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This review aimed to investigate the literature systematically and answer the question "Does the processing method of organic and inorganic agents incorporated into PMMA influence antimicrobial activity and cytotoxicity?". This systematic review was registered in the OpenScience Framework (osf.io/7nc28) and PRISMA guidelines were followed. The study design (PICOS) framework applied was P = polymethylmethacrylate; I = incorporation of organic and inorganic antimicrobials; C = control group; O = antimicrobial activity and cytotoxicity; and S = experimental in vitro studies. A custom search strategy was performed in Embase, Scopus, PubMed, and Science Direct databases. Studies were selected according to eligibility criteria in two steps. The risk of bias was evaluated by Joanna Briggs Institute's quasi-experimental studies tool. A qualitative analysis of the data was performed addressing: incorporation and polymerization methods, antimicrobial activity, and cytotoxicity of organic and inorganic agents added into PMMA. From a total of 1959 results, 34 studies were included in this review. The 3 organic agents evaluated showed antimicrobial efficacy and 1 was cytotoxic. Of the 31 inorganics, 4 showed no antimicrobial activity, and 8 reduced cell viability. Processing methods influenced the results. The incorporation of organic and inorganic antimicrobial agents into PMMA, depending on the processing method, changes the antimicrobial efficacy and cytotoxicity of the modified material. [ABSTRACT FROM AUTHOR]

The aging failure process of acrylic resin (AR) coatings widely used in ship anti-corrosion systems is highly complex. Currently, there are no established models or methods for predicting the aging of AR coatings in different marine environments. Therefore, this study proposes a framework for predicting the aging of AR coatings in marine environment based on short-term indoor accelerated tests. Initially, a comprehensive aging evaluation method for AR coatings is developed by integrating three commonly used coating performance evaluation indicators (gloss, color difference, and electrochemical impedance) based on the Technique for Order Preference by Similarity to Ideal Solution. Subsequently, an aging severity index is defined to quantify the impact of different environments on the coating aging process. Following this, 14 sets of indoor accelerated aging tests for AR coatings under various environmental conditions are conducted. Based on the test results, a comparative analysis of the predictive performance of three environmental effect models, namely multiple linear regression model, generalized Eyring model, and genetic algorithm-back-propagation model, is performed. Finally, utilizing the environmental effect models and global marine environmental data, the aging severity index of AR coatings in global marine environments is predicted and extrapolated. [ABSTRACT FROM AUTHOR]

Silica nanoparticles (SiNPs) and graphene oxide (GO) are two promising nanomaterial that have attracted considerable attention for their unique properties and applications. However, the conventional synthesis methods of SiNPs and GO often involve hazardous chemicals and high energy consumption, which pose environmental and economic challenges. Therefore, green and sustainable synthesis methods of SiNPs and GO are highly desirable. In this review, we summarize the recent advances in the green synthesis of SiNPs and GO using various natural sources, such as plants, fungi, bacteria, algae, clay, etc. We also discuss the functionalization of SiNPs and GO with acrylic resin to form hybrid nanocomposites for anti-corrosion applications. The advantages and challenges of these green methods are highlighted, and the future prospects are outlined. This review aims to provide a comprehensive overview of the current state-of-the-art in the green synthesis of SiNPs and GO-based nanocomposites for anti-corrosion applications, and to inspire further research in this emerging field. [ABSTRACT FROM AUTHOR]

Carbon fibre-reinforced polymers (CFRPs) are commonly used in aviation, automotive and renewable energy markets, which are constantly growing. Increasing the production of composite parts leads to increased waste production and a future increase in end-of-life components. To improve the recyclability of CFRPs, new materials that fit in with the idea of a circular economy should be used as a composite matrix. One such material is a commercially available thermoplastic liquid resin, Elium® (Arkema, France). In this work, the authors investigated how the mechanical recycling process affects the properties of thermoplastic-based carbon fibre composites. CFRPs with neat Elium® resin and resin modified with 0.02 wt.% single-walled carbon nanotubes or 0.02 wt.% multi-walled carbon nanotubes were manufactured using the resin infusion process. Afterwards, prepared laminates were mechanically ground, and a new set of composites was manufactured by thermopressing. The microstructure, mechanical, thermal and electrical properties were investigated for both sets of composites. The results showed that mechanical grinding and thermopressing processes lead to a significant increase in the electrical conductivity of composites. Additionally, a sharp decrease in all mechanical properties was observed. [ABSTRACT FROM AUTHOR]

Epoxy acrylate is produced by esterifying epoxy resin and acrylic acid through a ring-opening reaction. This process is highly exothermic and can be challenging to control gel formation. The thermal hazards of epoxy acrylate preparation were evaluated in this study by investigating the ring-opening esterification reaction between acrylic acid (AA) and bisphenol A epoxy resin (E-51) catalyzed by triethylamine (TEA). The heat release during the reaction process was analyzed using a reaction calorimeter (RC1mx) to simulate industrial conditions. Increasing the TEA catalyst content from 0.3 to 1.0 mass% resulted in a significant rise in reaction conversion from 75.35 ± 0.10% to 98.44 ± 0.10%. Differential scanning calorimetry (DSC) and accelerating rate calorimeter (ARC) were used to examine the thermal runaway process during epoxy acrylate synthesis. Increasing the TEA content from 0.3 to 1.0 mass% decreased the initial reaction temperature from 60.16 ± 0.62 to 45.33 ± 0.40 °C and the critical temperature of side reactions from 153.71 ± 1.51 to 117.85 ± 1.19 °C. The severity of the runaway was classified as medium at process temperatures of 80–110 °C. This study highlights the importance of considering reaction conditions to prevent uncontrolled reactions during epoxy acrylate synthesis, providing valuable insights for industrial epoxy acrylate preparation. [ABSTRACT FROM AUTHOR]

This study focused on antibacterial durability testing of surface coatings based on acrylic matrix-embedded UVA-activated ZnO. Such coatings on stainless steel were treated by dry rubbing, wet rubbing, and abrasive treatment to simulate wearing during everyday touching, cleaning, and aggressive scrubbing. Abrasive treatment caused clear topological changes to the surfaces, flattened the surface at the micrometer scale, and released a significant amount of surface material, which was partly acrylic matrix and partly the embedded ZnO. The highest release of Zn, the most prominent photocatalytic activity under UVA and the greatest antibacterial effect, was observed for abrasively treated surfaces. Although a small amount of surface material was released from surfaces after dry and wet rubbing, no significant increase in Zn release or photocatalytic activity was detected. On the contrary, antibacterial activity after those treatments decreased in comparison with untreated surfaces, likely due to partial surface masking by the released acrylic matrix. In summary, our results indicate that antimicrobial ZnO material immobilized in acrylic matrix creates stable surface coatings that may lose some of their efficacy during daily use and cleaning procedures, but activity of which will be retained during a more aggressive abrasion procedure. [ABSTRACT FROM AUTHOR]

