A polyethylene naphthalate composite material with high impact strength and a preparation method thereof

Abstract

The present invention discloses a polyethylene naphthalate composite material with high impact strength and a preparation method thereof, belonging to the field of composite materials. The preparation method includes: by mass parts, mixing 100 parts of polyethylene naphthalate, 10 - 40 parts of polyacrylate elastomer, 0.5 - 1.5 parts of heat stabilizer, and 0.5 - 1 part of antioxidant assistant uniformly, and melt-extruding to obtain the polyethylene naphthalate composite material with high impact strength. In the present invention, the polyacrylate elastomer with low crosslinking density is dispersed into the PEN resin to form a phase morphology with the characteristic of low matrix ligament thickness. This morphology can effectively increase the ductility of PEN, enabling it to exhibit better energy absorption and deformation ability under impact, thereby avoiding brittle fracture. The polyethylene naphthalate composite material provided by the present invention has excellent comprehensive performance, a simple preparation process, and easily available raw materials, and has broad prospects for industrial application.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material preparation, and particularly relates to a polyethylene naphthalate composite material with high impact strength and a preparation method thereof. Background Art

[0002] Polyethylene naphthalate (PEN) resin is a high-performance polyester material made from the monomers 2,6-naphthalate and ethylene glycol through polycondensation. PEN resin has the characteristics of high modulus, high strength and heat resistance, and is one of the most ideal engineering plastics. Therefore, as one of the emerging chemical materials that the Ministry of Industry and Information Technology and other departments have clearly pointed out to be vigorously developed, PEN resin has made significant progress in research and development and application in recent years, and is widely used in infrastructure construction, smart construction, impact-resistant fabrics, national defense and military industry, smart cars, smart sensors and other fields. This material is regarded as one of the most promising polymer materials in the 21st century due to its excellent physical and chemical properties.

[0003] The reason why PEN resin exhibits excellent performance in many applications is mainly attributed to its naphthalene ring structure. The naphthalene ring is a highly rigid aromatic ring structure, and its presence makes the PEN molecular chain more rigid. Compared with polyethylene terephthalate (PET), this improvement in rigidity brings significant performance advantages in thermal properties, mechanical properties, solvent resistance, and radiation resistance to PEN. Although PEN has many excellent properties mentioned above, due to the high rigidity of the naphthalene ring in its molecular chain, it is difficult for PEN products to undergo plastic deformation and break after being subjected to force, and the macroscopic manifestation is low impact strength, which seriously restricts its industrial application. The high rigidity of the molecular chain means that it is difficult for the chain segments to rotate and deform freely under the action of external forces, resulting in greater brittleness of the material, especially poor impact resistance when subjected to impact. High modulus and low toughness are typical characteristics of PEN resin. Although its high modulus makes the material outstanding in rigidity, its low toughness limits its application in high impact load or deformation environments. The disadvantage of insufficient impact strength has particularly limited the widespread application of PEN in automotive parts, electronic and electrical housings, and certain packaging materials, which usually require the material to have a certain degree of flexibility to cope with complex environmental stresses and impact loads. Therefore, improving the toughness of PEN to achieve its wider application scenarios has become an important topic in the field of materials research.

[0004] The results show that melt blending with another elastomeric material is one of the most effective and common toughening methods to date. During the blending process, the elastomeric material can absorb and disperse stress by forming a dispersed phase, thereby effectively improving the toughness of the material. For example, significant progress has been made in the study of PET toughening, providing a good reference: Patent CN1279115C uses an elastomer containing epoxy groups as a toughening phase, which effectively improves the impact strength after melt blending with PET; CN102382432A melt blends a thermoplastic polyurethane elastomer with a PET resin to obtain a high-toughness PET composite material; CN105482387B blends PET with a thermoplastic elastomer to obtain a transparent PET sheet with high impact strength.

[0005] However, although the research in the field of PET toughening is relatively mature, the research on toughening of PEN resin is still in its early stages. Existing research work is more focused on the performance enhancement of PEN film materials, such as improving its barrier properties, thermal stability and UV resistance, but there are relatively few studies on improving the toughness of PEN. For example, the CN103396658A patent proposes a method of melt-blending an elastomer and glass fiber with a PEN resin at the same time to prepare a PEN composite material with high strength and high modulus. However, the composite material is still limited in improving the impact strength, showing that there is still great research potential and room for improvement in the direction of toughening.

