Paraffin Wax Content Research Articles

Configurational Entropy Regulation in Polyolefin Elastomer/Paraffin Wax Vitrimers by Thermally Responsive Liquid-Solid Transition for Force Storage.

The work output of shape memory polymers during shape shifting is desired for practical application as actuators. Herein, a polyolefin elastomer (POE) and paraffin wax (PW) are co-cross-linked by dynamic boronic ester bonds to enhance the network elasticity and the stress transfer between the two phases, endowing high force storage capacity to the prepared vitrimers. Depending on the phase of PW, one-way force storage is realized by programming at a low temperature (25 °C), owing to which solid PW can promote the locking of POE chains in a low-entropy state, while reversible force storage can be realized by programming at a high temperature (75 °C), owing to which the relaxation of chains facilitated by liquid PW can promote the construction of a stable structure. Based on one-way force storage, a weight-lifting machine with a weight of 20 mg prestrained at 25 °C can lift a 100 g weight, showing a lifting ratio of no less than 5000, with a high work output of 0.98 J/g. A high-temperature alarm can be triggered at varied temperatures (43-56 °C) through controlled force release by adjusting the PW content and programmed prestrains. Based on the reversible force storage, crawling robots and artificial muscles with a work output of 0.025 J/g are demonstrated. The dynamic cross-linking network also confers mold-free self-healing capability to POE/PW vitrimers, and the repair efficiency is enhanced compared with the POE vitrimer due to the improved POE chain motion by liquid PW. The realized one-way and reversible force storage and self-healing by POE/PW vitrimers pave the way for the application of SMPs in the fields of soft robotic actuators.

Effects of paraffin wax content and test temperature on the stability of water-in-model waxy crude oil emulsions

Waxy crude oil is important fossil energy containing both paraffin wax and some asphaltene. The interactions between paraffin wax and asphaltene not only affect the crude oil rheology, but also the stability of crude oil emulsion. To further understand the influences of paraffin waxes on the W/O emulsion stability, in the course of this work, the effects of paraffin wax content and test temperature on the stability of W/O emulsions (with fixed asphaltene concentration of 0.5 wt%) were investigated grounded on the physical property tests of the oils, macroscopic stability measurement of the emulsions, microscopic observation of the emulsions and oil-water interfacial properties test. The results indicated that increasing the paraffin content enhances the WAT of the oils but weakens the asphaltene stability in the oil phase thus leading to the aggregation of asphaltene into a bigger size. The rheology of the model waxy oils deteriorates greatly with increasing the content of paraffin wax. The emulsion stability is outstandingly affected by the test temperature. At 30 °C (much more than the WAT), increasing the paraffin wax content benefits the asphaltene adsorption at the oil-water interface, which then reduces the interfacial tension but increases the strength of the asphaltene film formed at the interface, this facilitates the formation of smaller water droplets and improves the stability of the emulsion to some extent. At a test temperature of 15 °C (well below the WAT), increasing the content of paraffin wax also facilitates the formation of a stronger network structure of wax crystals, which dramatically improves the emulsion stability by immobilizing water droplets in the network. Meanwhile, the water droplets in the emulsion containing 15 wt% paraffin wax have the smallest size and largest number, and can efficiently act as the wax crystal nucleators thus dramatically changing the precipitated wax crystals into very small particles and facilitating the development of a wax crystal film around the droplets. This film also helps to improve the stabilization of the emulsion.

Cement mortars with ceramic molds shells and paraffin waxes wastes: Physical and mechanical behavior

Foundry industry produces millions of tons of wastes discarded in landfills. Many studies have focused on foundry sands, however other wastes are generated during the casting process and no reuse solutions are known. The main objective of this study was the incorporation of paraffin waxes and ceramic mold shells in cement mortars, evaluating the influence of different paraffin wax contents in the mortars physical and mechanical properties. The obtained results showed a decrease in the workability, water absorption, flexural and compressive strengths of the mortars. However, the mortars presented a satisfactory physical and mechanical behavior, evidencing a possible practical application.