Introduction: In in-vitro dental radiographic research, simulation of soft tissue is required to replicate the clinical condition as close as possible. This study aimed to find out which soft tissue simulation material have been studied to use in dentomaxillofacial radiology and showed similarity in radiodensity to the soft tissues of the maxillofacial region. Methods: In this scoping review, Web of Science, Embase, Scopus, Google scholar and PubMed databases were searched on April 9, 2023, considering the following PICOS: Population: soft tissue simulants, Intervention: X-ray-based imaging, Comparison: —, Outcome: properties of the soft tissue simulants, Study design: in-vitro studies. Screening, study selection, and data extraction were performed by two independent researchers. A third team member was consulted in the case of disagreement. Quality assessment of the included studies was made using Quality Assessment Tool For In-Vitro Studies (QUIN Tool). Results: Of the initial 1172 articles retrieved in the database search, 13 studies were included in the review. Seven studies had a low risk of bias. In 8 studies, computed tomography (CT) or cone beam computed tomography (CBCT), in 4 studies intraoral radiography, and in 2 studies panoramic radiography was used (one study has used CT/CBCT and panoramic radiography). The studies varied in the radiographic modality, acquisition parameters, selected outcomes, and gold standard. In the majority of the studies (n = 10, 77%), acrylic resin derivatives were used in the soft tissue simulant formula alone or as a major component. Wax was used in the simulant material in 8 studies (62%). In addition, in 3 studies (23%) ice/water was used as the main simulant. Conclusion: Ballistic gelatin, expanded 2-cm thick polystyrene with or without 1-cm utility wax, and 0.5 cm of acrylic resin were shown to have a radiographic density similar to soft tissue in standardized studies employing CBCT scanning. For intraoral radiographs, using self-polymerizing acrylic resin, utility wax, and wood, as well as a polymethylmethacrylate box filled with water in thicknesses ranging from 4 to 45 mm, provides suitable radiographic contrast. However, for 4 and 8 mm of wax and 4 mm of water, the radiographic contrast is not appropriate. In addition, 13–17 mm wax and 14.5 mm acrylic resin showed acceptable soft tissue densities in intraoral radiography. Further studies using different imaging modalities with standardized conditions and objective metrics are required to confirm the most appropriate soft tissue simulant material for in-vitro dental radiographic research. [ABSTRACT FROM AUTHOR]

This study investigated the flame retardancy of water-based intumescent coatings for plywood by conducting flame retardancy tests by using water-based acrylic resin mixed with various concentrations (1%, 3%, 5%, and 10%) of alkaline lignin. Intumescent coatings containing alkaline lignin demonstrated superior flame retardancy compared with those without additives. At a concentration of 5%, the alkaline lignin promoted the formation of an ideal char layer during combustion. The chemical structure and durability of the phosphorus–carbon structure in the intumescent coatings were investigated through Fourier transform infrared spectroscopy and solid-state nuclear magnetic resonance analysis (13C and 31P). The analysis results reveal that intumescent coatings containing 5% alkaline lignin were more effective in reducing flammability than those containing higher concentrations of alkaline lignin. [ABSTRACT FROM AUTHOR]

This study aimed to test the efficacy of different silica-based toothpastes with or without chitosan, as a method of cleaning the acrylic surfaces of denture prostheses. Acrylic resin specimens were prepared to evaluate surface roughness and gloss (n = 10), and Candida albicans adhesion/inhibition (n = 2). Two toothpastes with different degrees of abrasiveness were used: Colgate (CT) and Elmex (EX), with or without 0.5% chitosan (Ch) microparticles (CTCh or EXCh, respectively). The negative control was brushed with distilled water. Brushing was simulated with a machine. Surface roughness and gloss were analyzed before and after brushing. Candida albicans incidence/inhibition was tested qualitatively to determine the acrylic resin antifungal activity. The roughness and gloss data were analyzed with a generalized linear model, and the Kruskal Wallis and Dunn tests, respectively (α = 5%). Brushing with toothpastes increased roughness and reduced gloss, compared with the negative control (p < 0.05). CT showed a more significantly different change in roughness and gloss, in relation to the other groups (p < 0.05). Addition of chitosan to CT reduced its abrasive potential, and yielded results similar to those of EX and EXCh. Specimens brushed with CT showed a higher potential for Candida albicans adherence, despite its higher antifungal action. Addition of chitosan to the toothpaste made both toothpaste and brushing more effective in inhibiting Candida albicans. CT had the potential to increase roughness, reduce gloss, and increase Candida albicans adherence. In contrast, chitosan added to CT showed greater antifungal potential, and a higher synergistic effect than EX. [ABSTRACT FROM AUTHOR]

In this study, a polymeric adsorbent based on carboxymethyl tragacanth (CMT) grafted by poly acrylic acid-co-acrylamide (AAc-co-AAm) synthesized by radical polymerization for the first time was used to remove the fungicide penconazole (PEN) or Topas 20% from surface water. The parameters of solution pH, adsorption isotherm, and adsorption kinetics of PEN were studied by the synthetic adsorbent. The surface morphology and functional groups of CMT-g-poly (AAc-co-AAm) were confirmed by XRD, SEM and FT-IR techniques. Adsorption of PEN on CMT-g-poly (AAc-co-AAm) follows the Freundlich and pseudo-second-order models. The significant maximum adsorption capacity of the synthesized polymer was found to be 196.08 mg/g. The synthetic adsorbent had good reproducibility in PEN removal for up to 5 cycles. CMT-g-poly (AAc-co-AAm) is a cost-effective and non-toxic adsorbent for the decontamination of surface water from pesticides. [ABSTRACT FROM AUTHOR]

In this article, we review the existing types of binders for thermal and acoustic insulation made of glass and mineral fibers. The current interest in the development and modification of binders for the manufacture of thermal insulation used in the transport, construction, and other industrial sectors is associated with increased requirements for their operational, environmental, and fire-retardant characteristics. Directions in the development of binders for fiber thermal insulation materials that meet modern requirements are indicated. Thus, thermal protection systems should possess sufficient strength and flexibility to maintain their integrity during manufacture, transportation, and installation in target volumes, as well as sufficient elasticity to restore their volume after compression, low specific gravity, low coefficient of thermal conductivity, flame resistance, low smoke emission, and resistance to moisture gain during heating and cooling. [ABSTRACT FROM AUTHOR]

Polymethylmethacrylate (PMMA) acrylic resin is the most used material in dentistry for making prosthetic devices. The polymerization process can cause material failure, which favors the adhesion of microorganisms and reduces the properties of the acrylic resin in clinical practice. Therefore, the objective of this study was to carry out a systematic review in order to answer the question "What is the relation between porosity, wettability, sorption, and solubility properties of acrylic resins incorporated with antimicrobials?" The electronic search of the articles was carried out in four databases and articles published between 2012 and May 2022 were selected. The search terms were: (("acrylic resin" OR PMMA OR polymethylmethacrylate OR methacrylate) AND (antimicrobial OR antifungal OR antibacterial OR nanoparticle) AND (porosity OR wettability OR "sorption and solubility" OR "microbial adesion")). One thousand three hundred thirty articles were found in the databases, after removing the duplicates, 932 were analyzed by title and abstract, of these, 11 were selected for full reading, of which 06 met the inclusion criteria and were selected for review. After descriptive analysis, it can be concluded that acrylic resins incorporated with antimicrobials can maintain the ideal physicochemical properties for the clinical functioning of the material. [ABSTRACT FROM AUTHOR]

