Synthesis and photopolymerization of norbornyl epoxidized linseed oil

Norbornyl epoxidized linseed oil was synthesized via Diels-Alder reaction of cyclopentadiene with linseed oil at high pressure (∼200 psi) and high temperature (240 °C), followed by an epoxidation using hydrogen peroxide with a quaternary ammonium tetrakis(diperoxotungsto) phosphate(3−) epoxidation catalyst. The products were characterized using ¹H and ¹³C NMR, FT-IR, and electrospray ionization mass spectroscopy. Photo-induced curing kinetics of norbornyl epoxidized linseed oil coatings was investigated using real-time FT-IR spectroscopy with a fiber optic UV-curing system. The norbornyl epoxidized linseed oil was formulated with three different divinyl ether reactive diluent. The effect of divinyl ether concentration and types of divinyl ether on the curing reaction was investigated. It was found that the curing rate of norbornyl epoxidized linseed oil was lower than that of cycloaliphatic epoxide, but higher than epoxidized linseed oil. The incorporation of divinyl ethers increased the curing rate and overall conversion of the epoxide groups. Of the three divinyl ethers used, coating with triethyleneglycol divinyl ether showed the highest curing rate and coating with cyclohexane dimethanol divinyl ether showed the lowest curing rate.     

Synthesis and Characterization of Polyols Derived from Corn Oil by Epoxidation and Ozonolysis

In the present study, epoxidation and ozonolysis led to a decrease of 40.8 and 51.9 % in the degree of unsaturation of corn oil, respectively. Both products were initially characterized by Fourier transform infrared spectroscopy and ¹H- and ¹³C-nuclear magnetic resonance spectroscopies. The heteronuclear single-quantum correlation spectroscopy (HSQC) analysis of the polyol obtained by epoxidation showed that carbinol hydrogen signals, located between 3.65 and 3.47 ppm, were correlated to carbon signals between 74.4 and 71.7 ppm. HSQC analysis of the polyol obtained by ozonolysis revealed these same chemical shifts at 3.64 and 62.9 ppm, respectively. Compared to pure corn oil, the differential scanning calorimetry of both corn oil-based polyols displayed the absence of any detectable melting peaks. However, the epoxidized derivative had a higher thermal stability than the ozonated sample, as shown by thermogravimetric analysis.     

Photocrosslinkable modified vegetable oil based resin for wood surface coating application

An acrylated epoxidized linseed oil (AELO) was synthesized from epoxidized linseed oil through ring opening of the oxirane group using acrylic acid as ring opening agent. The occurrence of the acrylate group and the ring opening of oxirane group was monitored using FT-IR spectroscopy. The AELO was mixed with three different photoinitiators at two different concentrations. Wood surfaces were coated with the mixtures, subsequently cured under UV light and the resulting surface properties of the coated samples gloss, scratch resistance, solvent resistance, and coating adhesion were characterized. The efficiency of the photoinitiators and the influence of their concentration on the rate and the extent of the curing were studied by curing the AELO mixtures under a monochromatic wavelength of 365 nm and measuring absorption spectra during the cure by real time FT-IR spectroscopy. The decrease of absorption in the measured spectra at 1406 cm⁻¹ was used to calculate the conversion of acrylic double bonds with increasing time of UV light exposure to obtain information on the cure kinetics for each photoinitiator and concentration.     

Kinetics of tungsten‐catalyzed sunflower oil epoxidation studied by 1H NMR

Sunflower oil (SO) is a renewable resource that can be epoxidized, and the epoxidized SO has potential uses as an environmentally friendly and reactive material in polymeric formulations, especially for polyvinyl chloride. SO was epoxidized with peracetic acid, which was either preformed or prepared in situ. In order to optimize the formation of oxirane rings, the epoxidation and the extent of the side reactions were studied at different temperatures. The peracetic acid was obtained by acidic catalysis in the presence of a cation‐exchange resin. The optimum conversions were obtained within a 4‐h reaction period at 55 °C by the in situ epoxidation technique. The epoxidation was also carried out with hydrogen peroxide in the presence of peroxotungstic acid complexed with lipophilic phosphorus‐based ligands. ¹H NMR was used to define the new indices Δ and Ω, which are the mean numbers of C=C double bonds and oxirane rings per fatty acid chain, respectively. This allowed monitoring of the reaction and quantification of the results. Peroxotungstic catalysts appeared less performing than peracids in the epoxidation of SO, but were found very efficient for the epoxidation of the SO methyl esters.     

