Preparation process of thermal-insulation high-toughness PET-PE composite material

Abstract

The invention relates to the technical field of plastic alloy, and discloses a preparation process of a thermal-insulation high-toughness PET-PE composite material, and the thermal-insulation high-toughness PET-PE composite material is obtained by melting, blending, extruding and pelletizing 10-25 parts by weight of polyethylene glycol terephthalate, 75-90 parts by weight of polyethylene resin, 5-30 parts by weight of PET grafted silicon dioxide aerogel and the like. A polyethylene glycol terephthalate molecular chain is grafted on the surface of the silicon dioxide aerogel, and meanwhile, a fat long carbon chain similar to polyethylene resin is bonded through a glue bond, so that the silicon dioxide aerogel has good interfacial compatibility with PET and PE polyethylene resin in the composite material, and the composite material keeps good bending strength and impact strength; meanwhile, the silicon dioxide aerogel is uniformly dispersed in a composite material matrix to form a continuous heat insulation network, so that the heat conductivity of the composite material is reduced, and the composite material has good heat preservation and heat insulation performance.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic alloys, and specifically to a preparation process of a heat-insulating and high-toughness PET-PE composite material. Background Art

[0002] Polyethylene has excellent electrical insulation, high and low temperature resistance, flexibility and other advantages; polyethylene terephthalate (PET) has high mechanical strength, strong high-temperature resistance, and good chemical stability. Blending polyethylene and polyethylene terephthalate can produce plastic alloys with excellent properties, which are widely used in the fields of automobiles, electronic appliances, precision instruments, packaging materials, etc. Polyethylene, polyethylene terephthalate and their composite alloy materials have relatively large thermal conductivities and poor heat-insulating properties, which are not conducive to their practical applications in the fields of heat-insulating packaging, heat-insulating plates, etc.

[0003] The preparation method of silica aerogel is simple, inexpensive and easy to obtain, and it has a porous structure and low thermal conductivity, and has important applications in heat-insulating materials. However, the compatibility between silica aerogel and polymer materials such as polyethylene and polyethylene terephthalate is poor, and the mechanical strength of the aerogel is low, which has a great impact on the mechanical properties of the materials. Chinese Patent CN118496545B discloses a fragrant polyethylene garbage bag and its preparation method, using porous silica aerogel as a carrier for natural plant essential oils, then loading a polydopamine outer layer on the surface of the aerogel, and then grafting composite quaternized polyethyleneimine, and extruding and blowing with polyethylene to obtain a fragrant polyethylene garbage bag with water resistance and antibacterial properties. However, this patent does not solve the problem of large thermal conductivity and poor heat-insulating performance of polyethylene. Summary of the Invention

[0004] (1) Solved Technical Problem: Aiming at the deficiencies of the prior art, the present invention provides a preparation process of a heat-insulating and high-toughness PET-PE composite material, which solves the problem of poor heat-insulating and heat-protecting performance of PET-PE composite materials.

[0005] (2) Technical Solution: A preparation process of a heat-insulating and high-toughness PET-PE composite material:

[0006] (1) Molding polyethylene terephthalate into a film sheet, putting it into a plasma processor, and performing plasma treatment in an ammonia atmosphere, with an ammonia gas flow rate of 100-200 mL / min, a discharge power of 50-80 W, and a treatment time of 10-20 min to obtain amino-functionalized polyethylene terephthalate.

[0007] (2) Adding KH550 to water, performing ultrasonic treatment in an ultrasonic instrument and heating to 45-55 °C, adding silica aerogel, reacting for 10-20 min, drying to remove water, washing with ethanol, and drying to obtain KH550-silica aerogel.

[0008] (3) Add 5-aminoisophthalic acid, fatty acyl chloride, and a catalyst with a molar ratio of 1:(1 - 1.4):(3 - 3.6) to a solvent, stir and react at 20 - 30 °C for 18 - 24 h, distill under reduced pressure, and recrystallize the product from chloroform to obtain 5-(fatty acid ester)isophthalic acid. The reaction formula is:

[0009]

[0010] (4) Add aminated polyethylene terephthalate, KH550-silica aerogel, and 5-(fatty acid ester)isophthalic acid to a screw extruder, melt-blend and extrude to obtain PET grafted silica aerogel.

