Glycollic acid and lactic acid co-production technology and polyglycolic acid and polylactic acid co-production technology
Through the addition reaction of carbonyl compounds with chloroform and alkaline dissolution, efficient preparation of glycolic acid and lactic acid monomers or dimers is achieved, and the problem of difficulty in preparing polyglycolic acid and polylactic acid materials in the prior art is solved. The cost competitiveness, operational simplicity and resource sustainability of the co-production process.
Patent Information
- Application Number
- CN202310846066.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-11
- Publication Date
- 2025-01-14
AI Technical Summary
It is difficult to efficiently prepare degradable materials such as polyglycolic acid (PGA) and polylactic acid (PLA) at the same time, and separate processes have problems such as high cost, complex operation and unsustainable resources.
The mixture of carbonyl compounds such as formaldehyde and acetaldehyde was directly added with chloroform to obtain a halogenated alcohol intermediate. Glycolic acid and lactic acid monomers or dimers are prepared with high compatibility and selectivity under alkaline lysis conditions, and through coproduction Process to prepare polyglycolic acid and/or polylactic acid hybrid polymers to achieve facility and equipment sharing and resource sustainability.
It has achieved simultaneous compatibility in producing two major categories of environmentally degradable materials, which reduces production costs and investment intensity, improves operation simplicity and environmental friendliness, and represents a major technological breakthrough in this field.
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Abstract
Description
[Technical field]
[0001] The present invention relates to the field of new material chemicals, and in particular to the co-production technology of glycolic acid (GA) and lactic acid (LA), their dimers (GA-GA or LA-LA or GA-LA), polyglycolic acid (PGA) and polylactic acid (PLA) and hybrid poly (glycolic acid-lactic acid), a series of degradable green monomers or dimers or polymer materials. The technology uses the intermediates obtained by the direct addition reaction of simple carbonyl compounds such as formaldehyde and acetaldehyde and their mixture precursors and chloroform (chloroform) to be prepared simultaneously under alkaline hydrolysis conditions with high compatibility and selectivity; compared with the discrete preparation of the above-mentioned materials by separate processes, the co-production process disclosed for the first time in the present invention further implements excellent cost competitiveness, simple operation, process compatibility, and resource sustainability. [Background technology]
[0002] Polyhydroxy acids (PHAs), especially polyglycolic acid (PGA) and polylactic acid (PLA) type polyhydroxy acids and their derivatives, have received increasing attention in my country in recent years due to their excellent biodegradable properties. As shown in the following structure, this type of material includes four key substances, namely the corresponding monomer (PHA-1), dimer (PHA-2), cyclic ester (PHA-3), and polymer (PHA-4). They are widely used in oil and gas extraction, agricultural production, food and beverage packaging, and medical care.
[0003]
[0004] The present application has unexpectedly discovered that, using a mixture of commonly used carbonyl compounds (aldehydes or ketones) as raw materials, especially a mixture of formaldehyde and acetaldehyde as raw materials, and a mixture of halogenated alcohol intermediates obtained by direct addition of bulk C1-rich chemicals such as chloroform, and then acting under alkaline hydrolysis conditions, glycolic acid (GA) and lactic acid (LA) monomers or dimers thereof can be prepared in a compatible and highly selective co-production, and then polyglycolic acid (PGA) and / or polylactic acid (PLA) and / or poly (glycolic acid-lactic acid) hybrid polymers can be prepared. That is, the process disclosed in the present invention can simultaneously and compatibly produce two major types of environmentally degradable materials, with facilities and equipment and process flows highly shared, and investment intensity and production costs are greatly simplified, so the technology has excellent cost competitiveness, simple operation, environmental friendliness, and resource sustainability.