[0006] With the increasing requirements for material performance in the automotive, electronic appliances, smart devices and other industries, especially the high requirements for toughness and impact resistance, designing suitable elastomers to toughen PEN resins has become a technical problem that needs to be solved urgently. The blending of elastomers and PEN resins should not only consider improving impact toughness, but also maintain or minimize the impact on other excellent properties of PEN, such as its high thermal stability, excellent chemical resistance and radiation resistance. Summary of the invention

[0007] In view of the problem of low impact strength of PEN resin in the prior art, the object of the present invention is to provide a high-impact-strength polyethylene naphthalate composite material and a preparation method thereof. The composite material prepared by the method has the properties of high strength, high modulus and high impact strength.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0009] A method for preparing a polyethylene naphthalate composite material with high impact strength comprises the following steps:

[0010] By mass parts, 100 parts of polyethylene naphthalate, 10 - 40 parts of polyacrylate elastomer, 0.5 - 1.5 parts of heat stabilizer, and 0.5 - 1 part of antioxidant auxiliary are mixed evenly and melt - extruded to obtain a polyethylene naphthalate composite material with high impact strength.

[0011] A further improvement of the present invention lies in that the polyacrylate elastomer is prepared through the following process: By mass parts, 30 - 50 parts of butyl acrylate, 30 - 50 parts of methyl methacrylate, 5 - 30 parts of 2 - hydroxyethyl methacrylate, 1 - 30 parts of glycidyl methacrylate, 0.5 - 1.5 parts of oil - soluble initiator, and 200 parts of solvent are subjected to a polymerization reaction to obtain a polyacrylate solution; the polyacrylate solution is subjected to a self - crosslinking reaction under heating to obtain the polyacrylate elastomer.

[0012] A further improvement of the present invention lies in that the oil - soluble initiator is one of azobisisobutyronitrile, benzoyl peroxide, and di - tert - butyl peroxide.

[0013] A further improvement of the present invention lies in that the solvent is one or a mixture of two of toluene, xylene, mesitylene, ethyl acetate, and butyl acetate.

[0014] A further improvement of the present invention lies in that the temperature of the polymerization reaction is 70 - 130 °C and the time is 2 - 6 h.

[0015] A further improvement of the present invention lies in that the temperature of the self - crosslinking reaction is 200 - 300 °C and the time is 0.2 - 2 h.

[0016] A further improvement of the present invention lies in that the heat stabilizer is one of triphenyl phosphate, triphenyl phosphite, and diphenyl phosphate.

[0017] A further improvement of the present invention lies in that the antioxidant auxiliary is one of tris(2,4 - di - tert - butylphenyl) phosphite, distearyl disulfide, didodecyl disulfide, and antioxidant 1010.

[0018] A further improvement of the present invention lies in that the melt - extrusion is carried out in a twin - screw extruder. The temperatures of the first zone, second zone, third zone, fourth zone, fifth zone, and die head of the twin - screw extruder are 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence; the rotational speed of the extruder screw is 10 - 60 rpm; the rotational speed of the feeder is 1 - 6 rpm.

[0019] A polyethylene naphthalate composite material with high impact strength, the impact strength of the composite material is 80 - 135 kJ / m 2 and the tensile strength is 70 - 90 MPa, the Young's modulus is 1.8 - 2.5 GPa, and the temperature at 2% mass loss is > 300 °C.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] (1) Significantly improve the impact toughness. The present invention provides a polyacrylate elastomer with a low cross-linking structure, which can effectively improve the impact toughness of the composite material, increasing the impact strength of PEN from 2.0 kJ / m 2 to 80 - 135 kJ / m 2 , an increase of 40 - 62.5 times, showing great potential for industrial application.

[0022] (2) Improve the processing performance. The introduction of the polyacrylate elastomer can also improve the processing fluidity of the PEN material. The toughened PEN material is more easily molded during the processing, especially the injection molding and extrusion molding processes are optimized. This enables the material to better meet the processing requirements during the production of products with complex shapes, improving the production efficiency and product quality.