Sustainable Separation of Paraffin Wax by Span 80 Combined with Switchable Water

In this work, the approach for separating paraffin wax is proposed by using Span 80 combined with switchable water N,N,N′,N′-tetramethyl-1,6-hexanediamine (TMHDA), where the emulsification of paraffin wax can be promoted and paraffin wax is also separated sustainably. Here, the Span 80-containing mixture system exhibits an enhanced emulsification ability and CO2-switchable behavior upon the addition of TMHDA. Then, the paraffin wax is effectively emulsified by this switchable system containing Span 80 and TMHDA. Based on the detection of water separation rate, rheological behavior, and micrographs of emulsified paraffin wax, it is found that the emulsification of paraffin wax can be improved by increasing the paraffin wax content and Span 80 content, and the viscosity of the paraffin wax is reduced after emulsification by this switchable system, which ascribes to the dispersion of wax crystals. In addition, the paraffin wax is separated upon introducing CO2, and the TMHDA solution is recovered upon treating with N2 at 65 °C after separating the paraffin wax. The sustainable separation of paraffin wax results from the aggregation of wax crystals because of the reduced obstruction of oil droplets for wax crystals caused by the high ionic strength and the reduced surface activity of this system upon introducing CO2. Herein, it is expected that this sustainable separation can be applied in deposited wax removal in pipelines of crude oil transport.

Predicting wax appearance temperature and precipitation profile of normal alkane systems: An explicit co-crystal model

Wax precipitation is a major flow assurance issue for petroleum production, oil blending, downstream processing, and oil products usage. While numerous thermodynamic models have been proposed to calculate wax appearance temperature (WAT) and precipitation profile at temperatures below WAT, the existing models are correlative in nature and fail to comply with phase behavior experimentally observed for wax precipitation. This work presents a predictive thermodynamic model for wax precipitation based on an explicit co-crystal formation assumption for precipitated wax, a treatment consistent with experimental findings. With a simple Flory-Huggins expression accounting for the liquid phase nonideality and the treatment of lamella structure for wax precipitation below WAT, the model satisfactorily predicts WAT at low pressures for multicomponent paraffin mixtures and wax precipitation amounts and contents as the temperature drops below WAT.

Preparation and characterization of waste papers based composites and their applications in leather industries

In this work, the utilization of waste paper in the preparation of cellulous-based composite is described, with latex as a binder. Paraffin wax and acrylic woven fibers were also used at various weight ratios to get the best mechanical and physical properties. The results were compared with the performance the Dixon, regularly used material in shoes manufacturing. The following tests were performed: compression resistance, density, water absorption, shrinkage, and moisture content. Manual method was employed in the preparation of test specimens in addition to laboratory forging machine for finishing of the specimens. Results of compression test (Modulus of elasticity, compressive strength, resistance to crushing) of the Specimens that contain pulp paper and reinforced with latex and acrylic fibers and low content of paraffin wax showed the highest resistance to compression, The increase of additives contents within the mix resulted in an increase in density. To mimic the real application conditions of the insole, the specimens were subjected to water absorption test by irrigation for 2 hours. The best specimen compositions for the water resistance test are those with high (5-10%) wax content due to the fact that the wax is a water repellent material. The shrinkage is another important parameter for the use of the composite in shoe industry. Result of shrinkage and humidity of all specimens show comparable results to commercially available and Dixon are also very close to the requirements of the specification of leather industry. However, in comparison with the available carton and dixon, our specimens contain from weight fraction (50g) waste pulp, (20g) latex, (4g) paraffin wax, (0.7g) acrylic fibers, proved comparable performance.

Recycled Polyethylene/Paraffin Wax/Expanded Graphite Based Heat Absorbers for Thermal Energy Storage: An Artificial Aging Study.