New bio-epoxy from sacha inchi oil by epoxidation reaction

Sacha inchi oil with large amount of double bonds (DBs) in allylic positions and double-allylic positions was converted to an epoxidized oil by using H₂O₂ as the reactant. The success of this modification process has been demonstrated by Fourier transform infrared spectroscopy and ¹H-NMR spectra. The influence of the reaction agent, the components in the catalyst system such as Na₂WO₄, PTC (benzyldimethylstearylammonium chloride hydrate), H₃PO₄, and temperature on the epoxidation reaction has been studied systematically. Through the evaluation of oxirane oxygen of the epoxidized oil, the conversion of DBs, and the selectivity of the catalyst, the optimum conditions are found. They are as DB/H₂O₂/Na₂WO₄ molar ratio of 1/1.5/0.0075 and Na₂WO₄/PTC/H₃PO₄ molar ratio of 1/0.45/2. The reaction time was shortened to only 8 min when the epoxidation reaction was performed at 60°C. The epoxidized sacha inchi oil had the oxirane oxygen reaching 8.78% with a yield of 82.12% and a catalytic selectivity of 0.85.     

Synthesis of SIS-based hot-melt pressure sensitive adhesives for transdermal delivery of hydrophilic drugs

A series of epoxidized styrene–isoprene–styrene (SIS) copolymer was obtained with in situ epoxidation. Their epoxidation degrees were analyzed by ¹H nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy. SIS, Epoxidized SIS (ESIS), C5 resin, mineral oil and antioxidants were melt-blended to prepare SIS/ESIS-based hot-melt pressure sensitive adhesives (HMPSAs). Their compatibility was studied with differential scanning calorimetry (DSC). The adhesive performances of the HMPSAs were measured, including holding power and 180° peel strength. Geniposide was chosen as a representative hydrophilic drug and it’s in vitro release behavior in the HMPSAs was investigated using a modified Franz type horizontal diffusion cells. It was shown that SIS was successfully epoxidized without side reactions. Although the epoxidation impaired the compatibility between ESIS and other additives, the 180° peel strength increased with the epoxidation degrees of ESIS. Furthermore, the in vitro release behavior of hydrophilic drugs was obviously enhanced with the increment of epoxidation degrees.     

Epoxidized rice bran oil (ERBO) as a plasticizer for poly(vinyl chloride) (PVC)

With environmental and toxicity concerns becoming more critical, there are increasing efforts to remove phthalates from polymer compounds around the globe more rapidly. Phthalates can be replaced by natural products; in particular, those obtained from vegetable oils and fats. In the present study, a natural-based plasticizer, synthesized by epoxidation of non-toxic rice bran oil (RBO) with peroxy acid generated in situ has been added to poly(vinyl chloride). The influence of various reaction parameters on epoxidation was studied by investigating the reaction ratio, temperature, reaction time and stirring speed. Epoxidized rice bran oil (ERBO) obtained from an optimized reaction condition was analyzed by iodine number and oxirane content. FTIR was used to analyze epoxy group formation. Product ERBO was obtained with 82 % oxirane conversion within 3 h of reaction period. PVC sheets were formulated using a conventional plasticizer di-(octyl) phthalate and was partially replaced by synthesized ERBO. The effect of ERBO addition was tested by mechanical properties (tensile strength, modulus, elongation-at-break, shore D hardness) and compared with commercially available ESBO (epoxidized soybean oil). ERBO presented fairly good incorporation and plasticizing performance, as demonstrated by the results of mechanical properties, exudation, migration tests, thermal stability by thermogravimetric analysis, T _g values as shown by differential scanning calorimetry, replacing about 60 % of the total plasticizer.     

