Polyvinyl chloride containing environment-friendly amino acid plasticizing heat stabilizer and preparation method

Abstract

The invention relates to the technical field of polyvinyl chloride, and discloses polyvinyl chloride containing an environment-friendly amino acid plasticizing heat stabilizer and a preparation method, the polyvinyl chloride comprises 100 parts by weight of polyvinyl chloride, 4-8 parts by weight of the amino acid plasticizing heat stabilizer and the like; the lanthanum element in the heat stabilizer can capture hydrogen chloride generated by thermal decomposition of the polyvinyl chloride, inhibit the HCl removal chain decomposition reaction of the polyvinyl chloride, and improve the heat stabilization time and heat resistance of the polyvinyl chloride. The heat stabilizer contains a plurality of ester groups and plays a good plasticizing role, and meanwhile, the contained alkyl long chain plays a role of a molecular lubricant and promotes sliding of a polyvinyl chloride polymer chain segment, so that polyvinyl chloride is further plasticized and toughened, and the polyvinyl chloride has higher impact strength.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyvinyl chloride, in particular to a polyvinyl chloride containing an environmentally friendly amino acid plasticizing heat stabilizer and a preparation method. BACKGROUND

[0002] Polyvinyl chloride has high mechanical strength, good acid and alkali resistance, and excellent flame retardant performance, and is widely used in pipeline pipes, wire and cable, medical devices, packaging materials and other aspects. However, the thermal stability and heat resistance of polyvinyl chloride are poor, and it is easy to decompose at high temperature to produce hydrogen chloride and initiate chain decomposition reaction, which has a great influence on the performance of polyvinyl chloride. In addition, the toughness of polyvinyl chloride is poor, so it is necessary to add heat stabilizers, plasticizers and other additives to polyvinyl chloride.

[0003] Cardanol is a natural biomass compound, which is green, environmentally friendly, cheap and easy to obtain, and has important application in plasticizing and toughening of polyvinyl chloride, epoxy resin and other aspects. Patent CN106188617B discloses that cardanol and 1-chlorobutane are used as main raw materials to carry out Williamson etherification and low-temperature in-situ epoxidation reaction, and the prepared epoxy cardanol butyl ether can improve the flexibility and durability of plastic products, but the epoxy cardanol butyl ether does not improve the thermal stability and heat resistance of polyvinyl chloride. SUMMARY

[0004] (I) The technical problem solved by the present application is to solve the problems of poor thermal stability and toughness of polyvinyl chloride.

[0005] (II) Technical scheme: a preparation method of polyvinyl chloride containing an environmentally friendly amino acid plasticizing heat stabilizer:

[0006] (1) Cardanol, ethylenediaminetetraacetic dianhydride and triethylamine are added to tetrahydrofuran, stirred and reacted in a nitrogen atmosphere, then diluted with water, acidified by dropwise adding concentrated hydrochloric acid, precipitate is separated out, the precipitate is dried after filtration, and ethylenediaminetetraacetic dianhydride modified cardanol is obtained, and the structural formula is as follows:

[0007] .

[0008] (2) Ethylenediaminetetraacetic dianhydride modified cardanol and amino acid are added to ethanol, stirred, then lanthanum salt is added, heated to reaction temperature, dropwise added with sodium hydroxide aqueous solution, stirred and reacted, then filtered, washed with water and hot ethanol, and dried to obtain an environmentally friendly amino acid plasticizing heat stabilizer.

[0009] (3) Polyvinyl chloride, amino acid plasticizing heat stabilizer, plasticizer and lubricant are mixed in a mixing machine, then plasticized in an open mill to obtain polyvinyl chloride containing an environmentally friendly amino acid plasticizing heat stabilizer.

[0010] Furthermore, in (1), the ratio of cashew phenol, ethylenediaminetetraacetic acid dianhydride, and triethylamine is (2-2.4) mol: 1 mol: (6-8) mol.

