Hybrid Resin Research Articles

Radiopaque properties of polyetheretherketone crown at laboratory study

ObjectivesThere have been no reports on the radiopaque properties of new polyetheretherketone (PEEK) crowns for locating crowns during accidental ingestion or aspiration and detection of secondary caries, which is essential information for clinical application. This study aimed to investigate whether the radiopaque properties of PEEK crowns could be used to identify the site of accidental ingestion or aspiration and detect secondary caries. MethodsFour types of crowns were fabricated: three non-metal crowns (PEEK, hybrid resin, and zirconia) and one full metal cast crown (gold-silver-palladium alloy). Initially, the images for these crowns were compared using intraoral radiography, chest radiography, cone-beam computed tomography (CBCT), and multi-detector computed tomography (MDCT); computed tomography (CT) values were calculated. Subsequently, the images for the crowns placed on the secondary caries model with two artificial cavities were compared using intraoral radiography. ResultsThe PEEK crowns displayed the lowest radiopaque properties on radiography and very few artifacts were observed on CBCT and MDCT. On the other hand, the CT values of the PEEK crowns were a little lower than those of the hybrid resin crowns and considerably lower than the zirconia and full metal cast crowns. The cavity could be detected in the PEEK crown-placed secondary caries model through intraoral radiography. ConclusionsThis simulated study of radiopaque properties with four types of crowns suggested that a radiographic imaging system can be used to identify the site of accidental ingestion and aspiration of PEEK crowns and to detect secondary caries of the abutment tooth within a PEEK crown.

Calcination-Enhanced Laser-Induced Damage Threshold of 3D Micro-Optics Made with Laser Multi-Photon Lithography

Laser Direct Writing (LDW), also known as 3D multi-photon laser lithography of resins, is a promising technique for fabricating complex free-form elements, including micro-optical functional components. Regular organic or hybrid (organic–inorganic) resins are often used, with the latter exhibiting better optical characteristics, as well as having the option to be heat-treated into inorganic glass-like structures particularly useful for resilient micro-optics. This work is a continuation of our SZ2080™ calcination development of micro-optics, specifically studying the Laser-Induced Damage Threshold (LIDT). Such sol–gel-derived glass 3D micro-structures, particularly those that undergo heat treatment, have not been well-characterized in this respect. In this pilot study, we investigated the LIDT using the Series-on-One (S-on-1) protocol of functional micro-lenses produced via LDW and subsequently calcinated. Our results demonstrate that the LIDT can be significantly increased, even multiple times, by this approach, thus enhancing the resilience and usefulness of these free-form micro-optics. This work represents the first investigation in terms of LIDT into the impact of calcination on LDW-produced, sol–gel-derived glass micro-structures and provides important insights for the development of robust micro-optical devices.

Design of crosslinked networks with hydroxyurethane linkages via bio‐based alkyl methacrylates and diamines

AbstractA hybrid methodology is used to combine the favorable properties of non‐isocyanate polyurethanes (NIPUs) in the side chains with poly(methacrylates) as the backbone into thermoset hybrid resins with hydroxyurethane linkages (HNIPU)s. Using NIPUs linkages avoids the use of toxic isocyanates in the poly(urethane) segments. The backbone is synthesized from cyclic carbonated copolymer templates derived from atom transfer radical polymerization (ATRP) of an alkyl methacrylate (C13MA with average side‐chain length of 13)/glycidyl methacrylate (GMA) mixtures (initial GMA mol fraction = 0.1–0.4). The resulting flexible resins with pendent epoxy functional groups were subsequently carbonated and then reacted with 1,10‐diaminodecane (90°C, 24 h) to form rigid side chains via hydroxyurethane linkages. Manipulating template functionality (2–11 urethane linkages out of 35 backbone units) yielded crosslinked networks with Young's moduli from 0.1 to 71.9 MPa while decreasing tensile elongation at break from 105% to 10%. Swelling ratios (SR) of the networks in tetrahydrofuran (THF) decrease as urethane linkage concentration increases, indicating tighter networks, consistent with the rheologically obtained molecular weight between crosslinks. Gel content indicated less than 15% of the networks are soluble in THF. The HNIPU networks derived show their ready tunability by simply changing the precursor functionality.

