TW201305100A - Vegetable-oil derived plasticizer - Google Patents

Abstract

Green plasticizers are made by a process comprising the steps, in any order, of epoxidizing and transesterifying a natural oil, e.g., corn, sunflower, etc., having (1) an iodine number (IV) of 60 or more, and (2) a linolenic acid content of 5 weight percent (wt%) or less based on the weight of the oil.

Description

Plasticizer derived from vegetable oil Field of invention

This invention relates to plasticizers. In one aspect, the invention relates to an environmentally friendly plasticizer derived from a natural oil (i.e., an oil derived from a biological source), and in another aspect, the invention relates to a manufacturing The method of plasticizer.

Background of the invention

Soybean oil triglyceride is typically composed of about 15% by weight (wt%) saturated fatty acids and 85% by weight unsaturated fatty acids. Among the unsaturated fatty acids, about 24% by weight is derived from monounsaturated oleic acid, about 54% by weight is derived from di-unsaturated linoleic acid, and the remaining about 7% by weight is derived from polyunsaturated times. Linolenic acid. Soy epoxidized methyl ester (soybean-eFAME) can be used as the sole plasticizer for polyvinyl chloride (PVC) or other polymers (natural rubber, acrylate, etc.), or it can have as large as epoxidation A primary or auxiliary plasticizer within the plasticizer blend of soybean oil (ESO). eFAME usually contains various impurities resulting from the degradation of the epoxy ring. The majority of these impurities are derived from the epoxy ring degradation in the methyl epoxidized linoleate chain, and a smaller portion is derived from the epoxy ring in the methyl epoxidized linoleate portion. degradation. The primary degradation products are produced by a ring opening reaction of the epoxy group, which may give rise to a dihydroxy or monohydroxy group and another carboxylic acid group.

In some cases, two of the three epoxy rings within the methyl linolenic acid ester chain can be opened. In general, the hydrophilicity of these hydroxy-epoxides The properties are higher than the original methyl acrylate, so they can be leached preferentially to contact with water. In potential food and medical applications where the medium is waterborne or has a large amount of water, these impurities are more readily leached out of the food or associated specific matrix than the total plasticizer component.

Since epoxymethyl linolenate can produce the most hydrophilic degradation compound, it can then have the greatest potential to be leached out of contact with an aqueous or semi-aqueous medium, to the group that can make it, etc. Interested in plasticizers derived from natural oils that have been minimized.

Moreover, the impurity distribution of soybean-eFAME may vary depending on the method of its preparation. An existing commercial method for making soy-eFAME is to first transesterify soybean oil to produce fatty acid methyl esters (FAME), which are then epoxidized to produce eFAME. The eFAME prepared from this process showed a concentration of hydroxy-epoxide present in the sublinolenic acid ester chain. There is interest in a method for making eFAME in which the concentration of the present hydroxy-epoxide in the linoleic acid ester chain can be minimized.

Summary of invention

In one embodiment, the invention is a natural oil that has a very low content of linoleic acid in its fatty acid profile (eg, derived from a biological source (such as a plant, other than an oil derived from petroleum or other mineral source). The oil of seed, fish, animal fat, etc.) is an environmentally friendly plasticizer prepared by performing an epoxidation reaction and an ester conversion reaction (or an ester conversion reaction and an epoxidation reaction). An iodine value (IV) greater than (>) 60 or preferably > 80 or better > 100 is desirable because the presence of unsaturation is required to couple the oxygen of the ethylene oxide to the fatty acid chain. Thus, compatibility with a plastic (e.g., PVC) substrate can be enhanced. Table 1A shows that several have >95 IV and have a very low linoleic acid content (typically less than (<) 5% by weight (wt%) or more typically < 3% by weight or even typical, by weight of the oil An example of a natural oil feed of <2% by weight.

Table 1B shows several examples of natural oil feeds having >80 IV and very low linolenic acid content and which can be used as feedstock for environmentally friendly plasticizers for medical or food applications.

In one embodiment, the invention is an environmentally friendly plasticizer system or environmentally friendly plasticizer blend suitable for use in food and medical applications, the plasticizer system or blend being derived from an epoxidized natural oil (eg, ESO) It is prepared by an ester conversion reaction, and is not produced by an epoxidation reaction of an ester-converting natural oil (for example, FAME). Indicates that these natural oils with high iodine value and high linoleic acid content have successively passed through the ring. Oxidation and ester conversion have low hydrophilic impurity values as determined by electrospray ionization/liquid chromatography/mass spectrometry (ESI/LC/MS).

