scholarly journals Hydrolysis of PLA-like Plasma Polymer Films with Varying Degree of Crosslinking

2016 ◽  
Vol 3 (3) ◽  
pp. 168-171
Author(s):  
Z. Kolarova Raskova ◽  
J. Kousal ◽  
P. Stloukal ◽  
Z. Krtous
Keyword(s):  
Polymer Films ◽  
Plasma Polymerization ◽  
Surface Characterization ◽  
Gel Permeation Chromatography ◽  
Plasma Polymer ◽  
Biodegradable Films ◽  
Molecular Weights ◽  
Evaporation Technique ◽  
Hydrolysis Of ◽  
Sem Analyses

<p>Poly-lactide acid (PLA) based biodegradable films are of interest for packaging materials or bioapplications. Plasma-assisted vacuum evaporation technique uses oligomers released during thermal decomposition of source polymer as precursors for plasma polymerization. Conventionally prepared PLA with <em>mw</em> = 10000 g/mol was used as a source polymer. Films were prepared at various RF (13.56 MHz) plasma powers (0-20 W) in order to vary the amount of crosslinking in the film.</p><p>Swelling and hydrolysis of films were monitored in real time using spectroscopic ellipsometry. The concentration profile of products of hydrolysis was measured by liquid-chromatography (LC-MS). FTIR, XPS and SEM analyses were used for monitoring of film composition and surface characterization. Molecular weights of source polymer and of the plasma polymer were determined by gel-permeation chromatography (GPC). Possibility to prepare PLA-like plasma polymer films with controlled degradability by hydrolysis was demonstrated.</p>

Enzymatic Synthesis of Alkyds

1989 ◽  
Vol 174 ◽  
Author(s):  
Shimona Geresh
Keyword(s):  
Average Molecular Weight ◽  
Enzymatic Catalysis ◽  
Gel Permeation Chromatography ◽  
X Ray Diffraction ◽  
High Melting Point ◽  
Molecular Weights ◽  
Derivatives Of ◽  
Low Solubility ◽  
Butane Diol ◽  
Sem Analyses

AbstractThis paper describes the application of lipase-catalyzed polytransesterification to the preparation of two series of unsaturated “all trans” polyesters (alkyds): in the first series the starting materials were diesters of fumaric acid and 1,4-butane diol, and in the second, bischloroethyl fumarate and aromatic diols (benzene dimethanol and derivatives of bisphenol A). Most of the reactions were carried out in tetrahydrofuran and acetonitrile. As opposed to the extensive isomerization which occurs during the synthesis of unsaturated polyesters by chemical polycondensation, no isomerization of the double bond was found under the mild conditions of enzymatic catalysis. The “all trans” character of our alkyds was determined by nmr spectroscopy, and average molecular weights and dispersivity were measured by gel permeation chromatography. The average molecular weight was found to vary with the solvent. In acetonitrile a relatively high-melting point alkyd was obtained (m.p. 106–108°C), with low solubility in conventional solvents. Powder X-ray diffraction and SEM analyses revealed crystaUinity and layer-type structures.

Direct covalent attachment of silver nanoparticles on radical-rich plasma polymer films for antibacterial applications

2018 ◽  
Vol 6 (37) ◽  
pp. 5845-5853 ◽  
Author(s):  
Behnam Akhavan ◽  
Sadra Bakhshandeh ◽  
Hamed Najafi-Ashtiani ◽  
Ad C. Fluit ◽  
Edwin Boel ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Polymer Films ◽  
Plasma Polymerization ◽  
Covalent Immobilization ◽  
Single Step ◽  
Plasma Polymer ◽  
Covalent Attachment

Ion-assisted plasma polymerization for single-step, covalent immobilization of silver nanoparticles on surfaces.

scholarly journals Chitosan Films Obtained from Brachystola magna (Girard) and Its Evaluation on Quality Attributes in Sausages during Storage