Performance of bulk-fill versus conventional nanocomposite resin restorations supporting the occlusal rests of removable partial dentures: An in vitro investigation

Statement of problemPlacing removable partial denture (RPD) rests on composite resin restorations has long been a debatable issue. Despite developments in composite resins such as nanotechnology and bulk-filling techniques, studies investigating the performance of composite resin restorations when used to support occlusal rests remain scarce. PurposeThe purpose of this in vitro study was to investigate the performance of bulk-fill versus incremental (conventional) nanocomposite resin restorations when they are used to support RPD rests under functional loading. Material and methodsThirty-five caries-free intact maxillary molars of similar coronal size were collected and divided into 5 equal groups (n=7): Enamel (Control) group: rest seats prepared entirely in enamel; Class I Incremental group: Class I cavities restored with incrementally placed nanohybrid resin composite resin (Tetric N-Ceram); Class II Incremental group: Mesio-occlusal (MO) Class II cavities restored with Tetric N-Ceram; Class I Bulk-fill group: Class I cavities restored with high-viscosity bulk-fill hybrid resin composite (Tetric N-Ceram Bulk-Fill); and Class II Bulk-fill group: MO Class II cavities restored with Tetric N-Ceram Bulk-Fill. Occlusal rest seats were prepared mesially in all groups, and clasp assemblies were fabricated and cast in cobalt chromium alloy. Specimens with their clasp assemblies were subjected to thermomechanical cycling using a mechanical cycling machine (250000 masticatory cycles) and 5000 thermal cycles (5 °C to 50 °C). Surface roughness (Ra) was measured with a contact profilometer before and after cycling. Fracture analysis was done using stereomicroscopy, and margin analysis was done with a scanning electron microscope (SEM) before and after cycling. Statistical analysis of Ra was conducted using ANOVA followed by the Scheffé test for between-group comparison and paired t test for within-group comparison. The Fisher exact probability test was used for fracture analysis. The Mann–Whitney test was used for between-group comparison and Wilcoxon signed rank test for within-group comparison for the SEM images (α=.05). ResultsMean Ra increased significantly after cycling in all groups. Significant differences in Ra were found between enamel and all 4 resin groups (P<.001), with no significant differences between incremental and bulk-fill resin groups for both Class I and II specimens (P>.05). No significant differences were found between the 2 resin groups with regard to fracture and margin analysis (P>.05). ConclusionsThe surface roughness of enamel was significantly lower than that of both incremental and bulk-fill nanocomposite resins before and after functional loading. Incremental and bulk-fill nanocomposite resins showed comparable performance in terms of surface roughness, fracture behavior, and marginal adaptation.

Development of hybrid resin to reduce silica in borated water

Amberlite IRN-78 resin was incorporated with iron to make a hybrid resin for the removal of silica from the borated water of nuclear power plants. The hybrid resin contained 0.84 wt % iron compounds upon pyrolysis. In batch experiments carried out at room temperature, 1 g of the hybrid resin removed ∼60 μg silica from 1 ppm borated water in ∼120 min. The efficiency of the hybrid material increased with the resin quantity, decreased with silica concentration, and remained unchanged at different pH values. Freundlich and Temkin isothermal adsorption dominated the silica removal process and followed the pseudo-first-order and intra-particle diffusion mechanism simultaneously. The concentration of the leached iron remained appreciably under the safe limits of 200 μg/l during the experiments. This detailed study suggests the use of hybrid resin for the removal of silica from borated water streams and other similar systems.

Preparation and characterization of hybrid resin from used urea-formaldehyde and isocyanate resin

Hybrid resins composed of polymeric 4-4 diphenyl methane diisocyanate (pMDI) and used urea-formaldehyde (UUF) resins were prepared and studied. In these hybrid resins, high ratios of pMDI (e.g., 20%) were evenly dispersed in UUF resins by using acetone as a solvent for pMDI. The viscosity of the hybrid resin containing 15% of pMDI only changed from 216 to 424 mPa s with 30 h of storage. Chemical composition analysis showed that the free isocyanate groups were reacted with hydroxyl groups in the hybrid resins within 2 h. From a curing kinetics analysis, even without obvious active isocyanate groups, these hybrid resins still showed lower curing peak temperatures and Kissinger activation energies than the UUF resin. Moreover, the hybrid resins presented significantly higher dry and wet tensile shear strengths than the UUF resin. The effective use time of the hybrid resin with 15% pMDI reached up to 12 h. This study provided a new method for modifying UF resin with pMDI. These results also proved the feasibility of applying the hybrid resins in wood-based composites manufacturing.

