共查询到20条相似文献,搜索用时 15 毫秒
1.
Recently, bio-derived materials such as vegetable oils are significantly employed in lubricating oil formulations due to its high flash point, high lubricity, low evaporation loss, renewability, biodegradability, and eco-friendliness when compared to mineral oil. We investigated the performance of seven poly(alkyl lactate acrylate)s as viscosity modifiers in two vegetable oils, namely, coconut oil and sunflower oil, which differ in the percentage of polar compounds and degree of unsaturation. Poly(alkyl lactate acrylate)s having alkyl as hexyl to dodecyl group in different concentrations between 1 and 2 wt% were added to coconut and sunflower oil and parameters such as thickening power or Q factor, kinematic viscosity (μ), and viscosity index (VI) were calculated. The μ values at 40°C and 100°C of vegetable oils studied were lower than commercially available SAE20W40 engine oil, but the VI of coconut and sunflower oil was higher by about 22%. Value of Q factor higher than 1, indicated that these poly(alkyl lactate acrylate)s were VI improvers. VI increased with increase in the polymer concentration in both the vegetable oils. The length of the alkyl side chain of these polymers and the polarity of vegetable oil had predominant effect in determining the values of VI of vegetable oils. By using these polymer additives, VI was improved by 85.5% in coconut oil and by 61.7% in sunflower oil. Varying the concentration and alkyl group of these additives, one can largely modify the viscosity ranges enabling them to be used in different lubricating applications. 相似文献
2.
Hadeel Hosney Bassant Nadiem Ibrahim Ashour Ibrahim Mustafa Ayman El‐Shibiny 《应用聚合物科学杂志》2018,135(20)
Phthalate esters received a considerable attention owing to its various applications and the harmful health effects resulting from phthalate exposure; thus, finding an alternative to phthalate derivatives became a necessity. Phthalate esters are commonly used as plasticizer in polymer formulation; in particular for poly(vinyl chloride) (PVC) formulation. According to the researches in the last 18 years, epoxidized vegetable oils are one of the alternatives that are strongly encouraged to substitute phthalate esters since they were proven to be valid in various applications, eco‐friendly and sustainable resource. However, most of the production practices for epoxidized vegetable oil are via conventional epoxidation that concentrates on a catalyst that is homogeneous and non‐reusable. This type of catalyst, however, causes several problems later in the process. Therefore, the selective epoxidation of vegetable oils process requires new catalytic systems that are more aligned with the green chemistry principles. This article reviews the harmful health effects associated with the exposure to phthalate esters products, explains the usage of oleochemicals resources as a substitute to phthalate esters and describes different approaches for the epoxidation of vegetable oils. Finally, it draws attention to the usage of epoxy and bio‐based compounds as plasticizers in PVC manufacturing. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46270. 相似文献
3.
Fredrick Nzioka Mutua Cong Cheng Yusheng Dong Chuyu Zheng Bo Zhu Yong He 《Polymer Engineering and Science》2018,58(5):659-664
A novel bio‐based polyamide, poly(pentamethylene oxamide) (PA52), with high molecular weight has been prepared from dibutyl oxalate and renewable monomer of 1,5‐pentanediamine by a two‐step polymerization procedure. The chemical structures are analyzed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy while the properties are evaluated by differential scanning calorimetry, thermogravimetric analysis, and water uptake measurements for the obtained PA52. The results reveal that PA52 possesses distinguished properties such as high temperature resistance, excellent crystallizability and low water absorption. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers 相似文献
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Kinetics studies and characterization of poly(furfuryl alcohol) for use as bio‐based furan novolacs 下载免费PDF全文
Joshua M. Sadler In‐Chul Yeh Faye R. Toulan Ian M. McAninch Berend C. Rinderspacher John J. La Scala 《应用聚合物科学杂志》2018,135(34)
Poly(furfuryl alcohol) (PFA) is an attractive target for the development of bio‐based novolac resins. However, control of the polycondensation reaction is not well understood and side reactions are an important factor for PFA and the development of new resins. The polymerization reactions and kinetics of furfuryl alcohol and 2‐furyl ethanol into polymeric resins are detailed in this work. Nuclear magnetic resonance spectroscopy analysis of reaction kinetics, molecular weight analysis, and rheology analysis confirm that the polymerization reaction rate of 2‐furyl ethanol is much faster than that of furfuryl alcohol because the addition of this methyl group serves to stabilize the carbocation transition state. Side reactions, such as Diels–Alder crosslinking and in particular branching, are quantified and were found to be much more prevalent in the polymerization of PFA. The glass transition temperature was measured to be 376 K for PFA and only 294 K for poly(2‐furyl ethanol). Molecular dynamics simulations showed that the alternative structure that forms in PFA that causes branching results in greater backbone rigidity causing its higher glass transition temperature. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46608. 相似文献
6.