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1782
Author(s):  
Juan Manuel Tirado-Gallegos ◽  
Paul Baruk Zamudio-Flores ◽  
Miguel Espino-Díaz ◽  
René Salgado-Delgado ◽  
Gilber Vela-Gutiérrez ◽  
...  
Keyword(s):  
Weight Loss ◽  
Lipid Oxidation ◽  
Meat Products ◽  
Water Vapor Permeability ◽  
Good Alternative ◽  
Quality Attributes ◽  
Vapor Permeability ◽  
Biodegradable Films ◽  
Molecular Weights ◽  
Chitosan Films

High molecular weight chitosan (≈322 kDa) was obtained from chitin isolated from Brachystola magna (Girard) to produced biodegradable films. Their physicochemical, mechanical and water vapor permeability (WVP) properties were compared against commercial chitosan films with different molecular weights. Brachystola magna chitosan films (CFBM) exhibited similar physicochemical and mechanical characteristics to those of commercial chitosans. The CFBM films presented lower WVP values (10.01 × 10−11 g/m s Pa) than commercial chitosans films (from 16.06 × 10−11 to 64.30 × 10−11 g/m s Pa). Frankfurt-type sausages were covered with chitosan films and stored in refrigerated conditions (4 °C). Their quality attributes (color, weight loss, pH, moisture, texture and lipid oxidation) were evaluated at 0, 5, 10, 15 and 20 days. Sausages covered with CFMB films presented the lowest weight loss (from 1.24 to 2.38%). A higher increase in hardness (from 22.32 to 30.63 N) was observed in sausages covered with CFMB films. Compared with other films and the control (uncovered sausages), CFMB films delay pH reduction. Moreover, this film presents the lower lipid oxidation level (0.10 malonaldehyde mg/sample kg). Thus, chitosan of B. magna could be a good alternative as packaging material for meat products with high-fat content.

scholarly journals Synthesis and In Vitro Antimicrobial Evaluation of Photoactive Multi—Block Chalcone Conjugate Phthalimide and 1,8-Naphthalimide Novolacs

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1859
Author(s):  
Periyan Durairaju ◽  
Chinnasamy Umarani ◽  
Govindasami Periyasami ◽  
Perumberkandigai Adikesavan Vivekanand ◽  
Mostafizur Rahaman
Keyword(s):  
Spectroscopic Analysis ◽  
Photophysical Properties ◽  
Gel Permeation Chromatography ◽  
13C Nmr Spectroscopy ◽  
Antimicrobial Activities ◽  
Microbial Activities ◽  
E Coli ◽  
Molecular Weights ◽  
Antimicrobial Evaluation

Herein we report new multiblock chalcone conjugate phthalimide and naphthalimide functionalized copolymers with a topologically novel architecture synthesis using nucleophilic substitution and polycondensation methodology. The structures of the synthesized novolacs were elucidated on the basis of their spectroscopic analysis including FTIR, 1H NMR, and 13C NMR spectroscopy. Further, the number-average and weight-average molecular weights of the novolac polymers were determined by gel permeation chromatography (GPC). We examined the solubility of the synthesized polymers in various organic solvents including CHCl3, CH3CN, THF, H2O, CH3OH, DMSO, and DMF and found they are insoluble in both methanol and water. The novolac polymers were evaluated for their photophysical properties and microbial activities. The investigation of the antimicrobial activities of these polymers reveals significant antimicrobial activity against the pathogens E. coli, S. aureus, C. albicans, and A. niger.

Development of Oxidized Sulfur Polymer Films through a Combination of Plasma Polymerization and Oxidative Plasma Treatment

Langmuir ◽  
2014 ◽  
Vol 30 (5) ◽  
pp. 1444-1454 ◽  
Author(s):  
Behnam Akhavan ◽  
Karyn Jarvis ◽  
Peter Majewski
Keyword(s):  
Plasma Treatment ◽  
Polymer Films ◽  
Plasma Polymerization
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