Properties Of Wax Research Articles

Wax layers on Cosmos bipinnatus petals contribute unequally to total petal water resistance.

Cuticular waxes coat all primary aboveground plant organs as a crucial adaptation to life on land. Accordingly, the properties of waxes have been studied in much detail, albeit with a strong focus on leaf and fruit waxes. Flowers have life histories and functions largely different from those of other organs, and it remains to be seen whether flower waxes have compositions and physiological properties differing from those on other organs. This work provides a detailed characterization of the petal waxes, using Cosmos bipinnatus as a model, and compares them with leaf and stem waxes. The abaxial petal surface is relatively flat, whereas the adaxial side consists of conical epidermis cells, rendering it approximately 3.8 times larger than the projected petal area. The petal wax was found to contain unusually high concentrations of C(22) and C(24) fatty acids and primary alcohols, much shorter than those in leaf and stem waxes. Detailed analyses revealed distinct differences between waxes on the adaxial and abaxial petal sides and between epicuticular and intracuticular waxes. Transpiration resistances equaled 3 × 10(4) and 1.5 × 10(4) s m(-1) for the adaxial and abaxial surfaces, respectively. Petal surfaces of C. bipinnatus thus impose relatively weak water transport barriers compared with typical leaf cuticles. Approximately two-thirds of the abaxial surface water barrier was found to reside in the epicuticular wax layer of the petal and only one-third in the intracuticular wax. Altogether, the flower waxes of this species had properties greatly differing from those on vegetative organs.

Incorporation of a vacuum-formed polyvinyl chloride sheet into an orbital prosthesis pattern

Pattern formation is the most difficult and demanding step in the fabrication of a facial prosthesis. Traditionally, the pattern fabrication of an orbital prosthesis begins with the adaptation of softened base plate wax on the cast, over which the entire pattern is fabricated. However, owing to the inherent properties of wax, such as distortion and stress relaxation, incorporating discrepancies in the pattern adaptation is likely. This article describes a vacuum-formed polyvinyl chloride sheet to fabricate a durable, distortion-free base for pattern fabrication, thereby overcoming the drawbacks associated with a wax base.

A study of traditional Chinese wax–rosin adhesive

Wax–rosin adhesive made from beeswax and rosin is an ancient traditional Chinese adhesive widely used for joining and consolidating inlaid works during the Ming and Qing Dynasties. It is a dark yellow solid at room temperature, with a waxy surface lustre and a weak scent of plant resin, usually translucent or opaque, with an irregular shape when broken into fragments (Fig. 1). It can be easily removed mechanically and any residues can be cleaned with alcohol, demonstrating good reversibility without damaging objects such as jewellery, wooden objects, metal, lacquerware, and ceramics. This paper presents the adhesive properties of wax– rosin. Previous research [1] had revealed that the rosin concentration determines adhesive strength. If the ratio of the rosin to beeswax was too high, the adhesive became brittle. The optimum ratio of wax to rosin for stability against aging was determined experimentally, and the effects on adhesive strength of preparation time (the adhesive mixture was prepared by heating to 200°C with continuous stirring), purity of rosin and beeswax, and substrates for application, were studied. Results indicated that wax–rosin has the strongest adhesion when the preparation time is 40 minutes and that wax–rosin prepared from higher purity beeswax and rosin exhibits higher adhesive strength. Data from freeze-thaw aging indicated that beeswax with 95% purity (the best available locally) demonstrated better anti-aging properties than 70% purity beeswax, and that a higher proportion of beeswax had slightly improved the adhesive strength. Adhesive testing on metal, ceramic, and wood indicated that the tensile strength could reach 1 MPa even when the adhesive was applied onto smooth 黏蠟膠是中國一種由蜂蠟和松香製成的古老傳統膠

Improved thermal properties of paraffin wax by the addition of TiO2 nanoparticles

TiO2 nanoparticles about 20 nm in diameter in the form of anatase were prepared and characterized. The nanoparticles were successfully dispersed into a paraffin wax (PW) matrix without any surfactant. The differential scanning calorimetric instrument and the transient short hot-wire method were used to measure the thermal properties of the TiO2/PW composites. It is found that the phase-change temperature and latent heat capacity vary with TiO2 nanoparticles loading levels. When the loading is not over 1 wt%, the phase-change temperature drops, and the latent heat capacity increases. When the loading is over 2 wt%, the phase-change temperature increases, and the latent heat capacity drops. A significant increase in latent heat capacity is found around 0.7 wt% loading. The thermal conductivity of the composites increases monotonically with increasing TiO2 loading. But such a tendency tends to decrease when the loading is over 3 wt%.

