High-melting Waxes Research Articles

Performance Mapping toward Optimal Addition Levels and Processing Conditions for Different Types of Hydrocarbon Waxes Typically Used as External Lubricants in Sn-Stabilized PVC Pipe Formulations.

The mechanism of performance of hydrocarbon waxes used as external lubricants in typical PVC pipe formulations is not completely understood or defined. This study will benefit pipe manufacturers to tailor PVC processing conditions and wax addition levels to enhance the value of waxes with different molecular architectures in Sn-stabilized PVC formulations. A selection of waxes was comprehensively analyzed to understand how their structural and morphological differences impact the fusion behavior of a Sn-stabilized PVC compound. Results showed a high probability of fusion for waxes with melting points between 65 and 80 °C and a kinematic viscosity (at 135 °C) of less than 5 cSt across all experimental temperatures and concentration levels tested. The general probability of fusion increased with increasing temperature and decreasing wax concentration. Wax compositional differences only had a large impact on PVC fusion at lower experimental temperatures and high wax concentrations. The stable time and onset of degradation were found to be sensitive to experimental temperature but less so to wax concentration. High melting waxes had the lowest fusion torque but a narrow operating window in terms of concentration and temperature for a successful fusion to occur. Overall, fully refined paraffin waxes had the widest operating window and were less sensitive to a change in the wax concentration and experimental temperature than the rest of the waxes that were tested.

Approaches for the Synthesis of High-Melting Waxes: A Review

Approaches for the Synthesis of High-Melting Waxes: A Review

A comprehensive investigation into the structure-property relationship of wax and how it influences the properties of hot melt adhesives

A detailed study was conducted on seven different waxes used in hot melt adhesive formulations together with conventional resins and tackifiers, to characterize the waxes and investigate the effects of wax structure and morphology on the thermal behaviour and basic properties of the resultant hot melt adhesive formulations (HMAs). The waxes selected included representatives of each of the following types: Fischer-Tropsch wax (FT), fully refined paraffin wax (FRP), by-product polyethylene wax (BPPE), microcrystalline wax (microwax), alpha-olefin wax (AO), carnauba wax and first intention polyethylene wax (FIPE). Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), high temperature size exclusion chromatography (HT-SEC), nuclear magnetic resonance spectroscopy (NMR) and confocal laser scanning microscopy (CLSM) were used as analytical tools to characterize the waxes. Molecular chain architecture as determined by solution 13C NMR highlighted the superior chain linearity of FT wax. Methyl, ethyl and butyl short chain branching were detected in other waxes. Solid-state 13C CP-MAS NMR provided information on the semi-crystalline nature of the waxes. FIPE, AO and Microwax showed significant structural mobility at room temperature as observed by 1H Wideline NMR and was attributed to chain branching and mobile crystalline domains respectively. This was supported by CLSM micrographs. All waxes enhanced crystallinity in both metallocene catalysed polyethylene (mPE) and ethylene-vinyl acetate (EVA) based HMAs. This was confirmed by the characteristic splitting in FTIR bands and increased DSC enthalpies observed for the HMA relative to the neat polymers. Of the formulations containing high melting waxes, FT wax resulted in HMAs with narrower crystallization profiles, an important factor in determining HMA set times. HMA viscosities were found to be dependent on the molecular weight of the wax while the HMA melting temperatures and enthalpies were more dependent on the crystalline morphology of the waxes.

Sequential crystallization of high and low melting waxes to improve oil structuring in wax-based oleogels

The objective of this study was to investigate the combination of a high-melting wax (sunflower wax or rice bran wax) with a low-melting wax (berry wax) on the crystallization and gelation behavior of the corresponding oleogels in rice bran oil (RBO).

Crystallization and Gelation Behavior of Low- and High Melting Waxes in Rice Bran Oil: a Case-Study on Berry Wax and Sunflower Wax

Low-melting berry wax (BEW) has proven to be a good oil gelator with a positive contribution to the consistency and flexibility of the structured oil. Nevertheless, the properties of BEW and the corresponding oleogel have not yet been investigated in-depth. In this research, the difference in crystallization and gelling behavior between sunflower wax (SW), a high melting wax, and BEW, a low-melting wax, in rice bran oil (RBO) was investigated. The difference in melting and crystallization temperatures can be explained by the different chemical composition (long-chain wax esters in SW and short-chain fatty acids in BEW). The heterogeneity in crystal habits (unidirectional platelets versus microcrystalline particles) and polymorphism (orthorhombic versus hexagonal) are responsible for the varying gel strength and hardness of the respective SW- and BEW-oleogels. The microcrystalline BEW particles aligned and reorganized during 1-month storage at 5 °C, which leaded to an increase in the gel strength and hardness of BEW-oleogel. The gelling property of SW-oleogel however did not significantly differ after 4 weeks at 5 °C, despite of the appearance of spherulitic crystalline clusters. The changes in the physical properties of wax-based oleogels during storage time were further explored using differential scanning calorimetry, polarized light microscope, powder X-ray diffraction and rheology.