A series of electric field sensitive copolymer P(AA‐co‐AAEM) gels of acrylic acid (AA) with acetoacetoxy ethyl methacrylate (AAEM) were prepared by free‐radical copolymerization, with N,N′‐methylene bisacrylamide (MBAAm) and ammounium persulfate (APS) as crosslinking agent and initiator, respectively. The structures and properties of the gels were tunable by changing the monomer feed weighty ratio (R) (R = WAAEM/(WAAEM + WAA) of AAEM and AA. The influences of the NaCl concentration and pH buffer solutions on the equilibrium swelling ratios of the gels were studied in detail. It is shown that both NaCl concentration and pH value of the buffer solution affect the swelling properties of the P(AA‐co‐AAEM) gels greatly. Moreover, the gel deswelling behavior induced by a direct current electric field was investigated and an excellent electric‐sensitivity was found. Among all the samples, the gel with monomer feed weighty ratio (R) = 0.1479 showed the best electrical contraction properties. On the basis of the experimental results, the mechanism of the electricity‐induced deswelling behavior was presented. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
7.
Yadira D. Cerda‐Sumbarda Ivan Zapata‐Gonzalez Angel Licea‐Claverie Arturo Zizumbo‐Lopez Luis F. Ramos‐de Valle Adriana Espinoza‐Martínez 《Polymer Engineering and Science》2019,59(1):170-181
The preparation of poly(hexylacrylate)core‐poly(ethyleneglycol methacrylate)shell (PHA‐co‐PEGMA) nanogels, to be used as fillers in nanocomposite hydrogels, is reported. Stable nanogels with particle sizes between 90–300 nm were obtained varying the conditions of synthesis. The synthesis recipe of the nanogels could be easily scaled up. Purified and dispersed nanogels in aqueous solution were used as soft fillers for poly(2‐hydroxyethyl methacrylate) (PHEMA) hydrogels, crosslinked with ethylene glycol dimethacrylate (EGDMA). The obtained nanocomposite hydrogels exhibit a larger swelling capacity and a higher thermal stability in comparison with the non‐filled PHEMA hydrogels. Young, storage, and lost moduli, increase largely, in the better case up to 72.5% in the swollen state; while in the dry state the storage modulus increase up to 4.7 fold with a very low load on nanogels (0.64 wt%); resulting in biomaterials with improved properties with potential applications in medical devices. POLYM. ENG. SCI., 59:170–181, 2019. © 2018 Society of Plastics Engineers 相似文献
8.
Bis(2‐ethylhexyl) succinate in mixtures with epoxidized soybean oil as bio‐based plasticizers for poly(vinylchloride) 下载免费PDF全文
Bharat Indu Chaudhary Buu‐Dang Nguyen Patrick Smith Nse Sunday Michael Luong Alek Zamanskiy 《Polymer Engineering and Science》2015,55(3):634-640
Mixtures of bis(2‐ethylhexyl) succinate and epoxidized soybean oil (ESO) have been evaluated as bio‐based plasticizers for poly(vinylchloride). The rate of absorption of the bioplasticizers and their mixtures in the polymer was fast and, unlike that of petroleum‐derived plasticizers, did not vary significantly with molecular weight. These bio‐derived plasticizers and their mixtures were compatible with the polymer even at high loadings. The succinate was the most volatile and efficient plasticizer, but on heat aging of the polymer compositions, it also had the greatest deleterious effects. Diffusion coefficients and apparent activation energies of formulations containing bioplasticizer mixtures were controlled by the more volatile succinate. Mixtures comprising up to 50 wt% of the succinate yielded acceptably high‐tensile properties after thermal aging as well as better plasticization efficiency than the epoxy bioplasticizer. Although the succinate resulted in inferior volume resistivity of the polymer compositions, improvements were obtained with increasing proportions of the epoxidized derivative in plasticizer mixtures. Melt state viscosity‐shear rate curves of compositions containing dioctyl succinate (DOS) were similar to those made with two of the petroleum‐derived plasticizers, but a DOS/ESO mixture yielded extended non‐Newtonian behavior at low‐shear rates. POLYM. ENG. SCI., 55:634–640, 2015. © 2014 Society of Plastics Engineers 相似文献
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A blend of poly(methyl methacrylate) (PMMA) and poly(styrene‐co‐acrylonitrile) (PSAN) has been evaluated as a composite polymer electrolyte by means of differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, ac impedance measurements, and linear sweep voltammetry (LSV). The blends show an interaction with the Li+ ions when complexed with lithium perchlorate (LiClO4), which results in an increase in the glass‐transition temperature (Tg) of the blends. The purpose of using PSAN as another component of the blend is to improve the poor mechanical properties of PMMA‐based plasticized electrolytes. The mechanical property is further improved by introducing fumed silica as inert filler, and hence the liquid electrolyte uptake and ionic conductivity of the composite systems are increased. Room‐temperature conductivity of the order of 10?4 S/cm has been achieved for one of the composite electrolytes made from a 1/1 blend of PSAN and PMMA containing 120% liquid electrolyte [1M LiClO4/propylene carbonate (PC)] and 10% fumed silica. These systems also showed good compatibility with Li electrodes and sufficient electrochemical stability for safe operation in Li batteries. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1319–1328, 2001 相似文献
10.