In one embodiment, the invention is a method for making an environmentally friendly plasticizer, the method comprising the steps of: epoxidizing and ester converting a natural oil having the following: (1) 60 or higher IV, and (2) a linoleic acid content of 5% by weight or less based on the weight of the oil.

In one embodiment, the invention is a method for making an environmentally friendly plasticizer, the method comprising the steps of: epoxidizing having an iodine value (IV) of (1) 60 or higher, and (2) A natural oil of linoleic acid content of 5% by weight or more based on the weight of the oil, and then ester-transformed to the epoxidized oil to produce an epoxidized fatty acid alkyl ester. In one embodiment, the method further comprises the step of blending the ester-transformed epoxidized fatty acid alkyl ester, such as eFAME, with an epoxidized natural oil (eg, ESO) that has not been ester-transformed. The weight ratio of the natural oil (e.g., ESO) to the ester-transformed epoxidized natural oil (e.g., e-FAME) can vary widely and can be adjusted to suit the intended use of the plasticizer.

In one embodiment, the invention is an environmentally friendly plasticizer made by any of the methods of the previous embodiments.

In one embodiment, the invention is an eFAME-containing, and non-soybean oil-based fatty acid methyl ester (eg, eFAME based on corn or sunflower oil) An environmentally friendly plasticizer for at least one of them, wherein the non-soybean oil-based fatty acid methyl ester has the same method as ESI/LC/MS and high pressure liquid chromatography-evaporative light scattering detection (HPLC-ELSD). A hydrophilic extractable component of less than 2% (as area%) was determined.

The conditions of such epoxidation reactions and ester conversion reactions are well known in the art and may be varied for convenience.

Detailed description of the preferred embodiment definition

All parts and percentages are by weight and all test methods are widely used by the date of filing of this disclosure, unless otherwise indicated herein. In the case of U.S. patents, in particular, the disclosure of definitions (to the extent that they are consistent with any definitions expressly provided in this disclosure) and the general knowledge of the art, any referenced patent, patent application or publication The full text of the content is hereby incorporated by reference in its entirety in its entirety in its entirety in its entirety in

Numerical ranges within the meaning of the disclosure are intended to be illustrative, and unless otherwise specified, The range of values includes all values, including the lower and upper values, expressed in increments of one digit, with the proviso that there is a separation of at least two digits between any lower value and any upper value. As an example, if a composition, physical or other property (such as molecular weight, etc.) is from 100 to 1,000, individual values such as 100, 101, 102, etc., and sub-ranges, such as 100 to 144, 155 to 170, are explicitly recited. 197 to 200, etc. For ranges containing values less than one or containing fractions greater than one (e.g., 1.1, 1.5, etc.), one digit is considered to be 0.0001, 0.001, 0.01 or 0.1, if appropriate. For ranges containing single digits less than 10 (eg, 1 to 5), one digit is typically considered to be 0.1. These are only examples that are explicitly contemplated, and all possible combinations of numerical values between the lowest value and the highest value recited are intended to be explicitly disclosed in the present disclosure. The range of values for the weight ratio of the blend of the epoxidized natural oil (e.g., ESO) and the ester-modified epoxidized natural oil (e.g., e-FAME) is provided, among other things, within the present disclosure.

"Natural oil" and like terms mean oils derived from one or more biological sources (eg, seeds, plants, fish, animal fats, bacteria, algae, etc.) that are different from oils derived from petroleum or other mineral sources.

"Epoxidation reaction" and like terms mean a process for forming an epoxide (also known as ethylene oxide or alkylene oxide). An epoxide is a three-membered cyclic ether in which one oxygen atom is attached to each of two carbon atoms that have been bonded to each other.

"Fatty acid" and like terms mean a monocarboxylic acid consisting of an aliphatic chain typically having from 4 to 22 carbon atoms and a terminal carboxyl group (-COOH). The fatty acid may be saturated or unsaturated, branched or non-branched, and may or may not include one or more hydroxyl groups.

"Epoxidized fatty acid ester" and like terms mean a compound having at least one fatty acid molecular group containing at least one epoxide group.

"Ester conversion reaction" and the like means a method of exchanging an organic group R" of an ester with an organic group R' of an alcohol, that is,

“Environmental plasticizer” and similar terms mean that it can be increased from natural oil. The plasticity or flexibility of the plastic to which it is added.