An artificial aging study of novel heat absorbers based on phase change materials (PCMs) prepared from recycled high-density polyethylene (HDPE), paraffin wax (PW), and expanded graphite (EG) was investigated. The optimal composition of PCMs contained 40 wt% HDPE, whereas the paraffin wax content ranged from 40 to 60 wt% and the expanded graphite content ranged from 5 to 15 wt%. PCMs were artificially aged through exposure to UV irradiation, enhanced temperature, and humidity. It was clearly demonstrated that the addition of EG to PCMs led to the suppression of PW leakage and improved the photooxidation stability of the PCMs during the aging process. The best performance was achieved by adding 15 wt% of EG to the PCMs. The sample shows a leakage of paraffin wax below 10%, retaining a melting enthalpy of PW within PCMs of 54.8 J/g, a thermal conductivity of 1.64 W/mK and the lowest photooxidation, characterized by an increase in the concentration of carbonyl groups from all investigated materials after artificial aging. Furthermore, PCMs mixed with EG exhibited good mechanical properties, even after 100 days of exposure to artificial aging. Finally, this work demonstrates a justification for the use of recycled plastics in the formation of PCMs.

New hydrophobic silica nanoparticles capped with petroleum paraffin wax embedded in epoxy networks as multifunctional steel epoxy coatings

The silane amide precursors were prepared by amidation of oleic and stearic acid with γ-aminopropyltriethoxysilane. The stearyl and oleyl amines were added to vinyl trimethoxy silane to synthesize aminosilane precursors. The chemical structures, surface morphology, thermal stability of the prepared hydrophobic silica nanoparticles were investigated. The wetting characteristics, mechanical properties, thermal stability and corrosion resistance of the prepared hydrophobic silica nanoparticles with epoxy composites coated on the steel panels were studied. The data confirm that the all the prepared hydrophobic silica show higher contact angles (100-110°) when blended with epoxy up to 3Wt %. Moreover, the dispersion, hydrophobicity and paraffin wax contents of silica nanoparticles embedded into epoxy networks control the high corrosion resistivity of the composites as organic coatings of steel substrate. The salt spray resistance data elucidate that the epoxy modified with 1 Wt % of the hydrophobic silica/paraffin wax achieved higher salt spray resistances up to 1500 h with high rating.

Effect of paraffin wax on combustion properties and surface protection of Al/CuO-based nanoenergetic composite pellets

We systematically investigated the effect of a polymer binder on various combustion properties and surface protection of nanoenergetic composite pellets containing Al and CuO nanoparticles (NPs) as the fuel and oxidizer, respectively. Al/CuO NP-based composite pellets were then fabricated by a pelletization process and the effect of paraffin wax (PW) binder concentration was investigated. The burn rate decreased with increasing PW content as the binder thermochemically interfered with the aluminothermic reaction between Al and CuO. However, the presence of a critical amount of PW (< 20 vol% in the Al/CuO matrix) maintained, or even enhanced, the various combustion properties of Al/CuO composite pellets, including the total heat energy, maximum pressure, and pressurization rate, when they were ignited. Simultaneously, the presence of PW was also found to effectively protect Al/CuO pellets from severe oxidation under relatively high humidity conditions. This suggests that PW played key roles as an effective binder, versatile lubricant, and oxidation protection agent. In addition, it could also be used for controlling the combustion properties of nanoenergetic material-based pellets for various thermal engineering applications.

Structural, morphological and mechanical properties of gamma irradiated low density polyethylene/paraffin wax blends

The effect of gamma irradiation on the lattice structure, surface morphology, and mechanical properties was invested for LDPE/ paraffin wax blend films. Blends of LDPE/wax in content of 100/0, 98/2, 96/4, 94/6, 92/8, 90/10 and 85/15 (w/w) were prepared by melt-mixing at the temperature of 150 °C and then irradiated by gamma irradiation. It was found that increasing the wax content more than 15% lead to phase separation. The effect of gamma radiation on the structure, surface morphology, and mechanical properties has been investigated using the X-ray diffraction, scanning electron microscope and mechanical tests. Both The blending and gamma irradiation process has an influence on the structure and consequently on the surface morphology of the samples. The values of lattice parameters were calculated. The grain size, inter chain distance and interplanar spacing decrease with increasing paraffin and increase with increasing gamma absorbed doses. While the dislocation density, the microstrain, and the distortion parameters increase with increasing paraffin wax content and decreases with increasing gamma absorbed doses. The obtained values from X-ray indicates that notable changes of the atomic lattice structure for both unirradiated and irradiated blends, which also confirmed by studying the surface morphology of all blends. It was found that an increase in wax content induces a linear decrease in tensile strength; elongation at break, Young's modulus, and hardness. A linear increase of these mechanical parameters was observed with increasing gamma absorbed dose. The final results show the reliability of gamma radiation as a practical method for the control of long-term properties.

