Water Vapor Permeability and Mechanical Properties of Biodegradable Chitosan/Methoxy Poly(ethylene glycol)-b-Poly(ε-caprolactone) Nanocomposite Films

2008 ◽  
Vol 13 (3) ◽  
pp. 224-231 ◽  
Author(s):  
Supawut Khamhan ◽  
Yodthong Baimark ◽  
Sumalee Chaichanadee ◽  
Pranee Phinyocheep ◽  
Sumet Kittipoom
2021 ◽  
Vol 9 (8) ◽  
pp. 4679-4686
Author(s):  
Coby J. Clarke ◽  
Richard P. Matthews ◽  
Alex P. S. Brogan ◽  
Jason P. Hallett

Gels prepared from metal containing ionic liquids with cross-linked poly(ethylene glycol) have surface compositions and mechanical properties that can be controlled by Lewis basicity and acidity of the metal species.


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):  
Jie Liu ◽  
Yanchun Liu ◽  
Eleanor M. Brown ◽  
Zhengxin Ma ◽  
Cheng-Kung Liu

The leather industry generates considerable amounts of solid waste and raises many environmental concerns during its disposal. The presence of collagen in these wastes provides a potential protein source for the fabrication of bio-based value-added products. Herein, a novel composite film was fabricated by incorporating vegetable-tanned collagen fiber (VCF), a mechanically ground powder-like leather waste, into a chitosan matrix and crosslinked with genipin. The obtained composite film showed a compact structure and the hydrogen bonding interactions were confirmed by FTIR analysis, indicating a good compatibility between chitosan and VCF. The optical properties, water absorption capacity, thermal stability, water vapor permeability and mechanical properties of the composite films were characterized. The incorporation of VCF into chitosan led to significant decreases in opacity and solubility of the films. At the same time, the mechanical properties, water vapor permeability and thermal stability of the films were improved. The composite film exhibited antibacterial activity against food-borne pathogens. Results from this research indicated the potential of the genipin-crosslinked chitosan/VCF composites for applications in antimicrobial packaging. 


Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 384
Author(s):  
Juan Tirado-Gallegos ◽  
Paul Zamudio-Flores ◽  
José Ornelas-Paz ◽  
Claudio Rios-Velasco ◽  
Guadalupe Olivas Orozco ◽  
...  

Apple starch films were obtained from apples harvested at 60, 70, 80 and 90 days after full bloom (DAFB). Mechanical properties and water vapor permeability (WVP) were evaluated. The apple starch films at 70 DAFB presented higher values in the variables of tensile strength (8.12 MPa), elastic modulus (3.10 MPa) and lower values of water vapor permeability (6.77 × 10−11 g m−1 s−1 Pa−1) than apple starch films from apples harvested at 60, 80 and 90 DAFB. Therefore, these films were chosen to continue the study incorporating ellagic acid (EA). The EA was added at three concentrations [0.02% (FILM-EA0.02%), 0.05% (FILM-EA0.05%) and 0.1% (FILM-EA0.1%) w/w] and compared with the apple starch films without EA (FILM-Control). The films were characterized by their physicochemical, optical, morphological and mechanical properties. Their thermal stability and antioxidant capacity were also evaluated. The FILM-Control and FILM-EA0.02% showed a uniform surface, while FILM-EA0.05% and FILM-EA0.1% showed a rough surface and insoluble EA particles. Compared to FILM-Control, EA modified the values of tensile strength, elasticity modulus and elongation at break. The antioxidant capacity increased as EA concentration did. EA incorporation allowed obtaining films with higher antioxidant capacity, capable of blocking UV light with better mechanical properties than film without EA.


2020 ◽  
Vol 52 (5) ◽  
pp. 453-468
Author(s):  
Yong-Chan Chung ◽  
Ha Youn Kim ◽  
Jae Won Choi ◽  
Byoung Chul Chun

Graft polymerization of poly(ethylene glycol) methyl ether acrylate (PEGA) onto polyurethane (PU) was conducted to improve its water compatibility, tensile mechanical strength, shape memory, and low-temperature flexibility properties, as well as to control its water vapor permeability (WVP). Control PUs containing free poly(PEGA) were also prepared to compare with the poly(PEGA)-grafted PUs. The water compatibility of PU notably improved due to the grafting of poly(PEGA) based on water contact angle results. The soft segment melting temperature and glass transition temperature were not changed with the increase in the PEGA content. The tensile strength of PU sharply increased due to the grafting of poly(PEGA), whereas the free poly(PEGA) in the control PUs did not cause a similar increase. The maximum strain of PU was not affected by the grafting of poly(PEGA). The shape recovery at 0°C significantly increased compared with the unmodified PU. The low-temperature flexibility of PU improved, and the WVP through the PU membrane was reduced by the grafting of poly(PEGA) onto PU.


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