Additive manufacturing technology has significantly impacted contemporary industries due to its ability to generate intricate computer-designed geometries. However, 3D-printed polymer parts often possess limited application potential, primarily because of their weak mechanical attributes. To overcome this drawback, this study formulates liquid crystal/photocurable resins suitable for the stereolithography technique by integrating 4'-pentyl-4-cyanobiphenyl with a photosensitive acrylic resin. This study demonstrates that stereolithography facilitates the precise modulation of the existing liquid crystal morphology within the resin. Furthermore, the orientation of the liquid crystal governs the oriented polymerization of monomers or prepolymers bearing acrylate groups. The products of this 3D printing approach manifest anisotropic behavior. Remarkably, when utilizing liquid crystal/photocurable resins, the resulting 3D-printed objects are approximately twice as robust as those created using commercial resins in terms of their tensile, flexural, and impact properties. This pioneering approach holds promise for realizing autonomously designed structures that remain elusive with present additive manufacturing techniques. Complex computerized geometries can be obtained by additive manufacturing. However, the printing of purely three-dimensional polymer shapes possesses inherent poor mechanical stability. Here, the authors overcome this drawback by the light-driven orientation of liquid crystals to guide the alignment of acrylate prepolymers along the direction parallel to UV light vibrations. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the intraosseous arterial pathways and anastomoses in the alveolar aspects of the maxilla in order to better understand the arterial scattering pattern. Materials and methods: Eleven cadavers were selected for macroscopic intraosseous arterial analyses by corrosion casting. The red-colored acrylic resin was injected into the external carotid arteries. The specimens were kept in an enzymatic solution at 36 °C for about 60 days, depending on the process progression. After removal of the soft tissues and drying, the bone was macerated by potassium hydroxide to analyze the course and the mean diameters of the intraosseous anastomoses. Results: Vertico-oblique and horizontal intraosseous arteries and anastomoses between the greater palatine-, posterior superior alveolar-, and infraorbital arteries were detected. The vertico-oblique anastomoses were found on the anterolateral wall of the maxilla and the alveolar crest with a mean diameter of 0.46 mm; nevertheless, the horizontal (transalveolar) anastomoses were identified in the interdental septum/alveolar crest with the mean diameter of 0.41 mm. From the horizontal anastomoses, small intraseptal branches supplied the territory of the alveolar socket in various directions. Conclusions: The localization of intraosseous arterial anastomoses is critical in implant-related surgeries, predominantly to maintain proper circulation. Clinical relevance: Based on vertico-oblique and transalveolar anastomoses, simultaneous buccal- and palatal flap elevation (particularly on the palatal side) should be avoided to minimize patient morbidity and intra- or postoperative complications. Moreover, preserving transverse loops in the interdental septum is essential during implant surgeries, which can significantly influence collateral periosteal and osteal circulation to prevent ischemia. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the effect of acid erosion on different physical properties of resin composite with S-PRG (surface pre-reacted glass) fillers, by conducting simulations of intrinsic and extrinsic sources. Materials and methods: Cylindrical samples (Ø6 vs. 2 mm) of a conventional nanohybrid resin composite (Forma, Ultradent) and of a nanohybrid resin composite with S-PRG filler (Beautifil II, Shofu) were exposed to erosive cycling (5 days), based on (n=12) remineralizing solution (control); 0.3% citric acid (pH=2.6); or 0.01 M hydrochloric acid (pH=2). Roughness (Ra), microhardness (KHN), and color (CIEL*a*b*, CIEDE2000, and Vita scale (SGU)) factors were analyzed at the initial and final time points, and the general color changes (ΔEab, ΔE00, ΔSGU) were calculated. Final images were obtained using scanning electron microscopy (SEM). The data were evaluated by generalized models, Mann-Whitney, Wilcoxon, Kruskal-Wallis, and Dunn tests (α=0.05). Results: Regarding KHN, there was no difference between the groups or the time periods (p = 0.74). As for Ra, there was a significant increase in the Ra of both composites after cycling with hydrochloric acid, but only the resin composite with S-PRG filler showed a change in Ra after cycling with citric acid (p = 0.003). After cycling with citric and hydrochloric acid, the highest Ra values were found for the resin composite with S-PRG filler (p < 0.0001), corroborating the result of images (SEM) indicating loss of filler and porosities in this material. The resin composite with S-PRG filler showed higher ΔEab and ΔE00, in addition to more negative ΔSGU values and lower L* values after exposure to both acids, compared to the control (p < 0.05). Conclusion: The acidic conditions altered the roughness and color stability of the materials tested, pointing out that the resin composite containing S-PRG filler showed greater degradation of its physical properties than the conventional resin composite. Clinical relevance: Bioactive materials are relevant, considering that their properties interact with dental hard tissues; however, the S-PRG-based resin composite showed greater degradation under acidic conditions than the conventional resin composite. [ABSTRACT FROM AUTHOR]

A unique UV-Curing method is provided for decontamination of radioisotopes on the surfaces which has radiation dealing facilities. In this method acrylic UV-Curing resin was poured on a contaminated simulated surface followed by UV irradiation. The resin interacted with the contaminated surface and after polymerization, the solidified resin was then stripped off, leaving behind a clean surface. The present study is the proof-of-concept of a novel application of acrylic resin UV-Curing methodology for Radioactive surface contamination removal to create a economical clean, effective and safe environment with minimal waste generation post processing ready for environment friendly incineration. [ABSTRACT FROM AUTHOR]

Since few decades, researchers have continuously devoted significant efforts to develop coatings as an alternative approach to protect corrosion. Herein, a series of coatings containing various ratios of acrylic and epoxy resins were developed to investigate the corrosion protection on mild steel substrates. In addition, 1 wt% polydimethylsiloxane (PDMS) solution was incorporated as a modifier to enhance the corrosion protection performance and the hydrophobicity of the coatings. The chemical structures and thermal stability of the fabricated coatings were evaluated by the Fourier-Transform Infrared Spectroscopy (FTIR) and Thermogravimetric (TGA) analysis respectively. Furthermore, via the utilization of ultraviolet-visible (UV-Vis) spectroscopy and water contact angle (WCA) instrument, the degree of transparency and surface wettability of the coating samples were investigated. Electrochemical impedance spectroscopy (EIS) was employed to evaluate the corrosion protection performance of the coatings. Among all the coating samples, the EIS results revealed that the T1, T5, and T7 coating samples containing higher ratios of acrylic resin exhibited pronounced impedance modulus ( Z 0.01 H z ) values exceeding 10 10 Ω cm 2 throughout 60 days of exposure to the corrosive medium, 3.5 wt% NaCl solution. Moreover, this finding was supported by the breakpoint frequency measurement which showed that the T1 and T5 coating samples performed at a full capacitive region even after 60 days of immersion. From this investigation, it was concluded that the T5 coating sample exhibited optimum results, thus enhancing the overall corrosion protection performance. [ABSTRACT FROM AUTHOR]

The organosilicon modified cationic acrylic resin is prepared via solution polymerization technology, which butyl acrylate (BA), methyl methacrylate (MMA), styrene (St), vinyltriethoxysilane(VTES), dimethylaminoethyl methacrylate (DMAEMA) and hydroxy propyl methacrylate (HPMA) as the co-polymerized monomers, and proprylene glycol monomethyl ether (PGME) as solvent, and 2,2-azo-bis-iso-butyronitrile (AIBN) as the initiator to create a resin to introduce the Si-O bond into the polymer chains. The cathodic electrodeposition (CED) coatings were prepared by mixing the synthetic resin and blocked isocyanate. The influence of the amount of VETS on the resin and the resultant CED coatings is investigated in detail. The optimum amount of VETS is obtained, which is 5.0%. The hydrophobicity and the acid and alkaline resistance of the film are improved when VETS is introduced to co-polymerize with other monomers. [ABSTRACT FROM AUTHOR]