Star‐shaped poly(alkyl methacrylate)s (PAMAs) were prepared and blended into an additive‐free engine oil to assess the structure–property relationship between macromolecular structure and lubricant performance. These additives were designed with a comparable number of repeating units per arm and the number of arms was varied between 3 and 6. Well‐defined star‐shaped PAMAs were synthesized by atom transfer radical polymerization (ATRP) via a core‐first strategy from multi‐functional head‐groups. Observations of the polymer‐oil blends suggest that stars with less than four arms are favorable as a viscosity index improver (VII), and molecular weight dominates viscosity‐related effects over other structural features. Star‐shaped PAMAs, as oil additives, effectively reduce the friction coefficient in both mixed and boundary lubrication regime. Several analogs outperformed commercial VIIs in both viscosity and friction performance. Increased wear rates were observed for these star‐shaped PAMAs in the boundary lubrication regime suggesting pressure‐sensitive conformations may exist. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43611. 相似文献
11.
An Philippaerts Joost Van Aelst Bert Sels 《European Journal of Lipid Science and Technology》2013,115(7):717-720
Recent interest from academia, nutritionists, the chemical as well as the feed and food industry in conjugated linoleic acids (CLAs) and conjugated vegetable oils has grown spectacularly. CLA isomers, either in their natural or synthetic forms, have not only been associated with diverse health and physiological effects, but they are also interesting renewable compounds in the production of industrial products such as paints, glues, and polymers, due to their very reactive conjugated double bond system. Due to the depletion of the world crude oil reserves and the increasing trend to use renewable feedstock in the chemical industry, it is to be expected that the use of conjugated fatty acids and oils will continue to grow in the near future. As high amounts of CLAs and conjugated vegetable oils will be needed and natural resources are limited, efficient production processes are urgently needed. An efficient process for the production of CLA from methyl linoleate, using the Wilkinson catalyst, is described by Behr et al. in this issue of European Journal of Lipid Science and Technology. 相似文献
12.
Interpenetrating polymer networks (IPNs) based on a nitrile rubber (NBR)–phenolic resin (PH) blend and poly(alkyl methacrylates) were synthesized by a sequential method. The cured blends were swollen in a methacrylate monomer containing a crosslinker and initiator. The swollen rubber sheets were cured at 60°C. From the swelling study of the monomer, it was found that IPN formation in the blend is in between the rubber and poly(alkyl methacrylate) phases only. The IPNs thus formed were characterized for their tensile, dynamic mechanical, and solvent-resistance characteristics. The tensile strength of the IPNs are dependent on the PH content; at a lower content of PH (up to 20 parts), IPNs have a higher strength compared to their corresponding blends, whereas at a higher content of PH (beyond 30 parts), the strength decreases. But for every NBR/PH-fixed composition, the strength of IPNs was found to be increasing in the order of PBuMA < PEMA < PMMA. The dynamic property results showed that NBR/PH blends are incompatible. The storage modulus of IPNs are always higher than their corresponding blends at all temperatures. The tan δ peaks of IPNs are broad, indicating the presence of microphase-separated domains. The IPNs show superior solvent-resistance characteristics compared to the blends. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68:255–262, 1998 相似文献
13.
