Deliberately Designed Processes to Physically Tether the Carboxyl Groups of Poly(pentacosadiynoic acid) to a Poly(vinyl alcohol) Glassy Matrix to Make Poly(pentacosadiynoic acid) Thermochromically Reversible in the Matrix

Langmuir ◽  
2011 ◽  
Vol 27 (11) ◽  
pp. 6651-6660 ◽  
Author(s):  
Juan Guo ◽  
Lei Zhu ◽  
Ming Jiang ◽  
Daoyong Chen
Keyword(s):  
Vinyl Alcohol ◽  
Carboxyl Groups ◽  
Glassy Matrix ◽  
Poly Vinyl Alcohol ◽  
The Matrix

Entrapment of ethyl vanillin in calcium alginate and calcium alginate/poly(vinyl alcohol) beads

2013 ◽  
Vol 67 (2) ◽  
Author(s):  
Steva Levic ◽  
Verica Djordjevic ◽  
Nevenka Rajic ◽  
Milan Milivojevic ◽  
Branko Bugarski ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Calcium Alginate ◽  
Poly Vinyl Alcohol ◽  
Gel Formation ◽  
Ftir Analysis ◽  
Ethyl Vanillin ◽  
Freeze Thaw ◽  
Thermal Gravimetry ◽  
The Matrix ◽  
Cross Linker

AbstractElectrostatic extrusion was applied to the encapsulation of 3-ethoxy-4-hydroxybenzaldehyde (ethyl vanillin) in calcium alginate and calcium alginate/poly(vinyl alcohol) beads. The calcium alginate/poly(vinyl alcohol) hydrogel spheres were formed after contact with the cross-linker solution of calcium chloride, followed by the freeze-thaw method for poly(vinyl alcohol) gel formation. The entrapment of aroma in beads was investigated by FTIR and thermal analysis (thermogravimetry/differential thermal gravimetry; TGA/DTG). The mass loss in the temperature range of 150–300°C is related to degradation of the matrix and the release of ethyl vanillin. According to the DTG curve, the release of ethyl vanillin occurs at about 260°C. TGA measurements of the stored samples confirmed that formulations were stable for a period of one month. FTIR analysis provides no evidence for chemical interactions between flavour and alginate that would alter the nature of the functional groups in the flavour compound.

scholarly journals Effect of Microfibrillated Cellulose on Microstructure and Properties of Poly(vinyl alcohol) Foams

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 813 ◽  
Author(s):  
Gennaro Gentile ◽  
Mariacristina Cocca ◽  
Roberto Avolio ◽  
Maria Errico ◽  
Maurizio Avella
Keyword(s):  
Vinyl Alcohol ◽  
Cell Shape ◽  
High Speed ◽  
Microfibrillated Cellulose ◽  
Poly Vinyl Alcohol ◽  
Infrared Analysis ◽  
Cellulose Content ◽  
Scanning Calorimetry ◽  
Hydrogen Bond Interaction ◽  
The Matrix

Poly(vinyl alcohol) foams, containing different amounts of microfibrillated cellulose, were prepared through an eco-friendly procedure based on high-speed mixing and freeze-drying. The effect of filler amount on cell shape and regularity was studied by scanning electron microscopy (SEM) and the evolution of the microstructure was assessed through dynamic cryo-SEM. Fourier Transformed Infrared Analysis and Differential Scanning Calorimetry measurements revealed the presence of hydrogen bond interaction among cellulosic filler and the matrix. The modulus and compression deflection of neat PVA were significantly improved by increasing the amount of microfibrillated cellulose content with respect to foams realised with pulp cellulose fibers.

Preparation of cross-linked poly(vinyl alcohol) films from copolymers with benzoxaborole and carboxylic acid groups, and their degradability in an oxidizing environment

2020 ◽  
Vol 11 (14) ◽  
pp. 2469-2474
Author(s):  
Nao Hakuto ◽  
Katsuya Saito ◽  
Masayuki Kirihara ◽  
Yohei Kotsuchibashi
Keyword(s):  
Carboxylic Acid ◽  
Vinyl Alcohol ◽  
Carboxyl Groups ◽  
Poly Vinyl Alcohol ◽  
Carboxylic Acid Groups

Functionalized PVA films were prepared from copolymers with benzoxaborole and carboxyl groups.