Spatial Variability of Chemical Composition of Eurasian Oils

The study of relationships governing the variability of chemical composition of the Eurasian oils has been carried out on the basis of the statistical processing of the data on contents of total sulfur, resins,&lt;br /&gt;paraffin wax and asphaltenes in oils. These indices are considered as the principal chemicals of oils chemical composition. The data processed for Eurasian continent was chosen from database on petroleum chemistry, which is create by Institute of Petroleum Chemistry of Siberian Branch of Russian Academy of Sciences and nowadays includes more than 9,000 entries of oil physical-chemical data on all main world oil-bearing basins. Latitudinal and longitudinal dependencies of the above indices of oils chemical composition were studied by methods of statistical and cluster analyses and means of geographical information system (GIS) ArcView 3.1. The results of these studies are represented on the computer maps. It is shown that properties of oils are statistically inhomogeneous in Eurasia depending on geographic position. In average, contents of total sulfur, resins and asphaltenes in crude oil increase in direction from&lt;br /&gt;east to west. But the analysis doesn’t reveal longitudinal dependence of paraffin content, only a latitudinal dependence. In average, paraffin wax content in oils increases in direction from north to south. From the&lt;br /&gt;analysis of the results of geozoning of oil-bearing territories using the whole complex of indices, the zones of oils that are homogenous by their properties was revealed. The results obtained may be used to solve the&lt;br /&gt;problems of a rational use of hydrocarbon resources, in particular:&lt;br /&gt;a) siting the oil-refining and petrochemical enterprises, b) developing the regional nets of a rational transporting of hydrocarbons and petroleum products.

An experimental investigation on the degradation effect of ozone on hyperelastic behavior of an NR/BR blend

This research work is devoted to study the effect of ozone degradation and stabilization on the hyperelastic behavior of a natural rubber/butadiene rubber-based rubber blend used in tire sidewalls. Four rubber compounds with different paraffin wax contents were designed and prepared using the conventional machineries. Classical rubber tests including tensile, dynamic mechanical thermal analysis, hardness and fatigue-to-failure were carried out. To evaluate the effect of ozone degradation and wax content on stabilization, two sets of experiments were performed. In the first series, samples were tested without exposure to ozone, while the second series were carried out on samples after exposure to ozone according to a recently developed method. Five hyperelastic models including the neo-Hookean, Yeoh, Ogden, Arruda–Boyce and van der Waals equations were selected. The corresponding parameters of these equations were determined via nonlinear curve fitting on the experimentally obtained uniaxial stress–strain data using the material modeling module implemented in Abaqus code. For the first time in this work, the relationship between the predicted model parameters as well as the initial shear modulus of the above samples with structural changes that take place in rubber during the degradation are presented and discussed. It is also found that the parameters of nonlinear mechanistic models such as Arruda–Boyce and van der Waals can be related to chain scission which takes place during ozone attack on the polymer backbone in rubber compounds.