[0011] Furthermore, in (1), the reaction temperature is 40-55℃ and the reaction time is 8-12h.

[0012] Furthermore, in (2), the reaction temperature is 60-80℃ and the reaction time is 40-60min.

[0013] Furthermore, in (2), the ratio of ethylenediaminetetraacetic acid dianhydride-modified cashew phenol, amino acids, and lanthanum salt is (1-1.8) mol: (1.4-2.2) 1 mol: 1 mol.

[0014] Furthermore, in (2), lanthanum salts include lanthanum nitrate, lanthanum nitrate hydrate, lanthanum chloride, and lanthanum chloride hydrate.

[0015] Furthermore, the amino acids in (2) include glycine, alanine, β-alanine, valine, leucine, and isoleucine.

[0016] Furthermore, in (3), the amount of polyvinyl chloride is 100 parts by weight, the amount of amino acid plasticizer heat stabilizer is 4-8 parts by weight, the amount of plasticizer is 2-20 parts by weight, and the amount of lubricant is 1.4-2.2 parts by weight.

[0017] Furthermore, the plasticizers in (3) include dioctyl phthalate, dibutyl phthalate, and di-2-ethylhexyl phthalate.

[0018] Furthermore, the lubricant in (3) includes stearic acid, zinc stearate, and calcium stearate.

[0019] Furthermore, in (3), the mixing time in the mixer is 20-30 min.

[0020] Furthermore, in (3), the temperature of the open mill is 160-170℃ and the time is 4-8min.

[0021] (III) Beneficial technical effects: The present invention uses environmentally friendly bio-based cashew phenol as raw material to prepare ethylenediaminetetraacetic acid dianhydride modified cashew phenol containing multiple carboxyl groups, which form multidentate coordination with green environmentally friendly amino acids and lanthanum ions to obtain a highly structurally stable amino acid plasticizing heat stabilizer. When mixed with polyvinyl chloride, plasticizers, etc., high-performance polyvinyl chloride materials are obtained. The lanthanum element in the heat stabilizer can capture hydrogen chloride generated by the thermal decomposition of polyvinyl chloride, inhibit the deHCl chain decomposition reaction of polyvinyl chloride, and improve the thermal stability time and heat resistance of polyvinyl chloride.

[0022] The ethylenediaminetetraacetic acid dianhydride-modified cashew phenol and the heat stabilizer prepared by the present invention contain multiple ester groups and multiple alkyl long chains. The polar ester groups can form weak dipole-dipole interactions with chlorine atoms in polyvinyl chloride (PVC), reducing the original hydrogen bonds between PVC molecular chains and lowering the binding energy between molecular chains, thus playing a good plasticizing role. At the same time, the contained alkyl long chains can interpenetrate between PVC molecular chains, increasing the inter-chain spacing of PVC, reducing the frictional resistance between chain segments, acting as a molecular lubricant, promoting the sliding of PVC polymer chain segments, further plasticizing and toughening PVC, and giving PVC higher impact strength. Detailed Implementation

[0023] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention are now described.

[0024] Example 1:

[0025] (1) Add 0.2 mol (about 60.9 g) of cashew phenol, 0.1 mol of ethylenediaminetetraacetic acid dianhydride and 0.8 mol of triethylamine to 1 L of tetrahydrofuran. Heat to 40 °C under a nitrogen atmosphere and stir for 12 h. Add water to dilute and add concentrated hydrochloric acid to acidify the pH to 3. The precipitate is precipitated. After filtration, the precipitate is dried to obtain ethylenediaminetetraacetic acid dianhydride modified cashew phenol.

[0026] (2) Add 0.18 mol of ethylenediaminetetraacetic acid dianhydride-modified cashew phenol and 0.14 mol of glycine to 1.2 L of ethanol, stir, add 0.1 mol of lanthanum nitrate hexahydrate, heat to 70 °C, add dropwise 20% sodium hydroxide aqueous solution to adjust pH to 7.5, stir, reflux for 40 min, filter, wash with water and hot ethanol, dry, and obtain environmentally friendly amino acid plasticizer heat stabilizer.