To fabricate a photocatalytic acrylic paint, TiO2 nanoparticles were surface modified by a bi-functional amino silane (i.e. bis-3-(aminopropyltriethoxysilane)) at different concentrations and applied at 1, 3 and 5 wt% to an acrylic latex. It was found that the surface modification of nano TiO2 enhanced its specific surface area about 42%. The tensile properties of the pristine and nanocomposite acrylic films were assessed. The photocatalytic degradation of aqueous solution and stain of methylene blue (MB) were evaluated (under solar, visible, and UV illuminations) by nanoparticles and nanocomposites, respectively. Results showed that incorporating 3 wt% of the pure and modified nano TiO2 to arylic film caused 62 and 144% increment in the tensile strength. The modified nanoparticles showed higher MB degradation contents under UV, visible and solar irradiation (82, 70, 48%, respectively). The addition of pure and modified nanoparticles to the acrylic film caused decrement in the water contact angle from 84 to 70 and 46°, respectively. It also caused considerable enhancement in the glass transition temperature (Tg) of acrylic film compared to the pristine and pure nanocomposite films (i.e. about 17 and 9 °C, respectively). Furthermore, it was found that the modified nanocomposite caused more color change of MB stain (65%). [ABSTRACT FROM AUTHOR]

Background: Several denture base materials have evolved over the years. Beginning with metal and ending up with various types of acrylic materials in order to have a biocompatible, antimicrobial denture base. A flexible acrylic resin, such as Polyamides, has been introduced to address the drawbacks of heat-cured PMMA resin. This study was conducted to examine the water solubility and water sorption of flexible thermoplastic polyamides (Valplast) and two types of conventional heat-cured acrylic resin (PMMA) (Acrostone, Vertex). Methods: Specimens of thermoplastic polyamides and two types of conventional PMMA (Acrostone, Vertex) resin were manufactured and used in the current investigation in accordance with manufacturer instructions. A total of 45 specimens were milled into discs with a diameter of 50.0 mm diameter, 5.0 mm thick. To ascertain conformity with ADA Standard No. 12, water solubility and water sorption were measured. Results: All items complied with ADA regulations for water solubility and sorption. Flexible thermoplastic polyamide displayed less water solubility, and water sorption than heat-cured PMMA. Acrostone showed the higher water solubility, sorption followed by Vertex heat cure acrylic resin both heat cured showed significant higher water solubility than polyamides Valplast). Conclusions: Within the limitations of this in vitro experiment, heat cure PMMA resin demonstrated significantly greater water solubility and water sorption when compared to thermoplastic polyamides. [ABSTRACT FROM AUTHOR]

The commercial acrylic copolymer Paraloid B72 (PB72) and a synthesized nanostructured material (AMF) bearing silsesquioxane, methacrylate and fluorine units were analyzed to assess their performances as protective coatings for the conservation of Neolithic Cucuteni ceramic pottery when submitted to UV ageing. In the context of comparative evaluation of the protective efficiency, the present paper reports the use of a functional coating that operates via specific photochemical transformations at the coating-air interface as a UV resistant protection coating for cultural heritage artefacts. The main factors that influenced the photo-degradation behavior of the polymeric materials included their structure, the properties at the polymer/air interfaces, and the preferential orientation of functional groups at the surface of the polymeric coatings. [ABSTRACT FROM AUTHOR]

Acrylic and epoxy are common types of resin used in fabricating sockets. Different types of resin will affect the internal surface of a laminated socket. This paper is to determine the best combination of ratio for epoxy and acrylic resin for a laminated prosthesis socket and to evaluate the surface profile analysis of different combinations of laminated prosthetic sockets for surface roughness. Transfemoral sockets were created using various resin-to-hardener ratios of 2:1, 3:1, 3:2, 2:3, and 1:3 for epoxy resin and 100:1, 100:2, 100:3, 100:4, and 100:5 for acrylic resin. Eight layers of stockinette consisting of four elastic stockinette and four Perlon stockinette were used. A sample with a size of 4 cm × 6 cm was cut out from the socket on the lateral side below the Greater Trochanter area. The Mitutoyo Sj-210 Surface Tester stylus was run through the sample and gave the Average Surface Roughness value (Ra), Root Mean Square Roughness value (Rq), and Ten-Point Mean Roughness value (Rz). Epoxy resin shows a smoother surface compared to acrylic resin with Ra values of is 0.766 µm, 0.9716 µm, 0.9847 µm and 1.5461 µm with 3:2, 3:1, 2:1 and 2:3 ratio respectively. However, for epoxy resin with ratio 1:3, the resin does not cure with the hardener. As for acrylic resin the Ra values are 1.0086 µm, 2.362 µm, 3.372 µm, 4.762 µm and 6.074 µm with 100: 1, 100:2, 100:5, 100:4 and 100:3 ratios, respectively. Epoxy resin is a better choice in fabricating a laminated socket considering the surface produced is smoother. [ABSTRACT FROM AUTHOR]

The characteristics of multi-impurities and high-flow velocity in the marine environment can easily cause wear and tear of the surface coating of marine equipment, affecting the reliability and service life of the equipment. In this paper, silicon dioxide (SiO2) hybrid multi-walled carbon nanotubes (MWCNTs) composites were obtained by sol-gel method, and SiO2-MWCNTs acrylic silicone resin composite coatings were prepared. The results showed that SiO2-MWCNTs had good dispersion in acrylic silicone resin, and the lower surface energy could be found in the composite coating with 1.0wt.% hybrid material, with an average contact angle of 107.68°, the impact resistance reached 70 cm·2000 g and the interfacial bonding strength reached 3.29 MPa. The hardness and tribological properties of the composite coating with 2.0wt.% hybrid material were the highest, with the hardness reached 17.7 HV0.05, the wear volume and wear rate were 2.99 × 10− 3 mm3 and 0.12 mm3 N− 1 m− 1 respectively, which were 77.1% and 77.8% higher than those of pure acrylic silicone resin coating. This was mainly attributed to the effect of hybrid MWCNTs bridging to change the direction of crack, uniform distribution of reinforcement phase could formed a larger area of lubrication layer and reduced the friction coefficient and wear rate. In conclusion, the use of SiO2-MWCNTs could effectively improve the mechanical and tribological properties of silicone acrylate resin. [ABSTRACT FROM AUTHOR]

A new type of waterborne acrylic resin was prepared by the solution polymerization with octafluoroamyl methacrylate (OF-PMA), 2-butoxy ethanol, and acrylic monomers as raw materials and N, N-dimethyl ethanolamine as pH regulator. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy showed that the OF-PMA monomers were successfully grafted onto the resin. The effects of the addition mode and content of OF-PMA on the properties of waterborne acrylic resin were studied. The properties of waterborne acrylic polymer and its coating were tested by a thermogravimetric analyzer, an optical contact angle measuring instrument, and a tensile testing machine. The results showed that after the introduction of OF-PMA monomer into acrylic resin, the tensile strength of the resin was increased by 14.31 MPa. Moreover, the water resistance and heat resistance of resin coating were also improved obviously and the as-modified resin coating exhibited better fullness, adhesion of Gt0, and the hardness of 4H. The novel acrylic resin exhibits a potential application prospect in the fields of waterborne wood coatings. [ABSTRACT FROM AUTHOR]