Chemical and Mechanical Properties for Rosin-based Hybrid Resins

The increasing concern for the protection of the environment, through the use of renewable natural resources, has led in the last decades to the realization of a number of natural polymers or hybrids to be able to replace petroleum-based polymeric materials. Rosin is a low-cost wood resin extracted from conifers. In this paper, based on FTIR and Raman analyses, the spectra of natural Rosin resin and some hybrid resins with volume proportions of 45, 55 and 65% Rosin were studied. Some mechanical properties such as modulus of elasticity, elongation at break, tensile strength were determined from stress-strain diagrams obtained from tensile stress. Increasing the volume proportion of Rosin leads to a decrease in stiffness and strength properties and obtaining a visco-elastic behavior.

Effects of silicone resins on copolymerization of acrylated epoxidized soybean oil

AbstractIn this work, effects of the silicone resins on copolymerization of the acrylated epoxidized soybean oil were investigated. Rheological characteristics, curing behaviors, and thermal properties of acrylate epoxy soybean oil prepolymer (AP), silicone prepolymer (SP), and their hybrids (AP/SP) were studied in detail. Spots in a snowflake pattern were observed on the fracture section surface of cured AP/SP hybrid resins by SEM. According to the change of polymer groups revealed by Fourier transform infrared, a possible reaction between AP and SP was proposed. The curing mechanism of AP/SP hybrids was researched, which was suggested to be an autocatalytic curing process. Furthermore, the degree of cure, the activation energy (Eα) and the reaction frequency factor (A) of the curing reaction were estimated. It was found that the cure kinetic of AP/SP hybrid resins could be well‐described by a Sesthk‐Bergglen model with the numerical optimization based on the Kissinger method and the Malek approach. The experimental results show that the mass retention rates of AP/SP hybrid resins were significantly increased after curing, indicating that the thermal stability of AP was enhanced with the addition of SP.

Damping Properties of Large-Scale Overlap Joints Bonded with Epoxy Hybrid Resin or Polyurethanes: Experimental Characterisation and Analytical Description

Structures in various industries are exposed to dynamic loads. The dissipative properties of adhesively bonded joints can contribute to the damping of dynamically stressed structures. Dynamic hysteresis tests are carried out to determine the damping properties of adhesively bonded overlap joints by varying the geometry and test boundary conditions. The dimensions of the overlap joints are full-scale and thus relevant for steel construction. Based on the results of experimental investigations, a methodology is developed for the analytic determination of the damping properties of adhesively bonded overlap joints for various specimen geometries and stress boundary conditions. For this purpose, dimensional analysis is carried out using the Buckingham Pi Theorem. In summary, it can be stated that the loss factor of adhesively bonded overlap joints investigated within this study is in the range between 0.16 and 0.41. The damping properties can particularly be increased by increasing the adhesive layer thickness and reducing the overlap length. The functional relationships of all the test results shown can be determined by dimensional analysis. An analytical determination of the loss factor considering all identified influencing factors is enabled by derived regression functions with a high coefficient of determination.

A study on physical and morphological properties of novel bio-cotton/E-glass fiber–reinforced vinyl ester/epoxy resin hybrid interpenetrating polymer networks composites

A study on physical and morphological properties of novel bio-cotton/E-glass fiber–reinforced vinyl ester/epoxy resin hybrid interpenetrating polymer networks composites

Waterborne etherified MF and PVAc hybrid resin containing nanoclay as intumescent flame-retardant plywood coatings

Waterborne etherified MF and PVAc hybrid resin containing nanoclay as intumescent flame-retardant plywood coatings

Iodine Removal from Carbonate-Containing Alkaline Liquids Using Strong Base Resins, Hybrid Resins, and Silver Precipitation

