Wax Resin Research Articles

Characterization of a mixed mode fluorocarbon/weak anion exchange sorbent for the separation of perfluoroalkyl substances.

The ubiquitous presence and persistence of per- and polyfluoroalkyl substances (PFAS) in the environment have raised concerns in the scientific community. Current research efforts are prioritizing effective PFAS remediation through novel sorbents with orthogonal interaction mechanisms. Recognized sorption mechanisms between PFAS and sorbents include hydrophobic, electrostatic, and fluorine-fluorine interaction. The interplay of these mechanisms contributes significantly to improved sorption capacity and selectivity in PFAS separations. In this study, a primary/secondary amine-functionalized polystyrene-divinylbenzene (Sepra-WAX) polymer was modified to create a fluorinated WAX resin (Sepra-WAX-KelF-PEI). The synthesis intermediate (Sepra-WAX-KelF) was also tested to assess the improvement of the final product (Sepra-WAX-KelF-PEI). The adsorption capacity of Sepra-WAX, Sepra-WAX-KelF, and Sepra-WAX-KelF-PEI, and their interactions with PFAS were evaluated. The effect of pH, ionic strength, and organic solvents on PFAS sorption in aqueous solution was also investigated. The sorbents showed varied adsorption capacities for perfluorooctanoic acid, perfluoropentanoic acid, perfluoro-n-decanoic acid, and hexafluoropropylene oxide dimer acid, with the average extraction capacity of the four analytes being Sepra-WAX-KelF-PEI (523mg/g)>Sepra-WAX (353mg/g)>Sepra-WAX-KelF (220mg/g). Sepra-WAX-KelF-PEI provided the highest adsorption capacity for all analytes tested, proving that the combination of electrostatic and hydrophobic/fluorophilic interactions is crucial for the effective preconcentration of PFAS and its future applications for PFAS remediation from aqueous solutions.

Development of a Thermal Separation Probe Gas Chromatography–Mass Spectrometry Method for Evaluating Wax–Resin Removal by Evolon® CR

Historically, many canvas paintings were infused with wax–resin mixtures that have discolored over time, distorting the aesthetics of the work, limiting treatment options, and introducing unstable materials into the object. Removal of the wax–resin is often desirable, but before works of art can be treated, a protocol to evaluate the efficacy of the treatment must be established. A mock-up painting was infused with a known amount of a wax–resin mixture made from beeswax and dammar; this material was then extracted through six intervals of exposure to solvent-loaded and dry sheets of Evolon® CR, a non-woven textile with a high sorbent capacity. Samples from the Evolon® CR sheets from each extraction round were analyzed using thermal separation probe gas chromatography–mass spectrometry (TSP-GC/MS). Normalization of peak areas related to beeswax and dammar to those of Evolon® CR revealed the relative amount of wax and resin removed throughout the extraction. The data show that, under these test conditions, the beeswax and dammar appear to be extracted with the same relative efficiency, information that cannot be provided through UV-induced visible fluorescence imaging of the Evolon® CR sheets or weight data alone, but which is critical to capture as it has implications for treatment success and the long-term stability of an artwork.

Optimization of Wax Model Printing using a DLP 3D Printer for Castable Wax Resin material

Wax material can be used to make craft items as models that are printed using 3D printing. Custom and mass production processes for craft items can be carried out according to customer needs. This research aims to find the best process parameters in optimising the wax printing process as a printed model using 3D Printing DLP technology to have the best dimensional accuracy, geometric accuracy, and surface roughness. The method used is a design of experiment with factors in the form of exposure time and layer thickness, each of which has three levels to produce the best response: dimensional accuracy, geometry, and surface roughness. The research results show that print parameters with an exposure time value of 16 seconds and a layer thickness of 0.06 are the best experiments in producing dimensional accuracy of the print results. This is indicated by the smallest shrinkage percentage value of 0.41%. Meanwhile, to obtain smooth print results with minimal defects, printing is carried out with an exposure time parameter of 14 seconds with a layer thickness of 0.06 mm.

