Modified SG5 type polyvinyl chloride film and preparation method thereof
By using epoxy 1,6-hexanediol oleate as a plasticizer, the modified SG5 type PVC material is internally plasticized, which solves the problems of poor mechanical properties, cold resistance and thermal stability, and achieves a comprehensive improvement in material performance.
Patent Information
- Application Number
- CN202510006977.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-03
- Publication Date
- 2025-04-11
AI Technical Summary
During use, SG5 PVC materials have problems with poor mechanical properties, cold resistance and thermal stability, and the existing plasticizer types are limited and lack performance.
The environmentally friendly and superior cold-resistant plasticizer 1,6-hexanediol oleate is used for internal plasticization, and it is introduced into the SG5 type PVC chain through grafting reaction to prepare a modified SG5 type PVC material.
The mechanical properties, cold resistance and thermal stability of SG5 type PVC materials have been improved, and the comprehensive performance has been improved.
Smart Images
Figure CN119798735A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of materials, and more specifically to a modified SG5 type polyvinyl chloride film and a preparation method thereof. Background Art
[0002] Polyvinyl chloride (PVC) has been beneficial to modern civilization in all aspects. PVC is one of the most consumed plastics in the world. In recent years, the global market demand for PVC materials has continued to grow, from 38.3 million tons in 2013 to 54.31 million tons in 2020. The global demand for PVC is still rising, among which the Asia-Pacific region is the region with the highest consumption in the world. It is widely used in various fields with its excellent performance and low price. People can see them in almost every field of production and life. SG5 type PVC products include wallpaper, toys, boots, casing, window screens, gloves, curtains, etc., among which the demand for SG5 type PVC cables is increasing. However, there are still problems such as poor mechanical properties, cold resistance, and thermal stability during use. Therefore, the performance and applicable fields of SG5 type PVC are improved by internal plasticization modification.
[0003] To date, plasticizers are the most important additives in SG5 PVC products, and global plasticizer usage has increased from 8.4 million tons in 2014 to 10.3 million tons in 2019. Although plasticizers are versatile and inexpensive, they still have many problems. Therefore, the relevant properties of SG5 PVC materials can be improved through internal plasticization modification. This is mainly due to the fact that chlorine atoms in SG5 PVC chains are easily replaced by these aromatic thiol compounds containing thiol and thiolate groups, and then the plasticizers are grafted onto the side groups of the PVC chains through a series of substitution nucleophilic reactions. At present, the most studied is the use of thiol phthalate plasticizers to replace the chlorine atoms on the polyvinyl chloride chain to obtain internally plasticized polyvinyl chloride materials. Although the benzene ring in the plasticizer makes the modified polymer hard and the flexibility is lower than that of the traditional phthalate plasticized polyvinyl chloride system, it still has a good plasticizing effect, and the glass transition temperature will gradually decrease with the increase of the reactive plasticizer content. However, due to the presence of benzene rings, it has certain pollution and toxicity, and a pollution-free and high-performance plasticizer is needed for grafting modification. Summary of the invention
[0004] The present invention aims at the problem that the types of plasticizers commonly used for internal plasticization are limited and the performance is insufficient. The environmentally friendly and high-performance cold-resistant plasticizer 1,6-hexanediol oleate is used for internal plasticization, and the modified SG5 type PVC material is successfully prepared, and the film is prepared to test its performance. The results show that the SG5 type PVC material grafted with epoxy 1,6-hexanediol oleate has excellent mechanical properties, cold resistance and thermal stability, which effectively improves the comprehensive performance of the SG5 type PVC material.
[0005] The present invention provides a method for preparing a modified SG5 polyvinyl chloride (PVC) film, comprising: step 1: grafting thiosalicylic acid as an intermediate onto SG5 polyvinyl chloride to obtain thiosalicylic acid grafted polyvinyl chloride; step 2: using N,N-dimethylbenzylamine as a catalyst and chloroform as a solvent to react thiosalicylic acid grafted polyvinyl chloride and epoxy 1,6-hexanediol oleate, and then using methanol to precipitate and wash the product to obtain SG5 polyvinyl chloride modified with epoxy 1,6-hexanediol oleate; step 3: dissolving the SG5 polyvinyl chloride modified with epoxy 1,6-hexanediol oleate, standing, evaporating, and drying to obtain an SG5 polyvinyl chloride film modified with epoxy 1,6-hexanediol oleate internal plasticization.