[0023] Further, the tensile strength and modulus have less loss. The polyacrylate elastomer provided by the present invention is prepared by butyl acrylate, methyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate and an oil-soluble initiator, and has a low cross-linking structure with a strength higher than that of linear elastomers. Therefore, the mechanical strength and modulus of the composite material obtained by blending with PEN have less loss, overcoming the problem that the blending of an elastomer as a soft material with PEN inevitably causes a loss of tensile strength and modulus.

[0024] Further, the heat resistance is retained. The polyacrylate elastomer provided by the present invention is prepared by first performing a polymerization reaction and then a self-crosslinking reaction, and has excellent heat resistance. After blending with PEN, it will not significantly reduce the melting point or glass transition temperature (Tg) of PEN, which enables the toughened PEN material to still be applicable to high-temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The infrared spectrum of the low cross-linking polyacrylate elastomer provided by the present invention;

[0026] Figure 2 The thermogravimetric curve of the high impact strength polyethylene naphthalate composite material disclosed by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be described more comprehensively below in conjunction with the embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0028] The present invention provides a method for preparing a polyethylene naphthalate (PEN) composite material with high impact strength, and the steps are as follows:

[0029] Preparation of low cross-linking density polyacrylate elastomer:

[0030] By mass, 30 - 50 parts of butyl acrylate, 30 - 50 parts of methyl methacrylate, 5 - 30 parts of 2-hydroxyethyl methacrylate, 1 - 30 parts of glycidyl methacrylate, 0.5 - 1.5 parts of oil-soluble initiator and 200 parts of solvent are put into a four-necked flask. After heating to 70 - 130 °C, react for 2 - 6 h, and after cooling, a polyacrylate solution is obtained; the solution is baked at 200 - 300 °C for 0.2 - 2 h to cause self-crosslinking reaction, and a low cross-linking density polyacrylate elastomer is obtained.

[0031] Further, the oil-soluble initiator is one of azobisisobutyronitrile, benzoyl peroxide and di-tert-butyl peroxide. The solvent is one of toluene, xylene, mesitylene, ethyl acetate and butyl acetate or a mixture of one or two of them.

[0032] Preparation of polyethylene naphthalate composite material with high impact strength:

[0033] By mass, 100 parts of polyethylene naphthalate, 10 - 40 parts of low cross-linking polyacrylate elastomer, 0.5 - 1.5 parts of heat stabilizer and 0.5 - 1 part of antioxidant assistant are mixed in a mixer for 5 - 10 min; then the material is added to a twin-screw extruder for melt extrusion. The temperatures of the first, second, third, fourth, fifth zones and the die head of the extruder are 275 °C, 280 °C, 280 °C, 280 °C, 280 °C and 275 °C in sequence; the screw speed of the extruder is 10 - 60 rpm; the feeding speed of the feeder is 1 - 6 rpm, and a polyethylene naphthalate (PEN) composite material with high impact strength is obtained.

[0034] Further, the heat stabilizer is one of triphenyl phosphate, triphenyl phosphite and diphenyl phosphate; the antioxidant assistant is one of tris(2,4-di-tert-butylphenyl) phosphite, distearyl disulfide, didodecyl disulfide and antioxidant 1010.

[0035] The performance evaluation method of the polyethylene naphthalate composite material is as follows:

[0036] Impact strength test: The polyethylene naphthalate composite material is hot-pressed into a test specimen in a metal mold with a notch. The impact strength of the test specimen is tested on a cantilever beam notch impact testing machine (HESON, HS-JB-500B) according to GB / T3808 - 2002, and tested in parallel three times, and the average value is recorded.

[0037] Tensile Strength and Young's Modulus Test: The polyethylene naphthalate composite material was hot-pressed into a mold to obtain test specimens. According to the method of GB / T 1040.1-2018, the stress-strain curve of the specimens was tested on a tensile testing machine (CMT1503). The parallel experiment was carried out three times, and the average values of the tensile strength and Young's modulus were recorded.

[0038] Thermogravimetric Test: The thermogravimetric curve of the sample was tested on a synchronous thermal analyzer (Netzsch, Sta 449F5), and the temperature at a 2% mass loss was recorded.