Anti-microbial properties of human wax

Background: Human wax is a mixture of desquamated keratinocytes secreted in outer third of the wall of external auditory canal. The wax produced forms a physiological barrier between the external environment and deep external auditory canal. The antibacterial and antifungal properties of human wax due to its chemical composition have raised considerable debate. Different authors have different views regarding the antimicrobial property of human wax. Aims & Objective: Present study was undertaken to study the antimicrobial property of human wax and to assess its preventive actions against some common flora. Material and Methods: A prospective study of healthy individuals, both males and females, of all age groups, without any pathology in the external and middle auditory canal who presented at outpatient department of a tertiary care hospital in this region and few other private hospitals. Samples were collected from patients and studied for their antimicrobial effect. Results were recorded and analysed. Results: A total of 100 cases were included in the study, of which 52 sterile samples were tested with some common microbial flora. Data obtained was analysed. Conclusion: Variable results have been observed by different authors regarding antimicrobial properties of human wax. Our study highlights the antimicrobial property of human wax and signifies the role of further studies for antibacterial and antifungal role of human wax in diseased auditory canals. Key-Words: Human Wax; Cerumen; Anti-Microbial Properties

Rice Bran Wax-A Novel Excepient for Pharmaceutical Topical Dosage Forms

The crude rice bran wax was obtained from M/S Bajaj rice mills, Gondia (MS) which was dark brown in color & contains nonwaxy impurities & fixed oil. After purification around 38gm wax obtained which was almost white, light in weight and non-sticky. No instances of skin irritation or sensitization symptoms such as edema / rending of the skin were observed on the skin of Albino rabbits even after 24 hrs. Therefore wax was nontoxic & safe to use in pharmaceutical preparations. In the present study the melting range of rice bran wax was found to be 78–840 which is higher, may reduce the diffusion of drug across the layers of skin. Therefore, in the present study efforts will be made later on to reduce the melting range by addition of low melting point fats like mango kernel fat (M.P. 34.7oC). Solubility studies reveal that the wax is soluble in organic solvents like chloroform & petroleum ether showing typical solubility properties of waxes. Refractive index of a compound gives an idea of purity of the compound & the refractive index of the test sample was found to be 1.44 at 70oc. Sap value of rice bran wax is 68 – 72. The acid value of rice bran wax is 12 – 14. The iodine value of rice bran wax is 9 – 11. From the above data the physicochemical properties of rice bran wax was found to be within the range of other waxes used in topical preparations. Therefore rice bran wax may be utilized as a base in topical preparations. Different topical formulations such as ointments (oleaginous, modified hydrophilic ointment and modified bellers ointment base) were formulated with purified rice bran wax and compared with simple ointment (control) and marketed formulation. All these formulations contain 2% diclofenac sodium. All the formulations were evaluated for p H rheological studies like apparent viscosity, spread ability and diclofenac sodium content. P H of all formulations was found to be 5.98 – 7.30, thus indicating the suitability for application on the skin. Diclofenac sodium content of all the formulations was found to be above 95% indicating the suitability of the method adopted for preparing the formulations. Shelf life and release of diclofenac sodium content in vivo study will be made further.

Passive UHF RFID Tag for Heat Sensing Applications

A possible method of utilizing paraffin wax as a substrate material in developing a threshold heat sensing radio frequency identification (RFID) tag is discussed. A small narrowband passive UHF RFID tag is made on top of a multilayer substrate. Paraffin wax acts as the main heat sensitive layer of the substrate. The properties and characteristics of the paraffin layer change due to heat. The narrowband tag on top of the substrate is designed to be sensitive enough to detect any structural and physical changes of the substrate material. The changes in the properties of the substrate material will cause a shift in the operating frequency of the tag. This frequency shift will reduce the performance of the narrowband RFID sensor tag. The change in the properties of paraffin wax after being exposed to heat is irreversible under normal conditions and therefore, the proposed RFID tag can be referred to as a threshold heat sensing device. Such a low-cost solution can be useful in detecting heat exposures in various supply chains and transportation mishandling of heat sensitive items.

