Preparation and Evaluation of Some Terpolymers as Lube Oil Additives

In the present work, some polymeric additives were prepared to use as viscosity index improvers and pour point depressants for lube oil via copolymerization of hexadecylacrylate and dodecylacrylate with styrene. Structure of the prepared compounds was confirmed by infrared spectroscopy and nuclear magnetic resonance. The molecular weights of the prepared copolymers were determined by using gel permeation chromatograph. The efficiency of the prepared terpolymers as viscosity index improvers and pour point depressants for lube oil was investigation. It was found that all the prepared terpolymers are effective as viscosity index improvers and pour point depressants. The viscosity index of the prepared terpolymers increases with increasing the concentration of the additives and increases by increasing the percentage of hexadecylacrylate until 70%. The best result for viscosity index of the prepared terpolymers is when the percentage of styrene is 10%. The pour point of the prepared compound decreases with decreasing concentration of additive used.     

Lubricants from renewable energy sources – a review

Lubricant oils are known to decrease the friction coefficient between two contacting surfaces. It is essential for the correct function of almost the totality of mechanical machinery working in the entire world. Lubricant oils consist of about 80% of oily base stocks which attributes to their properties of viscosity, stability, and pour point to the lubricant plus additives supplemented to improve these properties. Petroleum lubricants are usually environmentally unacceptable due to their low biodegradability and toxicity. These oils contaminate the air, soil, and drinking water and affect human and plant life to a great extent. Thus, the demand for environmentally acceptable lubricants is increasing along with the public concerns for a pollution-free environment. Plant oils are promising as base fluid for biolubricants because of their excellent lubricity, biodegradability, viscosity–temperature characteristics, and low volatility. The purpose of this paper is to present a survey of the current status of biolubricating oil. This research provides an overview on the synthesis, tribochemical behavior; the effect of structure on friction/wear, load-bearing capacity, resistance to rise in specimen temperature, and varying response of antiwear/extreme-pressure additives in the presence of vegetable oil/derivative structures has also been discussed. Though a significant number of papers have been published in this area, there is still much to explore. A proper selection of base oil and additives is therefore essential for an efficient synthesis of biolubricating oil.     

Comparative study of the oxidative and thermal stability of vegetable oils to be used as lubricant bases

Demand for lubricating oils is increasing in the growing Brazilian economy. The use of vegetable bases in exchange of minerals can bring socio-economic and environmental benefits for Brazil. The purpose of this study is to compare the thermal and oxidative stability of vegetable oils related to the bases commonly used as lubricants. In this study, thermogravimetric analysis of castor oil, cotton oil, macauba’s almond oil, passion oil, paraffinic mineral oil, naphthenic oil (NH-140) and synthetic oil (Etro) was performed in inert and oxidative atmosphere to study the thermal and oxidative degradation of the vegetable oils related to the most common lubricants’ oils base. These oils’ oxidation stability were determined by standard procedures (ISO 6886). The use of mineral oil’s additives in these vegetable oils was tested to verify the viability of these additives to improve the oxidative stability of the vegetable oils. The castor oil and the cotton oil presented results of thermal analysis similar to the mineral and synthetic bases values. The castor oil was the only vegetable oil that showed a great oxidative stability. All other vegetable oils had their oxidative stability significantly increased by the additives.     

Polymers-Copolymer as Flow Improvers for Fuel Oils and Their Electrical Conductivity

In order to find efficient cold flow improvers for fuel oil, polymethylmethacrylate (PMMA), polystyrene (PS), and a copolymer [styrene (S)–methylmethacrylate (MMA) were prepared. The structure of these polymers and the copolymer were characterized by infrared spectral analysis and their molecular weights were measured. These polymers-copolymer were used as additives for fuel oils in order to lower their pour point. Accordingly, they were evaluated as flow improvers for fuel oil. The results indicated that PMMA possesses less performance as pour point depressant. While the addition of PS and the copolymer (S–MMA) yield excellent pour point depressants for fuel oil. Upon studying the prepared additives and their properties, it was found that the electrical properties of the copolymer were changed due to the presence of polar ion in MMA effect on the electrical properties. The highest electrical conductivity was found when styrene:MMA molar ratio was 1:1.     