The ability of several material types to remove aqueous iodine from a mildly alkaline, carbonate-rich nuclear waste stream was evaluated: strong base anion exchange resins (SBARs), hybrid resins, Ag-containing materials, and Bi-containing hybrid resins. A combination of batch testing and flow-through column testing was used in the evaluation. In batch testing, hybrid resins CHM-20, SIR-110-CE, and RTBI were shown to have high efficiency for the removal of both iodide and iodate simultaneously, while Ag-containing materials and SBAR demonstrated high capacity for iodide removal. One example of each material type (CHM-20, A532E, and Ionex 400) was further evaluated for their sorption isotherms and column performance. The Langmuir isotherm, or a Langmuir–Freundlich hybrid isotherm, best described the sorption of iodide to the CHM-20 hybrid resin and Purolite A532E. The Freundlich isotherm best described the uptake of iodate to CHM-20 and A532E and for both iodide and iodate to Ag-containing Ionex 400. In column testing, Purolite A532E had exceptional performance for overall iodide removal. However, with the capacity demonstrated, the A532E resin would exceed class C waste classification before breakthrough initiated, and column change-outs in processing would be dictated by eventual waste classification, not breakthrough. Ionex 400, a Ag-zeolite, was observed to degrade over time under mild alkaline column conditions, whereas the hybrid CHM-20 was limited in the single pass through design and would be best suited for applications where iodide and iodate are present and recirculation of the column effluent is feasible. This work highlights the feasibility of commercially available materials to separate radioiodine from liquid environments.

Physical and Mechanical Properties of Bamboo Fiber/Glass Fiber Mesh Reinforced Epoxy Resin Hybrid Composites: Effect of Fiber Stacking Sequence

ABSTRACT To further improve the preparation efficiency and properties of bamboo fiber reinforced polymer composites (BFRPs) fabricated by the vacuum-assisted resin transfer molding (VARTM) process. Here, the bamboo fiber/glass fiber mesh reinforced polymer hybrid composites (BGRPs) were fabricated by VARTM to determine the effects of three fiber stacking sequences (namely, GBBGBBG, BGBGBGB, and BBGGGBB; B: bamboo fiber, G: glass fiber mesh) on the physical and mechanical properties, as well as void characteristics of BGRPs (i.e. BGRP-1, BGRP-2, and BGRP-3). The results showed that the incorporation of glass fiber meshes could shorten the injection time of epoxy resin and improve the mechanical properties of BFRPs. BGRP-1 exhibited the lowest water absorption (1.31%) and the highest shear strength (15.55 MPa). Glass fiber meshes on the surface and bottom of BGRP-1, respectively, served as buffer layers to retard mechanical damage, so that BGRP-1 had the best drop hammer impact properties. BGRP-2 represented the highest flexural strength and flexural modulus of 92.22 MPa and 6.69 GPa, respectively. The mechanical properties of BGRP-3 were inferior to those of BGRP-1 and BGRP-2, and more voids were observed in the middle of BGRP-3 in micro-CT slices induced by inadequate epoxy resin impregnation on bamboo fibers.

Molecular Simulations of Low-Shrinkage Dental Resins Containing Methacryl-Based Polyhedral Oligomeric Silsesquioxane (POSS)

Nanocomposites of methacrylate-based polyhedral oligomeric silsesquioxane (POSS) are used as resins in dentistry to fill dental cavities. In this article, molecular dynamics simulations (MDS) are used to study and understand the interactions of monofunctional and multifunctional methacrylate groups on hybrid resins containing POSS additives for dental applications. These interactions are further related to the structural properties of the nanocomposites, which in turn affect their macro-properties that are important, especially when used for specific uses such as dental resins. For monofunctional methacrylate, nanocomposite of methacryl isobutyl POSS (MIPOSS) and for multifunctional methacrylate, methacryl POSS (MAPOSS) are used in this study. Molecular dynamic simulations (MDS) are performed on both MIPOSS and MAPOSS systems by varying the amount of POSS. On a weight percent basis, 1%, 3%, 5%, and 10% POSS are added to the resin. Density calculations, stress-strain, and powder diffraction simulations are used to evaluate the macro-properties of these nanocomposites and compare them with the experimental findings reported in the literature. The observations from the simulation results when compared to the experimental results show that MDS can be efficiently used to design, analyze, and simulate new nanocomposites of POSS.

A highly robust, concrete-inspired superhydrophobic nanocomposite coating.