Physical characterization of crystalline networks formed by binary blends of waxes in soybean oil

The objective of this study is to analyze the physical properties of 2.5% (wt. basis) binary wax in soybean oil (SBO) system. Differential scanning calorimetry, pulsed nuclear magnetic resonance, rheology, and polarized light microscopy were used to measure melting profiles, solid fat content, viscoelastic parameters, and crystal morphology, respectively. Binary blends were prepared using beeswax (BW), rice bran wax (RBW), and sunflower wax (SFW) in 0, 20, 50, 80 and 100% proportions. Melting behavior of binary waxes was significantly affected by the type and proportion of wax used. Melting Ton and Tp for RBW/SFW and RBW/BW blends were significantly higher than those observed for SFW/BW. Enthalpy values suggest that different molecules present in the wax affect intermolecular interactions in the binary blends by either inducing (SFW/BW) or delaying (RBW/BW) crystallization. Iso-solid diagrams show that there is certainly a softening effect when different proportions of RBW/BW and SFW/BW are used, while a solid solution is formed in RBW/SFW systems. Viscoelastic parameters (G′, G″) results show that RBW has the highest G′ value (3.1×104±1×103Pa) followed by SFW (2.7×104±0.2×104Pa) and BW having the lowest (90.7±74.4Pa). Higher G′ values in all proportions of RBW/SFW binary system in SBO indicate significantly more solid-like behavior than any other combinations. However, blending of two different waxes does not necessary result in a linear increase in elastic properties and in some cases no changes in elasticity is observed as the amount of the high melting wax is added to the low melting one.

Heavy wax distillate as a raw material for the production of solid hydrocarbons

This article discusses the feasibility of recovering solid hydrocarbons from a heavy wax distillate in order to expand the raw material base for the production of high-melting waxes. The examined distillate has a melting point of 45/sup 0/C, a wax content of 34% by weight, a viscosity (at 100/sup 0/C) of 8.2 mm/sup 2//sec, a molecular weight of 345, a content of paraffinic and naphthenic hydrocarbons of 59.1% by weight, contents of aromatic hydrocarbons (light, medium and heavy) of 8.9%, 5.1%, and 20.4% by weight, respectively, and a content of hydrocarbons forming and not forming urea adducts of 21.8% and 78.2%, respectively. The heavy wax distillate was filtered in a Bogdanov laboratory unit containing a filter press consisting of a crystallizer and a slack wax chamber. The filtration residue from the crystallizer beaker and the slack wax cake from the wax chamber are collected in a preweighed container. It is concluded that the heavy wax distillate can be successfully dewaxed for wax production if it is modified by dilution with a filtrate and the incorporation of a structure modifier.

Sunflower oil processing from crude to salad oil

AbstractWorld‐wide use of sunflower oil is second only to soybean oil. Interest in domestic use as a premium salad oil is very recent. The high ratio of polyunsaturated‐to‐saturated fatty acids makes sunflower oil a premium salad oil. Sunflower oil, however, contains a small amount of high melting wax which must be removed to avoid settling problems. It is possible to produce a brilliant, dewaxed, deodorized sunflower oil with over a 100‐hr cold test at 0 C. This quality oil can be produced by conventional caustic refining, dewaxing, bleaching and deodorization. A quality finished oil may also be produced by dewaxing and steam refining. This paper reviews various methods for processing sunflower oil from the crude state through the finished, dewaxed, deodorized salad oil.

Chemical composition of structure of solid hydrocarbon protective waxes

1. It has been found that protective waxes used as antiozonants differ in their hydrocarbon composition. 2. The main components of high-melting imported Superlawax and Russian Type 3V-2 wax are naphthenic hydrocarbons whose side chains have a predominantly isostructure and whose content lies between 42 and 65%. 3. Borislavskii ceresin contains ca. 30% naphthenic hydrocarbons with iso side chains. 4. In contrast to the high-melting waxes examined, AF-1 wax contains 78% of normal- and isoparaffins.

The switch is on to Carlisle high melting waxes

the switch is on to Carlisle high melting waxes