A novel organic-inorganic nanohybrid resin was synthesized through sol-gel process using nano magnesium oxide and specially designed acrylic resin. The uniqueness of this process is incorporation as well as dispersion of nano magnesium oxide into acrylic resin matrix where nano magnesium oxide is functional component. Magnesium oxide nanoparticles were successfully synthesized by sol-gel technique using magnesium nitrate as a precursor. Characterization of synthesized magnesium oxide nanoparticles and their distribution in acrylic resin matrix has been confirmed by spectroscopic, X-ray diffraction and SEM analysis. The coating based on such hybrid resin exhibited excellent anti-microbial activity. Such resin system has potential for application in antimicrobial coating. [ABSTRACT FROM AUTHOR]

Colonization of auto-polymerized acrylic resin by pathogenic Candida albicans is a common problem for denture users. In this study, zinc-modified phosphate-based glass was introduced into an auto-polymerized acrylic resin at concentrations of 3, 5, and 7 wt.%. The mechanical or physical properties (flexural strength, elastic modulus, microhardness, and contact angle), surface morphology of the resultant materials, and the antimicrobial effect on C. albicans were investigated. There were no statistical differences in the mechanical properties between the control and the zinc-modified phosphate-based glass samples (p > 0.05); however, the number of C. albicans colony-forming units was significantly lower in the control group (p < 0.05). Scanning electron microscopy revealed that C. albicans tended not to adhere to the zinc-modified-phosphate-based glass samples. Thus, the zinc-modified materials retained the advantageous mechanical properties of unaltered acrylic resins, while simultaneously exhibiting a strong antimicrobial effect in vitro. [ABSTRACT FROM AUTHOR]

Self-cleaning coatings are becoming an integral part of our daily life because of their utility in various applications. These coatings using nanoscale materials have received significant attention due to the importance of their potential. In the current research work, smart coating with self-cleaning, superhydrophilic application was prepared based on commercial grade water-based acrylic emulsion using nanocrystalline cellulose (NCC), nano-TiO2 (NT), and 3-aminopropyltrimethoxy silane (APTMS) composite in the current work. The sonication process achieved the adsorption of NT on NCC, which was further grafted with APTMS via hydrolysis. The primary confirmation of the chemical structures was done by FTIR spectroscopy, the determination of particle size was done by dynamic light scattering (DLS), morphology and elemental analysis by SEM–EDX, and crystallinity by X-ray diffraction (XRD) analysis. The coating was prepared by dispersing synthesized material in a commercial acrylic emulsion and characterized for mechanical, thermal, surface, and self-cleaning properties. The wettability of the as-prepared coating was analyzed by contact angle measurement. The coating with optimized formulation showed a water contact angle near 6° after photocatalytic activity, which confirms the excellent superhydrophilicity of the coating. Also, removing dust contaminants from the coating surface after water action indicates superior self-cleaning properties. [ABSTRACT FROM AUTHOR]

This study aimed to prepare a bioactive acrylic material by adding different types of glasses. Commercially available polymerized acrylic resin was mixed with 10% of four different types of glasses in the powder form and cured. Flexural strength, sorption, and solubility of the samples were tested according to ISO 20795-1:2013. The total number of samples used in the tests were 60. The materials were placed in artificial saliva of pH 4 and 7, and elution was performed for 0, 1, 28, and 42 days. The collected samples were analyzed using inductively coupled plasma atomic emission spectrometry to detect Ca, P, and Si ions and using ion chromatography to detect F ions. The materials obtained after modification with glasses showed lower compressive strength compared with pure polymethyl methacrylate but met the standard requirements. Two glass types showed higher solubility values compared with the value defined by the ISO standard. Biomin C and S53P4 released Ca, P, and Si ions, respectively, after 42 days in artificial saliva. Acrylic resins modified with 10% Biomin C and S53P4 glasses can be a valuable source of Ca and P ions under acid conditions for 28 and 42 days. [ABSTRACT FROM AUTHOR]

The radical copolymerization was used to synthesize cationic acrylic resin, which the methyl methacrylate (MMA) was used as the main hard monomer and styrene (St) was added to replace the function of MMA to reduce the cost of raw materials. Butyl acrylate (BA) was used as the main soft monomer to reduce the glass transition temperature of the polymer. Hydroxypropyl methacrylate (HPMA) was used to provide cross-linked hydroxyl groups for resin, and hydroxyl groups also had a certain hydrophilic properties. Dimethylaminoethyl methacrylate (DMAEMA) was used to provide tertiary amine group for the resin, which was acidified by organic acid to form ammonium salt. The cathodic electrodeposition (CED) coatings were prepared by mixing the resultant resin and blocked isocyanate. The conditions of synthesizing the cationic acrylic resin were optimized. The optimum synthetic conditions were the following. The mass ratio of (MMA + St) to BA was 3:2. The amount of DMAEMA was 12–15% in total monomer. The amount of HPMA was 20% in total monomer. The amount of the initiator was 2%. The neutralization degree was 80%. The reaction temperature was 90 °C. Both the conductivity of electrophoretic coating and its film were good when the cationic acrylic resin was synthesized under the optimum conditions. Besides, the characterization of Fourier transform infrared spectrometer (FTIR) and differential scanning calorimetry (DSC) confirmed that the cationic acrylic resin had been synthesized successfully. [ABSTRACT FROM AUTHOR]

This paper proposes a novel steganography method to show an aerial image that is formed with aerial imaging by retro-reflection by use of dual transparent balls made of acrylic resin. Our optical system forms a floating image screen in front of an acrylic ball that is placed on a beam splitter. We have confirmed our proposed optical system by performing optical ray-tracing simulations and experiments with a prototype aerial display. The ray-tracing results show that an acrylic ball plays the role of a ball lens, reducing the area of the retro-reflector and improving the luminance of the aerial image. Then, we measured the luminance distribution of the aerial image formed by the proposed method by imaging the aerial image of the stripe pattern with a luminance meter. From the measurement results, the luminance of the aerial image at a radius of about 5 mm from the center of the acrylic ball (radius 35 mm) was almost the same as that of the conventional method. In addition, an aerial image was observed within a radius of 25 mm, although the luminance was low. Thus, the simulation and experimental results confirm the effective range of aerial imaging in the proposed method. [ABSTRACT FROM AUTHOR]

Biofilm accumulation on the polymethyl methacrylate (PMMA) restorations negatively affect the prognosis of the provisional restorations or the following treatment. This study developed a novel antibacterial PMMA resin containing low concentration of dimethylaminohexadecyl methacrylate (DMAHDM). Four resins were tested: (1) PMMA resin (Control), (2) 1.25% DMAHDM, (3) 2.5% DMAHDM, (4) 5% DMAHDM. Adding 1.25% DMAHDM into the PMMA resin did not influence the mechanical properties, degree of conversion, monomer releasing, and color stability of the specimens (p > 0.05). The incorporation of DMAHDM into PMMA resin could greatly prevent saliva-derived biofilms adhesion compared with the control group (p < 0.05). The metabolism level of saliva-derived biofilms on the 1.25%, 2.5%, and 5% DMAHDM resins were reduced by 20%, 54%, and 62%, respectively. And the mechanism of DMAHDM disturbing the integrity of bacterial cell walls was confirmed by flow cytometric analysis. Adding 1.25% and 2.5% DMAHDM did not compromise cytocompatibility of the modified resin (p > 0.05). Therefore, novel PMMA resin containing low concentration DMAHDM is promising as a future antimicrobial provisional restoration material for preventing microbial-induced complications in clinical settings. [ABSTRACT FROM AUTHOR]