[0039] In industry, elastomers with a linear structure are commonly used as toughening agents, resulting in a significant loss of mechanical strength and modulus, up to more than 40%. The elastomer in the present invention has a low cross-linked structure and its own strength is higher than that of linear elastomers. Therefore, the mechanical strength and modulus of the composite material obtained by blending with PEN have less loss. The technical solution of the present invention will be described in detail through specific embodiments below:

[0040] Example 1

[0041] Preparation of Low Cross-Linked Density Polyacrylate Elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were added to a four-necked flask. After heating to 100 °C, the reaction was carried out for 4 h. After cooling, a polyacrylate solution was obtained. The solution was baked at 260 °C for 1 h to cause a self-crosslinking reaction, and a low cross-linked polyacrylate elastomer was obtained.

[0042] Preparation of High Impact Strength Polyethylene Naphthalate Composite Material: 100 g of polyethylene naphthalate, 15 g of low cross-linked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min. The mixed material was added to a twin-screw extruder and melt-extruded. The temperatures of the first, second, third, fourth, fifth zones, and the die head of the extruder were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence. The screw speed of the extruder was 40 rpm, and the feeding speed of the feeder was 3 rpm.

[0043] See Figure 1 , it can be seen that the stretching vibration peak of the hydroxyl group at 3420 cm -1 , the absorption peaks of methyl and methylene groups at 2950 cm -1 , the carbonyl absorption peak on the ester bond at 1720, and the absorption peak of the C-O-C group formed by the reaction of the hydroxyl group and epoxy at 1250 cm -1 , and the absorption peak at 822 cm -1This is the absorption peak of the epoxy group. The above infrared spectrum curve proves that the low-crosslinked polyacrylate elastomer has been successfully prepared.

[0044] See Figure 2 , it can be seen that the 2% thermal weight loss temperature of the polyethylene naphthalate composite prepared in Example 1 is 310 °C, indicating that the composite has good thermal stability.

[0045] Example 2

[0046] Preparation of low-crosslinked density polyacrylate elastomer: 30 g of butyl acrylate (BA), 50 g of methyl methacrylate (MMA), 10 g of 2-hydroxyethyl methacrylate (HEMA), 30 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were added to a four-necked flask. After heating to 100 °C, the reaction was carried out for 4 h. After cooling, a polyacrylate solution was obtained; the solution was baked at 260 °C for 1 h to cause self-crosslinking reaction, and a low-crosslinked polyacrylate elastomer was obtained.

[0047] Preparation of high-impact strength polyethylene naphthalate composite: 100 g of polyethylene naphthalate, 15 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder and melt-extruded. The temperatures of the first, second, third, fourth, fifth zones and the die head of the extruder were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0048] Example 3

[0049] Preparation of low-crosslinked density polyacrylate elastomer: 50 g of butyl acrylate (BA), 30 g of methyl methacrylate (MMA), 30 g of 2-hydroxyethyl methacrylate (HEMA), 10 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were added to a four-necked flask. After heating to 100 °C, the reaction was carried out for 4 h. After cooling, a polyacrylate solution was obtained; the solution was baked at 260 °C for 1 h to cause self-crosslinking reaction, and a low-crosslinked polyacrylate elastomer was obtained.

[0050] Preparation of Polyethylene Naphthalate Composite with High Impact Strength: 100 g of polyethylene naphthalate, 15 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder for melt extrusion, and the temperatures of the first, second, third, fourth, fifth zones and the die head of the extruder were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0051] Example 4

[0052] Preparation of Low-Crosslinked Polyacrylate Elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 0.8 g of benzoyl peroxide (BPO), and 200 g of toluene were put into a four-necked flask, heated to 120 °C and reacted for 4 h, and after cooling, a polyacrylate solution was obtained; the solution was baked at 260 °C for 1 h to cause self-crosslinking reaction to obtain a low-crosslinked polyacrylate elastomer.

[0053] Preparation of Polyethylene Naphthalate Composite with High Impact Strength: 100 g of polyethylene naphthalate, 15 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder for melt extrusion, and the temperatures of the first, second, third, fourth, fifth zones and the die head of the extruder were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0054] Example 5

[0055] Preparation of Low-Crosslinked Polyacrylate Elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.5 g of benzoyl peroxide (BPO), and 200 g of toluene were put into a four-necked flask, heated to 120 °C and reacted for 2 h, and after cooling, a polyacrylate solution was obtained; the solution was baked at 260 °C for 1 h to cause self-crosslinking reaction to obtain a low-crosslinked polyacrylate elastomer.