Nanomagnet-Bound Imidazole as a Heterogeneous Axial Ligand for MnIII(salophen)Cl: An Efficient, Recoverable and Recyclable Catalyst for Epoxidation of Alkenes with Sodium Periodate

Efficient alkene epoxidation with sodium periodate catalyzed by manganese(III) salophen supported on nanomagnetic materials is reported. First, the iron nanomagnets were silica coated, functionalized with imidazole and then manganese salophen was successfully bonded to their surface. The catalyst, [Mn^III(salophen)Cl]@SiIm-Fe, was characterized by elemental analysis, FT-IR and UV/Vis spectroscopic techniques, SEM and ICP. The [Mn^III(salophen)Cl]@SiIm-Fe was used for alkene epoxidation with sodium periodate at room temperature. Different aromatic and aliphatic terminal alkenes were epoxidized efficiently using sodium periodate as an oxidant. The effect of reaction parameters such as solvent and oxidant in the epoxidation of cis-cyclooctene was investigated. This new heterogenized epoxidation catalyst is easily recovered with a magnet and showed no appreciable loss of activity even after four consecutive runs.     

Epoxidation ofLesquerella andLimnanthes (Meadowfoam) oils

Lesquerella gordonii (Gray) Wats andLimnanthes alba Benth. (Meadowfoam) are species being studied as new and alternative crops. Triglyceride oil from lesquerella contains 55–60% of the uncommon 14-hydroxy-cis-11-eicosenoic acid. Meadowfoam oil has 95% uncommon acids, includingca. 60%cis-5-eicosenoic acid. Both oils are predominantly unsaturated (3% saturated acids), and have similar iodine values (90–91), from which oxirane values of 5.7% are possible for the fully epoxidized oils. Each oil was epoxidized withm-chloro-peroxybenzoic acid, and oxirane values were 5.0% (lesquerella) and 5.2% (meadowfoam). The epoxy acid composition of each product was examined by gas chromatography of the methyl esters, which showed that epoxidizedL. gordonii oil contained 55% 11,12-epoxy-14-hydroxyeicosanoic acid, and epoxidized meadowfoam oil contained 63% 5,6-epoxyeicosanoic acid, as expected for normal complete epoxidation. Mass spectrometry of trimethylsilyloxy derivatives of polyols, prepared from the epoxidized esters, confirmed the identity of the epoxidation products and the straightforward nature of the epoxidation process. Synthesis and characterization of these interesting epoxy oils and derivatives are discussed.     

Epoxidation of karanja (Pongamia glabra) oil by H2O2

Epoxidation of karanja oil (KO), a nondrying vegetable oil, was carried out with peroxyacetic acid that was generated in situ from aqueous hydrogen peroxide and glacial acetic acid. KO contained 61.65% oleic acid and 18.52% linoleic acid, respectively, and had an iodine value of 89 g/100 g. Unsaturated bonds in the oil were converted to oxirane by epoxidation. Almost complete epoxidation of ethylenic unsaturation was achieved. For example, the iodine value of the oil could be reduced from 89 to 19 by epoxidation at 30°C. The effects of temperature, hydrogen peroxide-to-ethylenic unsaturation ratio, acetic acid-to-ethylenic unsaturation ratio, and stirring speed on the epoxidation rate and on oxirane ring stability were studied. The rate constant and activation energy for epoxidation of KO were 10⁻⁶ L·mol⁻¹·s⁻¹ and 14.9 kcal·mol⁻¹, respectively. Enthalpy, entropy, and free energy of activation were 14.2 kcal·mol⁻¹, −51.2 cal·mol⁻¹·K⁻¹, and 31.1 kcal·mol⁻¹, respectively. The present study revealed that epoxides can be developed from locally available natural renewable resources such as KO.     