New eco-friendly binder based on natural rubber for ceramic injection molding process

The binder composition used for ceramic injection molding plays a crucial role on the final properties of sintered ceramic and to avoid defects on green parts. This study proposes a new eco-friendly binder based on natural rubber as a backbone polymer for ceramic injection molding of alumina. Three binders with different content of natural rubber and paraffin wax have been investigated. The powder volume fraction was kept constant. Physical properties were analyzed and four thermal debinding cycles on molded samples were applied for investigation of the influence of temperature and heating rate of sintered samples. All binders showed good rheological properties and yield stress was changed with homogeneity between powder-binder suspension. Thermal debinding affected the sintered properties of alumina samples. In result it was found that, between the binders used, the better binder components for injection process was obtained for 40%wt of natural rubber and 60%wt of paraffin wax.

Thermal characterizations of the paraffin wax/low density polyethylene blends as a solid fuel

Thermal characterizations of a novel solid fuel for hybrid rocket application, based on the paraffin wax blends with low density polyethylene (LDPE) concentration of 5% (SF-5) and 10% (SF-10) were conducted. Both the increased regression rate in comparison with the polymeric fuel, and the improved combustion efficiency in comparison with the pure paraffin fuel reveal that the blend fuels achieve higher combustion performance. The morphology of the shape stabilized paraffin wax/LDPE blends was characterized by the scanning electron microscopy (SEM). Although the SEM observation indicated the blends have uniform mixtures, they showed two degradation steps confirming the immiscibility of components in the crystalline phase from thermogravimetric analysis (TGA). The differential scanning calorimeter (DSC) results showed that the melting temperature of LDPE in the blends decreased with an increase of paraffin wax content. The decreasing total specific melting enthalpy of blended fuels with decreasing paraffin wax content is in fairly good agreement with the additive rule. In thermomechanical analysis (TMA), the linear coefficient of thermal expansion (LCTE) seems to decrease with an increase of LDPE loading, however, the loaded LDPE do merely affect the LCTE in case of the blends with low LDPE concentration. It was found that a blend of low concentration of LDPE with a relatively high concentration of paraffin wax can lead to a potential novel fuel for rocket application, a contrary case with respect to the field of phase change materials (PCM) where a blend of high concentration of LDPE is usually used with low concentration of paraffin wax.

Effect of FT Paraffin Wax Contents on Performance Properties of Crumb Rubber–Modified Asphalt Binders

AbstractThe performance properties of rubberized asphalt binders at high, intermediate, and low temperatures were evaluated as a function of Fischer–Tropsch (FT)–paraffin wax content. The rubberized binders were blended using five different wax content levels (0, 1.5, 2.5, 3.5, and 4.5% by binder weight) to produce warm rubberized binders. They were then artificially aged over the short term and long term through the rolling thin film oven (RTFO) and pressure aging vessel (PAV) procedures. Superpave binder tests were performed with the rotational viscometer, the dynamic shear rheometer (DSR), and the bending beam rheometer (BBR). In general, the results of this study suggested that (1) the viscosity of rubberized binders at 135°C can be reduced by the addition of a wax additive, as expected; (2) the rubberized binders with higher wax content can result in binder performance that meets current Superpave binder requirements, especially for cracking resistance parameters (i.e., G*sinδ and stiffness); and (3)...

Effects of the paraffin wax (PW) content on the thermal and permeation properties of the LDPE/PW composite films

A series of low density polyethylene/paraffin wax (LDPE/PW) composite films were fabricated via a twin-screw extruder, and their morphologies, thermal properties, gas and vapor permeations, and surface properties were interpreted as functions of the PW contents. The PW was well dispersed into the LDPE matrix at low PW contents, whereas phase separation and an increase in surface roughness occurred with increasing PW content. The parameter results of surface properties such as contact angle, surface free energy, and solubility showed that the hydrophobicity of the LDPE/PW composite films also increased, and their phase changes and permeation properties were significantly dependent on the PW contents in the LDPE matrix. With increasing PW contents, both the oxygen transmittance rate (OTR) and water vapor transmittance rate (WVTR) of the LDPE/PW composite films decreased at a relatively low measuring temperature (23 °C), and increased at a relatively high temperature (48 °C). These results relate to the morphological structure (including tortuous paths and crystallinity) of the composite films via the incorporation of PW.