[0005] It is worth emphasizing that previously, polyhydroxy acid-type materials were usually obtained through the biomass fermentation process of plant-based agricultural and forestry materials. The relevant product substances have a high structure-performance correspondence correlation with the corresponding fermentation bacteria strains. From the technical principle, it is impossible to simultaneously prepare two major types of monomer or polymer materials such as PGA and PLA in the same process or reaction flow. Therefore, the technology disclosed in the present invention represents a major technological breakthrough in this field. [Summary of the invention]
[0006] The present application has found that, as shown in reaction formula (IV), a trichloromethyl alcohol mixture (general formula I) shown in structural formulas A and B is efficiently prepared by coupling reaction of carbonyl compounds R1-C(O)-R2 and R3-C(O)-R4 with chloroform HCCl3 under reaction conditions conditions; a hydroxy acid mixture (general formula II) shown in structural formulas C and D is prepared by substitution reaction of the trichloromethyl alcohol mixture shown in structural formulas A and B and R5OH (alcohol or water) under reaction conditions conditions; or, a hydroxy acid dimer (general formula II) shown in structural formulas A and B is prepared by substitution reaction of the trichloromethyl alcohol mixture and R5OH (alcohol or water) under reaction conditions conditions. a mixture of trichloromethyl alcohols as shown in structural formulas A and B and R5OH (alcohol or water) are subjected to substitution and polymerization reaction under reaction conditions to prepare a polyhydroxy acid ester as shown in structural formula H (general formula IV); or, a hydroxy acid dimer mixture as shown in structural formula EG is subjected to polymerization reaction under reaction conditions to prepare a novel "hybrid" polyhydroxy acid ester as shown in structural formula H (general formula V); a mixed lactide as shown in structural formula Q prepared by thermal depolymerization of a low molecular weight polyhydroxy acid ester H of general formula V and R5OH (alcohol or water) are subjected to ring-opening polymerization reaction under reaction conditions to prepare a high molecular weight polyhydroxy acid ester as shown in structural formula H (general formula VI).
[0007]
[0008] wherein R1, R2, R3, R4, or R5 (including multiple groups in the same structure) are independently hydrogen, or a branched or straight-chain aliphatic hydrocarbon group containing 1 to 24 carbon atoms, or a (hetero) aromatic hydrocarbon group containing 4 to 24 carbon atoms;
[0009] Preferably, R1, R2, R3, or R4 are independently hydrogen, methyl, ethyl, (iso)propyl, (iso)butyl; more preferably, R1, R2, R3, or R4 are independently hydrogen or methyl.
[0010] n is an integer greater than 2; preferably, n is an integer between 100 and 100,000,000.
[0011] R6, R7, R8, or R9 are independently the same as R1. Preferably, R6, R7, R8, or R9 are independently hydrogen or methyl.
[0012] The conditions are at least one of a solvent, a temperature, a pressure (or a vacuum), and an additive.
[0013] The solvent is selected from at least one of substituted or unsubstituted aromatic hydrocarbons containing 1 to 24 carbon atoms, linear or branched aliphatic hydrocarbons, (sub)sulfones, amides, ethers, alcohols, esters, ketones, nitriles, carboxylic acids, water, amines, carbonates, ionic liquids, and supercritical carbon dioxide; or the liquid substrate itself simultaneously serves as a solvent medium.
[0014] In some preferred embodiments of the present invention, the solvent is selected from acetonitrile, ethanol, butanol, ethyl acetate, butyl acetate, water, dimethyl sulfoxide, dimethyl sulfone, benzyl sulfoxide, benzyl sulfone, cyclobutylene sulfoxide, cyclobutylene, trichlorosilane, dichloromethane, chloroform, dichloroethane, dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, chloroform, carbon tetrachloride, benzene, toluene, xylene, trimethylbenzene, tetramethylbenzene, acetonitrile, ethylbenzene, diethylbenzene, chlorobenzene, dichlorobenzene, benzene At least one of methyl ether, nitrobenzene, heptane, hexane, petroleum ether, dioxane, tetrahydrofuran, methyltetrahydrofuran, methyl tert-butyl ether, ethylene glycol dimethyl ether, bis(ethylene glycol) dimethyl ether, triethylene glycol dimethyl ether, propylene glycol methyl ether acetate, triethylamine, tributylamine, dimethylisopropylamine, pyridine, N,N-tetramethylethylenediamine, N-alkylmorpholine, N-alkylpyrrole, N,N-dimethylformamide, formylmorpholine, N,N-diethylformamide and N-methylpyrrolidone.