[0027] (3) Mix 1 kg of polyvinyl chloride, 40 g of amino acid plasticizer heat stabilizer, 200 g of dioctyl phthalate, 9 g of stearic acid and 13 g of calcium stearate in a mixer for 20 min, and then plasticize in a two-roll mill at 170 °C for 4 min to obtain polyvinyl chloride containing environmentally friendly amino acid plasticizer heat stabilizer.

[0028] Example 2:

[0029] (1) Add 0.24 mol (about 73.1 g) cashew phenol, 0.1 mol ethylenediaminetetraacetic acid dianhydride and 0.6 mol triethylamine to 1 L of tetrahydrofuran. Heat to 55 °C in a nitrogen atmosphere, stir and reflux for 8 h. Add water to dilute, add concentrated hydrochloric acid dropwise to acidify pH to 4, precipitate out, filter and dry the precipitate to obtain ethylenediaminetetraacetic acid dianhydride modified cashew phenol.

[0030] (2) Add 0.14 mol of ethylenediaminetetraacetic acid dianhydride-modified cashew phenol and 0.18 mol of β-alanine to 1.4 L of ethanol, stir, add 0.1 mol of lanthanum nitrate hexahydrate, heat to 60 °C, add 30% sodium hydroxide aqueous solution to adjust pH to 7, stir, reflux for 60 min, filter, wash with water and hot ethanol, dry, and obtain environmentally friendly amino acid plasticizer heat stabilizer.

[0031] (3) Mix 1 kg of polyvinyl chloride, 60 g of amino acid plasticizer heat stabilizer, 100 g of dioctyl phthalate, 8 g of stearic acid and 11 g of zinc stearate in a mixer for 30 min, and then plasticize in a two-roll mill at 160 °C for 8 min to obtain polyvinyl chloride containing environmentally friendly amino acid plasticizer heat stabilizer.

[0032] Example 3:

[0033] (1) Add 0.2 mol (about 60.9 g) cashew phenol, 0.1 mol ethylenediaminetetraacetic acid dianhydride and 0.7 mol triethylamine to 1 L of tetrahydrofuran. Heat to 45 °C under a nitrogen atmosphere and stir for 12 h. Add water to dilute and add concentrated hydrochloric acid to acidify the pH to 3. The precipitate is precipitated. After filtration, the precipitate is dried to obtain ethylenediaminetetraacetic acid dianhydride modified cashew phenol.

[0034] (2) Add 0.1 mol of ethylenediaminetetraacetic acid dianhydride-modified cashew phenol and 0.22 mol of alanine to 1.2 L of ethanol, stir, add 0.1 mol of lanthanum chloride hexahydrate, heat to 60 °C, add dropwise 20% sodium hydroxide aqueous solution to adjust pH to 7.5, stir, reflux for 60 min, filter, wash with water and hot ethanol, dry, and obtain environmentally friendly amino acid plasticizer heat stabilizer.

[0035] (3) Mix 1 kg of polyvinyl chloride, 40 g of amino acid plasticizer heat stabilizer, 20 g of dioctyl phthalate, 5 g of stearic acid and 9 g of zinc stearate in a mixer for 30 min, and then plasticize in a two-roll mill at 170 °C for 5 min to obtain polyvinyl chloride containing environmentally friendly amino acid plasticizer heat stabilizer.

[0036] Comparative Example 1:

[0037] (1) Add 0.18 mol adipic acid and 0.14 mol glycine to 1.2 L ethanol, stir, add 0.1 mol lanthanum nitrate hexahydrate, heat to 70 °C, add dropwise 20% sodium hydroxide aqueous solution to adjust pH to 7.5, stir, reflux for 40 min, filter, wash with water and hot ethanol, dry to obtain heat stabilizer.