In this study, the contents of ethyl cellulose (EC) as thickener in organic vehicle, which also acts as a binder, was examined using various control experiments; dibutyl phthalate (DBP) and dioctyl phthalate (DOP) were used as plasticizers, and acrylic resin (AR) was used as the thixotropic agent. In addition to thixotropic index, Bigham and Casson yield stress models were used for simulation, and the organic vehicle was dynamically simulated via the three interval thixotropy test; the viscosity recovery of the organic vehicle was investigated on the removal of shear stress. When the contents of the plasticizers, DBP and DOP, were 4 wt% and 6 wt%, respectively, the content of the thickener, EC, was 12 wt% and that of the thixotropic agent, AR, was 2 wt%, the comprehensive performance of the organic vehicle was greatly improved, especially in terms of thixotropy and recovery behavior. Our results demonstrate that the current organic vehicle is promising for the application of silver pastes used as inner electrodes in low-temperature co-fired ceramic (LTCC). [ABSTRACT FROM AUTHOR]

Purpose: The aim of this trial was to compare the microbial colonization of heat-cured silicone and heat-cured acrylic resin in obturators restoring acquired maxillary defects. Material and methods: The experiment was carried out on six partially edentulous patients having unilateral total maxillectomy defects approaching midline (class I Aramany classification) who are in need of definitive obturator. Selected patients received metal framework prosthesis with heat-cured acrylic resin bulb extending into the surgical site. At the time of delivery, a swab was obtained from the patients who represent the baseline for the group I. Patients were recalled after two and four weeks from wearing the obturator for microbiological evaluation and a swab was taken each time from the same place. In group II, the heat-cured acrylic resin was replaced with heat-cured silicone and a swab was obtained on the day of insertion as a baseline for group II. Patients were recalled after two and four weeks from the insertion of the relined obturator for microbiological evaluation and a swab was taken each time from the same place. Swabs were obtained from the nasal surface of the surgical defect and immediately cultivated into three different media Blood Agar, Sabouraud Dextrose Agar, and Macconkey media and incubated for microbiological evaluation. The identification and quantification of the isolated microorganisms were performed using the conventional microbiological cultivation method. Finally, the collected data were tabulated and statistically analyzed. Results: Statistical analysis of the collected data showed, that the difference between the two groups was insignificant. However, patients were more satisfied with obturators lined with heat-cured silicone. Conclusion: It was concluded that within the limitations of this study, both acrylic resin and resilient lining materials could be used as a material for obturator construction in maxillofacial cases. However, longer follow-up period might show different results. [ABSTRACT FROM AUTHOR]

Laser-induced cavitation bubble behavior on the solid walls of different materials was experimentally investigated by focusing the pulsed laser on the wall. To examine the influence of wall reflectivity on laser-induced cavitation, high-speed observations of the bubble behavior and impulsive-force measurements were carried out on aluminum, steel, copper, and acrylic resin walls. It was found that the bubble behaviors and impulsive forces vary with the wall materials, and their behaviors depend on the wall reflectivity. Increased bubble diameter, bubble collapse time, and high impulsive force were observed on the walls with high reflectivity. This result can be due to the increased laser illumination on the highly reflective walls. This promotes the heating of liquid near the wall at the laser breakdown in the first impact on the wall, while the increased bubble diameter by this effect promotes the bubble collapse phenomenon and intensive shockwave formation, resulting in the high impulsive forces on the wall in the second impact. [ABSTRACT FROM AUTHOR]

To compare the vertical root fracture (VRF) resistance of root canal-treated teeth instrumented with four different nickel–titanium (NiTi) rotary file systems and examine the dentinal crack pattern and direction using a new classification. Eighty mature mandibular premolars were selected and decoronated, leaving 13 mm of the root. The root samples were mounted in acrylic resin and divided randomly into five groups of different NiTi file systems: Group 1—control, Group 2—T-Pro, Group 3—HyFlex CM, Group 4—TG6 and lastly Group 5—ZenFlex. Samples in Group 2 and Group 3 were instrumented up to size 25/0.04, whereas Group 4 and Group 5 were instrumented up to size 25/0.06. Obturation was performed with AH Plus sealer and gutta-percha using single cone technique. Subsequently, all samples were subjected to occlusal compressive force until they were fractured. The force (N) needed to cause root fracture was recorded. The crack patterns and directions were also inspected under magnification and classified using a new and simple classification. The highest (VRF) resistance was noted in the control group (453.15 ± 92.23 N), followed by T-Pro (387.43 ± 76.81 N), HyFlex CM (381.88 ± 52.73 N), ZenFlex (369.15 ± 89.41 N) and finally TG6 (346.05 ± 72.08 N), but there was no significant difference between T-Pro and HyFlex (P = 0.438). A significantly higher prevalence (P = 0.001) of Type 1 crack pattern was observed, especially in samples instrumented with TG6. Majority of the cracks ran buccolingually except in some samples instrumented with ZenFlex (P = 0.898). Smaller file taper increased the VRF resistance of root canal-treated teeth. Majority of the dentinal crack exhibited Type 1 pattern and ran buccolingually. [ABSTRACT FROM AUTHOR]

To expand the applications of graphene which has so far been limited by the expensive nature of single-layer graphene, the effects of varying percentages of low-cost functionalized multilayer graphene nanosheets in siloxane-modified organic coatings were studied. The hydrophobic organic siloxane–acrylic resin was prepared by solution polymerization of acrylic monomers, and the graphene nanosheets were functionalized using fluorosilane. The coatings were sprayed on the LY12 aluminum substrate, and the wettability, anticorrosion, conductive, and accelerated weathering behaviors were comprehensively examined. It is shown that the increasing addition of functionalized graphene nanosheets increases the water contact angle and the surface conductivity. At 5% graphene loading, coating–substrate adhesion remains almost unchanged, while the electrochemical impedance parameters revealed good anticorrosion performance up to 10% loading. The surface measurements and Fourier transform infrared spectroscopy (FTIR) results confirmed the photostabilization ability of graphene loading in acrylic coatings during the accelerated weathering test. Also, the mechanical properties of the coatings were not damaged during the exposure, and pitting corrosion sites were observed only on the 20% graphene-filled coatings after 1000 h of exposure. These integrated analyses of mechanical properties and environmental accelerated tests are beneficial to engineering applications of graphene coatings. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the microhardness, roughness, profilometry and cross-sectional hardness of single increment materials submitted to different challenges. Methods: Thirty-six disks of each material, Filtek Supreme XTE (FT), Filtek One Bulk Fill (BK), Ketac Molar Easy Mix (KT) and Equia Forte + Coat (EQ) were immersed in saliva, pH cycling and Coke for 15 days. Half of each surface was used as its own control. Superficial microhardness, roughness, perfilometry analysis were performed. All samples were sectioned, embedded in acrylic resins, polished and cross-sectional hardness were made. Data were analyzed by ANOVA and Tukey's test (p < 0.05). Results: The KT presented superficial microhardness superior than EQ. However, in depth, EQ showed superior values. FT, KT suffered the effects of challenges on microhardness values. The highest roughness and wear values were found for KT. RC do not suffer wear. All materials suffered the effects of Coke and pH challenges in depths 10 µm and 60 µm. Conclusion: The single increment restorative material that suffered less action on its surface was the bulk-fill resin. The coat present in the hybrid ionomer was able to resist to the immersion actions. In addition, Coke was the most aggressive challenge. [ABSTRACT FROM AUTHOR]