[0056] Preparation of high-impact-strength polyethylene naphthalate composite material: 100 g of polyethylene naphthalate, 15 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide are mixed in a mixer for 5 min; the mixed material is added to a twin-screw extruder for melt extrusion. The temperatures of the first, second, third, fourth, fifth zones and the die head of the extruder are 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, 275 °C in sequence; the screw speed of the extruder is 40 rpm; the feeding speed of the feeder is 3 rpm.

[0057] Example 6

[0058] Preparation of low-crosslinked polyacrylate elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), 100 g of toluene, and 100 g of ethyl acetate are put into a four-necked flask, heated to 100 °C and reacted for 4 h, and then cooled to obtain a polyacrylate solution; the solution is baked at 260 °C for 1 h to cause self-crosslinking reaction to obtain a low-crosslinked polyacrylate elastomer.

[0059] Preparation of high-impact-strength polyethylene naphthalate composite material: 100 g of polyethylene naphthalate, 15 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide are mixed in a mixer for 5 min; the mixed material is added to a twin-screw extruder for melt extrusion. The temperatures of the first, second, third, fourth, fifth zones and the die head of the extruder are 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, 275 °C in sequence; the screw speed of the extruder is 40 rpm; the feeding speed of the feeder is 3 rpm.

[0060] Example 7

[0061] Preparation of low-crosslinked polyacrylate elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), 100 g of xylene, and 100 g of butyl acetate are put into a four-necked flask, heated to 100 °C and reacted for 4 h, and then cooled to obtain a polyacrylate solution; the solution is baked at 260 °C for 1 h to cause self-crosslinking reaction to obtain a low-crosslinked polyacrylate elastomer.

[0062] Preparation of Polyethylene Naphthalate Composite with High Impact Strength: 100 g of polyethylene naphthalate, 15 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder for melt extrusion. The temperatures of the first, second, third, fourth, fifth zones of the extruder and the die head were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0063] Example 8

[0064] Preparation of Low-Crosslinked Polyacrylate Elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were added into a four-necked flask. After heating to 100 °C, the reaction was carried out for 4 h. After cooling, a polyacrylate solution was obtained; the solution was baked at 220 °C for 1.5 h to cause self-crosslinking reaction, and a low-crosslinked polyacrylate elastomer was obtained.

[0065] Preparation of Polyethylene Naphthalate Composite with High Impact Strength: 100 g of polyethylene naphthalate, 15 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder for melt extrusion. The temperatures of the first, second, third, fourth, fifth zones of the extruder and the die head were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0066] Example 9

[0067] Preparation of Low-Crosslinked Polyacrylate Elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were added into a four-necked flask. After heating to 100 °C, the reaction was carried out for 4 h. After cooling, a polyacrylate solution was obtained; the solution was baked at 280 °C for 0.3 h to cause self-crosslinking reaction, and a low-crosslinked polyacrylate elastomer was obtained.

[0068] Preparation of high impact strength polyethylene naphthalate composite material: 100 g of polyethylene naphthalate, 15 g of low cross-linked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide are mixed in a mixer for 5 min; the mixed material is added to a twin-screw extruder for melt extrusion, and the temperatures of the first, second, third, fourth, fifth zones and the die head of the extruder are 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, 275 °C in sequence; the screw speed of the extruder is 40 rpm; the feeding speed of the feeder is 3 rpm.

[0069] Example 10

[0070] Preparation of low cross-linked density polyacrylate elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN) and 200 g of toluene are put into a four-necked flask, heated to 100 °C and reacted for 4 h, and after cooling, a polyacrylate solution is obtained; the solution is baked at 260 °C for 1 h to cause a self-crosslinking reaction to obtain a low cross-linked polyacrylate elastomer.

[0071] Preparation of high impact strength polyethylene naphthalate composite material: 100 g of polyethylene naphthalate, 10 g of low cross-linked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide are mixed in a mixer for 5 min; the mixed material is added to a twin-screw extruder for melt extrusion, and the temperatures of the first, second, third, fourth, fifth zones and the die head of the extruder are 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, 275 °C in sequence; the screw speed of the extruder is 40 rpm; the feeding speed of the feeder is 3 rpm.

[0072] Example 11

[0073] Preparation of low cross-linked density polyacrylate elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN) and 200 g of toluene are put into a four-necked flask, heated to 100 °C and reacted for 4 h, and after cooling, a polyacrylate solution is obtained; the solution is baked at 260 °C for 1 h to cause a self-crosslinking reaction to obtain a low cross-linked polyacrylate elastomer.