[0015] In the present invention, the reaction can also be carried out by using only a small amount of or even no conventional "solvent", and by adopting solid-phase heating and / or grinding of the raw materials, and / or promoting by ultrasonic and / or microwave irradiation, and by using supercritical carbon dioxide as the reaction medium.
[0016] The temperature is -70°C to 400°C. Preferably, the temperature is -30°C to 300°C. More preferably, the temperature is -20°C to 200°C.
[0017] The pressure is 0.001 atm-200 atm. Preferably, the pressure is 0.01 atm-50 atm.
[0018] The additives are reaction accelerators, synergists, catalysts, oxidants, polymerization inhibitors, reducing agents and / or functional additives.
[0019] Based on the molar amount of the reaction raw materials, the additive is used in a catalytic amount, an equivalent amount, or an excess amount (0.001-1000 equivalents).
[0020] Based on the molar amount of the reaction raw materials, the amount of alcohol or water R5OH used is 0.1-1000 equivalents; preferably, the amount used is 1-100 equivalents.
[0021] In the general formula (I-III), the additive or promoter in the reaction conditions is preferably a base; the base is a metal or its oxide, hydroxide, alkoxide, alkylamine, carbonate (bi) salt, carboxylate, sulfonate, organic amine, or nitrogen-containing heterocyclic compound. The preferred base is a metal oxide, hydroxide, or alkoxide; the more preferred base is sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, barium hydroxide, calcium oxide, and magnesium oxide. The use of calcium hydroxide, magnesium hydroxide, calcium oxide, or magnesium oxide is particularly preferred because the generated calcium chloride or magnesium chloride reduces the generation and treatment of solid waste.
[0022] In the general formula (IV-V), the additive or promoter in the reaction conditions is preferably a proton type or Lewis type acid; the acid is hydrochloric acid, sulfuric acid, nitric acid, hydrohalic acid, sulfonic acid, carboxylic acid, metal or its halide, sulfide, oxide, carboxylate, (hydrogen) sulfate, nitrate, (hypo)halate, molecular sieve, heteropoly acid. The preferred acid is hydrochloric acid or sulfuric acid.
[0023] In the general formula (VI), the additive or promoter in the reaction conditions is preferably an acid or a base, which has the same meaning as above.
[0024] Preferably, one way to perform the reaction formula (I) is the general formula (IA), wherein the intermediate mixture of trichloromethyl alcohol and methyltrichloromethyl alcohol is prepared by condensing formaldehyde, acetaldehyde and chloroform under reaction conditions. Preferably, the additive or promoter in the reaction conditions comprises a metal hydroxide as a base; the preferred base is sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, barium hydroxide, strontium hydroxide. Preferably, the solvent in the reaction conditions comprises at least one of N,N-dimethylformamide, formylmorpholine, N,N-diethylformamide and N-methylpyrrolidone.
[0025]
[0026] Preferably, one way to perform the reaction formula (II) is the general formula (IIB), wherein glycolic acid C and lactic acid D are prepared by alkaline hydrolysis of a mixture of trichloromethyl alcohol and methyltrichloromethyl alcohol and R5OH under reaction conditions. Preferably, R5 is independently hydrogen or methyl. Preferably, the additive or promoter in the reaction conditions comprises a metal (hydr)oxide as a base; the preferred base is calcium hydroxide, calcium oxide, magnesium hydroxide, magnesium oxide, sodium hydroxide, potassium hydroxide, barium hydroxide, aluminum hydroxide, strontium hydroxide. Preferably, the solvent in the reaction conditions comprises water or an alcohol or an amide.