[0011] (5) Add 10 - 25 parts by weight of polyethylene terephthalate, 75 - 90 parts by weight of polyethylene resin, 5 - 30 parts by weight of PET grafted silica aerogel, and 0.2 - 0.3 parts by weight of antioxidant to a screw extruder, melt-blend and extrude, and pelletize to obtain a heat-insulating and high-toughness PET-PE composite material.

[0012] Preferably, in (3), the solvent is N,N-dimethylformamide or tetrahydrofuran.

[0013] Preferably, in (3), the structural formula of the fatty acyl chloride is C n H 2n+1 COCl, where n is from 11 to 17.

[0014] Preferably, in (3), the catalyst is pyridine or 4-dimethylaminopyridine.

[0015] Preferably, in (4), the dosage of aminated polyethylene terephthalate is 100 parts by weight, the KH550-silica aerogel is 20 - 40 parts by weight, and 5-(fatty acid ester)isophthalic acid is 3 - 8 parts by weight.

[0016] Preferably, in (4), the temperature of the 1st - 5th sections of the screw extruder is 240 - 270 °C, and the screw speed is 30 - 60 r / min.

[0017] Preferably, in (5), the temperature of the 1st - 5th sections of the screw extruder is 180 - 265 °C, and the screw speed is 50 - 100 r / min.

[0018] (III) Beneficial technical effects: In the present invention, aminated polyethylene terephthalate, KH550-silica aerogel, and 5-(palmitate) isophthalic acid are melt-blended at high temperature. 5-(Palmitate) isophthalic acid contains two carboxyl groups, which respectively undergo amidation reactions with the amino groups of polyethylene terephthalate and silica aerogel, thereby grafting polyethylene terephthalate molecular chains onto the surface of silica aerogel, achieving the coating effect on silica aerogel. Moreover, 5-(palmitate) isophthalic acid contains long fatty carbon chains, and the long fatty carbon chains are chemically bonded into the PET-grafted silica aerogel.

[0019] In the present invention, polyethylene resin, polyethylene terephthalate, and PET-grafted silica aerogel are melt-blended to obtain a PET-PE composite material. Since the surface of silica aerogel is grafted with polyethylene terephthalate molecular chains, silica aerogel has good interfacial compatibility with PET in the composite material. At the same time, PET-grafted silica aerogel chemically bonds long fatty carbon chains similar to polyethylene resin, so that silica aerogel also has good interfacial compatibility with PE polyethylene resin in the composite material, and improves the dispersibility of the aerogel. The compatibility of silica aerogel with the PET-PE composite material is excellent, and has little influence on the mechanical properties of the composite material, enabling the material to still maintain good flexural strength and impact strength. At the same time, it is evenly dispersed in the composite matrix to form a continuous heat insulation network, reducing the thermal conductivity of the composite material and having good heat insulation and heat preservation properties. Specific embodiments

[0020] The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0021] The model of polyethylene terephthalate is K2012, from Dongguan Weicai Plastic Raw Materials Co., Ltd. The model of polyethylene resin is HMA-0...

[0022] Example 1:

[0023] (1) Mould the polyethylene terephthalate into a film sheet, put it into a plasma treatment instrument, and carry out plasma treatment in an ammonia atmosphere. The ammonia gas flow rate is 200 mL / min, the discharge power is 70 W, and the treatment time is 10 min to obtain aminated polyethylene terephthalate.

[0024] (2) Add 15 g of KH550 to 400 mL of water, perform ultrasonic treatment in an ultrasonic instrument and heat to 50 °C. Add 50 g of silica aerogel, react for 15 min, dry to remove water, wash with ethanol, and dry to obtain KH550-silica aerogel.

