Effect of Thermocycling on the Properties of Goat Skin Leather

2011 ◽  
Vol 399-401 ◽  
pp. 1573-1576
Author(s):  
Xue Jing Zheng ◽  
Shu Hao Huo ◽  
Jie Liu ◽  
Kun Wang ◽  
Ke Yong Tang

The pickled goat skins were crosslinked by chromium, aluminum, wattle extract and chestnut extract, respectively. The samples were thermal treated in a container held at different temperature for 5 h for different cycles. The xerothermic stability, water vapor permeability and dimensional stability of the samples were characterized before and after thermal treatment. The effect of thermocycling on the properties of tanned samples was discussed. It was found that the thermocycling at moderate temperature (50 °C) exerted little influence on the xerothermic shrinkage temperature (Txs) of the tanned collagen fibers. The treatment at higher upper limit temperature (100 °C and 150 °C) decreases the Txs and results in an impaired thermal stability. The water vapor transmission rate was decreased after the thermal treatment, likely due to the reduction of the amount of hydrophilic groups of collagen macromolecules as well as the decrease of the pore ratio of leather. Treatment at high temperature damaged the dimensional stability of the specimens.

2020 ◽  
Vol 897 ◽  
pp. 30-34
Author(s):  
Yan Ngo Fan ◽  
Wen Yi Wang ◽  
Chi Wai Kan ◽  
Kamol Promlawan ◽  
Wasana Changmuong ◽  
...  

This study evaluated the quick dry properties of summer men’s sportswear T-shirts of different brands (Nike, Adidas, Laishilong and Columbia) by studying the water vapor transmission behavior. The results indicate that Laishilong was the best sample in terms of water vapor transmission rate, whereas Columbia was the poorest. Moreover, samples of Nike, Adidas, Laishilong and Columbia, had similar water vapor transmission rate. This implies that they had comparatively similar performance in water vapor permeability.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sunghyun Yoon ◽  
Minho Seok ◽  
Mookyum Kim ◽  
Young-Ho Cho

AbstractThe present research proposes the present porous polydimethylsiloxane (PDMS) layer for the skin trouble reduced daily life skin attachable devices. The present research proposes the new pores forming method in the PDMS by crystallization and dissolution of the citric acid in the PDMS for fabricating high uniform and small size pores. The present porous PDMS layer (i) decreases the pore size 93.2%p and increases the pore size uniformity 425%p compared to the conventional porous PDMS layer of mixing sugars and PDMS; (ii) is able to be fabricated in the thickness of 21–101 µm by spin-coating; (iii) has the 2.2 times higher water vapor transmission rate (947 ± 10.8 g/day•m2) compared to the human skin water vapor transmission rate. The present porous PDMS layer reduces the skin trouble effectively by having the high water vapor permeability, therefore is applicable to the human daily-life skin attachable devices.


Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 506 ◽  
Author(s):  
Dulce C. González Sandoval ◽  
Brenda Luna Sosa ◽  
Guillermo Cristian Guadalupe Martínez-Ávila ◽  
Humberto Rodríguez Fuentes ◽  
Victor H. Avendaño Abarca ◽  
...  

The consumption of organic products has increased in recent years. One of the most important products in Mexico is nopal. Nopal’s content and properties make the formulation of edible films possible. In this study, we aimed to develop and characterize biodegradable edible films containing mucilage from Opuntia ficus-indica. The mucilage extraction yield, thickness, color, water vapor permeability, light transmission rate, film transparency, solubility, stability of dispersion, and puncture strength were measured. The use of mucilage from different cultivars affected the water vapor permeability (8.40 × 10−11 g·m−1·s−1·Pa−1 for cultivar Villanueva, 3.48 × 10−11 g·m−1·s−1·Pa−1 for Jalpa, and 1.63 × 10−11 g·m−1·s−1·Pa−1 for Copena F1). Jalpa provided the most soluble mucilage with the highest thickness (0.105 mm). Copena F1 provided the clearest film with the greatest transparency (3.81), the best yellowness index, and the highest resistance (4.44 N·mm−1). Furthermore, this film had the best light transmission rate (48.93%). The Copena F1 showed the best film formation solution viscosity. These results indicate that mucilage mixed with pectin is a potential source for the formulation of edible films.