Benoit Delage Benoit Briou Thomas Brossier Sylvain Catrouillet Jean‐Jacques Robin Vincent Lapinte 《Polymer International》2019,68(4):755-763
Well‐defined linear alkyl benzene surfactants (COxn) were successfully synthesized using cardanol as a green phenolic alternative and initiator for polyoxazoline (POx), the hydrophilic block of nonionic surfactants. Various hydrophilic lipophilic balance values were investigated by varying the POx length according to the [monomer]/[initiator] ratio. The chemical structure of the surfactants, in particular the terminal groups, was well identified by matrix assisted laser desorption ionization time of flight mass spectrometry demonstrating the good progress of the cationic ring‐opening polymerization. The COxn surfactants spontaneously self‐assembled in water at a critical aggregation concentration of 1–2 µmol L?1 into nano‐objects characterized by a hydrodynamic diameter of 11–24 nm and a number of aggregations ranging from 30 to 60 according to the worm‐like micelle model. © 2019 Society of Chemical Industry 相似文献
14.
Fibrous material based on a combination of poly(acrylic acid‐co‐hydroxyethyl methacrylate) with iron ions as a heterogeneous Fenton catalyst for dye oxidative decomposition 下载免费PDF全文
The Fenton method has been used to remedy dye wastewater because hydroxyl radicals generated from the Fenton reaction can oxidize the dye into small molecules. In comparison with a homogeneous reaction, a heterogeneous reaction with a solid material as a catalyst is a more appropriate alternative for dye wastewater treatment. Because of the large specific surface area and excellent applicability, a novel fibrous material based on a combination of functional polymer with iron ions was designed in this study and used as a heterogeneous catalyst for dye wastewater treatment by the Fenton method. The fibrous material was found to have good catalytic activity for the oxidative decomposition of a variety of dyes and good reusability; additionally, the fibrous material could remove the dye to a greater extent and leave fewer iron ions in the treated wastewater than a homogeneous Fenton catalyst such as iron(II) chloride (FeCl2). What is more, the fibrous material could adsorb the residual iron ions from the treated wastewater and make these iron ions take part in the next catalyzation. The previous results make us believe that the prepared fibrous material might be used to create a green approach for dye wastewater treatment. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44875 相似文献
15.
Organic‐acid‐catalyzed sol–gel route for preparing poly(methyl methacrylate)–silica hybrid materials
Jui‐Ming Yeh Kuan‐Yeh Huang Chung‐Feng Dai B. G. Chand Chang‐Jian Weng 《应用聚合物科学杂志》2008,110(4):2108-2114
In this study, a series of organic–inorganic hybrid sol–gel materials consisting of a poly(methyl methacrylate) (PMMA) matrix and dispersed silica (SiO2) particles were successfully prepared through an organic‐acid‐catalyzed sol–gel route with N‐methyl‐2‐pyrrolidone as the mixing solvent. The as‐synthesized PMMA–SiO2 nanocomposites were subsequently characterized with Fourier transform infrared spectroscopy and transmission electron microscopy. The solid phase of organic camphor sulfonic acid was employed to catalyze the hydrolysis and condensation (i.e., sol–gel reactions) of tetraethyl orthosilicate in the PMMA matrix. The formation of the hybrid membranes was beneficial for the physical properties at low SiO2 loadings, especially for enhanced mechanical strength and gas barrier properties, in comparison with the neat PMMA. The effects of material composition on the thermal stability, thermal conductivity, mechanical strength, molecular permeability, optical clarity, and surface morphology of the as‐prepared hybrid PMMA–SiO2 nanocomposites in the form of membranes were investigated with thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, gas permeability analysis, ultraviolet–visible transmission spectroscopy, and atomic force microscopy, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
16.
Poly(ethyl methacrylate) (PEMA) and poly(2‐hydroxyethyl methacrylate) (PHEMA) nanocomposites with sepiolite in pristine and silylated form were prepared using the solution intercalation method and characterized by the measurements of XRD, TEM, FTIR‐ATR, TG/DTG, and DSC. The TEM analysis indicated that the volume fraction of fibers in sepiolite decreased and the fiber bundles dispersed in PEMA and PHEMA at a nanometer scale. These results regarding TEM micrographs were in agreement with the data obtained by XRD. The increase in thermal stability of nanocomposites of PEMA is higher than that of PHEMA according to the data obtained from TG curves. The DTG analysis revealed that sepiolite/modified sepiolite caused some changes, as confirmed by FTIR in the thermal degradation mechanism of the polymers. Tg temperatures of PEMA and PHEMA usually increased upon the addition of sepiolite/modified sepiolite. In addition, modification of sepiolite with 3‐APTS had a slight influence on thermal properties of the nanocomposites. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers 相似文献
17.