Synthesis,characterization and performance evaluation of long chain methacrylate-octene copolymer for lubricant formulation

Abstract

In this study, the authors synthesized myristyl methacrylate monomers by esterification reaction of methacrylic acid and myristyl alcohol using conc. H₂SO₄ as catalyst. Homopolymer of the prepared ester was synthesized and a series of copolymers were prepared by varying the ratio between the ester and 1-octene by free radical polymerization using azobisisobutyronitrile as initiator. All the synthesized polymers were characterized by spectral studies (FT-IR and NMR) and their average molecular weights were determined by gel permeation chromatography (GPC). Thermogravimetric analysis (TGA) was selected as the method to investigate the thermal behavior of the polymers at high temperature. Performances of the polymers as additives, and their responses as flow improvers and viscosity modifiers in the base fluid were carefully assessed by standard methods in terms of pour point and viscosity index. In addition, photo micrographic image was employed to examine the wax crystallization behavior of the additives. The results of the experimental work showed that although the copolymers were thermally more stable than the homopolymer, the latter showed better flow improving efficiency and induced better viscosity modification. The viscosity modification and the pour point performance of the additives also depend on the concentration of the additives in the base fluid.     

Effect of gemini surfactant additives on pour point depressant of crude oil

Efficiencies of cationic gemini surfactant additives in improving the pour point depressant of crude oil were investigated. The length of alkyl chain is a major factor affecting the improvement of the pour point depression. The adsorption behavior of these gemini surfactants at air/solution and oil/solution interfaces were investigated by measuring the surface tension and interfacial tension as functions of concentration. It is found that there is a good relation between surface properties especially interfacial tension of the gemini surfactants and their efficiency in depressing the pour point. Also, the surface parameters and free energies of micellization and adsorption confirm the decreasing and improving of pour point depression. Crystallization study in crude oil revealed the relationship between the structure and activity of gemini surfactant additives. It is found that the x-ray diffraction patterns of waxes with additives are remarkably different from those without additives. The mechanism of the depressants action has been suggested according the adsorption of each additive. Adsorption of the additive on the surface of the wax particles inhibits their growth and alters the crystal habits through micelle core. Pretreatment of the crude oil with pour point depressants has received the greatest acceptance due to its simplicity and economy.     

Kinetics of the Production of Castor Oil Maleate through the Autocatalyzed Thermal Reaction and the Free Radical Reaction

Castor oil maleate is used in drying oils, water‐soluble paints, healthcare products, synthetic lubricants, and as a monomer in several polymers. This maleate can be produced by a direct autocatalyzed reaction between castor oil and maleic anhydride. However, the reaction rate can be increased using a free radical catalyst. In this work, the influence of the concentration of benzoyl peroxide (BPO) and temperature in the kinetics and productivity of castor oil maleate was studied. The optimal operating condition was found at 120°C, 1 mol of maleic anhydride/mol of castor oil, and 0.003 mol of BPO/mol of castor oil, yielding 90.0% of castor oil maleate in 90 min. A kinetic model was developed, and the model parameters were estimated both for the thermal autocatalyzed reaction and the free radical reaction.     

一种苯并咪唑黄原酸酯的合成及其摩擦学性能

由于操作条件及环境保护的要求日益苛刻,环境友好型润滑油添加剂越来越受到人们的关注,润滑油添加剂向着低灰份、多功能、绿色环保方向发展。本文设计合成了三个环保型含氮硫化合物,采用质谱,红外光谱,元素分析对其结构进行了表征。考察了该类添加剂在菜籽油中的溶解性;采用热重分析对其热稳定性进行了评价;并在四球摩擦磨损试验机上考察了所合成的含氮硫化合物在菜籽油中的摩擦学性能。结果表明,该类添加剂在菜籽油中的溶解度都能达到2%,最低热分解温度为129℃,最高达532℃;在菜籽油中的极压值最高达1186N,是菜籽油的2倍,是ZDDP的1.3倍,抗磨性能最好的是B3,极压值最好的是B2。     