Processing and tribology of thermoplastic polyurethane particulate composite materials

AbstractThe processing, mechanical and tribological properties of wax containing thermoplastic polyurethane–filler composites were studied for different weight ratios of graphite, TiO2, MoS2, and ZrO2 microparticles and SiO2 nanoparticles. The composites were compounded by extrusion and processed by compression molding. The rheological, thermal, and mechanical properties were measured, and the wear characteristics were tested with ball‐on‐plate reciprocating tribometer tests under fixed friction conditions and then observed by scanning electron microscopy. Correlations between the friction, wear, and mechanical properties were observed, and their mechanisms are discussed. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Putrescine and carnauba wax pretreatments alleviate chilling injury, enhance shelf life and preserve pomegranate fruit quality during cold storage

Keeping in mind to reduce chilling injury and retain quality; pomegranate ( Punica granatum L., cv. Mridula) fruits were treated with putrescine, carnauba wax and putrescine + carnauba wax prior to cold storage at 2 °C. Before analyzing physical, physiological and biochemical parameters fruits were subjected to post cold storage exposure at 20 °C for 3 days. Untreated fruits developed rapidly chilling injury, with main symptoms being brown discolouration of the skin, surface pitting, weight and firmness loss during storage. All these undesirable changes were significantly delayed by putrescine + carnauba wax application. Respiration and ethylene evolution rate were also brought down by combined application of putrescine and carnauba wax treatment. The superiority of combine treatment over other applications seems arises due to additive benefit of antisenescence and barrier properties of putrescine and carnauba wax, respectively.

The Effect of Shearing in the Thermo-mechanical Properties of Candelilla Wax and Candelilla Wax–Tripalmitin Organogels

We investigated the shearing effect in the thermo-mechanical properties of candelilla wax (CW) and candelilla wax–tripalmitin (CW-TP) organogels developed using safflower oil as the liquid phase. A shear rate of 600 s−1 was applied during cooling (1 °C/min) of 3% CW and 3% CW-1% TP solutions, until reaching nucleation (i.e., 47 °C) or metastable conditions (i.e., 52 °C) then allowing the development of the organogel under quiescent conditions at 15 °C. The thermal and rheological properties of these organogels were compared with the ones of organogels developed under static conditions. The X-ray results showed that under static conditions the CW crystallized in an orthorhombic $$ \left( {{{\hbox{O}}_{ \bot }}} \right) $$ subcell packing with a lateral stacking with a length (L) equivalent to the hydrocarbon chain’s length. During organogelation of the 3% CW-1% TP solution, CW and TP co-crystallized in a $$ {{\hbox{O}}_{ \bot }} $$ subcell packing with TP in a 2L stacking organization. The application of shearing did not modify the molecular packing of the crystals or the melting properties of the organogels. However, the CW and CW-TP organogels developed with shearing showed the formation of larger crystals (i.e., fiber-like or plate-like) in comparison with the ones developed under static conditions. The presence of 1% TP increased the solid fat content, and thus the CW-TP organogels showed higher elasticity (G′) than CW organogels. The organogels developed with the application of shearing until reaching metastable conditions (i.e., CW 52 °C and CW-TP 52 °C) had the highest G′ and yield stress of all organogels investigated. In the same way, creep and recovery analyses showed that CW 52 °C and CW-TP 52 °C organogels had the highest resistance to deformation, lowest instantaneous recovery, and highest extended recovery of all organogels studied. We concluded that application of shear and the extent of its application as a function of supercooling determine crystal size and the proportion of transient to junction zones throughout the three-dimensional crystal network and, therefore, the organogels' rheological properties.

Using a multi-layered transducer model to estimate the properties of paraffin wax deposited on steel

When using ultrasound for detecting low impedance materials on the surface of high impedance materials, a major challenge is the contrast difference between the strong reverberations from the high impedance material and the weak echoes received from the low impedance material. The purpose of this work is to present the theoretical and experimental validation of an ultrasonic methodology for estimating the acoustical properties of paraffin wax on the surface of steel. The method is based on modeling and inversion of the complete electro-acoustic channel from the transmitted voltage over the active piezoelectric element, to the received voltage resulting from the acoustic reverberations in the multilayered structure. In the current work, two conceptually different models of the same multi-layer transducer structure attached to steel is developed and compared with measurements. A method is then suggested for suppressing the strong reverberations in steel, hence isolating the wax signals. This contrast enhancement method is fitted to the model of the structure, facilitating parameter inversion from the wax layer. The results show that the models agree well with measurements and that up to three parameters (travel time, impedance and attenuation) can be inverted from the wax simultaneously. Hence, given one of the three parameters, density, sound speed or thickness, the other two can be estimated in addition to the attenuation.

Influence of the Alkane Molar Distribution on the Physical Properties of Synthetic Waxes

The purpose of this paper is to compare the structure and the mechanical properties of several model mixtures exclusively constituted of pure linear alkanes so as to better understand the condition...