Dialkyl furan‐2,5‐dicarboxylates,epoxidized fatty acid esters and their mixtures as bio‐based plasticizers for poly(VInylchloride) 下载免费PDF全文
Dialkyl furan‐2,5‐dicarboxylates and epoxidized fatty acid esters (EFAE) of varying molecular weights and volatilities, as well as their mixtures, were investigated as alternative plasticizers for poly(vinylchloride) (PVC). The EFAE utilized were epoxidized soybean oil (ESO) and epoxidized fatty acid methyl ester (e‐FAME). All plasticizers were compatible with PVC, with plasticization efficiencies usually increasing with decreasing molecular weights of the plasticizers (except in the case of ESO, which was remarkably effective at plasticizing PVC, in spite of its relatively high molecular weight). In comparison with phthalate and trimellitate plasticizers, the alternatives generally yielded improved balance of flexibility and retention of mechanical properties after heat aging, with particularly outstanding results obtained using 30?50 wt % e‐FAME in mixtures with diisotridecyl 2,5‐furandicarboxylate. Although heat aging characteristics of the plasticized polymer were often related to plasticizer volatilities, e‐FAME performed better than bis(2‐ethylhexyl) 2,5‐furandicarboxylate, and bis(2‐ethylhexyl) phthalate of comparatively higher molecular weights. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42382. 相似文献
18.
Jun Shen Wei Jiang Ying Liu Rongqing Wei Xiaoning Liu Yu Zhong Jie Xu Linling Li Gi Xue 《应用聚合物科学杂志》2012,124(5):3905-3911
Poly(methyl methacrylate)‐poly(L ‐lactic acid)‐poly(methyl methacrylate) tri‐block copolymer was prepared using atom transfer radical polymerization (ATRP). The structure and properties of the copolymer were analyzed using infrared spectroscopy, gel permeation chromatography, nuclear magnetic resonance (1H‐NMR, 13C‐NMR), thermogravimetry, and differential scanning calorimetry. The kinetic plot for the ATRP of methyl methacrylate using poly(L ‐lactic acid) (PLLA) as the initiator shows that the reaction time increases linearly with ln[M]0/[M]. The results indicate that it is possible to achieve grafted chains with well‐defined molecular weights, and block copolymers with narrowed molecular weight distributions. The thermal stability of PLLA is improved by copolymerization. A new wash‐extraction method for removing copper from the ATRP has also exhibits satisfactory results. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
19.
Interpenetrating polymer networks based on carboxylated nitrile rubber and poly(alkyl methacrylate)s
N. R. Manoj D. Ratna V. Dalvi L. Chandrasekhar M. Patri B. C. Chakraborty P. C. Deb 《Polymer Engineering and Science》2002,42(8):1748-1755
A series of interpenetrating polymer networks (IPNs) based on carboxylated nitrile rubber (XNBR) and poly(alkyl methacrylate)s such as poly(methyl methacrylate) (PMMA), poly(ethyl methacrylate) (PEMA) and poly(butyl methacrylate) (PBuMA) were synthesized. The compositions of the IPNs were also varied by changing the swelling time of the rubber in the methacrylate monomer. The tensile and dynamic mechanical properties of the IPNs were studied. The dynamic mechanical properties in the range of 1–105 Hz were obtained by the time‐temperature superposition of the data under multifrequency mode, which indicated high tanδ with good storage modulus in the entire frequency range. This indicates the suitability of these IPNs as vibration and acoustic dampers. 相似文献
20.
This study was to design a mucoadhesive based on the biological and physicochemical properties of the buccal mucosa to achieve optimal mucoadhesion in the aqueous buccal environment. Since the buccal surface is negatively charged, a series of novel mucoadhesive poly[acrylic acid‐co‐poly(ethylene glycol) monomethylether monomethacrylate‐co‐dimethylaminoethyl methacrylate] [poly (AA‐PEGMM‐DMEMA)] were synthesized by incorporating the cationic monomer DMEMA into poly(AA‐PEGMM) to enhance the interactions between the mucohadhesive polymer and the buccal mucosa. The compositions of poly(AA‐PEGMM‐DMEMA) were varied by changing the content of DMEMA from 0 to 4.8 mol % while keeping the mole ratio of AA to PEGMM at a constant 9 : 1. It was found that the force of mucoadhesion of poly(AA‐PEGMM‐DMEMA) increased initially, as DMEMA content increased, and reached the maximum at 1% of DMEMA. Further increasing the content of DMEMA decreased the mucoadhesion. The polymers with 0.5 to 2.9% DMEMA appeared to have maximum mucoadhesion after prehydration for 5 min. An ATR–FTIR spectroscopy study revealed that intrapolymer interactions and intersurface interactions played opposite roles in the mucoadhesion performance of the polymers. Optimal mucoadhesion can be achieved by balancing these two interactions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94:2431–2437, 2004 相似文献