新型聚丙烯酸酯类柴油降凝剂分子模型的建立及验证

在前期工作得出的正构烷烃含量与浊点、冷滤点、凝点的定量关系模型基础上，选择柴油降凝剂的基团对柴油降凝剂分子结构进行了设计，得出了设计模型。结果表明，将含氮基团引入柴油降凝剂可以显著提高柴油降凝剂的性能。根据设计模型合成了一系列聚丙烯酸单酯和混合酯柴油降凝剂，并通过对柴油降凝剂的性能测试结果和自行设计的计算程序对设计模型进行了验证，结果表明，从柴油正构烷烃含量对柴油降凝剂的配比进行设计是可行的。     

Effects of Operating Conditions on the Copolymerization of Castor Oil Maleate–Styrene by Suspension Polymerization

This work studies the synthesis of copolymers (MACO‐St) of castor oil maleate (MACO) and styrene (St) initiated using benzoyl peroxide (BPO) as free radical initiator through suspension polymerization. The study investigates the effects of temperature (100–140 °C), the molar ratio between styrene and MACO (2:1–4:1), BPO concentration (0.10–0.20 wt%), and water concentration (50–100 wt%) on the molecular weight distribution, thermal stability, viscosity, and biodegradability of the copolymers. Suspension polymerization allows the production of a broad range of number average molecular weight (3465–18 995 g mol^?1) and molecular weight distributions with dispersions (?) ranging from 1.8 to 4.4. The reaction presents high yields of castor oil into copolymers (>90%), which displays thermal stability up to 200 °C and are highly biodegradable according to the International Organization of Standardization reference.     

Polymer additive analysis by pyrolysis-gas chromatography. III. Lubricants

Lubricants are widely used in thermoplastic polymers to increase the overall rate of processing or to improve surface release properties. Because of the low level of lubricants normally used in a polymer, it may not be possible to analyze the additive directly by common spectroscopic or thermal chemical techniques. However, lubricants as well as other additives in the polymer can be qualitatively analyzed by pyrolysis-gas chromatography (Py-GC) after extraction. In this work, several lubricants have been studied to demonstrate that Py-GC is a viable tool to investigate lubricants. The advantages of using Py-GC in the analysis of lubricant have also been discussed.     

Rapid analysis of lubricants by atmospheric solid analysis probe–ion mobility mass spectrometry

Formulated lubricants are complex mixtures composed of base oil(s) and additives with various functions (detergents, corrosion inhibiter, antioxidant, viscosity modifiers, etc.). Because of the aliphatic nature of base oil and the chemical diversity of additives, the characterization of lubricant is currently a long and complex process. The comprehensive analysis of lubricant samples involves several techniques such as nuclear magnetic resonance, mass spectrometry, chromatography and infrared spectroscopy. The coupling of atmospheric solid analysis probe (ASAP) with ion mobility‐mass spectrometry (IM‐MS) has been shown to be an efficient tool for the characterization of complex mixture containing vaporizable polar to non‐polar compounds. This approach affords the coupling of a direct ionization technique that does not require sample preparation, with a bi‐dimensional separation method with high peak capacity. In this work, we show that ASAP‐IM‐MS is a suitable method for rapid and direct characterization of lubricant samples. Indeed, base oil and additives yielded, by ASAP, ions series which could be separated by IM‐MS. Molecular additives such as Zn‐dithiocarbamate, phosphite, thiophosphate and Alkyl diphenylamine were ionized as molecular ions [M]^+? or protonated molecules [M + H]⁺, depending of their polarity. In some cases, fragment ions were observed, confirming the additive identification. In addition, high molecular weight polymeric additives such as poly(alkyl methacrylate) (PAM) were pyrolized in the ASAP source leading to characteristic fragment ions. ASAP‐IM‐MS is shown to be a powerful tool for studying complex mixtures, allowing the first comprehensive analysis of lubricants in just a few minutes. Copyright © 2014 John Wiley & Sons, Ltd.     