[0006] In some embodiments, in step 1, 10-12 grams of SG5 polyvinyl chloride and 250 mL of cyclohexanone are added to a container, and the mixture is stirred at room temperature until completely dissolved; 20-25 grams of thiosalicylic acid and 26-28 grams of potassium carbonate are added to the mixture, and the mixture is placed in a water bath and set to a temperature of 60°C and stirred for reaction for 30-35 hours, and nitrogen is introduced to keep the internal reaction in a nitrogen environment, and then washed with methanol solution and vacuum dried to obtain thiosalicylic acid grafted polyvinyl chloride.
[0007] In some embodiments, in step 2, 5-10 g of thiosalicylic acid grafted polyvinyl chloride, 25-28 g of epoxy 1,6-hexanediol oleate, and 1.5 ml of N,N-dimethylbenzylamine are dissolved in 350 ml of chloroform, placed in a water bath and set to a temperature of 60-80°C, stirred for reaction for 24-30 hours, and after methanol precipitation and vacuum drying, SG5 polyvinyl chloride modified with epoxy 1,6-hexanediol oleate is obtained.
[0008] In some embodiments, in step 3, 6-9 g of SG5 polyvinyl chloride modified with epoxy 1,6-hexanediol oleate and 150 ml of tetrahydrofuran are added to a container, magnetically stirred until the solution is clear and transparent, poured into a culture dish, covered with plastic wrap, and allowed to stand for 24-32 hours before turning the film over, evaporating at ambient temperature for 2-4 days, and then drying in a constant temperature oven at 50-70°C for 3-5 days to remove the tetrahydrofuran, and finally cut into strips for use.
[0009] The present disclosure also provides a modified SG5 type polyvinyl chloride film, and the modified SG5 type polyvinyl chloride film is prepared by the preparation method of the modified SG5 type polyvinyl chloride film.
[0010] The modification using epoxy 1,6-hexanediol oleate disclosed in the present invention has the following advantages: (1) epoxy 1,6-hexanediol oleate is a macromolecular straight-chain structure, which can be well present inside the PVC chain, increase the movable space inside, improve the mechanical properties of the material, and increase the heat resistance of the PVC material to a certain extent; (2) epoxy 1,6-hexanediol oleate replaces part of the Cl ions on the PVC chain during the grafting process, and in the first stage of dehydrochlorination, due to the reduction of Cl ions, the phenomenon of combining with part of hydrogen to form HCl is reduced, further improving the thermal stability of the PVC material; (3) Due to the introduction of the macromolecular straight-chain structure of epoxy 1,6-hexanediol oleate into the side group of the PVC chain, its Tg is reduced, showing better cold resistance, and is suitable for more fields.
[0011] The internal plasticizer disclosed in the present invention is epoxy 1,6-hexanediol oleate, which is a biomass plasticizer, non-toxic, environmentally friendly, superior in performance and low in price. The process of internal plasticization modification of SG5 type PVC is simple and the process is safe. The SG5 type PVC material modified by internal plasticization of epoxy 1,6-hexanediol oleate achieves a unified balance of superior mechanical properties, excellent thermal stability and stable cold resistance. Compared with the commercial dioctyl adipate (DOA) plasticizer, the PVC material modified by internal plasticization of epoxy 1,6-hexanediol oleate has similar cold resistance, but better mechanical properties, and greatly improved thermal stability, and has better commercial competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is the DMA curve of SG5 type PVC, Example 1, Example 2, and the material prepared in Example 3. DETAILED DESCRIPTION
[0013] The following embodiments may enable those skilled in the art to more fully understand the present disclosure, but do not limit the present disclosure in any way.
[0014] Unless otherwise stated, the materials, reagents, etc. used in the following examples can be obtained from commercial sources.
[0015] The preparation of the modified SG5 PVC film disclosed in the present invention is mainly divided into three steps: (1) Grafting thiosalicylic acid as an intermediate onto SG5 PVC: Grafting thiosalicylic acid onto SG5 PVC chain by oil bath, precipitation, washing, vacuum drying and other methods; (2) Preparation of SG5 PVC material modified by epoxy 1,6-hexanediol oleate internal plasticization: Using N,N-dimethylbenzylamine as a catalyst and chloroform as a solvent, the final product, epoxy 1,6-hexanediol oleate modified SG5 PVC material, is obtained by precipitation and washing with methanol after reaction; (3) Preparation of SG5 PVC film modified by epoxy 1,6-hexanediol oleate internal plasticization: Using solution casting method, dissolving SG5 PVC modified by epoxy 1,6-hexanediol oleate internal plasticization, and obtaining SG5 PVC film modified by epoxy 1,6-hexanediol oleate internal plasticization after standing, evaporation and drying.