[0027]
[0028] Preferably, one way to perform the reaction formula (III) is the general formula (IIIA), wherein a mixture of trichloromethyl alcohol and methyltrichloromethyl alcohol and R5OH are subjected to alkaline hydrolysis under reaction conditions to prepare glycolic acid dimer E, lactic acid dimer F and glycolic acid-lactic acid hybrid dimer G. Preferably, R5 is independently hydrogen or methyl. Preferably, the additive or promoter in the reaction conditions contains a metal (hydr)oxide as a base; the preferred base is calcium hydroxide, calcium oxide, magnesium hydroxide, magnesium oxide, sodium hydroxide, potassium hydroxide, barium hydroxide, aluminum hydroxide, strontium hydroxide. Preferably, the solvent in the reaction conditions contains water or alcohol or amide.
[0029]
[0030] Preferably, one way to perform the reaction formula (IV) is the general formula (IVA), wherein the polymerized hydroxy acid H is prepared by alkaline hydrolysis and polymerization of a mixture of trichloromethyl alcohol and methyltrichloromethyl alcohol and R5OH under reaction conditions. Preferably, the additive or promoter in the reaction conditions comprises a metal (hydr)oxide as a base; the preferred base is calcium hydroxide, calcium oxide, magnesium hydroxide, magnesium oxide, sodium hydroxide, potassium hydroxide, barium hydroxide, aluminum hydroxide, strontium hydroxide. Preferably, the additive or promoter in the reaction conditions preferably comprises a protic or Lewis acid; the preferred acid is hydrochloric acid, sulfuric acid, nitric acid, a hydrohalic acid, a sulfonic acid, a carboxylic acid, a metal or its halide, a sulfide, an oxide, a carboxylate, a (hydrogen) sulfate, a nitrate, a (hypo)halate. More preferably, the acid is hydrochloric acid or sulfuric acid. Preferably, the solvent in the reaction conditions comprises water or an alcohol or an amide. Preferably, R6, R7, R8, or R9 are independently hydrogen or methyl; with the constraint that R6 and R7 are not simultaneously methyl; and R8 and R9 are not simultaneously methyl.
[0031]
[0032] Preferably, one way to perform the general reaction formula (V) is the general formula (VA), wherein the novel "hybrid" polymeric hydroxy acid H is prepared by polymerization of the dimer mixture EG under reaction conditions. Preferably, R5 is independently hydrogen or methyl. Preferably, the additive or promoter in the reaction conditions comprises a metal (hydr)oxide as a base; the preferred base is calcium hydroxide, calcium oxide, magnesium hydroxide, magnesium oxide, sodium hydroxide, potassium hydroxide, barium hydroxide, aluminum hydroxide, strontium hydroxide. Preferably, the additive or promoter in the reaction conditions preferably comprises a protic or Lewis acid; the preferred acid is hydrochloric acid, sulfuric acid, nitric acid, a hydrohalic acid, a sulfonic acid, a carboxylic acid, a metal or its halide, a sulfide, an oxide, a carboxylate, a (hydrogen) sulfate, a nitrate, a (hypo)halate. More preferably, the acid is hydrochloric acid or sulfuric acid. Preferably, the solvent in the reaction conditions comprises water or an alcohol or an amide. Preferably, R6, R7, R8, or R9 are independently hydrogen or methyl; with the constraint that R6 and R7 are not simultaneously methyl; and R8 and R9 are not simultaneously methyl.