A Comparative Study to Assess Accuracy of Casts Prepared using Direct Impression Technique with and without Splinting of Multiple Dental Implants Utilising Two Different Splinting and Impression Materials.

The current study examined the accuracy of casts generated using direct impression processes with and without splints for multiple dental implants utilizing two different splinting materials and impression materials. Dental replacement base intensity alleviating acrylic tar was used to create a reference model of a mandible with four inserts (Uniti, Equinox, D-3.7 mm, and L-13 mm) in the front. Polyether and polyvinyle siloxane impression materials were used to make impressions of the reference model utilizing direct non-splinted and splinted techniques. Polyether impression material was found to produce more accurate impressions than polyvinyl siloxane, and impressions made using transfer copings splinted with pattern resins were found to be more accurate than those made using either unsplinted copings or copings splinted with light-cured wax resin. All six impression techniques resulted in casts that were different from the reference model. Next, the polyether-splinted (SPR) technique is the nonsplinted technique employing polyether and polyvinyle siloxane imprint materials, and then, the splinted techniques using polyether and polyvinyle siloxane and produced the most accurate casts in comparison with the reference model.

Nanocomposite Organogel for Art Conservation─A Novel Wax Resin Removal System.

We describe a new, safe, and effective method for removing wax resin adhesive from the canvases of paintings conserved by the once widely used Dutch Method, which involved attaching a new canvas to the back of a painting using an adhesive made of beeswax and natural resin. First, a low-toxicity cleaning mixture for dissolving the adhesive and removing it from the canvases was developed, and then a nanocomposited organogel was obtained. The ability of the organogel to remove the adhesive from canvases was investigated on the lining of the 1878 painting "Battle of Grunwald" by Jan Matejko, with promising results. Additionally, we found that the organogel can be used several times with no visible loss of cleaning ability. Finally, the effectiveness and safety of the method were confirmed on two oil paintings (one from the National Museum in Warsaw): all the wax resin adhesive was removed and the painting regained its original brightness and vivid colors.

Comparison of the Color Change of Porcelain Laminate Veneers Produced by Different Materials After Luting with Three Resin Cements.

This study aimed to compare color change of porcelain laminate veneers fabricated with two lithium disilicate ceramics and a zirconia-reinforced lithium silicate ceramic material after luting with conventional dual-cure, amine-free dual-cure, or light-cure resin cements using artificial accelerated aging (AAA). Ninety noncarious human maxillary central incisors were embedded in autopolymerizing acrylic resin blocks to prepare conventional laminate veneers with incisal coverage. Prepared teeth were randomly divided into 3 groups (n=30) to fabricate laminate veneer restorations using: (1) lithium disilicate ceramic, (2) lithium disilicate ceramic with high-density micronization, and (3) zirconia-reinforced lithium silicate ceramic. Impressions of the preparations were taken with a laboratory scanner. Acquired 3D images were processed into a surface tessellation language file. Data were exported for 3D printing on a printer, and laminate veneers were printed in castable wax resin. Ceramic veneers were heat-pressed after investment according to the manufacturer's recommendations and further divided into three groups (n=10) according to luting cement type: (1) light-cure resin cement, (2) amine-free dual-cure resin cement, and (3) conventional dual-cure resin cement. Color measurements were performed from the middle of each specimen with a spectrophotometer before and after AAA for 300 hours with a total energy of 150 kJ/m2. Color changes were calculated with the CIEDE 2000 (ΔE00) formula. Color differences were assessed using two-way analysis of variance (ANOVA) (α=0.05), and the paired t-test was used to compare the L*, a*, and b* parameters in each group before and after aging. There were no significant differences between the ceramic groups (p>0.05). The color changes of the materials ranged from 2.26 to 3.13. All materials were above the clinically acceptable limit (ΔE00>1.8). The conventional dual-cure resin cement group showed more color change (p>0.05). Color changes were observed in all porcelain laminate veneers after artificial accelerated aging. The zirconia-reinforced lithium silicate veneers showed similar color changes as lithium disilicate veneers; the amine-free dual-cure resin cement showed a similar color change as light-cure resin cement after aging.