[0016] The specific preparation process of the present disclosure is:
[0017] Preparation of thiosalicylic acid grafted PVC material: 10-12 g of SG5 PVC and 250 mL of cyclohexanone were added to a 500 mL flask. The mixture was stirred at room temperature until all materials were completely dissolved. 20-25 g of thiosalicylic acid and 26-28 g of potassium carbonate were added to the mixture, placed in a water bath and set to 60 ° C for 30-35 h of stirring reaction, and nitrogen was introduced to keep the internal reaction in a nitrogen environment, then washed with methanol solution, and vacuum dried to obtain thiosalicylic acid grafted SG5 PVC material.
[0018] Preparation of SG5 type PVC material modified by epoxy 1,6-hexanediol oleate internal plasticization: 5-10 grams of SG5 type PVC material grafted with thiosalicylic acid, a certain amount of epoxy 1,6-hexanediol oleate (25-28 grams), and 1.5 milliliters of N,N-dimethylbenzylamine are dissolved in 350 milliliters of chloroform, placed in a water bath and set to a temperature of 60-80°C, stirred for reaction for 24-30 hours, and after methanol precipitation and vacuum drying, the SG5 type PVC material modified by epoxy 1,6-hexanediol oleate internal plasticization is obtained.
[0019] Preparation of epoxy 1,6-hexanediol oleate internal plasticizer modified SG5 type PVC film: add 6-9g epoxy 1,6-hexanediol oleate internal plasticizer modified SG5 type PVC material and 150ml tetrahydrofuran into a 250ml beaker, stir magnetically until the solution is clear and transparent, pour it into a 150mm culture dish, and cover it with plastic wrap with small holes to prevent the solvent from evaporating too quickly. After standing for 24-32h, turn the film over, evaporate at ambient temperature for 2-4d, and then dry it in a constant temperature box at 50-70℃ for 3-5d to remove the tetrahydrofuran, and finally cut it into strips for use.
[0020] The following description is given in conjunction with embodiments to provide a better understanding of the present disclosure.
[0021] Example 1
[0022] Preparation of SG5 PVC film: Add 12g SG5 PVC resin and 150ml tetrahydrofuran into a 250ml beaker, stir magnetically until the solution is clear and transparent. Then add 50% dioctyl adipate (DOA) plasticizer, stir for 24h, pour into a 150mm Petri dish, and cover with plastic wrap with small holes to prevent the solvent from evaporating too quickly. After standing for 24h, turn over the PVC film, evaporate at ambient temperature for 2d, and then dry in a constant temperature box at 50℃ for 3d to remove tetrahydrofuran, and finally cut into strips for use.
[0023] Example 2
[0024] Preparation of 1,6-hexanediol oleate: 0.6383 mol of oleic acid and 0.3192 mol of 1,6-hexanediol were added to a 250 ml three-necked flask, and 0.0276 mol (1.5% of the mass of oleic acid) of concentrated sulfuric acid catalyst was added to the mixture. The three-necked flask was placed in an oil bath pot and heated to 130°C under a nitrogen atmosphere with magnetic stirring for reaction. After the reaction was completed, 5.33 g of 15 wt% sodium hydroxide solution was added to neutralize the excess oleic acid, and the excess 1,6-hexanediol and sodium hydroxide were removed by water washing, and the liquid was allowed to stand for separation, and the residual water was removed by rotary evaporation to obtain a product with high purity.
[0025] Preparation of epoxy 1,6-hexanediol oleate: First, add 0.15mol of 1,6-hexanediol oleate to a three-necked flask, then add 1.23mol (70% of the mass of 1,6-hexanediol oleate) of hydrogen peroxide, 0.196mol (15% of the mass of 1,6-hexanediol oleate) of formic acid and 0.006mol (1% of the mass of 1,6-hexanediol oleate) of concentrated sulfuric acid. Put it in a water bath and set the temperature to 60℃ and stir to react for 8h. When the ester is completely converted, wash with water to remove the excess acid and oxidant, then remove the residual water by rotary evaporation, and finally obtain the purified product epoxy 1,6-hexanediol oleate.
[0026] Preparation of SG5 PVC material: Add 12g SG soft 5 PVC resin and 150ml tetrahydrofuran into a 250ml beaker, stir magnetically until the solution is clear and transparent. Then add 50% epoxy 1,6-hexanediol oleate plasticizer, stir for 24 hours, pour it into a 150mm Petri dish, and cover it with a plastic wrap with small holes to prevent the solvent from evaporating too quickly. After standing for 24 hours, turn the PVC film over, evaporate at ambient temperature for 2 days, and then dry it in a constant temperature box at 50℃ for 3 days to remove the tetrahydrofuran, and finally cut it into strips for use.