[0033]
[0034] Preferably, one way to implement the general reaction formula (VI) is the reaction formula (VIA-B). It should be noted that the new "hybrid" low molecular weight polyhydroxy acid (ester) H prepared by the general formula (V) has a molecular weight of usually below 50,000. Such low molecular weight polyhydroxy acids can be cyclized to glycolide Q1, lactide Q2, and / or mixed lactide Q3 under vacuum thermal cracking conditions, which is well known to those skilled in the art; and high molecular weight polyhydroxy acid (ester) H can be prepared by re-ring-opening polymerization of Q1-Q3, usually 50,000-200,000 or more. Therefore, as shown below, the mixed lactide represented by the structural formula Q prepared by thermal depolymerization of the low molecular weight polyhydroxy acid H of the general formula V and R5OH (alcohol or water) are subjected to ring-opening polymerization under reaction conditions to prepare the high molecular weight polyhydroxy acid represented by the structural formula H (general formula VIA); or, the mixed lactide mixture Q1-Q3 prepared by thermal depolymerization of the low molecular weight polyhydroxy acid H of the general formula V and R5OH are subjected to ring-opening polymerization under reaction conditions to prepare the high molecular weight polyhydroxy acid H (general formula VIB). Preferably, R6, R7, R8, or R9 are independently hydrogen or methyl; the constraint is that R6 and R7 are not methyl at the same time; R8 and R9 are not methyl at the same time.
[0035]
[0036] The present application also claims the right to use the substance AH prepared by the disclosed co-production process as a synthon or synthetic raw material in the manufacture of segmented biodegradable green materials containing polyhydroxy acids (PHAs) or polyglycolic acid (PGA) or polylactic acid (PLA).
[0037] The gist of the present invention is further explained below with reference to specific embodiments. [Specific implementation method]
[0038] Example:
[0039]
[0040] 0.36 g of paraformaldehyde, 0.53 g of acetaldehyde, 2.4 g of chloroform, and 4 ml of DMF were added to the flask in sequence at room temperature, and 0.48 g of sodium hydroxide was added in batches under ice-water cooling, and the reaction was monitored by TLC. After reacting for 2-3 hours, 3 ml of water and about 1.5 ml of concentrated hydrochloric acid were added to adjust the pH of the system to 4-5. The mixed solution was extracted with dichloromethane, and the combined organic phase was dried, concentrated, and separated and purified on silica gel column chromatography to obtain 1.27 g of trichloroethanol (85% yield) and 1.46 g of trichloromethyl isopropanol (90% yield).
[0041] Example:
[0042]
[0043] 2.68 g of trichloroethanol and 2.35 g of trichloromethyl isopropanol were mixed in 50 ml of 10% sodium hydroxide solution at room temperature, and the mixture was kept warm at 40-45 degrees Celsius for 6 hours under efficient stirring. The system was cooled to room temperature and neutralized with dilute hydrochloric acid. After reduced pressure concentration, the residue was washed and filtered on diatomaceous earth with a small amount of methanol to remove most of the sodium chloride salt. The filtrate was concentrated and eluted on a silica gel column chromatography with methanol-ethyl acetate to obtain 1.3 g of glycolic acid (92%) and 1.2 g of lactic acid (94%) pure products.
[0044] Example:
[0045]
[0046] 3.5 g of calcium hydroxide was placed in a flask at room temperature, 50 ml of water was added, and then 2.5 g of a mixture of trichloroethanol and trichloromethyl isopropanol in a mass ratio of 1 / 1 was added thereto, and the mixture system was reacted at 120 degrees Celsius for 5 hours. After the system was cooled to room temperature, 7 g of anhydrous sodium sulfate was added and stirred for about 1 hour, and filtered on diatomaceous earth to obtain a yellow transparent liquid, and the pH value of the system was adjusted to weak acidity (pH of about 6-7) with dilute hydrochloric acid, the mixture was washed and filtered on diatomaceous earth with methanol-ethyl acetate, and the clear liquid was analyzed on HPLC high performance liquid chromatography to obtain a 46 / 41 / 13 mixture of dimer glycolic acid, dimer lactic acid, and dimer glycolic acid-lactic acid.