"Environmental plasticizer blend" and similar terms mean a mixture containing an environmentally friendly plasticizer and one or more other compounds, particularly another environmentally friendly plasticizer. In one embodiment, the environmentally friendly plasticizer blend comprises an epoxidized fatty acid ester derived from a natural oil that has not been subjected to ester conversion, such as ESO, and an epoxidized fatty acid ester derived from an ester-transformed natural oil. , for example, e-FAME.

Natural oil

Typical natural oils that may be used in the practice of the invention include, but are not limited to, derived animal and plant sources (such as corn, sunflower, cottonseed, safflower, olive, palm, flaxseed, canola, rapeseed, soybean, tung, fish) , tallow, bacteria: algae, etc.) oil. In one embodiment, the natural oils used to practice the invention typically have an IV greater than 60, typically greater than 80, and more typically greater than 100 (as determined by AOCS Tg 1-64), and The weight of the oil is typically < 5% by weight, more typically < 3% by weight, and typically < 2% by weight of the linoleic acid content.

Epoxidation of the natural oil

As a non-limiting example, a solution of peroxyacid (e.g., a solution of peracetic acid in ethyl acetate) is used to epoxidize the double bond of the fatty acid in the natural oil. In one embodiment, the peroxyacid is maintained at less than 35% by weight and the temperature is maintained at 60 ° C or lower, based on the weight of the solution. After the reaction was completed, the ethyl acetate and by-product acetic acid were removed by vacuum stripping. These general reaction conditions are well known and can be varied for convenience. In one embodiment, the epoxidation reaction can be carried out in a manner such that The oxygen content of the ethylene oxide in the final product is greater than 65% by weight based on the weight of the final product.

Non-limiting examples of suitable epoxidized fatty acid esters that may be used in the practice of the present invention include epoxidized animal and vegetable oils, such as epoxidized naturally occurring oils such as epoxidized soybean oil (ESO), epoxidized corn oil, epoxidized sunflower oil Epoxidized palm oil, epoxidized linseed oil, epoxidized canola oil, epoxidized rapeseed oil, epoxidized safflower oil, epoxidized pine oil, epoxidized tung oil, epoxidized fish oil, epoxidized tallow oil, cerium oxide Sesame oil and the like, and various epoxidized esters, such as epoxidized propylene glycol dioleate, epoxidized methyl stearate, butyl succinate, 2-ethylhexyl epoxide stearate, epoxidized hard fat Acid stearyl ester, soybean oil epoxidized with 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, epoxidized derivatives of the foregoing, and any of the foregoing combination. In one embodiment, a naturally occurring epoxidized oil (e.g., Vernonia oil) can be used in place of the first step of the process of the invention for making an epoxidized alkyl ester of a natural oil.

Alcohol

Alcohols useful in the practice of the invention include, but are not limited to, a first alcohol and a second alcohol, such as an alkanol having from 1 to 18 carbon atoms, such as methanol, n-propanol, isopropanol, n-butanol , second-butanol, isobutanol, pentanol, hexanol, 2-ethylhexanol, tridecyl alcohol, stearyl alcohol, etc.; a cycloalkanol having 5 to 12 carbon atoms, such as cyclohexanol, Cycloheptanol or the like; an aralkyl alcohol having 7 to 40 carbon atoms, such as benzyl alcohol, 2-phenylethanol, etc.; a polyol having 2 to about 15 carbon atoms, such as ethylene glycol, propylene glycol, 1,3 - butanediol, 1,4-butanediol, 1,5-pentanediol, hexamethylene glycol, decethylene glycol, 1,12-dihydroxy octadecane, glycerol, etc.; Polymeric polyols, such as polyvinyl alcohol; glycol ethers and polyalkylene glycol ethers, such as methyl glycol, ethyl glycol, butyl glycol, diethylene glycol, triethylene glycol , tetraethylene glycol, higher carbon number polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol ether, polybutylene glycol and the like. Other suitable hydroxyl-containing compounds are disclosed in U.S. Patent Nos. 3,347,926, 3,654,370 and 4,014,933.