[0025] (3) Add 20 mmol of 5-aminoisophthalic acid, 24 mmol of palmitoyl chloride, and 60 mmol of 4-dimethylaminopyridine to 80 mL of N,N-dimethylformamide, stir and react at 20 °C for 24 h, perform reduced pressure distillation, and recrystallize the product from chloroform to obtain 5-(palmitate)isophthalic acid. The structural formula is:

[0026]

[0027] (4) Add 100 g of aminated polyethylene terephthalate, 20 g of KH550-silica aerogel, and 3 g of 5-(palmitate)isophthalic acid to a screw extruder. The temperatures of the 1st - 5th sections are 240 °C, 260 °C, 270 °C, 270 °C, 265 °C, the screw speed is 50 r / min, and melt-blend and extrude to obtain PET grafted silica aerogel.

[0028] (5) Add 100 g of polyethylene terephthalate, 900 g of polyethylene resin, 50 g of PET grafted silica aerogel, and 3 g of antioxidant 1076 to a screw extruder. The temperatures of the 1st - 5th sections are 180 °C, 245 °C, 260 °C, 265 °C, 265 °C, the screw speed is 50 r / min, melt-blend and extrude, and pelletize to obtain a heat-insulating and high-toughness PET-PE composite material.

[0029] Comparative Example 1:

[0030] (1) Add 100 g of polyethylene terephthalate, 20 g of silica aerogel, and 3 g of 5-(palmitate)isophthalic acid (prepared in Example 1) to a screw extruder. The temperatures of the 1st - 5th sections are 240 °C, 260 °C, 270 °C, 270 °C, 265 °C, the screw speed is 50 r / min, and melt-blend and extrude to obtain PET-silica aerogel.

[0031] (2) Add 100 g of polyethylene terephthalate, 900 g of polyethylene resin, 50 g of PET-silica aerogel, and 3 g of antioxidant 1076 to a screw extruder. The temperatures of the 1st - 5th sections are 180 °C, 245 °C, 260 °C, 265 °C, 265 °C, the screw speed is 50 r / min, melt-blend and extrude, and pelletize to obtain a heat-insulating and high-toughness PET-PE composite material.

[0032] Comparative Example 2:

[0033] (1) Add 100 g of polyethylene terephthalate, 20 g of KH550-silica aerogel (prepared in Example 1), and 3 g of 5-(palmitate) isophthalic acid (prepared in Example 1) to a screw extruder. The temperatures of the 1st - 5th sections are 240 °C, 260 °C, 270 °C, 270 °C, and 265 °C, and the screw speed is 50 r / min. Carry out melt blending and extrusion to obtain PET-silica aerogel.

[0034] (2) Add 100 g of polyethylene terephthalate, 900 g of polyethylene resin, 50 g of PET-silica aerogel, and 3 g of antioxidant 1076 to a screw extruder. The temperatures of the 1st - 5th sections are 180 °C, 245 °C, 260 °C, 265 °C, and 265 °C, and the screw speed is 50 r / min. Carry out melt blending and extrusion, and pelletize to obtain a heat-insulating and high-toughness PET-PE composite material.

[0035] Comparative Example 3:

[0036] (1) Add 100 g of amino-functionalized polyethylene terephthalate (prepared in Example 1), 20 g of silica aerogel, and 3 g of 5-(palmitate) isophthalic acid (prepared in Example 1) to a screw extruder. The temperatures of the 1st - 5th sections are 240 °C, 260 °C, 270 °C, 270 °C, and 265 °C, and the screw speed is 50 r / min. Carry out melt blending and extrusion to obtain PET-silica aerogel.

[0037] (2) Add 100 g of polyethylene terephthalate, 900 g of polyethylene resin, 50 g of PET-silica aerogel, and 3 g of antioxidant 1076 to a screw extruder. The temperatures of the 1st - 5th sections are 180 °C, 245 °C, 260 °C, 265 °C, and 265 °C, and the screw speed is 50 r / min. Carry out melt blending and extrusion, and pelletize to obtain a heat-insulating and high-toughness PET-PE composite material.