New Nonlinear Polyurethane: Synthesis and Optical Properties

The compound 3,4-di-(2′-hydroxyethoxy)-4-diphenyl-hydrazonomethyl was synthesized from the reaction of 3,4-dihydroxy-4-diphenyl-hydrazonomethyl with 2–chloro–1–ethanol in a 1:2 mole ratio, and subsequent reaction with methylene–4,4′–diphenyldiisocyanate (MDI) to produce the new nonlinear polyurethane. The chemical structures of the resulting monomers and polymer were characterized by CHN analysis, FT-IR, ¹H-NMR, and UV-Vis spectroscopy. The nonlinear optical properties of new polyurethane have been studied via second harmonic generation (SHG). The values of electro-optic coefficient d₃₃ and d₃₁ of the poled polyurethane film were 6.62 × 10^?8 and 3.05 × 10 ^?8 esu, respectively. Thermal behavior of this polyurethane was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC).     

Preparation and characterization of tung oil-based flame retardant polyols

Three kinds of tung oil-based structural flame retardants polyols (TOFPs) were prepared by new methods in this paper. First, tung oil was used to produce monoglyceride and diglyceride by transesterification with glycerol by sodium methoxide. The products after transesterification were epoxidized by peracetic acid which was in-situ generated from acetic acid and hydrogen peroxide in the presence of sulfuric acid catalyst. And then, TOFPs were prepared from epoxidized alcoholysis tung oil (EGTO) with 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), diethyl phosphate (DEP) and diethanolamine (DEA) by ring-opening reactions, respectively. GPC was used to evaluate the conversion rate, at optimum reaction conditions, selectivity for monoglyceride in transesterification. The influence of different parameters such as temperature, mole ratio or mass ratio on the conversion rate of transesterification and epoxidation were investigated. The molecular structures of TOFPs were characterized by FTIR and ¹HNMR. Finally, tung oil-based polyurethane foams (TOPUFs) were prepared by a one-shot process using TOFPs with polyisocyanate. The LOI values of TOPUFs whose content of DOPO-EGTO, DEP-EGTO and DEA-EGTO were 100 wt% can reach to 26.2%, 25.1%, and 24.4%, respectively.     

Kinetic Study on Oxirane Cleavage of Epoxidized Palm Oil

A ring-opened product (EPO-HOAc) was prepared using epoxidized palm oil (EPO) and acetic acid (HOAc). The kinetics of the oxirane cleavage of EPO were investigated at 50, 60, 70, 80, and 90 °C, respectively, in the presence of HOAc. The rate equation of oxirane cleavage was as follows: r = k[Ep][CH₃COOH]^1.6 ([Ep] is the molar concentration of oxiranes, [CH₃COOH] is the molar concentration of HOAc), and the activation energy of oxirane cleavage was 40.28 kJ mol⁻¹. The structure of EPO-HOAc was confirmed by FT-IR and ¹H NMR. The oxidative stability of EPO-HOAc was better than that of palm oil (PO), and the pour point of EPO-HOAc was lower than that of PO and EPO, which made EPO-HOAc more suitable for biodegradable lubricant materials than PO and EPO.     

Synthesis,thermal degradation and dielectric properties of poly[2-hydroxy,3-(1-naphthyloxy)propyl methacrylate]

