Effects of different monomer systems on shear bond strength of bonding cement to zirconia

2019 ◽  
Vol 9 (8) ◽  
pp. 978-983 ◽  
Author(s):  
ElZahraa Eldwakhly ◽  
Selma Adnan Saadaldin ◽  
Abdulaziz Abdullah Al-Khureif ◽  
Mai S. Soliman
Keyword(s):  
Contact Angle ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Failure Modes ◽  
Hydrolytic Stability ◽  
Silica Coating ◽  
Chemical Compositions ◽  
Water Contact ◽  
Angle Measurements ◽  
Contact Angle Measurements

Plenty of surface treatments to zirconia (ZrO2) are available. However, the long-term hydrolytic stability is still a major concern for the investigators. This paper explores the effects of different monomer systems on mold enclosed shear bond strength (ME-SBS) of bonding cement to zirconia (ZrO2) using commercially available silane primers with different monomer systems. Eighteen ZrO2 blanks (KaVo™ Everest) were subjected to tribo-chemical silica coating and divided into the following primer groups: (1) Sil (control); (2) Composite; (3) G-Multi; and (4) Monobond Plus. Each group was then subdivided into three subgroups (n = 6) depending on storage conditions: (1) 24-h dry storage, (2) 2-month water aging, and (3) 4-month water aging. Elemental analyses and contact angle measurements were conducted. The ME-SBSs and failure modes were analyzed. The data were subjected to the two-way analysis of variance (ANOVA) followed by Tukey's post hoc test for pairwise comparisons (p < 0.05). Similar chemical compositions with marginal differences in content weight (%) were observed. The water contact angle measurements on treated ZrO2 were <32° in all groups. After 4-month water aging, the highest ME-SBS was exhibited by Group 4 (18.3 ± 6.5 MPa). The Monobond Plus primer systems have the ability to resist hydrolysis at the bonding cement/ZrO2 interface.

scholarly journals High-Performance Dental Adhesives Containing an Ether-Based Monomer

2019 ◽  
Vol 99 (2) ◽  
pp. 189-195 ◽  
Author(s):  
S. Yamauchi ◽  
X. Wang ◽  
H. Egusa ◽  
J. Sun
Keyword(s):  
Contact Angle ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Water Solubility ◽  
Dental Restoration ◽  
Dental Adhesives ◽  
Dental Resins ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Dentin Tubules

Dental adhesives are vital for the success of dental restorations. The objective of this study is to make strong and durable dental adhesives that are free from 2 symbolic methacrylate-based dental resins—2-bis[4-(2-hydroxy-3-methacryl-oxypropoxy)-phenyl]-propane (Bis-GMA) and 2-hydroxyethyl-methacrylate (HEMA)—and have equivalent/improved bonding strength and durability. We formulated, prepared, and evaluated 2 dental adhesives using mixtures of a hydrolytically stable ether-based monomer, triethylene glycol divinylbenzyl ether (TEG-DVBE), with urethane dimethacrylate (UDMA) or pyromellitic glycerol dimethacrylate. These adhesives were composed of equimolar ester-/ether-based vinyl functional groups. They were compared with Bis-GMA/HEMA-based commercial and experimental dental adhesives in terms of shear bond strength and microtensile bond strength (µTBS) to human dentin and the µTBS bond stability under extended thermocycling challenges. In addition, the resins’ infiltration to dentin tubules, mechanical performance, and chemical properties were assessed by scanning electron microscopy, ISO standard flexural strength and modulus measurements, contact angle measurements, and water sorption/solubility measurements. The hybrid TEG-DVBE-containing dental adhesives generated equivalent shear bond strength and µTBS in comparison with the controls. Significantly, these adhesives outperformed the controls after being challenged by 10,000 thermocycles between 5 °C and 55 °C. Water contact angle measurements suggested that the hybrid dental adhesives were relatively more hydrophobic than the Bis-GMA/HEMA controls. However, both TEG-DVBE-containing adhesives developed more and deeper resin tags in dentin tubules and formed thicker hybrid layers at the composite-dentin interface. Furthermore, the water solubility of UDMA/TEG-DVBE resins was reduced approximately 89% in comparison with the Bis-GMA/HEMA controls. The relatively hydrophobic adhesives that achieved equivalent/enhanced bonding performance suggest great potentials in developing dental restoration with extended service life. Furthermore, the TEG-DVBE-containing materials may find wider dental applications and broader utility in medical device development.

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 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.

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.

scholarly journals Fabrication of a Low Adhesive Superhydrophobic Surface on Ti6Al4V Alloys Using TiO2/Ni Composite Electrodeposition

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 121 ◽  
Author(s):  
Jianbing Meng ◽  
Xiaojuan Dong ◽  
Yugang Zhao ◽  
Rufeng Xu ◽  
Xue Bai ◽  
...  
Keyword(s):  
Contact Angle ◽  
Wear Resistance ◽  
Superhydrophobic Surface ◽  
Ph Value ◽  
Chemical Compositions ◽  
Sliding Angle ◽  
Water Contact ◽  
Angle Measurements ◽  
Surface Morphologies ◽  
Composite Electrodeposition

A superhydrophobic surface with low adhesion and good wear resistance was fabricated on Ti6Al4V substrates via TiO2/Ni composite electrodeposition, and subsequently modified with a fluoroalkylsilane (FAS) film. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and optical contact angle measurements were used to characterize the surface morphologies, chemical compositions, and surface wettability. The superhydrophobicity of the as-prepared surface results from the fabrication of a hierarchical structure and the assembly of low-surface energy fluorinated components. The as-prepared surface had a water contact angle as high as 162.6° and a sliding angle close to 1.8°. Scratch and abrasion tests showed that the superhydrophobic coating provided a superior wear resistance and stable mechanical abrasion protection. In addition, the influence of processing conditions, such as working voltage, deposited time, pH value, and TiO2 concentration, was also investigated.

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