[0027] Example 3
[0028] Preparation of SG5 PVC grafted with thiosalicylic acid: 10 g (0.33 mol) of SG5 PVC and 250 mL of cyclohexanone were added to a 500 mL flask. The mixture was stirred at room temperature until all the PVC resin was completely dissolved. 20 g (0.13 mol) of thiosalicylic acid and 26.88 g (0.19 mol) of potassium carbonate were added to the mixture, placed in a water bath and set to 60 ° C for stirring and reaction for 30 h, and nitrogen was introduced to keep the internal reaction in a nitrogen environment, then washed with methanol solution, and vacuum dried to obtain the material after SG5 PVC grafted with thiosalicylic acid.
[0029] Preparation of SG5 type PVC material modified by epoxy 1,6-hexanediol oleate internal plasticizer: 5g of SG5 type PVC material modified by thiosalicylic acid and a certain amount of epoxy 1,6-hexanediol oleate (25.91g) and 1.5ml N,N-dimethylbenzylamine were dissolved in 350ml chloroform, put into a water bath and set the temperature to 65℃ and stirred for reaction for 24h. After methanol precipitation and vacuum drying, SG5 type PVC material modified by epoxy 1,6-hexanediol oleate internal plasticizer was obtained.
[0030] Preparation of SG5 type PVC film modified by epoxy 1,6-hexanediol oleate internal plasticizer: Add 6g of SG5 type PVC material modified by epoxy 1,6-hexanediol oleate internal plasticizer and 150ml of tetrahydrofuran into a 250ml beaker, stir magnetically until the solution is clear and transparent, pour it into a 150mm culture dish, and cover it with plastic wrap with small holes to prevent the solvent from evaporating too quickly. After standing for 24 hours, turn the film over, evaporate it at ambient temperature for 2 days, and then dry it in a constant temperature box at 50℃ for 3 days to remove the tetrahydrofuran, and finally cut it into strips for use.
[0031] Material performance test: Mechanical properties (elongation at break, tensile strength) are measured in accordance with GB / T 13022-91 under ambient conditions using an electronic tensile testing machine at a tensile rate of 50 mm / min. Dumbbell-shaped specimens are cut using a specific mold. The test length of each specimen is 25 mm (L) * 3.5 mm (W) * 0.2 mm (H). During the test, the average of five test results for each specimen is taken as the final test result.
[0032] Dynamic mechanical analysis (DMA) was performed on PVC films using a dynamic thermomechanical analyzer. Rectangular specimens (30 mm*5 mm*1 mm) were tested in tensile mode at a fixed frequency of 1 Hz and heated from -40°C to 80°C at a rate of 10°C / min. Table 1 shows the effects of different plasticizers on the properties of SG5 type PVC composites.
[0033] Table 1
[0034]
[0035]
[0036] From the data in Table 1, it can be seen that the internal molecular chains of SG5 PVC are difficult to move freely, resulting in the hard and brittle texture of pure PVC material. The tensile strength and elongation at break of the SG5 PVC after plasticization in Example 2 are higher than those of the PVC plasticized in Example 1, indicating that a certain plasticizing effect has been achieved. Compared with the tensile strength and elongation at break of the plasticized PVC in Example 3 and Example 1, the plasticizing effect of Example 3 is better. This shows that the PVC material after internal plasticization modification of epoxy 1,6-hexanediol oleate is more effective in improving the mechanical properties of the plasticized film, and a larger movable space appears between the PVC chains after grafting, which enhances the mechanical properties of the material.