2-Hydroxy-3-(1-naphthyloxy)propyl methacrylate (NOPMA) monomer was synthesized from reaction of 2-[(2-naphthyloxy)methyl]oxirane with methacrylic acid in the presence of pyridine. The polymerization of NOPMA was carried out by free radical polymerization method in the presence of AIBN at 60 °C. The structure of monomer and polymer was characterized by ¹H-NMR, ¹³C-NMR and FT-IR spectroscopy techniques. The glass transition temperature and average-molecular weights of poly(NOPMA) were measured using differential scanning calorimetry and gel permeation chromatography, respectively. The thermal degradation behavior of poly(NOPMA) has been investigated by FT-IR studies of the partially degraded polymer and thermogravimetry. The cold ring fractions (CRFs) were collected at two different temperatures, initially fraction-1 (CRF₁) is from room temperature to 320 °C, and the other fraction-2 (CRF₂) is from 320 to 500 °C. The volatile products of the degradation were trapped at ?195 °C (in liquid nitrogen). All the fractions were characterized by FT-IR, ¹H and ¹³C-NMR spectroscopic techniques, and the cold ring fractions (CRFs) were also characterized by GC–MS. For the degradation of polymer, the major compound between products of CRFs is α-naphthol. The GC–MS, FT-IR and NMR data showed that depolymerization corresponding to monomer was not prominent below 320 °C in the thermal degradation of poly(NOPMA). The mode of thermal degradation containing formation of the major products was identified. The dielectric permittivity (ε′), the loss factor (ε″) and conductivity (σ_ac) were measured using a dielectric analyzer in the frequency range of 50 Hz to 20 kHz.     

Design and synthesis of bio-based epoxidized alkyd resin for anti-corrosive coating application

Alkyd resins with long aliphatic chain in their backbone are not suitable for high-performance applications. To overcome this limitation of alkyd resins, their backbone structure is usually chemically modified. In this study, an alkyd resin was successfully synthesized from renewable resources, including itaconic acid and linseed oil. Subsequently, the unsaturated backbone of the alkyd resin was converted to oxirane ring through epoxidation reaction in the presence of hydrogen peroxide and acetic acid. The epoxidized alkyd (EA) resin backbone was modified with various amounts of 3-amino propyltrimethoxysilane (APTMS) from 10 to 40 mol percent to enhance the anti-corrosive properties of coatings prepared from the alkyd resins. The structural elucidation of synthesized resins was described by physicochemical analysis and Fourier transform infrared and ¹H nuclear magnetic resonance spectroscopies. The EA resin and APTMS-modified EA resin were cured by itaconic acid in 1:1 stoichiometric ratio on the equivalent weight basis. The differential scanning calorimetric and thermogravimetric analysis results showed that thermal properties improved with increasing APTMS content. The cured coatings were characterized for their mechanical properties, chemical and solvent resistance, gel content, and water absorption. The corrosion-resistance performance of coatings was evaluated by electrochemical impedance spectroscopy and salt-spray test. It was observed that the highly cross-linked structure of the APTMS-modified EA coatings enhanced the corrosion protective property of coating films.     

Synthesis and characterization of low viscous and highly acrylated epoxidized methyl ester based green adhesives derived from linseed oil

Both epoxidized linseed oil and transesterified epoxidized linseed oil were acrylated to form UV curable bio-based oligomers. The synthesis was confirmed by FTIR and ¹H NMR and oxirane oxygen content (OOC). The OOC value of epoxidized linseed oil was determined to be 8.2 % which was reduced to 8.0 % after transesterification confirming the retaining of epoxy groups. The lower OOC of acrylated epoxidized linseed oil (AELO) (2.1 %) and acrylated epoxy methyl esters (AEME) (0.9 %) revealed successful acrylation. The degree of acrylation in AEME was higher (~ 90 %) than AELO (~ 77%) and most importantly, the viscosity of AEME was much lower than AELO revealing better processability for industrial use.     

Characterization of epoxidized natural rubber by 2D NMR spectroscopy

Assignment of signals in aliphatic region of ¹H NMR spectrum for epoxidized natural rubber was carried out through NMR spectroscopy. The epoxidized natural rubber was prepared by epoxidation of purified natural rubber with peracetic acid in latex stage followed by degradation with propanal and ammonium persulfate. The resulting liquid epoxidized natural rubber was characterized through 1D- and 2D-NMR spectroscopy. The unknown signals in the aliphatic region of the ¹H NMR spectrum were assigned through ¹³C NMR and two-dimensional heteronuclear shift correlation (HETCOR) measurement. The assignments were proved by two-dimensional inverse detected heteronuclear long-range shift correlation (HMBC) and two-dimensional homonuclear shift correlation (COSY) measurements, and they were supported with epoxidized squalene as a model compound through NMR spectroscopy.     