Use of wax emulsions for improvement of wood durability and sorption properties

Waxes are used for treatment of wood surfaces for several decades predominately as surface treatments because they weakly penetrate into the wood. In order to overcome this issue, water emulsions were applied in the present experiment. Five water emulsions of various concentrations were used, namely montan wax, polyethylene, ethylene copolymer and oxidized polyethylene wax. Performance of wax treated beech (Fagus sylvatica) and Norway spruce (Picea abies) against white rot, brown rot and blue stain fungi was tested. In parallel, sorption properties of wax treated wood were determined. The treated specimens were more resistant to wood decay fungi. Polyethylene and oxidized polyethylene wax were found to be particularly efficient. Although this treatment does not improve resistance to blue stain fungi, it reduces the sorption of water.

Surface hydrophobicity alteration of fractionated paraffin wax, crude by-product polyolefin wax and their blend

The surface compositions of crude by-product polyolefin wax (wax K) from a naphtha cracking unit, fractionated commercial paraffin wax (wax J) and their blend (wax M) were compared, under various conditions, by using FT-IR. Then a practical criterion was theoretically derived by back-of-the-envelope-calculation to estimate the diffusivity for the surface enrichment of hydrophilic functional groups. The hydrophobicity in terms of chemical structure and functional groups was altered by changing the environment as well as by blending wax K with wax J. The surface properties of wax J and wax M turned out more hydrophobic than that of wax K within the experimental period of water-submerged condition, even though the structure and functional groups on the surfaces of all waxes under ambient atmospheric condition are extremely similar. Thus the blend of wax M behaved unlike wax K but similarly to wax J in terms of alteration of hydrophobicity. Such values of diffusivity as 1.35×10−11 cm2/s and 1.96×10−11 cm2/s are established for wax J and wax M, respectively, under 1 day water-submerged condition. Furthermore, under 1 week water-submerged condition, the values of their diffusivity for wax J, wax K and wax M are estimated as 3.06×10−12 cm2/s, 7.23×10−11 cm2/s and 1.50×10−11 cm2/s, respectively. The obtained values of diffusivity are consistent, in terms of the order of magnitude, with the value of diffusion coefficient of 5.75×10−11 cm2/s obtained, using a very complicated empirical-formula, by Chen et al. for the investigation of surface-modifier enrichment. Thus, the suggested criterion may be very useful and practically applied to clarify the process of surface enrichment from general polymer-blends.

Immunohistochemical Demonstration of S-100 Protein in the Chicken Uropygial Gland During the Post-Hatching Period

S-100 proteins are calcium-activated signaling proteins that interact with other proteins to modulate biological functions such as cell migration, growth, proliferation, differentiation, apoptosis, contraction, and the inflammatory response. Although S-100 proteins are expressed in neuronal and non-neuronal tissues, their localization in the uropygial gland was not known. This study concerns the immunohistochemical detection of localization of S-100 alpha, S-100 beta, and wbS-100 in the chicken uropygial gland during development from days 1-150 days post-hatching. In 1-day-old chicks, the nuclei and cytoplasm of cells in the luminal epithelium and the tubules of the gland stained positively for S-100 alpha, S-100 beta, and wbS-100. Seven days after hatching, immunoreactivity for S-100 alpha, S-100 beta, and wbS-100 was detected in the nucleus and cytoplasm of cells in the germinative and intermediate layers of the central zone, but was found only in the germinative layer of the peripheral zone. In addition, in cells of the degenerative and secretory layers of both the central and peripheral zones, S-100 alpha, S-100 beta, and wbS-100 were present in the plasma membrane. In uropygial glands studied from days 7-150 post-hatching, the number of immunopositive cells in the central zone Increased with the advance of age and glandular growth. The results indicated that the chicken uropygial gland contains both alphabeta and beta beta dimers. Although the biological significance of the expression of wbS-100 and its subunits in the uropygial gland remains unknown, these notable calcium-binding proteins may be associated with the processes of gland-cell differentiation and apoptosis, and the antimicrobial properties of preen wax or lipids.

High temperature properties of wax modified binders and asphalt mixtures

The influence of adding two commercial waxes (FT-paraffin and polyethylene wax) to binders of penetration grades 50/70 and 160/220 were investigated for high temperature performance of binders and asphalt concrete mixtures. Binder properties were determined by conventional test methods, dynamic mechanical analysis and bending beam rheometer testing. The high temperature properties of asphalt concrete were investigated using the French rutting tester. The addition of FT-paraffin and polyethylene wax increased the rutting resistance of mixtures for both types of binder. The FT-paraffin modified asphalt mixtures showed the best rutting resistance. Adding polyethylene wax showed the highest stiffening effect in terms of rutting factor by DMA for the binders. However, this could not be verified in asphalt mixture testing. Adding FT-paraffin improved the rutting resistance of asphalt mixtures containing low or high penetration binder, but for the mixture containing high penetration binder the specification limit was exceeded.