The accuracy comparison of 3D-printed post and core using castable resin and castable wax resin.

The purpose of this research was to compare the accuracy of three-dimensionally (3D) printed post and core fabricated with two different materials: reinforced wax and castable resin. MATERIALSAND METHODS: Fifteen extracted single root central incisors were selected. Root canal treatment and tooth preparation for crown were performed on all teeth. Eleven millimeters post space was created with standardized prefabricated fiber post drill. Polyvinylsiloxane impression material was used for root canal impressions. Each impression was then 3D scanned using an extraoral scanner and cast posts and cores were designed using 3Shape software. The digitally designed post and cores were 3D printed with two different materials: castable wax resin and castable resin. The castable resin patterns were scanned before and after complete polymerization. The wax patterns were also scanned. Digital volumetric measurement using Geomagic® Control X™ software was performed to determine accuracy. The printed post and core had reduced volume (16.09± 3.839 mm3 ) compared to the digital design (17.828± 3.904, p < 0.05). Before complete polymerization, the accuracy of 3D printed resin pattern (16.464± 3.017) was found to be superior to post and core printed with wax (16.193± 3.018, p < 0.05). However, no volume difference was found between completely polymerized resin (16.09± 3.839) and wax (16.044± 3.834, p = 1). 3D printed post and core showed significant volume shrinkage from the digital files used to create them. However, different materials had no effect on the accuracy of 3D printed post and core.

3D Helical Micromixer Fabricated by Micro Lost‐Wax Casting

AbstractMicromixers produced by micro fabrication techniques have attracted attention for micro total analysis systems and lab‐on‐a‐chip applications in point‐of‐care testing. However, the fabrication and setup of micromixers have become more complex and more difficult. Considering the practical use of micromixers in medical and industrial applications, their designs can be simplified while maintaining high mixing efficiency. Rapid prototyping, represented by 3D printing having micro‐scale resolutions, is one promising technology to replace conventional fabrication methods such as soft lithography. Here, a 3D helical micromixer fabricated by micro‐scale lost‐wax casting is reported. The molds for lost‐wax casting are fabricated by fine 3D printing of a hard wax resin which can be removed from a polydimethylsiloxane block just by heating and washing with water, and a fine and smooth structure is realized. The optimized helical micromixer fabricated by lost‐wax casting promotes mixing efficiency compared with other micromixers. In addition, a monolithic microchannel having the helical 3D bridge structure is presented in this study. The demonstration is an important advancement toward the industrial applications of micromixers fabricated by micro‐scale 3D printing. The ability to fabricate complex structures can simply lead to the creation of more sophisticated mixers in the future.

Effect of perfluoropolyether on properties of polyurethane coating agents

Polyurethane- and polysiloxane-based coating agents are widely used in automobiles and electronic devices for sealing. To study a component which affects their surface properties, polyurethane resins (PUR) were synthesized from polyester polyol, perfluoropolyether (PFPE) diol, and toluene diisocyanate. The coating agents were subsequently prepared by adding various amounts of PE wax, carbon black, matting agents, and silicone resin. The effects of the soft and hydrophobic PFPE diol content in the coating agent on the surface properties, such as hydrophobicity, noise generation, and friction coefficient were investigated. Although the bulk content of PFPE diol in polyols is 1.7 wt% or less, hydrophobicity, workability, friction coefficient, and noise generation of the newly designed PUR coating agents were improved while their tensile strength and abrasion resistance decreased. These results indicate that the PFPE diol chains in the modified PURs are segregated at the surface layer and affected surface properties as well as bulk properties.

Researches on the capitalization of some medicinal plants to obtain essential oils by using the performant innovative installation EUV 2x1000 type

The article includes research on the production of essential oils from medicinal plants by applying water vapour distillation, the method most commonly used for the extraction of essential oils from plants. The results consist of extracting the essential oil from 2 types of medicinal plants: lavender and mint with the help of the EUV installation. The paper highlights the important aspects of obtaining quality products, on economically advantageous terms, addressing both specialists, farmers in larger farms and family associations. The article presents the experimental research results on obtaining essential oils from medicinal plants. Oils obtained by this method contain only volatile components, while wax and volatile resins are not found in the finished product.