[0038] (2) Mix 1 kg of polyvinyl chloride, 40 g of heat stabilizer, 200 g of dioctyl phthalate, 9 g of stearic acid and 13 g of calcium stearate in a mixer for 20 min, and then plasticize in a two-roll mill at 170 °C for 4 min to obtain polyvinyl chloride containing environmentally friendly amino acid plasticizing heat stabilizer.

[0039] Comparative Example 2:

[0040] (1) Add 0.18 mol of ethylenediaminetetraacetic acid dianhydride-modified cashew phenol and 0.14 mol of n-butyric acid to 1.2 L of ethanol, stir, add 0.1 mol of lanthanum nitrate hexahydrate, heat to 70 °C, add dropwise 20% sodium hydroxide aqueous solution to adjust pH to 7.5, stir, reflux for 40 min, filter, wash with water and hot ethanol, dry to obtain heat stabilizer.

[0041] (2) Mix 1 kg of polyvinyl chloride, 40 g of heat stabilizer, 200 g of dioctyl phthalate, 9 g of stearic acid and 13 g of calcium stearate in a mixer for 20 min, and then plasticize in a two-roll mill at 170 °C for 4 min to obtain polyvinyl chloride containing environmentally friendly amino acid plasticizing heat stabilizer.

[0042] Comparative Example 3:

[0043] (1) Add 0.18 mol cashew phenol and 0.14 mol glycine to 1.2 L ethanol, stir, add 0.1 mol lanthanum nitrate hexahydrate, heat to 70 °C, add dropwise 20% sodium hydroxide aqueous solution to adjust pH to 7.5, stir, reflux for 40 min, filter, wash with water and hot ethanol, dry to obtain heat stabilizer.

[0044] (2) Mix 1 kg of polyvinyl chloride, 40 g of heat stabilizer, 200 g of dioctyl phthalate, 9 g of stearic acid and 13 g of calcium stearate in a mixer for 20 min, and then plasticize in a two-roll mill at 170 °C for 4 min to obtain polyvinyl chloride containing environmentally friendly amino acid plasticizing heat stabilizer.

[0045] Comparative Example 4:

[0046] (1) Add 0.2 mol phenol, 0.1 mol ethylenediaminetetraacetic acid dianhydride, and 0.8 mol triethylamine to 1 L of tetrahydrofuran. Heat to 40 °C under a nitrogen atmosphere and stir for 12 h. Dilute with water, acidify the pH to 3 with concentrated hydrochloric acid, and precipitate. Filter and dry the precipitate to obtain ethylenediaminetetraacetic acid dianhydride-modified phenol with the following structural formula: .

[0047] (2) Add 0.18 mol of ethylenediaminetetraacetic acid dianhydride-modified phenol and 0.14 mol of glycine to 1.2 L of ethanol, stir, add 0.1 mol of lanthanum nitrate hexahydrate, heat to 70 °C, add dropwise 20% sodium hydroxide aqueous solution to adjust pH to 7.5, stir, reflux for 40 min, filter, wash with water and hot ethanol, dry to obtain heat stabilizer.

[0048] (3) Mix 1 kg of polyvinyl chloride, 40 g of heat stabilizer, 200 g of dioctyl phthalate, 9 g of stearic acid and 13 g of calcium stearate in a mixer for 20 min, and then plasticize in a two-roll mill at 170 °C for 4 min to obtain polyvinyl chloride containing environmentally friendly amino acid plasticizing heat stabilizer.

[0049] Comparative Example 5: Sodium cashew phenolate was prepared according to the method described in the journal article "Research and Application of Sodium Cashew Phenolic Carboxylate Biomass Foaming Agent for Drainage and Gas Production" (July 2022, Vol. 39, No. 4). The structural formula is as follows: .