Ester conversion reaction

The ester conversion reaction of the epoxidized fatty acid (natural oil) employs equipment and conditions well known in the art. The epoxidized fatty acid and the alcohol are contacted with each other under ester conversion reaction conditions having an acid or base catalyst. In one embodiment, the ester conversion reaction of soybean oil is carried out using methanol to produce a methyl ester of the fatty acids in the oil. Glycerol can be removed from the reaction products due to insolubility. In one embodiment, the epoxidized fatty acid ester can be any epoxidized fatty acid esters of C ₁ -C _14, which comprises a methyl, ethyl, propyl, butyl, and 2-ethylhexyl acrylate. In one embodiment, the epoxidized fatty acid is an epoxide of one of the fatty acid methyl esters. In one embodiment, the epoxidized fatty acid is ESO and its ester converted derivative is eFAME. In one embodiment, the eFAME is water washed in one or more stages to reduce or remove undesirable by-products.

Environmental plasticizer blend

The environmentally friendly plasticizer blend or system of the present invention comprises a mixture of an epoxidized fatty acid ester derived from a natural oil that has not been subjected to ester conversion, and an epoxidized fatty acid ester derived from a natural oil ester-transformed. The epoxidized natural oil which has not been ester-converted and the ester-transformed epoxidized natural oil are blended with each other to form a homogeneous substance under any suitable conditions using known equipment and techniques. Or substantially homogeneous blend. The relative amounts of the weight % of the components of the blend may vary widely, but the weight ratio of the ester-free converted epoxidized fatty acid ester to the ester-transformed epoxidized fatty acid ester is typically greater than (>) 0: less than ( <) 100 to <100: > 0, more typically from 10:90 to 90:10, more typically from 20:80 to 80:20 and more typically from 30:70 to 70:30. The environmentally friendly plasticizer blend can contain one or more additives such as antioxidants, stabilizers, and the like.

In one embodiment, the epoxidized fatty acid ester that has not been ester-transformed is ESO, and the ester-transformed epoxidized fatty acid ester is e-FAME.

In one embodiment, the plasticizer for medical applications is made from ESO and eFAME. In one embodiment, the invention is compatible with the environmentally friendly plasticizer blend and PVC. It is well known that the solubility of a plasticizer in PVC increases as the amount of oxygen in the composition of the ethylene oxide increases. In general, eFAME prepared from the FAME epoxidation process has a lower oxygen content of ethylene oxide than eFAME prepared by the ester conversion reaction from soybean oil. It can increase the plasticizing efficiency, so that the glass transition temperature (Tg) of PVC can be similarly reduced by using it at a lower filling amount. Moreover, eFAME prepared from the ester conversion reaction method has a lower acid value than eFAME prepared by the epoxidation reaction method of FAME. The environmentally friendly plasticizer is used in combination with known amounts and known methods.

The environmentally friendly plasticizer and environmentally friendly plasticizer blend of the present invention can be used in a wide range of applications including, but not limited to, various medical devices, such as with aqueous substances (such as various body fluids (such as blood and urine), Salt, etc.) In contact with syringes, tubes, etc., and for various foods and medical substances (such as various drinks) Packaging of materials (eg milk, water, juice, carbonated beverages, etc.), meat, frozen vegetables, blood bags and salt bags.

Specific embodiment Test conditions

ESI/LC/MS and ESI/LC/MS/MS (medium resolution conditions)

One microliter of six-thousandths of the samples were shot to couple with the Agilent 6520 QT of a four-pole time flying MS system via a dual spray electric spray (ESI) interface operating in a cationic (PI) mode. On an Agilent 1200SL two-gradient liquid chromatograph. The following analytical conditions were used: Column: 50 x 2.1 mm ID 1.8 micron Zorbax Eclipse Plus C18

Column temperature: 60 ° C

Mobile phase: 80/20 A/B to 100B (10 minutes in 25 minutes)

A = 0.1 v% formic acid in water

B = 0.1 v% formic acid in acetonitrile

Flow rate: 0.35 ml / min

UV detection: diode array 210 to 400 nm

ESI conditions: gas temperature -350 ° C gas flow rate -10 ml / min

Capillary-3.5kV Nebulizer - 40PSI

Rupture device -145V

Automatic MSMS conditions: mode - + TOFMS and + TOFMSMS; centroid

Resolution 12000 (+)

2Ghz extended dynamic range

Scan -100 to 1700amu (+MS) rate -3 scans / sec

Scan -50 to 1700 amu (+MS/MS) rate -3 scans per second

Collision energy: 3.5V+4V/100amu

Collision gas: nitrogen isolation width ~9amu

Reference ion: 121.050873: 922.009798 (+) 119.03632, 966.0008 (-)