Composite tribological materials based on molybdenum disulfide nanoparticles and polytetrafluoroethylene microgranules

Tribological materials based on molybdenum disulfide nanoparticles localized on the surface of ultradispersed polytetrafluoroethylene were prepared. The composition and properties of the new composite materials were studied. Introduction of ultradispersed additives based on polytetrafluoroethylene with MoS₂ and on polytetrafluoroethylene and nanodiamonds prepared by detonation synthesis (taken as reference samples) decreases the viscosity of MS-20 aviation oil. The dependence of the friction coefficient on the Sommerfeld number for the composites obtained was examined. Introduction of additives leads to a decrease in the friction coefficient with increasing linear sliding velocity, in contrast to the initial oil for which the trend is opposite. The dependence of the friction coefficient on the concentration of additives in the initial oil was demonstrated. Modification of polytetrafluoroethylene microgranules with 3 wt % MoS₂ nanoparticles allows the amount of additive to the oil to be considerably reduced.     

Hydrophobic modification of cellulose nanocrystal via covalently grafting of castor oil

Hydrophobic cellulose nanocrystals (CNs) have been prepared by grafting isocyanate-terminated castor oil, a kind of natural vegetable oil, onto their surface. The existence of castor oil component in the modified cellulose nanocrystals was verified by Fourier transform infrared spectroscopy, solid-state ¹³C NMR spectra and X-ray photoelectron spectroscopy. At the same time, X-ray diffraction and transmission electron micrographs further proved that the crystalline structure and large aspect ratio of cellulose nanocrystals were essentially preserved after chemical grafting. Furthermore, the surface of modified cellulose nanocrystals appeared to be hydrophobic as indicated by contact angle measurements. The value of the polar component of surface energy decreased from 21.5 mJ/m² to almost zero via grafting castor oil. These novel hydrophobic castor oil-grafted cellulose nanocrystals appear as valuable alternatives to formulate bionanocomposites with non-polar polymers for optimized performances.     

Submicron carbon-based hybrid nano-pour-point depressant with outstanding pour point depressant and excellent viscosity depressant

We have investigated the effective utilization potential of carbon nanomaterials in the field of pour point depressants, and reported three kind of carbon-based hybrid nano-pour-point depressants with different dimensions. In this paper, poly-α-olefins-acrylate high-carbon ester pour point depressant (PAA-18) was prepared by esterification and polymerization as the basic pour point depressant. Then, the basic pour point depressant PAA18 was modified by solvothermal method with graphene oxide (GO), carbon nanospheres (Cna) and carbon nanotubes (OCNTs). The morphology and structure of the composites were analyzed by SEM, FTIR and XRD. The results showed that PAA18 was successfully in situ polymerized on GO, Cna and OCNTs. We took the simulated oil as the experimental object, and evaluated its pour point, rheological properties and wax crystal morphology, and achieved excellent results. In the three carbon-based hybrid nano-pour-point depressants with different carbon contents, the oxidation carbon nanotubes composite pour point depressant (PAA18-1 % OCNTs) with carbon content of 1 % had the best pour point and viscosity reduction effect when the dosage was 1250 ppm, which could make the pour point of the simulated oil containing wax decrease by 16 °C. PAA18-1 % OCNTs reduced the pour point by 5 °C more than PAA18. This paper provides reference for the application of carbon nanomaterials in the field of pour point depressant.     

Synthesis of linseed oil based biodegradable homo and copolymers: role as multifunctional greener additives in lube oil

Abstract

Homopolymer of linseed oil and its four copolymers with styrene, 1-decene, isodecyl acrylate and octyl acrylate, respectively, have been synthesized in this present context. The prepared polymers are characterized by NMR and FTIR spectroscopy. The molecular weights have been measured by gel permeation chromatography. Their effectiveness as pour point depressant (PPD), viscosity index improver (VII) and their shear stability in terms of permanent shear stability index have been evaluated in lube oil. The copolymers acted as better PPDs than the homopolymer whereas the homopolymer of linseed oil excelled as VII. Further it was observed that all the prepared polymers were stable enough under severe mechanical shear.     

Synthesis, characterization, degradation of biodegradable castor oil based polyesters

A new family of castor oil based biodegradable polyesters was synthesized by catalyst free melt condensation reaction between two different diacids and castor oil with d-mannitol. The polymers synthesized were characterized by NMR spectroscopy, FT-IR and the thermal properties were analysed by DSC. The results of DSC show that the polymer is rubbery in physiological conditions. The contact angle measurement and hydration test results indicate that the surface of the polymer is hydrophilic. The mechanical properties, evaluated in the tensile mode, shows that the polymer has characteristics of a soft material. In vitro degradation of polymer in PBS solution carried out at physiological conditions indicates that the degradation goes to completion within 21 days and it was also found that the rate of degradation can be tuned by varying the curing conditions.     