Origin of late charged gas and its effect on property of oils in the Ordovician in Tazhong area

Abstract Natural gases in Ordovician reservoirs of the Tazhong area of the Tarim Basin appear derived by oil-cracking gas. The gases show very different geochemical characteristics. Most of the gases in the middle and eastern part of the No. 1 fault-slope zone are characterized by high gas dryness coefficients and have methane δ 13 C 1 values heavier than primary gas. These features are different from gases in the western part of the No. 1 fault-slope zone. Thus, we propose that there existed mixing between more mature, 13 C-rich methane dominated gas and less mature wet gas with 13 C-depleted methane. The hypothesis is supported by (1) roughly a positive correlation between the gas dryness coefficient and methane δ 13 C 1 value, (2) significantly heavier δ 13 C 1 values in the eastern part of the study area than in the west, and (3) significantly heavier δ 13 C 1 values than anticipated for unaltered gas co-generated with C 2 –C 4 . The charge and mixing of the dry gas into the Ordovician pools may have resulted in increase in wax contents of the oils, gas/oil ratios, gas dryness coefficients and methane δ 13 C values, leading to a positive correlation between gas/oil ratio and paraffin wax content as a result of continuous fractionation and removal of light components of an oil with progressive gas influx and thus gas washing.

Thermal and mechanical characterization of injection moulded high density polyethylene/paraffin wax blends as phase change materials

Thermal and mechanical properties of blends based on high density polyethylene and paraffin wax were investigated. The blends were prepared from 5 to 50 vol. % of paraffin wax employing a twin-screw extruder. Thermal behaviour of samples was determined by differential scanning calorimetry, thermogravimetric and dynamic mechanical analyses. A displacement of melting temperature of polyethylene was detected as a consequence of the plasticization effect of wax. These results revealed that melting temperatures and latent heats of samples are suitable for their application as phase change materials. Blends were processed by injection moulding which is an advantageous method to obtain pieces of this kind of materials. The evolution of loss tangent versus temperature of injected samples showed the lack of miscibility between the components of the blend. Tensile tests were carried out to characterize the mechanical strength of blends. Elongation at break decreased as paraffin wax content increased, and Young's modulus decreased with wax content but in the case of blends with a 30 vol. % of wax and more, brittle rupture occurred and no yield point was observed.

Preparation of Aluminum Feedstock for Green Part Specimen Using Metal Injection Molding

In metal injection molding, to identify the homogenous aluminum based feedstock is a challenging issues. In this study, a metal injection molding of aluminum feedstock which contains of high density polyethylene, stearic acid and paraffin wax as binder system was performed. The feedstock are used to produce tensile and gear shape green specimens using injection molding machine. The process ability of the metal injection molding feedstock depends on different parameters such as their binder composition and amount of metal powder used. From this study, the percentage of volume shrinkage experienced a sudden increase at the metal composition more than 50%. It also shown that, the paraffin wax content, affects the feedstock performances.

Repositionable pressure-sensitive adhesive possessing thermal-stimuli switchable transparency

Described is the formulation for a repositionable pressure-sensitive adhesive (PSA) capable of reversibly switching between opaque and transparent via a thermal trigger. The smart adhesive is generated by casting films from a solution of polydimethylsiloxane (PDMS), its organometallic crosslinker and a paraffin wax/dodecane solution on poly(ethylene terephthalate) (PET) sheets. Once cured, the PDMS/paraffin wax composite films demonstrate characteristics consistent with commercial repositionable PSAs. Properties were found to be dependent on the paraffin wax content and degree of crosslinking in the PDMS. Performance of the developed adhesive films is highly stable remaining unchanged subsequent to extended use and repeated repositioning. The appearance of the films can be switched between opaque at room temperature to transparent for temperatures above 53 °C. The change in optical properties is nearly instantaneous and there appears to be no limitation on how many times the cycle can be repeated. The mechanism involved is unique involving the melting of the paraffin wax, which appears to allow for the formation of a more homogeneous composite structure. This adhesive formulation may be well suited for use as a low-cost, convenient smart window coating.