Immobilization of a molybdenum-glycine Schiff base complex within the nanocages of zeolite Y with flexible ligand method

Immobilization of a molybdenum-glycine Schiff base complex onto the supercages of zeolite Y was achieved through the flexible ligand method. The prepared material was characterized by different physicochemical techniques. FT-IR spectroscopy confirmed the immobilization of the complex onto the nanocages of zeolite Y. X-ray diffraction analysis revealed that textural properties of zeolite Y support were preserved during the immobilization process. Nitrogen adsorption–desorption analysis demonstrated the decrease in surface area of the prepared material in comparison with parent zeolite Y. Inductively coupled plasma optical emission spectroscopy showed the presence of 0.75 mmol g^?1 molybdenum in the final material. The obtained material exhibited high catalytic activity, stability, and recyclability in the epoxidation of olefins with tert-butylhydroperoxide as oxidant.     

Revisiting the Enzymatic Epoxidation of Vegetable Oils by Perfatty Acid: Perbutyric Acid Effect on the Oil with Low Acid Value

Enzymatic epoxidation of vegetable oils in the presence of free fatty acids has been well studied in recent years, by mainly using long chain fatty acids (e.g., stearic acid) as the active oxygen carrier. However, for the previous enzymatic processes, the acid value (AV) of final epoxidized oils using long chain fatty acids is high, and the free fatty acid is not easily removed in the post treatment with water. Aiming at developing a more sustainable process, enzymatic epoxidation of sunflower oil was revisited using different free fatty acids catalyzed by Novozym 435 (lipase B from Candida antarctica, provided by Novozymes, Bagsvaerd, Denmark). When long chain stearic acid was introduced into the epoxidation in toluene solvent, the epoxy oxygen group content (EOC) of 6.41 ± 0.19 % was obtained. Due to the poor water solubility of stearic acid, the AV of the final epoxidized oil product was very high (53.40 ± 1.34) after it was washed with water. Alternatively, current study shows that the epoxidation process using short chain butyric acid produced the final epoxidized oil with lower AV of 2.57 ± 0.11. When the enzymatic epoxidation of sunflower oil was optimized in the presence of butyric acid and Novozym 435, EOC of 6.84 ± 0.21 % was obtained, reaching an oxriane conversion of 96.4 ± 3.0 %. Therefore, introducing short chain butyric acid as an active oxygen carrier will provide an alternative to the present enzymatic epoxidation process and produce the desired epoxidized oil products with much lower AV only after simple water‐treatments, which will make the enzymatic epoxidation more attractive.     

Development of hot-melt pressure–sensitive adhesives for transdermal drug delivery

Styrene–isoprene–styrene (SIS) copolymer was epoxidized by in situ epoxidation to prepare a series of epoxidized SIS resins (ESIS). Their epoxidation degrees, phase structures, and compatibility with hydrocarbon resin were characterized with ¹H nuclear magnetic resonance spectroscopy, atomic force microscopy, and differential scanning calorimetry, respectively. These ESIS resins were melt-mixed with synthetic hydrocarbon resin, mineral oil, and antioxidants to fabricate a series of ESIS-based hot-melt pressure–sensitive adhesives (HMPSAs), which were used as carriers of transdermal drug delivery system. Their adhesive performances were measured, including holding power and 180^o peel strength. Geniposide and oleanic acid were representatively chosen as hydrophilic and lipophilic drug, respectively. Their in vitro release behaviors in ESIS-based HMPSAs were investigated using a modified Franz-type horizontal diffusion cells. Although the introduction of epoxide groups could alter the compatibility and phase structures between SIS resins and additives, the adhesive performances were slightly affected, as SIS resins had lower epoxidation degree (<15%). It is even more important that the cumulative release rate of both hydrophilic and lipophilic drugs is markedly enhanced with the increase of epoxidation degree in these ESIS-based HMPSAs. Therefore, this kind of HMPSAs has a promising future as a carrier of transdermal drug delivery system as their SIS resins are appropriately epoxidized.