[0050] (1) Add 0.18 mol of sodium cashew phenolate and 0.14 mol of glycine to 1.2 L of ethanol, stir, add 0.1 mol of lanthanum nitrate hexahydrate, heat to 70 °C, add dropwise 20% sodium hydroxide aqueous solution to adjust pH to 7.5, stir, reflux and cool for 40 min, filter, wash with water and hot ethanol, dry to obtain heat stabilizer.

[0051] (2) Mix 1 kg of polyvinyl chloride, 40 g of heat stabilizer, 200 g of dioctyl phthalate, 9 g of stearic acid and 13 g of calcium stearate in a mixer for 20 min, and then plasticize in a two-roll mill at 170 °C for 4 min to obtain polyvinyl chloride containing environmentally friendly amino acid plasticizing heat stabilizer.

[0052] The thermal stability of polyvinyl chloride was tested according to GB / T 2917.1-2002 standard. The impact strength of simply supported beams was tested according to GB / T 1043.1-2008 standard.

[0053] Table 1 Properties of Polyvinyl Chloride

[0054] Thermal stabilization time (min) impact strength (kJ / m 2 ) Example 1 27.4 23.50 Example 2 41.3 16.13 Example 3 45.8 8.67 Comparative Example 1 27.9 19.21 Comparative Example 2 26.2 23.97 Comparative Example 3 26.4 16.85 Comparative Example 4 27.6 18.62 Comparative Example 5 27.0 21.38

[0055] In Examples 1-3, amino acid plasticizing heat stabilizers were added to the polyvinyl chloride (PVC). The amino acids contain amino and carboxyl coordination groups, and the multiple carboxyl groups of the ethylenediaminetetraacetic acid dianhydride-modified cashew phenol form polydentate coordination with lanthanum ions, resulting in a highly structurally stable amino acid plasticizing heat stabilizer. The lanthanum element can capture the hydrogen chloride generated by the thermal decomposition of PVC, inhibiting the deHCl chain decomposition reaction of PVC and improving the thermal stability time and heat resistance of PVC. Furthermore, the ethylenediaminetetraacetic acid dianhydride-modified cashew phenol contains multiple ester groups and multiple long alkyl chains. The polar ester groups can form weak dipole-dipole interactions with the chlorine atoms in PVC, reducing the original hydrogen bonds between PVC molecular chains and lowering the binding energy between molecular chains, thus playing a good plasticizing role. Simultaneously, the long alkyl chains can interweave between PVC molecular chains, increasing the inter-chain spacing, reducing the frictional resistance between chain segments, acting as a molecular lubricant, promoting the sliding of PVC polymer chain segments, further plasticizing and toughening PVC, and giving PVC higher impact strength.

[0056] Compared with Example 1, Comparative Example 1 used adipic acid instead of ethylenediaminetetraacetic acid dianhydride to modify cashew phenol. The heat stabilizer prepared did not contain cashew phenol ester structure, and had poor plasticizing and toughening effect on polyvinyl chloride, resulting in lower impact strength.

[0057] Comparative Example 2 used butyric acid, which does not contain amino groups, to replace glutamic acid. However, the coordination effect with lanthanum ions was not good, and the heat stabilizer prepared for polyvinyl chloride had a shorter heat stabilization time than in Example 1.

[0058] The cashew phenol in Comparative Example 3 does not contain carboxyl groups and has a very weak coordination effect with lanthanum ions. After washing with ethanol and other substances, the cashew phenol content in the heat stabilizer is very low, resulting in poor toughening and plasticizing effect on polyvinyl chloride and lower impact strength than in Example 1.

[0059] The ethylenediaminetetraacetic acid dianhydride-modified phenol and its prepared heat stabilizer in Comparative Example 4 do not contain alkyl long chains, resulting in poor toughening effect on polyvinyl chloride and lower impact strength than in Example 1.