Dependence of composition of asphaltene–resin–wax deposits on the water cut value

The deposit formation process in water/oil emulsions based on waxy high-resin oils with different amounts of the aqueous phase has been studied. It has been shown that the deposition rate greatly increases with an increase in the relative amount of the aqueous phase. Relationships of the component composition of paraffin hydrocarbons and the structural group composition of asphaltenes in asphaltene–resin–wax deposits with the water content of the emulsions have been revealed.

Influence of object translucency on the scanning accuracy of a powder-free intraoral scanner: A laboratory study

Statement of problemLimited information is available regarding the influence of object translucency on the scanning accuracy of a powder-free intraoral scanner. PurposeThe purpose of this in vitro study was to evaluate the scanning accuracy of a confocal microscopy principle powder-free intraoral scanner on ceramic copings and to analyze the relationship between scanning accuracy and object translucency. MethodsSix slice specimens (12×10 mm) and 6 offset copings (1.00-mm thickness) were made from different translucent homogeneous ceramic blocks (CEREC Blocs, S0-M to S5-M, highest to lowest translucency). The primary sintered zirconia offset coping was produced in the same way as the control. Optical parameters related to the translucency of each slice were measured with a spectrophotometer. Three-dimensional (3D) datasets of the surface morphology of offset copings were obtained by using the intraoral scanner. The same white wax resin bases were used for registration. Quantitative parameters of scanning trueness and precision were measured. One-way ANOVA was used to analyze the values of each parameter among the 6 ceramic blocks. Bivariate correlation was used to analyze the relationships between each parameter of scanning accuracy and translucency (α=.05). ResultsTranslucent copings showed a positive 3D bias (S0-M to S5-M: 0.149 ±0.038 mm to 0.068 ±0.020 mm), a narrower collar diameter (Dd=−0.067 mm), larger convergence angle (ΔΦ=2.79 degrees), and larger curvature radius of the internal gingivoaxial corner (Δρ=0.236 mm). The smaller the percentage sum of scattering and absorption, the greater was the occurrence of scanning bias (r=−0.918) and curvature (r=−0.935) decrease. ConclusionsUse of the tested powder-free intraoral scanner, higher translucency objects (greater translucency than S1-M/A1C) resulted in lower scanning accuracy and morphological changes. Therefore, more suitable methods of measurement are still required.

Effect of the structure of pour-point depressant additives on the deposition of solid petroleum hydrocarbons

A number of pour-point depressants of the ester and polyaminoaldehyde types have been synthesized. Their physicochemical and dielectric properties have been examined; by comparing these properties, additional information has been obtained to confirm the previously proposed mechanism of action of these additives and compositions thereof on solid petroleum hydrocarbons and the relation of the performance to the dielectric properties of the polyaminoaldehyde additives has been revealed, findings that can facilitate their selection in the development of inhibitors of asphaltene—resin—wax deposition in crude oil.

An automatic robotic system for three-dimensional tooth crown preparation using a picosecond laser.

Laser techniques have been introduced into dentistry to overcome the drawbacks of traditional treatment methods. The existing methods in dental clinical operations for tooth crown preparation have several drawbacks which affect the long-term success of the dental treatment. To develop an improved robotic system to manipulate the laser beam to achieve safe and accurate three-dimensional (3D) tooth ablation, and thus to realize automatic tooth crown preparation in clinical operations. We present an automatic laser ablation system for tooth crown preparation in dental restorative operations. The system, combining robotics and laser technology, is developed to control the laser focus in three-dimensional motion aiming for high speed and accuracy crown preparation. The system consists of an end-effector, a real-time monitor and a tooth fixture. A layer-by-layer ablation method is developed to control the laser focus during the crown preparation. Experiments are carried out with picosecond laser on wax resin and teeth. The accuracy of the system is satisfying, achieving the average linear errors of 0.06 mm for wax resin and 0.05 mm for dentin. The angle errors are 4.33° for wax resin and 0.5° for dentin. The depth errors for wax resin and dentin are both within 0.1 mm. The ablation time is 1.5 hours for wax resin and 3.5 hours for dentin. The ablation experimental results show that the movement range and the resolution of the robotic system can meet the requirements of typical dental operations for tooth crown preparation. Also, the errors of tooth shape and preparation angle are able to satisfy the requirements of clinical crown preparation. Although the experimental results illustrate the potential of using picosecond lasers for 3D tooth crown preparation, many research issues still need to be studied before the system can be applied to clinical operations.