[0047] Example:
[0048]
[0049] At room temperature, 3.5 grams of calcium hydroxide are placed in a flask, and after adding 50 milliliters of water, a 1 / 1 mass ratio mixture of 2.9 grams of trichloroethanol and trichloromethyl isopropanol is added thereto, and the mixture system is reacted at 120 degrees Celsius for 5 hours. After the system is cooled to room temperature, 7 grams of anhydrous sodium sulfate are added and stirred for about 1 hour, and filtered on diatomite to obtain a yellow transparent liquid, and the pH value of the system is adjusted to be weakly acidic (pH is about 6-7) with dilute hydrochloric acid. The mixture is washed and filtered with methanol-ethyl acetate on diatomite, and the obtained dimerized glycolic acid / dimerized lactic acid / dimerized glycolic acid-lactic acid mixture clear liquid (mass ratio 45 / 37 / 18) is directly mixed with 10 milliliters of water and then 0.1 milliliter of concentrated sulfuric acid is slowly added. After the addition of 20 milliliters of toluene, the system is refluxed for 1-2 hours, and the solvent is evaporated under reduced pressure. The residue is rinsed with deionized water and filtered to obtain 1.3 grams of polyglycolic acid-lactic acid white solid product.
[0050] It should be emphasized that the above embodiments are merely illustrative and not restrictive. Based on the disclosure of this application, any adjustment or change in reaction conditions or parameters that may be commonly adopted by practitioners will not deviate from the gist of the present invention. The scope of protection of this patent shall be based on the relevant rights record items.
Claims
1. A co-production technology for glycolic acid and lactic acid, dimers thereof, polyglycolic acid PGA, polylactic acid PLA and hybrid poly(glycolic acid-lactic acid), a series of biodegradable materials. As shown in reaction formula (IV): carbonyl compounds R1-C(O)-R2 and R3-C(O)-R4 are subjected to coupling reaction with chloroform HCCl3 under reaction conditions to prepare a trichloromethyl alcohol mixture (general formula I) shown in structural formulas A and B; a trichloromethyl alcohol mixture (general formula A) shown in structural formulas A and B and R5OH are subjected to substitution reaction under reaction conditions to prepare a hydroxy acid mixture (general formula II) shown in structural formulas C and D; a trichloromethyl alcohol mixture (general formula B) shown in structural formulas A and B and R5OH are subjected to substitution reaction under reaction conditions to prepare a hydroxy acid dimer mixture (general formula II) shown in structural formulas EG. Compound (general formula III); a trichloromethyl alcohol mixture shown in structural formulas A and B and R5OH are subjected to substitution and polymerization reaction under reaction conditions to prepare a polyhydroxy acid ester shown in structural formula H (general formula IV); a hydroxy acid dimer mixture shown in structural formula EG is subjected to polymerization reaction under reaction conditions to prepare a polyhydroxy acid ester H (general formula V); a mixed lactide shown in structural formula Q prepared by thermal depolymerization of a low molecular weight polyhydroxy acid ester H of general formula V and R5OH (alcohol or water) are subjected to ring-opening polymerization reaction under reaction conditions to prepare a high molecular weight polyhydroxy acid ester shown in structural formula H (general formula VI): Wherein R1, R2, R3, R4, or R5 (including multiple groups in the same structure) are independently hydrogen, or a branched or straight-chain aliphatic hydrocarbon group containing 1-24 carbon atoms, or a (hetero)aromatic hydrocarbon group containing 4-24 carbon atoms; preferably, R1, R2, R3, or R4 are independently hydrogen, methyl, ethyl, (iso)propyl, (iso)butyl; n is an integer greater than 2; preferably, n is an integer between 100-100,000,000. R6, R7, R8, or R9 are independently the same as R1. Preferably, R6, R7, R8, or R9 are independently hydrogen or methyl. conditions are at least one of solvent, temperature, pressure (or vacuum), and additives.
2. According to claim (1), the solvent is at least one of substituted or unsubstituted aromatic hydrocarbons, linear or branched aliphatic hydrocarbons, (sub)sulfones, amides, ethers, alcohols, esters, ketones, nitriles, carboxylic acids, water, amines, carbonates, ionic liquids, and supercritical carbon dioxide, or the substrate itself acts as a solvent medium. The preferred solvent is at least one of water, amides, or alcohols; the preferred amide is at least one of N,N-dimethylformamide, formylmorpholine, and N,N-diethylformamide. The temperature is -70°C-400°C. The pressure is 0.001atm-200atm. The additive refers to a reaction promoter, a synergist, a catalyst, an oxidant, an inhibitor, a reducing agent, and / or a functional aid. Based on the substrate equivalent, the additive is used in an amount of 0.001-1000 equivalents.