Flow Characteristics and Viscosity Functions in Asphalt Binders Modified by Wax

Warm mix asphalt (WMA), obtained by means of special bitumen modifiers, such as wax or other organic additives, represents a promising technical solution to reduce the temperatures required for asphalt production and pavement construction. In this experience, an extended program of rheological analyses was carried out in order to evaluate the effects of different type of wax on bitumen viscous flow and dynamic properties at high pavement service temperatures. Five different organic additives, including both natural and synthetic waxes, were considered and eleven bitumen-wax blends were produced and studied using rheological testing. Viscosity measurements performed in the domain of the mixing and paving temperatures have shown essential changes in binders' rheological behavior mainly due to the crystallizing/melting properties of waxes. Changes in viscosity functions depended on the chemical structure of wax as well as on its physical characteristics. However, the viscosity of all blends at 120°C was lower than the viscosity of the base bitumen and the consequent reductions in mixing and compaction temperatures were quantitatively evaluated for all binders. The study of the flow characteristics of the bitumen-wax blends at high pavement service temperatures was carried out using complex viscosity master curves evaluated in the linear viscoelastic domain. Increasing resistance to viscous deformation referable to wax modifications was recorded by analyzing viscoelastic properties in the low frequency domain and different contributions were found with regard to each type of wax. For the polyamidic wax-modified binders, the results indicated the presence of a complex behavior characterized by the absence of a Newtonian region of flow. The final contribution of the experience is related to the development of wax modification of asphalt binders in order to produce WMA for pavement engineering applications.

Characterization of Asphaltenes and Resins Separated from Water-in-Oil Emulsions

Knowledge of the properties and behavior of asphaltenes and resins is indispensable for the design of preventive and curative measure for emulsion problems created by the presence of asphaltene, resins, and other organic and inorganic solids. In order to understand the phenomena of water-oil emulsions formed in Kuwaiti oil fields and determine the factors involved in the stabilization of these emulsions, the role of asphaltenes, resins and wax separated from various samples of oil field emulsions formed in Burgan oil field have been evaluated. Physicochemical properties of asphaltenes, resins, wax, and de-asphalted de-resined (DADR) oil samples have been studied via FT-IR, 1H, and 13C NMR, elemental analysis, and differential scanning calorimetry (DSC). These emulsion samples contain different amounts of water ranges from 24 to 35%, asphaltene content ranges from 0.9 to 1.7%, and resin content from 3.7 to 4.6%. IR-FT spectra were performed to identify the various functional groups which have an effect on the stability of water-oil emulsions. The freezing behavior of an emulsion was characterized by differential scanning calorimetry to determine whether the water in the emulsion is free water or emulsified water.

Presence of Isoalkanes in Waxes and Their Influence on Their Physical Properties

The purpose of this paper is to display the influence of isoalkanes on the structure and mechanical properties of waxes. This work was carried out by means of X-ray diffraction, differential thermal analyses, and dynamic mechanical analyses. Isoalkanes coming from an industrial wax were added in different quantities to a synthetic mixture of linear alkanes. The disorder generated by this addition was estimated by X-ray diffraction; it modifies the structural transformations versus temperature and therefore the mechanical properties. The branched chains of isoalkanes hinder the molecules motions, especially the rotation along the long axis. Thus, some phases usually formed at high temperature are not observed when increasing the temperature. With regard to the mechanical properties, the effect of the branched alkanes was studied using two industrial waxes with Gaussian distribution composition. The dynamic mechanical analyses have shown that the storage modulus (E′) is also affected by the isoalkane quantity.

Antimicrobial activity of wax and hexane extracts from Citrus spp. peels

Antibacterial and antifungal properties of wax and hexane extracts of Citrus spp. peels were tested using bioautographic and microdilution techniques against three plant pathogenic fungi (Penicillium digitatum, Curvularia sp., and Colletotrichum sp.), two human pathogens (Trichophyton mentagrophytes and Microsporum canis), and two opportunistic bacteria (Escherichia coli and Staphylococcus aureus). Two polymethoxylated flavonoids and a coumarin derivative, were isolated and identified from peel extracts, which presented antimicrobial activity especially against M. canis and T. mentagrophytes: 4',5,6,7,8-pentamethoxyflavone (tangeritin) and 3',4',5,6,7,8-hexamethoxyflavone (nobiletin) from C. reticulata; and 6,7-dimethoxycoumarin (also known as escoparone, scoparone or scoparin) from C. limon.