2018 ◽  
Vol 912 ◽  
pp. 136-140 ◽  
Author(s):  
Mayra Keroly Sales Monteiro ◽  
Francisco Klebson Gomes dos Santos ◽  
Ricardo Henrique de Lima Leite ◽  
Edna Maria Mendes Aroucha ◽  
Jussier Oliveira Vitoriano ◽  
...  

Bentonite clay was initially treated with a quaternary ammonium salt to increase its hydrophobicity, and then was dispersed in a gelatin matrix to serve as barrier to water vapor. The clays were characterized by IR spectroscopy in the infrared (FTIR), and X-ray diffraction (XRD), before and after ion exchange. The ion exchange held in the clay provokes on gelatin film a reduction of 65% in the water vapor permeability (WVP); a decrease in solubility of 55%; an increase of 35º in drop contact angle of water on the surface of the film; and 30% of raise in opacity.


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.


2021 ◽  
Author(s):  
Minho Seok ◽  
Sunghyun Yoon ◽  
Mookyum Kim ◽  
Young-Ho Cho

We present a porous polydimethylsiloxane (PDMS) pulsewave sensor with haircell structures that improves both water vapor transmission rate (WVTR) and signal-to-noise ratio (SNR).


Author(s):  
Réka Lilla Kovács ◽  
Lajos Daróczi ◽  
Péter Barkóczy ◽  
Eszter Baradács ◽  
Eszter Bakonyi ◽  
...  

AbstractIn this work, we evaluate the water vapor transmission rate (WVTR), the permeability (P), solubility (S), and diffusion (D) coefficients of Paraloid B44, Paraloid B72, and Incralac coatings in the temperature range of 5–35°C. The Arrhenius function—diffusion activation energy and preexponential factor—has also been determined from the data: $$D_{B44} = 35.2\;{\text{cm}}^{2} \;{\text{s}}^{ - 1} \exp \left( { - 25\;{\text{kJ mol}}^{ - 1} /{\text{RT}}} \right)$$ D B 44 = 35.2 cm 2 s - 1 exp - 25 kJ mol - 1 / RT ; $$D_{B72} = 9.5\;{\text{cm}}^{2} \;{\text{s}}^{ - 1} \exp \left( { - 23\;{\text{kJ mol}}^{ - 1} /{\text{RT}}} \right)$$ D B 72 = 9.5 cm 2 s - 1 exp - 23 kJ mol - 1 / RT ; $$D_{\text{Incralac}} = 622.8\;{\text{cm}}^{2} \;{\text{s}}^{ - 1} { \exp }\left( { - 28\;{\text{kJ mol}}^{ - 1} /{\text{RT}}} \right)$$ D Incralac = 622.8 cm 2 s - 1 exp - 28 kJ mol - 1 / RT . These resins are important coating materials, for example, for conservators to protect metallic artifacts, such as statues, against corrosion. Despite Paraloid B44 and B72 resins being considered as reference materials in conservation practice, that is, new coating materials (either water vapor retarders or transmitters) are often compared to them, there are no comprehensive data for the quantities describing the vapor permeability (P, S, D) of these materials. The measurements are based on the ISO cup-method using substrate/coating composite samples. The strength of this technique is that it can also be used when the coating is non-self-supporting; nevertheless, P, S, and D can be deduced for the coating layer itself, and it seems to be a standardizable procedure for comparative performance testing of coating materials. Paraloid B72 layers exhibited higher WVTRs—from 39 to 315 g m−2 day−1 as the temperature increased from 5 to 35°C—compared to Paraloid B44 and Incralac coatings—from 17 to 190 g m−2 day−1, respectively. The transmission rate parameters were also compared to the results of corrosion tests. Incralac was the most effective corrosion inhibitor, and the performance of the B44 was better than the B72, which is in good agreement with the transmission rate tests.


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