[0038] Comparative Example  4:

[0039] (1) Add 100 g of amino-functionalized polyethylene terephthalate (prepared in Example 1), 20 g of KH550-silica aerogel (prepared in Example 1), and 3 g of isophthalic acid to a screw extruder. The temperatures of the 1st - 5th sections are 240 °C, 260 °C, 270 °C, 270 °C, and 265 °C, and the screw speed is 50 r / min. Carry out melt blending and extrusion to obtain PET-grafted silica aerogel.

[0040] (2) Add 100 g of polyethylene terephthalate, 900 g of polyethylene resin, 50 g of PET-grafted silica aerogel, and 3 g of antioxidant 1076 into a screw extruder. The temperatures of the 1st - 5th sections are 180 °C, 245 °C, 260 °C, 265 °C, and 265 °C respectively, and the screw speed is 50 r / min for melt blending and extrusion, followed by pelletizing to obtain the heat-insulating and high-toughness PET-PE composite material.

[0041] Example 2:

[0042] (1) Mould polyethylene terephthalate into a film sheet, place it in a plasma processor, and perform plasma treatment in an ammonia atmosphere. The ammonia flow rate is 150 mL / min, the discharge power is 50 W, and the treatment time is 20 min to obtain amino-functionalized polyethylene terephthalate.

[0043] (2) Add 20 g of KH550 into 500 mL of water, perform ultrasonic treatment in an ultrasonic instrument and heat to 55 °C, then add 50 g of silica aerogel, react for 10 min, remove water by drying, wash with ethanol, and then dry to obtain KH550-silica aerogel.

[0044] (3) Add 20 mmol of 5-aminoisophthalic acid, 20 mmol of stearoyl chloride, and 60 mmol of pyridine into 60 mL of tetrahydrofuran, stir and react at 30 °C for 18 h, perform vacuum distillation, and recrystallize the product from chloroform to obtain 5-(stearate) isophthalic acid. The structural formula is

[0045] (4) Add 100 g of amino-functionalized polyethylene terephthalate, 30 g of KH550-silica aerogel, and 5 g of 5-(stearate) isophthalic acid into a screw extruder. The temperatures of the 1st - 5th sections are 240 °C, 260 °C, 270 °C, 270 °C, and 265 °C respectively, and the screw speed is 30 r / min for melt blending and extrusion to obtain PET-grafted silica aerogel.

[0046] (5) Add 200 g of polyethylene terephthalate, 800 g of polyethylene resin, 180 g of PET-grafted silica aerogel, and 3 g of antioxidant 1076 into a screw extruder. The temperatures of the 1st - 5th sections are 180 °C, 245 °C, 260 °C, 265 °C, and 265 °C respectively, and the screw speed is 100 r / min for melt blending and extrusion, followed by pelletizing to obtain the heat-insulating and high-toughness PET-PE composite material.

[0047] Example 3:

[0048] (1) Polyethylene terephthalate was molded into a film sheet and placed in a plasma processor. Plasma treatment was carried out in an ammonia atmosphere with an ammonia gas flow rate of 100 mL / min, a discharge power of 80 W, and a treatment time of 20 min to obtain amino-functionalized polyethylene terephthalate.

[0049] (2) 25 g of KH550 was added to 500 mL of water, ultrasonicated in an ultrasonic instrument and heated to 45 °C. 50 g of silica aerogel was added and reacted for 20 min. After drying to remove water, it was washed with ethanol and then dried to obtain KH550-silica aerogel.

[0050] (3) 20 mmol of 5-aminoisophthalic acid, 28 mmol of lauroyl chloride, and 72 mmol of 4-dimethylaminopyridine were added to 80 mL of N,N-dimethylformamide, and the mixture was stirred and reacted at 25 °C for 24 h. Then, it was distilled under reduced pressure, and the product was recrystallized from chloroform to obtain 5-(laurate) isophthalic acid. The structural formula is:

[0051] (4) 100 g of amino-functionalized polyethylene terephthalate, 40 g of KH550-silica aerogel, and 8 g of 5-(laurate) isophthalic acid were added to a screw extruder. The temperatures of the 1st - 5th zones were 240 °C, 260 °C, 270 °C, 270 °C, and 265 °C, and the screw rotation speed was 60 r / min. They were melt-blended and extruded to obtain PET grafted silica aerogel.