HPLC/ELSD conditions

HPLC arrangement

Mobile phase: H ₂ O/acetonitrile (A/B)

Column: ODS C-18; 2.1 x 100 mm, 3 micron particle size

Flow rate: 0.30 ml / min

Oven temperature: 70 ° C

Injection volume: 2 microliters

Operating time: 11 minutes

Late time: 2 minutes

ELSD arrangement

Instrument: Alltech 3300 ELSD

Tube temperature: 70 ° C

Gas flow: 1.80 SLPM

Gain: 1.0

N ₂ regulator: 60 psig

Example 1

The oxygen (% by weight) and the acid value (mg KOH/g) of ethylene oxide of two experimental eFAME samples prepared from a supplier and subjected to an ester conversion reaction of ESO were analyzed. The first sample was determined to be 6.84 and 0.4, respectively, and the second sample was determined to be 6.9 and 0.2, respectively.

Comparative example 1

Three different eFAME batches were obtained from a single supplier and all were made by soy-FAME epoxidation. The oxygen and acid values of the ethylene oxide of the three batches were determined to be 6.4 and 1.1, 6.34 and 1.56, 0.6 and 0.57, respectively. The oxygen values of these ethylene oxides were significantly lower than those of the eFAME samples shown in Example 1 and have been found to be significantly higher.

Example 2&3

A pure eFAME sample (a sample prepared by a supplier) prepared by the ester conversion reaction of ESO was analyzed by ESI/LC/MS. Table 3 shows an excerpt of the area % of the most hydrophilic molecules (hydroxyl-containing) of the two different laboratory eFAME samples prepared in this manner (samples 2 & 3). Again, a summary of the specified mass spectral data, including all tested components, is provided in Table 4, which shows the structure of these hydrophilic molecules. The exact mass measurements of all tested components are within one of the proposed structures, milliDalton. These results indicate that for Samples 2 and 3, the specified total area % of these hydrophilic molecules (A, B, C, and D) are about 1.32% and 1.14%, respectively, and three hydrophilicities. The structures (labeled A, B, and D in Table 4) are below the detection level (ND in Table 3).

Comparative Examples 2, 3 and 4

Three eFAME samples (Comparative Samples 2, 3 and 4) made by the epoxidation reaction of soybean-FAME were also analyzed by ESI/LC/MS technology and the results in Table 3 indicate that for all of these samples. In other words, there is a structure containing four hydroxyl groups (labeled as A). The area % of the molecule ranges from 0.87% (for Comparative Sample 2) to 1.43% (for Comparative Sample 3), and Comparative Sample 4 shows a value close to Comparative Sample 3 (1.33%). ). When considering all four structures (labeled A, B, C, and D), the area % of Comparative Samples 2-4 was about 3.83, 5.71, and 4.36%, respectively, or in other words, Example 2 and The eFAME samples prepared by the ester conversion reaction of ESO are about 3 to 4 times higher.

Example 5&6

Water extractables of two eFAME samples (each obtained from different suppliers and made by ester conversion of ESO) were analyzed by water leaching studies. In the water leaching test, 0.04 grams of each sample was added to 8 grams of deionized (DI) water. Of course The sample was then placed in a 40 ° C oven. After 24 hours, high pressure liquid chromatography-evaporative light scattering detection (HPLC-ELSD) analysis was carried out on 1 ml of the sample taken from the bottom of the vial. The area of the retention spike at 1.9 minutes was designated as the water soluble component from eFAME. The amount of these water leachable compounds in eFAME was estimated by comparing the peak area at 1.8 minutes with the total peak area of pure eFAME (dissolved in acetonitrile) from 1.5 to 4 minutes. The results showed that for an eFAME sample, the weight-% of the water-extracted fraction was 0.12% by weight and the other eFAME sample was 0.18% by weight.

Compare Examples 5 and 6

The same leaching tests as described in Examples 5 and 6 above were carried out on two eFAME samples (each made from different suppliers and made by the epoxidation process of FAME). After water extraction at 40 ° C for 24 hours, the results showed that the weight % of the water-extracted fraction was 0.55% by weight for one eFAME sample and 1.28 % by weight for the other eFAME sample.

