scholarly journals Preparation and characterization of polyethylene glycol/poly(L-lactic acid) blends

2017 ◽  
Vol 89 (1) ◽  
pp. 141-152 ◽  
Author(s):  
Ioanna-Georgia Athanasoulia ◽  
Petroula A. Tarantili
Keyword(s):  
Contact Angle ◽  
Lactic Acid ◽  
Degradation Process ◽  
Water Contact ◽  
Wetting Ability ◽  
Angle Measurements ◽  
Low Concentrations ◽  
Contact Angle Measurements ◽  
Twin Screw ◽  
Poly Ethylene

AbstractThe effect of incorporation of poly(ethylene glycol) (PEG) on thermomechanical and hydrophilicity properties of poly(L-lactic acid) (PLLA) was investigated. PEG/PLLA blends, containing 10, 20, 30 and 40 wt% PEG, were prepared by melt-extrusion in a co-rotating twin-screw extruder. By DSC analysis, it was observed that the Tg of PLLA phase in PEG/PLLA blends decreased accompanied by a significant decrease in Tcc and increase in their melting enthalpy. Therefore, the addition of PEG enhances the crystallization ability of PLLA phase due to its lubricating effect which increased mobility of PLLA chains. From TGA it was observed that low concentrations of PEG (10 & 20 wt%) increase the Tonset of thermal degradation, probably due to improved heat resistance of the crystalline phase. At higher PEG content, the Tonset decreases, as the lubricating effect becomes the controlling mechanism for the initiation of degradation process. Decrease in tensile strength and modulus was recorded especially in PLLA blends with PEG content higher than 20 wt%. The elongation at break decreases reaching a maximum at 20 wt% PEG and then dropped again. To investigate the effect of PEG on the wetting ability of PLLA, water contact angle measurements were performed. The results indicate that the introduction of PEG lowers the contact angle values in PEG/PLLA film surfaces, as compared to pure PLLA, suggesting improved hydrophilic properties.

scholarly journals Synthesis, Hydrophilicity and Micellization of Coil–Brush Polystyrene-b-(polyglycidol-g-polyglycidol) Copolymer—Comparison with Linear Polystyrene-b-Polyglycidol

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 253
Author(s):  
Mariusz Gadzinowski ◽  
Maciej Kasprów ◽  
Teresa Basinska ◽  
Stanislaw Slomkowski ◽  
Łukasz Otulakowski ◽  
...  
Keyword(s):  
Contact Angle ◽  
Self Assembly ◽  
Original Method ◽  
Critical Micellization Concentration ◽  
Water Contact ◽  
1H And 13C Nmr ◽  
Similar Composition ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Static Conditions

In this paper, an original method of synthesis of coil–brush amphiphilic polystyrene-b-(polyglycidol-g-polyglycidol) (PS-b-(PGL-g-PGL)) block copolymers was developed. The hypothesis that their hydrophilicity and micellization can be controlled by polyglycidol blocks architecture was verified. The research enabled comparison of behavior in water of PS-b-PGL copolymers and block–brush copolymers PS-b-(PGL-g-PGL) with similar composition. The coil–brush copolymers were composed of PS-b-PGL linear core with average DPn of polystyrene 29 and 13 of polyglycidol blocks. The DPn of polyglycidol side blocks of coil–b–brush copolymers were 2, 7, and 11, respectively. The copolymers were characterized by 1H and 13C NMR, GPC, and FTIR methods. The hydrophilicity of films from the linear and coil–brush copolymers was determined by water contact angle measurements in static conditions. The behavior of coil–brush copolymers in water and their critical micellization concentration (CMC) were determined by UV-VIS using 1,6-diphenylhexa-1,3,5-trien (DPH) as marker and by DLS. The CMC values for brush copolymers were much higher than for linear species with similar PGL content. The results of the copolymer film wettability and the copolymer self-assembly studies were related to fraction of hydrophilic polyglycidol. The CMC for both types of polymers increased exponentially with increasing content of polyglycidol.

Non-woven Membranes Electrospun from Polylactic Acid Incorporating Silver Nanoparticles as Biocide

2012 ◽  
Vol 1376 ◽  
Author(s):  
Haydee Vargas-Villagran ◽  
Elvia Teran-Salgado ◽  
Maraolina Dominguez-Diaz ◽  
Osvaldo Flores ◽  
Bernardo Campillo ◽  
...  
Keyword(s):  
Contact Angle ◽  
Silver Nanoparticles ◽  
Polylactic Acid ◽  
Chloroform Solution ◽  
Average Diameter ◽  
Electrospinning Process ◽  
Water Contact ◽  
X Ray Scattering ◽  
Angle Measurements ◽  
Contact Angle Measurements

ABSTRACTIn this research, we describe the electrospinning processing of polylactic acid (PLA) and the influence of silver nanoparticles on the morphology and microstructure of produced non woven membranes thus produced. The PLA was electrospun from a chloroform solution and a filamentary and granular morphology was obtained, the filaments having an average diameter of 1.25 μm, When silver nanoparticles (of ca. 12 nm size) were incorporated, the filaments diameter was reduced to an average of 0.65 μm, and the density of beads was also reduced. The membranes were rather amorphous, as revealed by X-ray scattering, presumably due to the quenching process associated with the electrospinning process. Water contact angle measurements showed that silver nanoparticles induced significant hidrophobicity in the membranes as neat PLA membrane had a contact angle of 54° and PLA/Ag membrane exhibited an angle of 115°.

scholarly journals Amphiphilic Polyphosphonate Copolymers as New Additives for PDMS-Based Antifouling Coatings