Durability is still the main issue hindering the practical applications of superhydrophobic surfaces. In the case of superhydrophobic coatings, employing nanoparticles for constructing and retaining superhydrophobic surfaces without lowering the robustness is still a conundrum. Herein, inspired by concrete, which has a high filler portion and high robustness, we fabricated a superhydrophobic coating using a synthesized hydrophobic organic/inorganic hybrid resin and categorized micro/nano fillers with varying sizes. The hybrid resin improved the hydrophobicity and robustness of the coating. Also, by optimizing the content of categorized wearable (silica sand with varying sizes)/functional (aluminum nanoparticles)/low-surface-energy (PTFE) phases, the prepared superhydrophobic surfaces could achieve long abrasion distance coupled with a high retention rate. Also, the prepared sample retained its superhydrophobicity after abrasion by sandpaper (180 grit) for 10 m under a pressure as high as 22.5 kPa or 600 grit sandpaper for 12.8 m under the same pressure or when impacted by 1400 g sand particles from 30 cm. Also, the coating had a strong adhesion of 5B with the substrate. Thus, the designed attractive materials have the potential for self-cleaning, anti-icing, and anti-fouling applications in industries.

Full arch immediate occlusal loading using site specific implants: A clinical series of 10 patients (13 arches).

Osseointegration of dental endosseous implants has proven to be effective, predictable, and clinically successful. Unloaded healing protocols were originally used in treating edentulous patients. Full arch immediate occlusal loading protocols have been shown to be as effective as unloaded healing protocols. This paper reports on the results, benefits, and limitations of one specific immediate loading protocol using site specific implants for fresh extraction and healed extraction sites. Ten consecutive patients [{13 arches} (age range: 64-81 years; average: 70.1) (4males/6 females) were treated by the first 2 authors in private practice settings. Hopeless teeth were scheduled for extraction with immediate implant placement and immediate loading with insertion of full arch, screw-retained, acrylic resin interim prostheses within 24 hours. Implants were also placed into healed edentulous ridges. Insertion torque values for each implant were recorded. Interim prostheses were removed after at least 3 months of healing. Implants were reverse torque tested (35 Ncm) and evaluated for macroscopic mobility. Definitive full arch prostheses were made. Patients were followed for 21 to 48 months postimplant surgery. Panoramic radiographs were taken immediately postimplant placement and 1 year postoperative. Thirteen arches were treated; 11 ultrawide diameter implants were placed into molar sockets, 26 inverted body-shift implants were placed into anterior sockets; 25 standard diameter, tapered implants were placed into edentulous sites; 2 zygomatic implants were placed in one patient. The total number of implants placed was 64 (4preexisting implants were also used and not included in this study). The minimum implant insertion torque value was 20 Ncm. After 12 to 18 months of function (average 14 months), the implant and prosthetic survival rates were 100%. Eight patients were restored with definitive zirconia or acrylic resin hybrid fixed prostheses. Two patients were restored with bar titanium frameworks and removable overdenture prostheses. No prosthetic complications were reported for the definitive prostheses. The results of this clinical series with site specific implants and immediate full arch occlusal loading in treating edentulous patients resulted in 100% clinical implant and prosthetic survival rates. According to this study, this protocol can be used with high levels of anticipated success.

Numerical Investigation on Free Vibration Analysis of Kevlar/Glass/Epoxy Resin Hybrid Composite Laminates

This paper investigates the free vibration analysis of kevlar/glass/epoxy resin hybrid composite laminates. The ABAQUS software is studied to obtain the natural frequency with different fiber hybridization effects. The 3D shell element models evaluate natural frequency and mode shape in the quasi-isotropic laminated composite. The numerical analysis results are studied and compared between ABAQUS and ANSYS software. It was shown that the natural frequency value between ABAQUS and ANSYS software provided almost the same value. The error value between ABAQUS and ANSYS ranged from 1.03 % to 2.30 %. It was found that the error between the experimental and numerical results was from 1.15 % to 13.51 %. It was concluded that the percentage error value was significantly dependent on the mesh size. Furthermore, the reasonable agreement between experimental and ANSYS results can better analyze the free vibration of composite laminates.