Example 7

The procedure for producing a canola oil-based eFAME sample in the laboratory is as follows: first, the canola oil is epoxidized to produce ECO (epoxidized canola oil), and then the ECO ester conversion is carried out to produce eFAME. . For the epoxidation reaction, 50 grams of canola oil was fed into a 250 ml glass reactor. C=C:H ₂ O ₂ :formic acid using a molar ratio of 1:2:0.5. The solution strength of the newly added H ₂ O ₂ was at 50% by weight and its feed rate was controlled at 50 g/hr. The reaction temperature was at 60 °C. A total of 6 hours of reaction time was allowed, then the mixer was stopped and the aqueous and oil phases were separated. The ECO thus produced was converted to a methanol ester by a molar ratio of methanol to oil of 6:1. A 25% sodium methoxide solution (in methanol) was used as the catalyst and 1% by weight of the catalyst was added based on the oil. The reaction temperature was maintained at 60 ° C for a reaction time of 3 hours, after which the stirrer was stopped and the oil layer and the aqueous layer were separated for a specific period of time. The thus obtained canola seed-eFAME water extractables were analyzed by water leaching studies. In the water leaching test, 0.04 grams of each sample was added to 8 grams of deionized (DI) water. The sample was then placed in a 40 ° C oven. After 24 hours, high pressure liquid chromatography-evaporative light scattering detection (HPLC-ELSD) analysis was carried out on a 1 ml sample taken from the bottom of the vial. The area of the retention spike at 1.9 minutes was designated as the water soluble component from eFAME. The amount of these water leachable compounds in eFAME was estimated by comparing the peak area at 1.8 minutes with the total peak area of pure eFAME (dissolved in acetonitrile) from 1.5 to 4 minutes. The result showed that the weight % of the water-extracted fraction was 0.34% by weight.

Comparative Example 7

The procedure for producing a canola oil-based eFAME sample in the laboratory is as follows: First, the oil ester conversion reaction is carried out to produce canola-FAME, and then the FAME is epoxidized to produce canola seed eFAME. The canola oil was converted to methanolate by a molar ratio of methanol to oil of 6:1. A 25% solution of sodium methoxide (in methanol) was used as the catalyst, and 1% by weight of the catalyst was added based on the oil, and the reaction temperature was maintained at 60 ° C for 3 hours, and then the mixer was stopped. The oil layer and the water layer are separated at a specific time. The canola seed-FAME thus produced was epoxidized with H ₂ O ₂ and formic acid. For the epoxidation reaction, 50 grams of canola oil was fed into a 250 ml glass reactor. A molar ratio of 1:2:0.5 to C=H ₂ O ₂ :formic acid was used as the reactant. The solution strength of the newly added H ₂ O ₂ was 30% by weight and the feed rate was controlled at 25 g/hr. The reaction temperature was maintained at 40 °C. A total of 11 hours of reaction time was continued, then the agitator was stopped and the aqueous and oil phases were separated. The thus prepared canola seed-eFAME was subjected to the same water leaching test as described in Examples 5 and 6 above. Water extraction was carried out at 40 ° C, and after 24 hours, the result showed that the water-extracted portion had a weight % of 1.

Although the present invention has been described in detail by the foregoing description of the preferred embodiments, Many variations and modifications can be made by those skilled in the art, as long as they do not depart from the spirit and scope of the invention as described in the following claims.

Claims (10)

A method for making an environmentally friendly plasticizer comprising the steps of: epoxidizing and transesterifying a natural oil having (1) to 60 or higher. The iodine value (IV), and (2) is 5% by weight (wt%) or less of the linoleic acid content based on the weight of the oil. The method of claim 1, wherein the natural oil is subjected to epoxidation and ester conversion. The method of claim 1, wherein the natural oil is subjected to ester conversion and epoxidation. The method of claim 1, wherein the natural oil is derived from at least one of a corn kernel, sunflower seeds, cottonseed, safflower seeds, and olives. A method for producing an environmentally friendly plasticizer, the method comprising the step of epoxidizing a natural oil, wherein the natural oil has an iodine value (IV) of (1) to 60 or higher, and (2) a The linoleic acid content of 5% by weight (wt%) or more by weight; then the ester conversion of the epoxidized oil is carried out to produce an epoxidized fatty acid alkyl ester. The method of claim 5, wherein the oil is at least one of soybean oil, linseed oil, and canola oil. An environmentally friendly plasticizer prepared by the method of claim 5 of the patent scope. A plastic containing an environmentally friendly plasticizer of claim 7 of the scope of the patent application. An article containing the plastic of item 8 of the patent application. For example, the object of claim 9 is wherein the plastic is PVC.