The aim of this study was the colour fastness investigation of the new synthetized direct symmetrical azo-stilbene dye, using two of the film field domain reference tests, namely the wet-scrub and the UV tests. The dye was incorporated in a water-based resin, and then was applied on a PCV foil. The film colour parameters were determined before and after 200 wet-scrub cycles. Further, the dye was mixed with an acrylo-polyurethanic resin and then was applied on an aluminium plate, which was exposed to UV radiation for 414 h. The film colour parameters were recorded periodically. The maxima of the reflectance spectra depend on the UV time exposure. The quality of the film was analysed by the degree of gloss. A second focus was the elimination of the dye's traces from wastewaters (these may be resulted from the industries which apply surface coating methods), using the active carbon powder. The main operational adsorption process parameters influence were investigated. Equilibrium, kinetic and thermodynamic studies were performed. The adsorption process was confirmed by the CIEL*a*b* colour space analysis. All colour studies were investigated using UV–Vis spectroscopy. [ABSTRACT FROM AUTHOR]

A novel strategy was proposed to fabricate alkali-resistant PVDF membrane via sodium lauryl sulfate (SDS) attached to the surface of membrane and immobilized by UV-curable polyester acrylate and tri(propylene glycol) diacrylate (TPGDA). The attached anionic surfactant, SDS, on the membrane surface can resist the alkali corrosion by NaOH, and the curing of the resin can immobilize the SDS on the membrane firmly. Due to the unique alkali resistance of SDS and resin formed, the UV-curable resin-modified PVDF membrane showed greatly enhanced alkali-resistant ability. Characterization of SEM and FTIR showed that polyester acrylate and TPGDA were cured successfully under the action of 1-hydroxycyclohexyl phenyl ketone (184) and ultraviolet light. Whiteness, differential scanning calorimeter and X-ray photoelectron spectrometer characterization showed that the modified PVDF membrane had a lower degree of dehydrofluorination than the pristine PVDF membrane after alkali treatment. Results of the detailed alkali-resistant analysis indicated that the F/C ratio of the UV-curable resin-modified PVDF membrane decreased by 2.6% after alkali treatment compared to pristine PVDF membrane decreased by 19.28%. The alkali-resistant performance was mainly attributed to the immobilized SDS. This study provided a facile and scalable method for designing alkali-resistant PVDF membrane, which shows a promising potential in the treatment of alkaline wastewater and alkaline-cleaning PVDF membrane. [ABSTRACT FROM AUTHOR]

Purpose: To compare the range of reach of our newly designed omni-directional ureteroscope (URF-Y0016), compared to the commonly used URF-P6, FlexX2s, and LithoVue™ scopes, in the upper, middle, and lower calyces in an ex-vivo pyelocaliceal model. Methods: We fabricated a three-dimensional pyelocaliceal model of the upper, middle, and lower pole calyces using urethane and acrylic resin. The inner surface of the dome of each calyx was engraved with reference lines along eight directions, set at 10° of latitude from the top to the base of the dome, and at angles of 0–90°, to precisely determine the range of reach of each scope. The main feature of the URF-Y0016 scope is the omni-directional bending of the tip of the flexible ureteroscope, with the control of these four directions integrated into a handgun-type control unit with a joystick. The range of reach within each calyx was measured by four expert surgeons. Results: The URF-Y0016 scope provided a greater range of reach along all directions in the lower pole calyx compared to URF-P6, FlexX2s, and LithoVue™ scopes (p < 0.001), particularly along the anterior–posterior direction in the lower lobe calyx. However, the URF-Y0016 scope did not influence the improvement of reach range in the upper and middle pole calyx compared to URF-P6, FlexX2s, and LithoVue™ scopes (p = 0.08, p = 0.296). Conclusion: The novel design of the URF-Y0016 could improve treatment outcomes for calyceal stones in the lower pole in practice. [ABSTRACT FROM AUTHOR]

In this study, the effect of crosslinking density of an acrylic-melamine clearcoat on water vapor transmission rate was evaluated. Four types of acrylic resins with different OH contents were used as the main polymeric backbone of the acrylic-melamine clearcoat. Also, three different acrylics to melamine–formaldehyde ratios were used in the coating formulations to obtain various crosslinking densities. It was observed that other film properties such as surface hydrophilicity and molecular homogeneity had a crucial impact on the clearcoat water vapor transmission rate together with the crosslinking density. Surprisingly, results showed that samples with acrylic resin with less OH content and lower melamine–formaldehyde crosslinker had the lowest water vapor transmission rate among other samples. These results were in agreement with the water contact angle and the data deduced from dynamic mechanical thermal analysis (DMTA) results of clearcoats. [ABSTRACT FROM AUTHOR]

Currently, there is tremendous interest in the development of surface coatings for outdoor applications that are self-cleaning with strong antibacterial properties. Herein, aniline was polymerized in situ with silver–N-doped TiO2 composites to fabricate PANI–Ag–N–TiO2 nanocomposites, which were then mixed with an acrylic resin to form coatings on type 316L stainless steel. Under UV–Vis light illumination, the PANI–Ag–N–TiO2 coatings delivered a stable photocathodic potential of − 0.79 V, a much larger negative potential than was realized using PANI–N–TiO2 (− 0.55 V) or PANI–TiO2 (− 0.40 V) coatings. The addition of Ag nanoparticles thus greatly enhanced the photo-cathodic response. Antimicrobial experiments demonstrated that the PANI–Ag–N–TiO2 coating offers good antibacterial activity (> 95% inhibition) against E. coli under UV–Vis light irradiation for 30 min, due to the generation of hydrogen peroxide or other reactive oxygen species capable of damaging the membrane of E. coli cells. Results suggest that PANI–Ag–N–TiO2 composite coatings offer good antifouling performance in marine environments. [ABSTRACT FROM AUTHOR]

Objectives: This in situ study aims to evaluate the effects of chlorhexidine (CHX) mouth rinsing on biofilm formation and moreover on the disruption of existing mature dental biofilms. Methods: Biofilms were formed in situ by five volunteers on bovine enamel specimens fixed to individual acrylic splints. For biofilm formation analysis, the volunteers intraorally exposed the splint for 48 h. Mouth rinsing using 10 ml of 0.2% CHX or water as control was performed for 30 s every 12 h. For analysis of biofilm disruption, the biofilm was formed on enamel specimens for 48 h. Then, the first CHX rinse was carried out. A second rinse followed after an additional 12 h, again for 30 s using 10 ml of 0.2% CHX. Biofilm vitality was imaged by fluorescence microscopy after vital fluorescence staining. Additionally, the ultrastructure of the biofilm was examined by transmission electron microscopy. Results: Rinses with 0.2% CHX significantly reduced biofilm formation on enamel. Both biofilm colonization and vitality were dramatically impaired. Moreover, a considerable biofilm disruption induced by the CHX rinses was observed. Remarkably, a single application of CHX to a 48-h mature biofilm causes biofilm ultrastructure alterations and induces a substantial reduction in biofilm thickness and bacterial vitality. Conclusions: CHX mouth rinses induced a significant inhibition of biofilm formation on native enamel. Furthermore, an important biofilm disrupting effect under in situ conditions was detected. Clinical Relevance: CHX rinses could be used as a short-term treatment protocol for biofilm management focused on patients unable to reach adequate oral hygiene. [ABSTRACT FROM AUTHOR]