Mechanical, morphological and biodegradation studies of microwave processed nanostructured blends of some bio-based oil epoxies with poly (vinyl alcohol)

Bioresource based blends exploit the synergy between polymers derived from renewable resource and commercial polymers to obtain desirable physical, mechanical, and biodegradable properties. With the aim to develop a sustainable resource based biodegradable mulch films, nanostructured blends of epoxies of linseed oil (LOE) and dehydrated castor oil (DCOE) with poly (vinyl alcohol) (PVA) were prepared in the weight ratios of 20/80, 50/50 and 80/20. Microwave-assisted blending was used for the synthesis of DCOE/LOE blends with PVA and the results were compared with conventional solution blending using FT-IR, TGA-DTA and optical measurements. The results revealed that microwave-assisted blending proved to be an efficient method for the formation of compatible blends in a short span of time as compared to conventional solution blending. Transmission electron microscopy (TEM) analysis of DCOE/PVA and LOE/PVA blends synthesized by microwave-assisted method confirmed the formation of a nanostructured blend. Scanning electron microscopy (SEM), respirometry and mechanical measurements were carried out to compare the morphology, biodegradability, and the mechanical strength of DCOE/PVA and LOE/PVA blends. It was observed that DCOE/PVA blends exhibited higher biodegradability, better mechanical properties, and lower moisture absorption characteristics as compared to LOE/PVA blends. The mechanical strength, moisture absorption, and biodegradability of these blends were also compared with blends of other bioresource based polymers such as sugarcane bagasse (SCB), waste gelation (WG), apple peal (AP), and starch/glycerol with PVA, as available from the cited literature in the text.     

Modelling relation between oxidation resistance and tribological properties of non-toxic lubricants with the use of artificial neural networks

The lubricants based on vegetable oils, as environmental friendly, are urgently sought. However, in addition to ecological characteristics, the lubricating properties have to be met. To meet these requirements the active additives influencing the lubricating properties and oxidation resistance are used. The useful lifetime of lubricants is determined largely by their abilities to resist oxidation. The article presented the results of new, ecological lubricants development. The oxidation performances of different developed lubricants have been tested. The experimentally determined oxidation stability of the compositions based on vegetable oils are presented. Analysed oxidation onset temperature was obtained from the differential scanning calorimetry (DSC) curves, which provides the rapid prediction of the oxidative stability of lubricants. Besides the lubricating composition based on vegetable oils, the developed greases-based mineral, or synthetic oil were investigated. The properties of these greases were evaluated using the measurement of parameters describing structure (penetration) and resistance to high temperature (dropping point). The lubricating properties of both the greases and vegetable oil compositions were tested on four-ball testing machine. In the results of the modelling of the lubricating properties the neural network models for the both types of the lubricants were developed. A discussion of the research results and analysis of models validity is given below. The experimental results are compared with the calculated using the neural models. An acceptable agreement was achieved.     

The influence of reactive organoclay on a biorenewable castor oil‐based polyurethane prepolymers toughened polylactide nanocomposites

Polylactide (PLA) is the most extensively reviewed and utilized biodegradable and renewable thermoplastic polyester, with potential to replace conventional petroleum‐based polymeric materials. To improve the toughness of PLA, castor oil‐based polyurethane prepolymer (COPUP) toughened PLA nanocomposites were prepared via the melt mixing process and investigated for its mechanical, thermal and morphological properties. X‐ray diffraction and transmission electron microscopy studies revealed the formation of polymer blend nanocomposites. Mechanical tests revealed optimum performance characteristics at PLA/COPUP ratio of 70:30. Further, loading of the organoclay showed higher tensile strength and modulus of the blend nanocomposites as compared to optimized blend. The morphological results indicated that the surface roughness increases as a function of the organoclay incorporation. Thermogravimetric measurements reveal that the thermal stability of the blend increases with the incorporation of organoclay. The improved mechanical properties along with its biodegradability might lead to new industrial and biomedical applications. Copyright © 2016 John Wiley & Sons, Ltd.