[0074] Preparation of high impact strength polyethylene naphthalate composite material: 100 g of polyethylene naphthalate, 40 g of low cross-linked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide are mixed in a mixer for 5 min; the mixed material is added to a twin-screw extruder for melt extrusion. The temperatures of the first, second, third, fourth, fifth zones and the die head of the extruder are 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, 275 °C in sequence; the screw speed of the extruder is 40 rpm; the feeding speed of the feeder is 3 rpm.

[0075] Example 12

[0076] Preparation of low cross-linked density polyacrylate elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN) and 200 g of toluene are put into a four-necked flask, heated to 100 °C and reacted for 4 h, and then cooled to obtain a polyacrylate solution; the solution is baked at 260 °C for 1 h to cause self-crosslinking reaction to obtain a low cross-linked polyacrylate elastomer.

[0077] Preparation of high impact strength polyethylene naphthalate composite material: 100 g of polyethylene naphthalate, 15 g of low cross-linked polyacrylate elastomer, 1.2 g of triphenyl phosphate, and 0.5 g of distearyl disulfide are mixed in a mixer for 5 min; the mixed material is added to a twin-screw extruder for melt extrusion. The temperatures of the first, second, third, fourth, fifth zones and the die head of the extruder are 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, 275 °C in sequence; the screw speed of the extruder is 40 rpm; the feeding speed of the feeder is 3 rpm.

[0078] Example 13

[0079] Preparation of low cross-linked density polyacrylate elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN) and 200 g of toluene are put into a four-necked flask, heated to 100 °C and reacted for 4 h, and then cooled to obtain a polyacrylate solution; the solution is baked at 260 °C for 1 h to cause self-crosslinking reaction to obtain a low cross-linked polyacrylate elastomer.

[0080] Preparation of high impact strength polyethylene naphthalate composite material: 100 g of polyethylene naphthalate, 15 g of low cross-linked polyacrylate elastomer, 1 g of triphenyl phosphite, and 1.0 g of antioxidant 1010 were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder and melt-extruded. The temperatures of the first, second, third, fourth, fifth zones, and die head of the extruder were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0081] Example 14

[0082] Preparation of low cross-linked density polyacrylate elastomer: 35 g of butyl acrylate (BA), 45 g of methyl methacrylate (MMA), 5 g of 2-hydroxyethyl methacrylate (HEMA), 1 g of glycidyl methacrylate (GMA), 0.5 g of di-tert-butyl peroxide, and 200 g of mesitylene were put into a four-necked flask, heated to 70 °C and reacted for 6 h, and then cooled to obtain a polyacrylate solution; the solution was baked at 200 °C for 2 h to cause self-crosslinking reaction to obtain a low cross-linked polyacrylate elastomer.

[0083] Preparation of high impact strength polyethylene naphthalate composite material: 100 g of polyethylene naphthalate, 10 g of low cross-linked polyacrylate elastomer, 0.5 g of diphenyl phosphate, and 1 g of tris(2,4-di-tert-butylphenyl) phosphite were mixed in a mixer for 7 min; the mixed material was added to a twin-screw extruder and melt-extruded. The temperatures of the first, second, third, fourth, fifth zones, and die head of the extruder were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence; the screw speed of the extruder was 10 rpm; the feeding speed of the feeder was 1 rpm.

[0084] Example 15

[0085] Preparation of low cross-linked density polyacrylate elastomer: 45 g of butyl acrylate (BA), 35 g of methyl methacrylate (MMA), 10 g of 2-hydroxyethyl methacrylate (HEMA), 5 g of glycidyl methacrylate (GMA), 1.5 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were put into a four-necked flask, heated to 130 °C and reacted for 2 h, and then cooled to obtain a polyacrylate solution; the solution was baked at 300 °C for 0.2 h to cause self-crosslinking reaction to obtain a low cross-linked polyacrylate elastomer.