[0052] (5) 250 g of polyethylene terephthalate, 750 g of polyethylene resin, 300 g of PET grafted silica aerogel, and 2 g of antioxidant 1076 were added to a screw extruder. The temperatures of the 1st - 5th zones were 180 °C, 245 °C, 260 °C, 265 °C, and 265 °C, and the screw rotation speed was 100 r / min. They were melt-blended and extruded, and then pelletized to obtain a heat-insulating and high-toughness PET-PE composite material.

[0053] The PET-PE composite material was injection-molded in an injection molding machine with the temperatures of the 1st - 3rd zones being 240 °C, 260 °C, and 270 °C to make specimens. The thermal conductivity was tested according to the ASTM D5930-09 standard. The impact strength was tested according to the GB / T 1843-2008 standard. The flexural strength was tested according to the GB / T 9341-2008 standard.

[0054] Table 1 Performance Test of PET-PE Composite Material

[0055]

[0056] After testing, the thermal conductivity of the PET-PE composite material in Example 1 was only 0.1729 W·m -1 ·K-1 , excellent thermal insulation, and the bending strength reaches 35.70MPa, the impact strength reaches 9.16kJ / m 2 The mechanical properties are excellent, mainly because in the high-temperature melt blending process, 5-(palmitate) isophthalic acid contains two carboxyl groups, which react with the amino groups of polyethylene terephthalate and the amino groups of KH550-silica aerogel to undergo amidation reaction, thereby grafting the polyethylene terephthalate molecular chain on the surface of the silica aerogel, achieving the coating effect on the silica aerogel, and 5-(palmitate) isophthalic acid contains a long aliphatic carbon chain, and the long aliphatic carbon chain is chemically bonded to the PET grafted silica aerogel, which is further melt-blended with polyethylene resin and polyethylene terephthalate to obtain a PET-PE composite material. Due to the grafting of the silica aerogel surface The polyethylene terephthalate molecular chain makes the silica aerogel have good interface compatibility with the PET in the composite material. At the same time, the PET-grafted silica aerogel is chemically bonded with a long fatty carbon chain similar to the polyethylene resin, which makes the silica aerogel and the PE polyethylene resin in the composite material also have good interface compatibility and improves the dispersibility of the aerogel. The silica aerogel has excellent compatibility with the PET-PE composite material and has little effect on the mechanical properties of the composite material, so that the material still maintains good bending strength and impact strength. At the same time, it is evenly dispersed in the composite material matrix to form a continuous thermal insulation network, which reduces the thermal conductivity of the composite material and has good thermal insulation properties.

[0057] Compared with Example 1, the polyethylene terephthalate and silica aerogel of Comparative Example 1 do not contain amino groups and cannot react with 5-(palmitate)isophthalic acid. Polyethylene terephthalate is not grafted into the silica aerogel, and no fatty long carbon chains are chemically bonded in the PET-silica aerogel. As a result, the PET-silica aerogel has poor compatibility with PET and PE polyethylene resins, poor dispersibility in the composite material, a significant impact on the mechanical properties of the composite material, low flexural strength and impact strength, high thermal conductivity, and poor thermal insulation performance.

[0058] The polyethylene terephthalate of Comparative Example 2 does not contain amino groups. Grafting polyethylene terephthalate onto silica aerogel results in poor compatibility between the PET-silica aerogel and the PET in the composite material. The flexural strength and impact strength of the composite material are lower than those in Example 1, and the thermal conductivity is large, resulting in poor thermal insulation performance.

[0059] The silica aerogel of Comparative Example 3 does not contain amino groups, and polyethylene terephthalate cannot be grafted into the silica aerogel through 5-(palmitate)isophthalic acid. As a result, the silica aerogel has poor compatibility with the PET and PE polyethylene resins in the composite material, poor dispersion in the composite material, a significant impact on the mechanical properties of the composite material, low flexural strength and impact strength, high thermal conductivity, and poor thermal insulation performance.