Effect of different coatings on post-harvest quality and bioactive compounds of pomegranate (Punica granatum L.) fruits.

The effect of three different coatings; resin wax (Britex Ti), carnauba wax (Xedasol M14), and chitosan (1 and 2%w/v) on postharvest quality of pomegranate fruits were investigated. Fruits quality characteristics and bioactive compounds were evaluated during 40, 80 and 120days storage at 4.5°C and 3 additional days at 20°C. The results showed that uncoated fruits showed higher respiration rate, weight loss, L* and b* values of arils, total soluble solids (TSS)/titratable acidity (TA), and pH than coated fruits during storage. Coating treatments could delay declining TSS and TA percent, a* value of arils, as well as bioactive compounds such as total phenolics, flavonoids and anthocyanins content and antioxidant activity. The coated fruits with commercial resin and carnauba waxes showed significantly lower respiration rate and weight loss than other treatments, however carnauba wax could maintain considerably higher fruits quality and bioactive compounds than other coating treatments. The results suggested that postharvest application of carnauba wax have a potential to extend storage life of pomegranate fruits by reducing respiration rate, water loss and maintaining fruit quality.

Study on Consist Property of High Wax and Super-Viscous Crude Oil

The consist property analysis of Daqing and Nile-Oman high wax crude oil and Liaohe super-viscous crude oil was carried on in the paper. The result showed the key factor of high wax crude oil pour point increasing lies in the wax crystal forming and growing and agglomerating at low temperature. The reason of high viscosity of Liaohe super-viscous crude oil has correlation to the high nitrogen polar group weight. The polar groups can form hydrogen bond to make adhesion stronger. At the same time, the crude oil flowing was restrained by increase the macromolecule connection agglomeration in crude oil. The analysis of resin wax ratio of crude oil showed the better viscosity decline effect was appeared only in the condition of resin wax ratio was appropriate.

A Comparison of Acrylic and Multilithic Teeth Bond Strengths to Acrylic Denture Base Material

Debonding of denture teeth from the denture base can be frustrating for both the clinician as well as his or her patients. The wear resistance of composite denture teeth has been well investigated since their introduction, but there have been few studies about the bonding of these teeth to acrylic denture base resins. The aim of this study was to compare the bond strengths of two brands of acrylic and one brand of multilithic denture teeth to acrylic denture base material. In this experimental-laboratory study, three types of denture teeth--Yaghoot, Super Brilian, and Major--were used. After grinding the glossy ridge lap surfaces, the teeth were mounted on two sides of triangular-shaped wax models. Then the wax elimination and resin processing laboratory procedures were carried out as is done with the fabrication of a complete denture. Each of the specimens was tested using a universal testing machine with a cross head speed of 5 mm/min at an angle of 130 degrees to the long axis of the teeth. The data were analyzed using one-way ANOVA and Chi-square tests. The mean bond strength in the Yaghoot group was 717.43+/-293.59 N while in the Super Brilian group it was 578.40+/-395.38 and in the Major group, 547.95+/-296.75N. However, there was no significant difference between the three groups (p=0.194). Although the mean bond strength in the multilithic group was higher than in the other groups, no significant difference was found between the three groups. There was no significant difference between the three groups with regard to the prevalence and type of fracture site. The bonding strength of multilithic denture teeth to denture base resins was found to be comparable to, and even slightly higher than, acrylic conventional denture teeth, making them a promising choice for clinicians in the fabrication of removable dentures.