[0037] Figure 1 It is the DMA curve of the materials prepared by SG5 PVC, Example 1, Example 2, and Example 3. Whether SG5 PVC products can be used normally in a low-temperature environment depends on whether the plasticizer can have a good plasticizing effect in the environment. The cold resistance of the SG5 PVC sample can be evaluated by the glass transition temperature (Tg). Generally, the lower the Tg of the SG5 PVC test piece after plasticization, the better the flexibility at low temperatures, that is, the better the cold resistance. The Tg of different test pieces can be accurately tested by DMA. It can be seen that the Tanδ curves of the four SG5 PVC test pieces have only one peak, indicating that the compatibility between the four plasticizers and SG5 PVC is good. It can be seen from Table 1 that the Tg of the SG5 PVC film plasticized in Example 2 is 23.05°C, which enhances the cold resistance of the SG5 PVC material to a certain extent. The Tg of the plasticized SG5 PVC film in Example 3 is much lower than that of the pure SG5 PVC, and is 6.03°C lower than that in Example 2, indicating that the plasticizer in Example 3 can improve the cold resistance of the SG5 PVC, mainly because: the introduction of flexible side groups into the polymer chains with greater rigidity can reduce their Tg, and the larger the flexible side groups, the greater the flexibility of the entire molecule, and the lower the Tg. Since epoxy 1,6-hexanediol oleate has a flexible long chain of C24, when epoxy 1,6-hexanediol oleate is introduced into the SG5 PVC macromolecular chain, the flexibility of the molecular chain is greatly increased, compensating for the steric effect caused by the size of the substituent, and the macroscopic performance is a significant reduction in Tg. Therefore, the SG5 PVC material modified by epoxy 1,6-hexanediol oleate has excellent cold resistance.
[0038] The present invention discloses a simple synthesis process, using epoxy 1,6-hexanediol oleate as a modified material, and successfully preparing an epoxy 1,6-hexanediol oleate internal plasticization modified SG5 type PVC material through a thiosalicylic acid nucleophilic reaction and a ring-opening reaction, and preparing the material into a film to obtain an SG5 type PVC material with good mechanical properties and excellent cold resistance, thereby further improving the comprehensive performance of the SG5 type PVC material.
[0039] Those skilled in the art will appreciate that the above embodiments are merely exemplary embodiments and that various changes, substitutions, and alterations may be made without departing from the spirit and scope of the present disclosure.
Claims
1. A method for preparing a modified SG5 type polyvinyl chloride (PVC) film, characterized in that: include: Step 1: Grafting thiosalicylic acid as an intermediate onto SG5 type polyvinyl chloride to obtain thiosalicylic acid grafted polyvinyl chloride; Step 2: using N,N-dimethylbenzylamine as a catalyst and chloroform as a solvent to react thiosalicylic acid grafted polyvinyl chloride and epoxy 1,6-hexanediol oleate, and then using methanol to precipitate and wash the product to obtain epoxy 1,6-hexanediol oleate modified SG5 type polyvinyl chloride; Step 3: dissolving the SG5 polyvinyl chloride modified by epoxy 1,6-hexanediol oleate, standing, evaporating and drying to obtain the SG5 polyvinyl chloride film modified by epoxy 1,6-hexanediol oleate internal plasticization.
2. The method for preparing the modified SG5 type polyvinyl chloride film according to claim 1, characterized in that: In step 1, 10-12 grams of SG5 polyvinyl chloride and 250 mL of cyclohexanone are added to a container, and the mixture is stirred at room temperature until it is completely dissolved; 20-25 grams of thiosalicylic acid and 26-28 grams of potassium carbonate are added to the mixture, and the mixture is placed in a water bath and set to a temperature of 60° C. and stirred for reaction for 30-35 hours, and nitrogen is introduced to keep the internal reaction in a nitrogen environment, and then washed with methanol solution, and vacuum dried to obtain thiosalicylic acid grafted polyvinyl chloride.
3. The method for preparing the modified SG5 type polyvinyl chloride film according to claim 1, characterized in that: In step 2, 5-10 g of thiosalicylic acid grafted polyvinyl chloride, 25-28 g of epoxy 1,6-hexanediol oleate, and 1.5 ml of N,N-dimethylbenzylamine are dissolved in 350 ml of chloroform, placed in a water bath and set to a temperature of 60-80° C., stirred for reaction for 24-30 h, and after methanol precipitation and vacuum drying, SG5 polyvinyl chloride modified with epoxy 1,6-hexanediol oleate is obtained.
4. The method for preparing the modified SG5 type polyvinyl chloride film according to claim 1, characterized in that: In step 3, 6-9 g of SG5 polyvinyl chloride modified with epoxy 1,6-hexanediol oleate and 150 ml of tetrahydrofuran are added to a container, and after magnetic stirring until the solution is clear and transparent, it is poured into a culture dish and covered with plastic wrap. After standing for 24-32 hours, the film is turned over and evaporated at ambient temperature for 2-4 days, and then dried in a constant temperature box at 50-70°C for 3-5 days to remove the tetrahydrofuran, and finally cut into strips for use.
5. A modified SG5 polyvinyl chloride film, wherein the modified SG5 polyvinyl chloride film is prepared according to the method for preparing the modified SG5 polyvinyl chloride film according to any one of claims 1 to 4.