[0060] The ester group content of sodium cashew phenolate carboxylate and the heat stabilizer prepared therefrom in Comparative Example 5 was significantly lower than that in Example 1, resulting in poor toughening effect on polyvinyl chloride and lower impact strength than in Example 1.

[0061] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A polyvinyl chloride containing an environmentally friendly amino acid plasticizing heat stabilizer, characterized in that, The polyvinyl chloride comprises 100 parts by weight of polyvinyl chloride, 4-8 parts by weight of amino acid plasticizer heat stabilizer, 2-20 parts by weight of plasticizer, and 1.4-2.2 parts by weight of lubricant; The preparation method of the environmentally friendly amino acid plasticizing heat stabilizer includes: adding ethylenediaminetetraacetic acid dianhydride-modified cashew phenol and amino acids to ethanol, stirring, adding lanthanum salt, heating to the reaction temperature, adding sodium hydroxide aqueous solution dropwise, stirring the reaction, filtering, washing, and drying to obtain the environmentally friendly amino acid plasticizing heat stabilizer.

2. The polyvinyl chloride containing an environmentally friendly amino acid plasticizing heat stabilizer according to claim 1, characterized in that, The plasticizers include dioctyl phthalate, dibutyl phthalate, and di-2-ethylhexyl phthalate.

3. The polyvinyl chloride containing an environmentally friendly amino acid plasticizing heat stabilizer according to claim 1, characterized in that, The lubricant includes stearic acid, zinc stearate, and calcium stearate.

4. The polyvinyl chloride containing an environmentally friendly amino acid plasticizing heat stabilizer according to claim 1, characterized in that, The reaction temperature is 60-80℃, and the reaction time is 40-60 min.

5. The polyvinyl chloride containing an environmentally friendly amino acid plasticizing heat stabilizer according to claim 1, characterized in that, The ratio of the modified cashew phenol, amino acid, and lanthanum salt in the ethylenediaminetetraacetic dianhydride is (1-1.8) mol: (1.4-2.2) 1 mol: 1 mol.

6. The polyvinyl chloride containing an environmentally friendly amino acid plasticizing heat stabilizer according to claim 5, characterized in that, The lanthanum salts include lanthanum nitrate, lanthanum nitrate hydrate, lanthanum chloride, and lanthanum chloride hydrate.

7. The polyvinyl chloride containing an environmentally friendly amino acid plasticizing heat stabilizer according to claim 5, characterized in that, The amino acids include glycine, alanine, β-alanine, valine, leucine, and isoleucine.

8. The polyvinyl chloride containing an environmentally friendly amino acid plasticizing heat stabilizer according to claim 4, characterized in that, The method for preparing the ethylenediaminetetraacetic dianhydride-modified cashew phenol is as follows: Cashew phenol, ethylenediaminetetraacetic dianhydride, and triethylamine are added to tetrahydrofuran in a ratio of (2-2.4) mol: 1 mol: (6-8) mol. The mixture is heated to 40-55℃ under a nitrogen atmosphere and stirred for 8-12 hours. Water is added for dilution, concentrated hydrochloric acid is added dropwise for acidification, and a precipitate is formed. The precipitate is filtered and dried to obtain ethylenediaminetetraacetic dianhydride-modified cashew phenol.

9. A method for preparing polyvinyl chloride containing an environmentally friendly amino acid plasticizing heat stabilizer as described in any one of claims 1-8, characterized in that, The preparation method is as follows: polyvinyl chloride, amino acid plasticizing heat stabilizer, plasticizer, and lubricant are mixed in a mixer, and then plasticized in a two-roll mill to obtain polyvinyl chloride containing environmentally friendly amino acid plasticizing heat stabilizer.

10. The method for preparing polyvinyl chloride containing an environmentally friendly amino acid plasticizing heat stabilizer according to claim 9, characterized in that, The mixing time in the mixer is 20-30 minutes; the temperature of the open mill is 160-170℃, and the time is 4-8 minutes.