3. According to claim (1-2), in the general formula (I-III), the additive or promoter in the reaction conditions is preferably a base; the base is a metal or its oxide, hydroxide, alkoxide, alkylamine, carbonate (bi) salt, carboxylate, sulfonate, organic amine, or nitrogen-containing heterocyclic compound. The preferred base is a metal oxide, hydroxide, or alkoxide; the more preferred base is sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, barium hydroxide, calcium oxide, magnesium oxide. In the general formula (IV-V), the additive or promoter in the reaction conditions is preferably a protic or Lewis acid; the acid is hydrochloric acid, sulfuric acid, nitric acid, hydrohalic acid, sulfonic acid, carboxylic acid, metal or its halide, sulfide, oxide, carboxylate, sulfate (bi) salt, nitrate, (hypo)halate, molecular sieve, heteropoly acid. The preferred acid is hydrochloric acid or sulfuric acid. In the general formula (VI), the additive or promoter in the reaction conditions is preferably an acid or a base, which is defined as above.
4. According to claim (1), preferably, one way to carry out the reaction formula (I) is the formula (IA), wherein the intermediate mixture of trichloromethyl alcohol and methyl trichloromethyl alcohol is prepared by condensation of formaldehyde, acetaldehyde and chloroform under reaction conditions:
5. According to claim (1), a preferred method of implementing the general formula (II) is the general formula (IIB), wherein glycolic acid C and lactic acid D are prepared by alkaline hydrolysis of a mixture of trichloromethyl alcohol and methyltrichloromethyl alcohol and R5OH under reaction conditions. Preferably, R5 is independently hydrogen or methyl:
6. According to claim (1), a preferred way to implement general formula (III) is general formula (IIIA), wherein a mixture of trichloromethyl alcohol and methyltrichloromethyl alcohol and R5OH are subjected to alkaline hydrolysis under reaction conditions to prepare glycolic acid dimer E, lactic acid dimer F and glycolic acid-lactic acid hybrid dimer G. Preferably, R5 is independently hydrogen or methyl:
7. According to claim (1), a preferred method of implementing the general formula (IV) is the general formula (IVA), wherein the polymeric hydroxy acid H is prepared by alkaline hydrolysis and polymerization of a mixture of trichloromethyl alcohol and methyltrichloromethyl alcohol under reaction conditions:
8. According to claim (1), a preferred method of implementing general formula (V) is general formula (VA), wherein a mixture of at least two of the dimers EG is polymerized under reaction conditions to prepare a polymeric hydroxy acid H:
9. According to claim (1), a preferred method for executing the general formula (VI) is reaction formula (VIA-B), wherein the mixed lactide represented by the structural formula Q prepared by thermal depolymerization of the low molecular weight polyhydroxy acid H of the general formula V and R5OH (alcohol or water) are subjected to ring-opening polymerization under reaction conditions to prepare the high molecular weight polyhydroxy acid represented by the structural formula H (general formula VIA); or, the mixed lactide mixture Q1-Q3 prepared by thermal depolymerization of the low molecular weight polyhydroxy acid H of the general formula V and R5OH are subjected to ring-opening polymerization under reaction conditions to prepare the high molecular weight polyhydroxy acid H (general formula VIB):
10. According to claims (1-9), the substance AH prepared by the co-production process disclosed in the present invention is used as a synthon or synthetic raw material in the manufacture of biodegradable green materials containing polyhydroxy acids (PHAs) or polyglycolic acid (PGA) or polylactic acid (PLA) or hybrid PGA-PLA polymer chain segments.