Use of soft wax and pour-type denture base resin to augment lip support for a removable prosthesis

aAssociate Professor, Division of Removable Prosthodontics, Department of Oral Rehabilitation, Fukuoka Dental College. bChief, Central Dental Laboratory, Fukuoka Dental College Medical and Dental Hospital. cProfessor, Division of Removable Prosthodontics, Department of Oral Rehabilitation, Fukuoka Dental College. (J Prosthet Dent 2008;100:242-243) The placement of removable prostheses to replace anterior missing teeth affects the soft tissue and facial profile. A maxillary denture produces a more noticeable change than does a mandibular denture.1 Patients who are completely edentulous or partially edentulous in the anterior region may be concerned about their facial appearance and may desire to alter their protheses to increase the degree of lip support. In such situations, autopolymerizing acrylic resin has been used, primarily due to its easy handling. However, porosities form in this type of acrylic resin, resulting in poor esthetics such as discoloration or staining.2 The chairside and laboratory procedures for augmenting lip support provided by a removable prosthesis using soft wax and autopolymerizing pour-type denture base resin are described. The occurrence of air bubbles can be avoided by polymerizing the resin in a pressure-polymerizing unit. The advantages of this technique are that almost no air bubbles are formed and the esthetic result is good. The disadvantages of this technique are that it requires a somewhat more complicated procedure and it takes a longer time to complete compared to the use of autopolymerizing acrylic repair resin. A contraindication for the use of this technique is when the situation requires rearrangement of the anterior artificial teeth to augment lip support.

Stradivarius in the Jungle: Traditional Knowledge and the Use of “Black Beeswax” Among the Yuquí of the Bolivian Amazon

Native Amazonians traditionally use two methods to feather, or fletch, arrows—they either tie feathers to the shaft or use an adhesive. This paper discusses the latter method, analyzing the use of “black beeswax” arrow cement, derived from an insect product, the wax–resin cerumen of native stingless bees (Meliponini). Such mixtures of beeswax and plant resins, prepared by cooking, have a long history of human use in the Old World: in encaustic painting, beaumontage for furniture repair, sealing waxes, and varnishes for fine musical instruments. This study explores the special properties of meliponine cerumen, containing a resin compound, geopropolis, which makes an excellent arrow cement. Like their Old World counterparts, native Amazonians discovered that cooking a mixture of cerumen and plant resins from bee nests produces an adhesive that dries to a hard finish. We compare both raw and cooked samples of cerumen with infra-red spectroscopy. The wax–resin compound yields adhesive material that is tough, flexible, and has many qualities of both sealing wax and varnish. The Yuqui of the Bolivian Amazon provided the cerumen samples for this analysis, and we describe their methods of preparing and applying arrow cement. We also discuss how social change and globalization negatively affect Yuqui traditional knowledge, which survives, in this case, largely because there is a modest market for bows and arrows in the tourist trade.

Segmental axonopathy of Merino sheep in New Zealand

AIM: To investigate an axonopathy of Merino sheep that caused progressive hindlimb ataxia and slight to moderate paresis, with the purpose of understanding its pathogenesis. METHODS: Tissues were fixed in buffered paraformaldehyde or paraformaldehyde and glutaraldehyde, processed into wax and epoxy resin, respectively, and examined by light and electron microscopy. Fresh frozen spinal cord and trigeminal nerve roots were subjected to homogenisation, centrifugation and two-dimensional electrophoresis. Selected protein spots were identified using matrix-assisted laser desorption ionisation (MALDI) mass spectrometry. RESULTS. By light microscopy, there were large pale foamy spheroidal axonal swellings affecting peripheral as well as central axons. By electron microscopy, these were shown to contain many membrane-bound vesicles. The main abnormalities in expressed proteins involved cytoskeletal elements and myosin heavy chain, the latter interpreted as associated with the molecular motor myosin Va. CONCLUSIONS: The disorder is the same as that described in Merinos in Australia as segmental axonopathy, and believed to have an inherited aetiology. The lesions and protein changes indicate abnormalities of the cytoskeleton, its relationship with the myelin sheath, and myosin Va molecular motor. The consequence appears to be abnormal axonal transport and inability to maintain the integrity of axons and their myelin sheaths.