Characterization of cellulose nanocrystals extracted from El Diss and El Retma local plants and their dispersion in poly(vinyl alcohol-co-ethylene) matrix in the presence of borax

2020 ◽  
pp. 096739112091087
Author(s):  
Lilia Benchikh ◽  
Abdelhafid Merzouki ◽  
Yves Grohens ◽  
Melia Guessoum ◽  
Isabelle Pillin
Keyword(s):  
Water Absorption ◽  
North Africa ◽  
Cellulose Nanocrystals ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
The Matrix ◽  
Dsc Analyses ◽  
Local Plants

This study aims to investigate the potential of two local fibers, namely El Diss and El Retma, which are abundant in the mountains of North Africa (Sétif, Algeria), to provide cellulose nanocrystals (CNCs). Then, the isolated CNCs from El Diss were used as a reinforcement for a poly(vinyl alcohol-co-ethylene) matrix (EVOH) in the absence and in the presence of borax which was added to improve the interactions between the CNCs and the matrix. The extracted CNCs from both El Diss (CNCD) and El Retma (CNCR) were characterized by Zeta-sizer analysis using dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electronic microscopy. Also, untreated EVOH/CNCD nanocomposites and borax-treated EVOH/CNCD/BOR have been characterized using FTIR, differential scanning calorimetry (DSC) analyses, and by the study of their water absorption behavior. The DLS analysis provided the transversal length of the particles and showed that the surface of the obtained CNCs is negatively charged due to the presence of sulfated ions. Also, FTIR results confirmed the elimination of extra cellulosic substances, whereas TGA proved that the degradation of CNCs occurs at relatively lower temperatures compared with the neat fibers. The incorporation of borax to EVOH/CNCD nanocomposites showed its efficiency in improving the interactions at the interface between EVOH and the CNCD, which significantly affected the material’s thermal properties as concluded from DSC results and their water absorption behavior.

scholarly journals Characterization of Lignocellulosic Fibers Reinforced with Poly(vinyl alcohol)

2021 ◽  
Vol 6 (1) ◽  
pp. 6-15
Author(s):  
Manasa V Anand ◽  
◽  
R Ravishankar ◽  
Kiran S Vasist ◽  
Madhu H N ◽  
...  
Keyword(s):  
Environmental Sustainability ◽  
Vinyl Alcohol ◽  
Food Packaging ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Poly Vinyl Alcohol ◽  
Crystalline Cellulose ◽  
Uniform Dispersion ◽  
The Matrix ◽  
Biocomposite Film

The demands for materials made of plastics are rapidly increasing, especially in food packaging application. Recently, attention has been drawn to the use of bio-reinforced composites in packaging, automotive, medical and construction applications due to increased concern for environmental sustainability. Poly(vinyl alcohol) (PVA) films reinforced with crystals (unbleached) prepared by solution casting method possessed significantly improved properties compared to film reinforced with cellulose (bleached). From the results, PVA films with the addition of 4% (w/w) of crystalline cellulose exhibited best combination of properties. In addition to good mechanical properties, this composite has good water resistance and biodegradability. The water absorption of biocomposite was found to be 22.63%. From X - ray diffraction (XRD) analysis, diffraction peaks of biocomposite was observed at 2θ = 22.4384. From scanning electron microscopy (SEM) analysis it was found that fractures at surfaces of biocomposite film were smooth and even without any porosity and uniform dispersion of jute crystals in the matrix.

scholarly journals Evaluation of Acetaminophen Release from Biodegradable Poly (Vinyl Alcohol) (PVA) and Nanocellulose Films Using a Multiphase Release Mechanism

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 301 ◽  
Author(s):  
Kelsey L. O’Donnell ◽  
Gloria S. Oporto-Velásquez ◽  
Noelle Comolli
Keyword(s):  
Vinyl Alcohol ◽  
Controlled Drug Release ◽  
Poly Vinyl Alcohol ◽  
Release Mechanism ◽  
Burst Release ◽  
Release Drug ◽  
Therapeutic Value ◽  
The Matrix ◽  
Biodegradable Poly ◽  
Model Drug

Biodegradable polymers hold great therapeutic value, especially through the addition of additives for controlled drug release. Nanocellulose has shown promise in drug delivery, yet usually requires chemical crosslinking with harsh acids and solvents. Nanocellulose fibrils (NFCs) and 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO)-mediated oxidized nanocellulose fibrils (TNFCs) with poly (vinyl alcohol) (PVA) could be aqueously formulated to control the release of model drug acetaminophen over 144 h. The release was evaluated with a multiphase release mechanism to determine which mechanism(s) contribute to the overall release and to what degree. Doing so indicated that the TNFCs in PVA control the release of acetaminophen more than NFCs in PVA. Modeling showed that this release was mostly due to burst release—drug coming off the immediate surface, rather than diffusing out of the matrix.

High modulus poly (vinyl alcohol) fibers by zone drawing

1986 ◽  
Vol 1 (6) ◽  
pp. 861-869 ◽  
Author(s):  
Paul D. Garrett ◽  
David T. Grubb
Keyword(s):  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
High Modulus

BIODEGRADATION BEHAVIOR OF POLY(VINYL ALCOHOL) - WOOD COMPOSITES

2019 ◽  
Vol 18 (1) ◽  
pp. 125-136 ◽  
Author(s):  
Luiza Jecu ◽  
Iuliana Raut ◽  
Elena Grosu ◽  
Mariana Calin ◽  
Violeta Purcar ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Wood Composites
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