViSh particles and the PHBV matrix was already good and that such filler surface treatment was not required in that case. It was concluded that ViSh particles can be interestingly used as low cost fillers in PHBV-based biocomposites to decrease the overall cost of materials.


2009 ◽  
Vol 4 (3) ◽  
pp. 442-449 ◽  
Author(s):  
Yuhua Zhang ◽  
Masatoshi Ishida ◽  
Yutaka Kazoe ◽  
Yohei Sato ◽  
Norihisa Miki

2018 ◽  
Vol 105 ◽  
pp. 637-644 ◽  
Author(s):  
M.K.S. Monteiro ◽  
V.R.L. Oliveira ◽  
F.K.G. Santos ◽  
E.L. Barros Neto ◽  
R.H.L. Leite ◽  
...  

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