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3414
Author(s):  
Elisa Guazzelli ◽  
Niccolò Lusiani ◽  
Gianfranca Monni ◽  
Matteo Oliva ◽  
Chiara Pelosi ◽  
...  
Keyword(s):  
Water Soluble ◽  
Model Organisms ◽  
Water Contact ◽  
Angle Measurements ◽  
Antifouling Coatings ◽  
Contact Angle Measurements ◽  
Biological Tests ◽  
Poly Ethylene ◽  
Alternative Solutions ◽  
Hydrolysis Of

Poly(ethyl ethylene phosphonate)-based methacrylic copolymers containing polysiloxane methacrylate (SiMA) co-units are proposed as surface-active additives as alternative solutions to the more investigated polyzwitterionic and polyethylene glycol counterparts for the fabrication of novel PDMS-based coatings for marine antifouling applications. In particular, the same hydrophobic SiMA macromonomer was copolymerized with a methacrylate carrying a poly(ethyl ethylene phosphonate) (PEtEPMA), a phosphorylcholine (MPC), and a poly(ethylene glycol) (PEGMA) side chain to obtain non-water soluble copolymers with similar mole content of the different hydrophilic units. The hydrolysis of poly(ethyl ethylene phosphonate)-based polymers was also studied in conditions similar to those of the marine environment to investigate their potential as erodible films. Copolymers of the three classes were blended into a condensation cure PDMS matrix in two different loadings (10 and 20 wt%) to prepare the top-coat of three-layer films to be subjected to wettability analysis and bioassays with marine model organisms. Water contact angle measurements showed that all of the films underwent surface reconstruction upon prolonged immersion in water, becoming much more hydrophilic. Interestingly, the extent of surface modification appeared to be affected by the type of hydrophilic units, showing a tendency to increase according to the order PEGMA < MPC < PEtEPMA. Biological tests showed that Ficopomatus enigmaticus release was maximized on the most hydrophilic film containing 10 wt% of the PEtEP-based copolymer. Moreover, coatings with a 10 wt% loading of the copolymer performed better than those containing 20 wt% for the removal of both Ficopomatus and Navicula, independent from the copolymer nature.

Ionizable polyol from cottonseed oil for anionic waterborne polyurethane-silanol dispersions

2019 ◽  
Vol 10 (4) ◽  
pp. 77-94
Author(s):  
Sashivinay Kumar Gaddam ◽  
Aruna Palanisamy
Keyword(s):  
Contact Angle ◽  
Soft Segment ◽  
Testing Machine ◽  
Waterborne Polyurethane ◽  
Cottonseed Oil ◽  
Average Particle ◽  
Water Contact ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Synthetic Methodologies

A novel cottonseed oil-based ionizable polyol was introduced as ionic soft segment in waterborne polyurethane dispersion (PUD) synthesis. The ionizable polyol was synthesized by ring opening of epoxidized cottonseed oil (ECSO) with 4-aminobenzoic acid (PABA) and blended with hydroxylated cottonseed oil polyol (HCSO) in different weight ratios to develop a series of mixed polyols having different hydroxyl numbers viz., 146, 130 and 114 mg KOH/g. Three different PUDs were synthesized using the mixed polyols, isophorone diisocyanate, and 3-aminopropyltriethoxysilane. The chemical structure, thermo-mechanical properties, and surface properties of cured PUD films were examined using Fourier-transform infrared spectroscopy (FTIR), Dynamic mechanical thermal analysis (DMTA), universal testing machine (UTM) and contact angle measurements respectively. The effect of Si–O–Si cross-linking network density, which increases with an increase in OH values of the mixed polyol was also investigated. All the PUDs prepared in this study exhibited good storage stability (>4 months), and the average particle sizes of PUDs ranged from 18 to 124 nm. The highest hydroxyl mixed polyol derived PUD film (PUD-35 film) exhibited high thermal stability, mechanical strength; Tg value, water contact angle value, chemical, and abrasion resistance properties due to the extended siloxane cross-link network structure. The introduction of ionizable polyol into the soft segment led to an improvement in hard and soft segment phase mixing of PUDs, and this strategy could enrich the exploration of new synthetic methodologies in the field of bio-based PUD manufacturing.

Organic–inorganic sol-gel thick films for humidity barriers

2008 ◽  
Vol 23 (8) ◽  
pp. 2084-2090 ◽  
Author(s):  
Andrei Jitianu ◽  
Glenn Amatucci ◽  
Lisa C. Klein
Keyword(s):  
Contact Angle ◽  
Thick Films ◽  
Sol Gel ◽  
Attenuated Total Reflection ◽  
Inorganic Materials ◽  
Angle Measurements ◽  
Glass Slides ◽  
Contact Angle Measurements ◽  
Sol Gel Process ◽  
Poly Ethylene

Hybrid thick films were deposited on Surlyn, a copolymer of poly(ethylene- co-methacrylic acid) and a common adhesion film for metal surfaces. Hybrid organic–inorganic materials were prepared by a sol-gel process. Methyltriethoxysilane (MTES) with tetraethoxysilane (TEOS), phenyltriethoxysilane (PhTES) with TEOS, and methyltrimethoxysilane (MTMS) with tetramethoxysilane (TMOS) were investigated. The inorganic component was selected to form the network for the film, while the organic component was selected to repel water and fill porosity. The films were deposited on Surlyn and on glass slides. The properties of the films were investigated using attenuated total reflection Fourier transform infrared (FTIR) and Raman spectroscopy. Contact-angle measurements indicated that the contact angle increased from ∼76.5° for Surlyn alone to ∼89.6° for Surlyn coated with MTES.

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