[0060] The isophthalic acid in Comparative Example 4 does not contain a long fatty carbon chain, resulting in poor compatibility between the PET grafted silica aerogel and the PE polyethylene resin in the composite material, resulting in lower bending strength and impact strength than Example 1, and higher thermal conductivity and poor thermal insulation performance.

[0061] The present invention is not limited to the above-mentioned embodiments. Any modification, improvement, or substitution that can be conceived by those skilled in the art without departing from the essential content of the present invention shall fall within the scope of the present invention.

Claims

1. A preparation process of a heat-insulating and highly tough PET-PE composite material, characterized in that, The preparation process includes: Step (1): Add aminated polyethylene terephthalate, KH550-silica aerogel, and 5-(fatty acid ester)isophthalic acid into a screw extruder, melt and blend them for extrusion to obtain PET grafted silica aerogel; Step (2): Add 10-25 parts by weight of polyethylene terephthalate, 75-90 parts by weight of polyethylene resin, 5-30 parts by weight of PET grafted silica aerogel, and 0.2-0.3 parts by weight of antioxidant into a screw extruder, melt and blend them for extrusion, and pelletize to obtain a heat-insulating and high-toughness PET-PE composite material.

2. The preparation process of the heat-insulating and high-toughness PET-PE composite material according to claim 1, wherein In the above (1), the dosage of aminated polyethylene terephthalate is 100 parts by weight, the KH550-silica aerogel is 20-40 parts by weight, and the 5-(fatty acid ester)isophthalic acid is 3-8 parts by weight.

3. The preparation process of the heat-insulating and high-toughness PET-PE composite material according to claim 1, characterized in that, In the above (1), the temperature of the 1st to 5th sections of the screw extruder is 240-270 °C, and the screw speed is 30-60 r / min.

4. The preparation process of the heat-insulating and high-toughness PET-PE composite material according to claim 1, characterized in that, In the above (2), the temperature of the 1st to 5th sections of the screw extruder is 180-265 °C, and the screw speed is 50-100 r / min.

5. The preparation process of the heat-insulating and high-toughness PET-PE composite material according to claim 2, characterized in that, The preparation process of the aminated polyethylene terephthalate includes: Molding polyethylene terephthalate into a film sheet, putting it into a plasma processor, and performing plasma treatment in an ammonia atmosphere. The ammonia flow rate is 100-200 mL / min, the discharge power is 50-80 W, and the treatment time is 10-20 min to obtain aminated polyethylene terephthalate.

6. The preparation process of the heat-insulating and high-toughness PET-PE composite material according to claim 2, characterized in that, The preparation process of the KH550-silica aerogel is: Add KH550 into water, ultrasonically treat it in an ultrasonic instrument and heat it to 45-55 °C, add silica aerogel, react for 10-20 min, dry to remove water, wash and then dry to obtain KH550-silica aerogel.

7. The preparation process of the heat-insulating and high-toughness PET-PE composite material according to claim 2, characterized in that, The preparation process of the 5-(fatty acid ester)isophthalic acid includes: Add 5-aminophthalic acid, fatty acyl chloride, and a catalyst with a molar ratio of 1:(1-1.4):(3-3.6) into a solvent, stir and react at 20-30 °C for 18-24 h, perform vacuum distillation, and recrystallize the product to obtain 5-(fatty acid ester)isophthalic acid.

8. The preparation process of the heat-insulating and high-toughness PET-PE composite material according to claim 7, characterized in that, The solvent is N,N-dimethylformamide or tetrahydrofuran.

9. The preparation process of the heat-insulating and high-toughness PET-PE composite material according to claim 7, characterized in that, The structural formula of the fatty acyl chloride is C n H 2n+1 COCl, where n is 11 - 17.

10. The preparation process of the heat-insulating and high-toughness PET-PE composite material according to claim 7, characterized in that, The catalyst is pyridine or 4-dimethylaminopyridine.

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