A lower expansive heavy metal adsorbent, high crosslinked sodium carboxyl methylstarch-g-poly (acrylic acid-co-acrylamide) resin (HCAA), has been prepared by enhancing the crosslinking degree of the traditional water-absorbing polymer under the graft copolymerization reaction. Further heavy metal adsorption experiments, morphology analysis, and structure characteristic observations indicate that HCAA resin has an excellent heavy metal adsorption properties for Cr3+, Cu2+, Ni2+, and Zn2+ of 80.08, 158.07, 155.71, and 137.15 mg/g, respectively. The nanoholes in network structures of HCAA resin expanding in solution provide an effective diffusion and exchange channels for heavy metal ions and Na+. The adsorption process of HCAA containing –COONa is attributed to ion exchange process, and its essence is to form the coordination bond with heavy metals. The adsorption capacity differences of –COO− have been explained by using the coordination chemistry theory. In addition, the adsorption selectivity of an expansive adsorbent containing –COONa are heavy metals > H2O >> Na+. Our research puts forward an insight that increasing the crosslinker content on the basis of the traditional super absorbent resin can obtain a lower expansive adsorbent to heavy metal pollutants. [ABSTRACT FROM AUTHOR]

Intumescent coatings are a great alternative for passive protection of metal substrates against fire, with binder polymer being one of the main components of an intumescent system. The objective of this work was to compare five different resin types (epoxy, acrylic, alkyd, silicone, and silicone–epoxy hybrid) in an intumescent formulation and to study the influence of resin concentration on the fire protection performance of the coating. Results from TGA and MCC analysis of resins and coatings indicated that coatings containing silicone are thermally stable and release smaller amounts of heat. In the fire resistance test, samples containing epoxy and silicone resins had lower temperatures (130–160°C) compared to the other samples. It has also been found that it is possible to decrease resin concentration in formulations containing epoxy and silicone resins up to 25.6% and to maintain or even improve their fire protection capability. [ABSTRACT FROM AUTHOR]

We investigated the adsorption of Cd2+ and Pb2+ using straw/bentonite-g-poly(acrylic acid-co-acrylamide) resin as an adsorbent in single and binary-component systems. The resin was characterized by various analytical techniques. Adsorption experiments were conducted by varying the pH, adsorbent dosage, initial concentration and temperature. Adsorption data for Cd2+ and Pb2+ fitted the Langmuir isotherm in the single-component system. Kinetic data for Cd2+ and Pb2+ followed the pseudo-second-order kinetic in a single-component system. A maximum adsorption for Cd2+ occurred at pH 5, whereas for Pb2+, the maximum Cd2+ adsorption occurred at pH 3. The maximum Cd2+ and Pb2+ adsorption capacities were 315.1 mg g−1 and 355.5 mg g−1, respectively. In the binary-component system, the presence of Cd2+ could improve the adsorption capacity of Pb2+ and the presence of Pb2+ could reduce the adsorption capacity of Cd2+ when the Cd2+ concentration was high. This study provides realistic and valid data on resin use to remove heavy metal ions from aqueous solutions. [ABSTRACT FROM AUTHOR]

Introduction: On majority of roads, horizontal road markings are essential safety feature that must be periodically renewed to maintain appropriate performance. Results: The use of a premium road marking system resulted in prolonged the service life as compared to a standard system, which would be financially-neutral in the long term despite much higher unit and initial costs; advantageously, 54% less glass beads and 63% less paint would be required over 10-year life cycle. When these products usage savings are recalculated into raw materials consumption, the premium system would demand about 21% more of titanium dioxide, but that would be offset by approximately 25% reduction in the consumption of acrylic resin and circa 97% reduction in organic solvents usage and emissions. Conclusions: The results from this analysis can be used by road administrators to select the best systems, by policy makers seeking minimisation of environmental impacts, and by contractors who won performance tenders. [ABSTRACT FROM AUTHOR]

Epoxy acrylic resin (EAR) has been widely used in the chemical industry for many years. However, its potential hazard is still to be ascertained. Currently, it is known that the exothermic polymerization reaction of the EAR in acrylic acid occurs at about 90 °C in the first phase and the epoxy ring opening and exothermic reaction occur at about 200 °C in the second phase. Runaway reaction may occur if the temperature is not well controlled. The amount of catalyst is a factor that may bring about a change in the reaction rate. Hence, this study aims to test and ascertain the effects of the catalyst in terms of its dosage on the runaway reaction of the EAR to understand the extent of the effect of the catalyst on the process. A differential scanning calorimeter was used in this study to analyze the potential hazards of the EAR. The experimental results of the research can be used as a reference for field personnel to design processes and control damage. They will give more confidence to the public and the personnel in relevant industries in terms of the EAR process and storage. Catalysts of different types and dosages used in the epoxy resin and acrylic acid reaction may affect the reaction of exothermic rates. Therefore, it is suggested to conduct a heating test to determine whether or not any adiabatic test is needed when using a new process or formula to ensure operating safety. [ABSTRACT FROM AUTHOR]

Bisphthalonitrile (BPh) resin was modified by diallyl bisphenol A/bismaleimide resin prepolymer (DP/BMI). Differential scanning calorimeter (DSC) and Fourier transform infrared spectroscopy were used to characterize the curing acceleration of modified bisphthalonitrile (MBPh) resin. The results show that DP/BMI resin has a good acceleration effect on the curing of BPh resin, and the peak temperature of MBPh resin was 250.6 °C. MBPh resin was blended with novolac cyanate ester (NCE) resin, and DSC, rheometer, and thermogravimetric analyzer were used to investigate the curing reaction thermodynamics, rheological properties, and heat resistance of MBPh/NCE resin system. The results show that the addition of MBPh resin had little impact on the lowest viscosity (1–6 Pa s) of NCE resin. The DSC peak temperature of MBPh/NCE resin decreased to 235.7 °C after adding 30 wt% of MBPh resin. The addition of MBPh obviously increased the temperature at 90% carbon yield of NCE resin, with the 90% carbon yield temperature rising by nearly 100 °C. The mechanical properties of MBPh/NCE resin system were evaluated by tensile properties, bend properties, impact strength, and fracture toughness. The results show that MBPh had little impact on the tensile properties and bend properties of MBPh/NCE resin, and slightly increased their impact strength and fracture toughness. [ABSTRACT FROM AUTHOR]

This study investigated (i) the degradation effect of 405-nm blue light-emitting diode (LED) light irradiation on Candida albicans and C. glabrata biofilms formed on denture base resin and (ii) the effects of 405-nm blue LED light irradiation on the mechanical and surface characteristics of the resin. Polymethyl methacrylate denture base resin discs were prepared, and C. albicans or C. glabrata biofilms formed on the denture base resin discs. Each biofilm was irradiated with 405-nm blue LED light under a constant output power (280 mW/cm2) for different times in a moisture chamber with 100% relative humidity. Postirradiation, each biofilm was analyzed using a colony-forming unit assay, fluorescence microscopy, and scanning electron microscopy (SEM). Parallelepiped specimens of acrylic resin were prepared, and changes in their flexural strength (FS), flexural modulus (FM), and surface roughness (Ra) preirradiation and postirradiation with 405-nm blue LED light were evaluated. Irradiation for 30 min completely inhibited colony formation in both Candida species. Fluorescence microscopy showed that almost all Candida cells were killed because of irradiation. SEM images showed various cell damage patterns, such as wrinkles, shrinkage, and cell surface damage. An increase in FS was noted postirradiation, but no significant changes were observed in FM and Ra preirradiation and postirradiation. In conclusion, irradiation with 405-nm blue LED light induces degradation of C. albicans and C. glabrata biofilms on denture base resin, even in the absence of photosensitizers, without resin surface deterioration. [ABSTRACT FROM AUTHOR]