Recyclable nanocomposite foams of Poly(vinyl alcohol), clay and cellulose nanofibrils – Mechanical properties and flame retardancy

2019 ◽  
Vol 182 ◽  
pp. 107762 ◽  
Author(s):  
Lilian Medina ◽  
Federico Carosio ◽  
Lars A. Berglund
Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 691
Author(s):  
O. Sánchez-Aguinagalde ◽  
Ainhoa Lejardi ◽  
Emilio Meaurio ◽  
Rebeca Hernández ◽  
Carmen Mijangos ◽  
...  

Chitosan (CS) and poly (vinyl alcohol) (PVA) hydrogels, a polymeric system that shows a broad potential in biomedical applications, were developed. Despite the advantages they present, their mechanical properties are insufficient to support the loads that appear on the body. Thus, it was proposed to reinforce these gels with inorganic glass particles (BG) in order to improve mechanical properties and bioactivity and to see how this reinforcement affects levofloxacin drug release kinetics. Scanning electron microscopy (SEM), X-ray diffraction (XRD), swelling tests, rheology and drug release studies characterized the resulting hydrogels. The experimental results verified the bioactivity of these gels, showed an improvement of the mechanical properties and proved that the added bioactive glass does affect the release kinetics.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2104
Author(s):  
Sibusiso Alven ◽  
Blessing Atim Aderibigbe

The management of chronic wounds is challenging. The factors that impede wound healing include malnutrition, diseases (such as diabetes, cancer), and bacterial infection. Most of the presently utilized wound dressing materials suffer from severe limitations, including poor antibacterial and mechanical properties. Wound dressings formulated from the combination of biopolymers and synthetic polymers (i.e., poly (vinyl alcohol) or poly (ε-caprolactone) display interesting properties, including good biocompatibility, improved biodegradation, good mechanical properties and antimicrobial effects, promote tissue regeneration, etc. Formulation of these wound dressings via electrospinning technique is cost-effective, useful for uniform and continuous nanofibers with controllable pore structure, high porosity, excellent swelling capacity, good gaseous exchange, excellent cellular adhesion, and show a good capability to provide moisture and warmth environment for the accelerated wound healing process. Based on the above-mentioned outstanding properties of nanofibers and the unique properties of hybrid wound dressings prepared from poly (vinyl alcohol) and poly (ε-caprolactone), this review reports the in vitro and in vivo outcomes of the reported hybrid nanofibers.


2012 ◽  
Vol 602-604 ◽  
pp. 157-160
Author(s):  
Wei Min Kang ◽  
Jing Yan ◽  
Bo Wen Cheng

Polyurethane-poly (vinyl alcohol)/chitosan (PU-PVA/CS) blend nanofiber nonwovens were successfully prepared by coelectrospinning in this paper. The morphology, diameter and structure of the electrospun nanomaterials were examined by SEM and FITR, and their mechanical properties were tested. The diameter distribution of the nanofibers was measured by Image-Pro Plus. The results show that the ideal nanofibers with the diameter in 50-350 nm can be obtained with the proper technical parameters of PU and PVA/CS nanofibers as follows: the spinning voltage at 30 kV and 40 kV, the extruding speed at 6 mL/h and 0.5 ml/h, the collecting distance at 150 mm and 200 mm, respectively.


1990 ◽  
Vol 58 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Urushizaki Fumio ◽  
Yamaguchi Hiroshi ◽  
Nakamura Kumiko ◽  
Numajiri Sachihiko ◽  
Sugibayashi Kenji ◽  
...  

2021 ◽  
Author(s):  
Yanhong Jin ◽  
Yuanyuan Jing ◽  
Wenxin Hu ◽  
Jiaxian Lin ◽  
Yu Cheng ◽  
...  

Abstract Lignin has been used as a sustainable and eco-friendly filler in composite fibers. However, lignin aggregation occurred at high lignin content, which significantly hindered the further enhancement of fiber performance. The incorporation of graphene oxide (GO) enhanced the mechanical properties of the lignin/poly(vinyl alcohol) (PVA) fibers and affected their structure. With the GO content increasing from 0 to 0.2%, the tensile strength of 5% lignin/PVA fibers increased from 491 MPa to 631 MPa, and Young's modulus increased from 5.91 GPa to 6.61 GPa. GO reinforced 30% lignin/PVA fibers also showed the same trend. The tensile strength increased from 455 MPa to 553 MPa, and Young's modulus increased from 5.39 GPa to 7 GPa. The best mechanical performance was observed in PVA fibers containing 5% lignin and 0.2% GO, which had an average tensile strength of 631 MPa and a Young’s modulus of 6.61 GPa. The toughness values of these fibers are between 9.9-15.6 J/g, and the fibrillar and ductile fracture microstructure were observed. Structure analysis of fibers showed that GO reinforced 5% lignin/PVA fibers had higher crystallinity, and evidence of hydrogen bonding among GO, lignin, and PVA in the gel fibers was revealed. Further, water resistance and swelling behavior of composite PVA fibers were studied to further evidence the structure change of composite fibers.


2015 ◽  
Vol 19 (4) ◽  
pp. 1353-1356 ◽  
Author(s):  
Jiang-Hui Zhao ◽  
Lan Xu ◽  
Qixia Liu

Poly(vinyl alcohol) nanofibers were prepared by bubble electrospinning. After the ethanol post-treatment, poly(vinyl alcohol) nanofibers showed enhanced hydrophobicity with water contact angle change from 0 to 78.9?, and the break strength of poly(vinyl alcohol) nanofibers was dramatically improved from 8.23 MPa to 17.36 MPa. The facile strategy with improved hydrophobicity and mechanical properties of poly(vinyl alcohol) nanofibers will provide potential benefits for applications of this material, especially in filtration field.


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