Synthesis of octavinyl polyhedral oligomeric silsesquioxane (ovi‐POSS) based organic/inorganic hybrid resin microspheres for rapid and efficient oils absorption

AbstractIn this work, a hybrid nanocomposite of poly(styrene‐co‐butyl acrylate‐co‐dodecyl acrylate) and octavinyl polyhedral oligomeric silsesquioxane (ovi‐POSS) was synthesized by suspension polymerization and the composite resin was characterized by Fourier transform infrared, scanning electron microscopy energy‐dispersive spectrometer and thermal gravimetric analysis. The effects of ovi‐POSS content on the oil absorbency of hybrid composite resin were investigated. The results indicated that the maximum saturated oil absorption rate of sample PSBLA/ovi‐POSS‐1 with 1 wt% ovi‐POSS content toward four oils and organic solvents (toluene, xylene, gasoline, and diesel) are, respectively, 20.51, 18.56, 12.48, and 7.03 g g−1, and the process taken just about 5 min. The absorption kinetic model fitting proved that the adsorption behavior of the four oils on PSBLA/ovi‐POSS‐1 resin microspheres was dominated by the physical adsorption. Besides, PSBLA/ovi‐POSS‐1 has good oil retention rate (stay over 95% after centrifuging at 3000 rpm for 5 min) and reusability (for 12 times). These excellent oil absorption performances are attributed to the loose network structure of the composite resin. The rapid and efficient oils absorption properties give the composite resin potential practical applications in many areas.

The evaluation of an inorganic-organic poly(carborane-siloxane-arylacetylene) hybrid resin system

The realization of aerospace vehicle technologies demanding extreme service conditions is facilitated by the development of materials with greater oxidative stability at high temperatures. Thermal performance of polymer composites can be increased by incorporating a hybrid (organic-inorganic) resin as a thermal barrier coating. One such resin system, meta-poly (carborane-siloxane-arylacetylene) ( m-PCSAA), developed by the U.S. Naval Research Laboratory, shows potential for such application and is further investigated in this work. The resin has a low viscosity (0.1 Pa s) with large processing window (2.5 h) from 100°C to 230°C. These processing characteristics are advantageous for infusion processes or the inclusion of fillers for coating applications. Curing was accomplished in two stages, corresponding to two exothermic reactions. After the first curing stage, the resin exhibits elastomeric behavior, and after the second curing stage is rigid with a high glass transition temperature (∼330°C). The materials exhibited high char yields (89%) in air at 1000°C and may be useful in space or for attritable technology. No cracks were observed during long-term service at 288°C, but significant degradation and cracking were observed after aging at 316°C. The materials exhibited high coefficients of thermal expansion; 186.9 and 168.6 μm/(m∙°C) after first and second curing stage respectively. Similar to epoxies and polyimides, the resin acquired up to 3% moisture at 70°C and 85% relative humidity.

Study of hybrid isocyanate and high‐mono‐hydroxymethyl urea content urea‐formaldehyde resins

AbstractBased on the difference in the reaction rate of different groups of urea‐formaldehyde resins and isocyanate resins, this study designed two different urea‐formaldehyde resins: a normal urea‐formaldehyde resin (UF) and one with high mono‐hydroxymethylurea content (UF*) to react with polymeric methylene diphenyl diisocyanate (pMDI) resin. The difference in mono‐ and di‐hydroxymethyl urea content between UF and UF* resins was analyzed by nuclear magnetic resonance (NMR) spectroscopy, and results showed that the mono‐hydroxymethyl urea content of the UF* resin was much higher than that of the conventional UF resin. The fourier transform infrared spectrometer (FTIR) analysis of differences between UF* and UF resin showed that the UF* process did not change the main structure of the conventional urea formaldehyde resin. Differential scanning calorimeter (DSC) analysis showed that the curing temperature of the hybrid UF*‐pMDI resin was reduced 27.3°C compared to that of the UF‐pMDI resin. When these hybrid resins were used to bond plywood respectively, test results showed that the UF*‐pMDI resin improved the dry and wet bonding strength by 2.6% and 3.9%, respectively, compared with the UF‐pMDI resin under the condition of hot pressing time (3 min) and temperature (140°C), meeting the requirement of Chinese standard of GB/T 9846–2015 for Class III board. This study provides a new path for further improving the performance and design of hybrid resins based on isocyanate and urea‐formaldehyde resin.