[0086] Preparation of Polyethylene Naphthalate Composite with High Impact Strength: 100 g of polyethylene naphthalate, 30 g of low-crosslinked polyacrylate elastomer, 1.2 g of triphenyl phosphite, and 0.7 g of didodecyl disulfide were mixed in a mixer for 10 min; the mixed material was added to a twin-screw extruder for melt extrusion. The temperatures of the first, second, third, fourth, fifth zones, and the die head of the extruder were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence; the screw speed of the extruder was 60 rpm; the feeding speed of the feeder was 6 rpm.

[0087] Comparative Example 1

[0088] Preparation of Low-crosslinked Polyacrylate Elastomer: 60 g of butyl acrylate (BA), 10 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were added into a four-necked flask, heated to 100 °C and reacted for 4 h, and then cooled to obtain a polyacrylate solution; the solution was baked at 260 °C for 1 h to cause self-crosslinking reaction to obtain the low-crosslinked polyacrylate elastomer.

[0089] Preparation of Polyethylene Naphthalate Composite with High Impact Strength: 100 g of polyethylene naphthalate, 15 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder for melt extrusion. The temperatures of the first, second, third, fourth, fifth zones, and the die head of the extruder were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0090] Comparative Example 2

[0091] Preparation of Low-crosslinked Polyacrylate Elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 50 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were added into a four-necked flask, heated to 100 °C and reacted for 4 h, and then cooled to obtain a polyacrylate solution; the solution was baked at 260 °C for 1 h to cause self-crosslinking reaction to obtain the low-crosslinked polyacrylate elastomer.

[0092] Preparation of high-impact-strength polyethylene naphthalate composite: 100 g of polyethylene naphthalate, 15 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder for melt extrusion, and the temperatures of the first, second, third, fourth, fifth zones, and die of the extruder were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0093] Comparative Example 3

[0094] Preparation of low-crosslinked polyacrylate elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were put into a four-necked flask, heated to 50 °C and reacted for 4 h, and after cooling, a polyacrylate solution was obtained; the solution was baked at 260 °C for 1 h to cause self-crosslinking reaction to obtain a low-crosslinked polyacrylate elastomer.

[0095] Preparation of high-impact-strength polyethylene naphthalate composite: 100 g of polyethylene naphthalate, 15 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder for melt extrusion, and the temperatures of the first, second, third, fourth, fifth zones, and die of the extruder were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0096] Comparative Example 4

[0097] Preparation of low-crosslinked polyacrylate elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were put into a four-necked flask, heated to 100 °C and reacted for 1 h, and after cooling, a polyacrylate solution was obtained; the solution was baked at 260 °C for 1 h to cause self-crosslinking reaction to obtain a low-crosslinked polyacrylate elastomer.

[0098] Preparation of Poly(ethylene naphthalate) Composite Material with High Impact Strength: 100 g of poly(ethylene naphthalate), 15 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder and melt-extruded. The temperatures of the first, second, third, fourth, fifth zones of the extruder and the die head were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0099] Comparative Example 5

[0100] Preparation of Low-Crosslinked Polyacrylate Elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were put into a four-necked flask, heated to 100 °C and reacted for 4 h, and after cooling, a polyacrylate solution was obtained; the solution was baked at 150 °C for 1 h to cause self-crosslinking reaction to obtain a low-crosslinked polyacrylate elastomer.

[0101] Preparation of Poly(ethylene naphthalate) Composite Material with High Impact Strength: 100 g of poly(ethylene naphthalate), 15 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder and melt-extruded. The temperatures of the first, second, third, fourth, fifth zones of the extruder and the die head were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0102] Comparative Example 6

[0103] Preparation of Low-Crosslinked Polyacrylate Elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were put into a four-necked flask, heated to 100 °C and reacted for 4 h, and after cooling, a polyacrylate solution was obtained; the solution was baked at 340 °C for 1 h to cause self-crosslinking reaction to obtain a low-crosslinked polyacrylate elastomer.

[0104] Preparation of Polyethylene Naphthalate Composite Material with High Impact Strength: 100 g of polyethylene naphthalate, 15 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder for melt extrusion. The temperatures of the first, second, third, fourth, fifth zones and the die head of the extruder were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0105] Comparative Example 7

[0106] Preparation of Low-Crosslinked Polyacrylate Elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were put into a four-necked flask, heated to 100 °C and reacted for 4 h, and then cooled to obtain a polyacrylate solution; the solution was baked at 260 °C for 1 h to cause self-crosslinking reaction to obtain a low-crosslinked polyacrylate elastomer.

[0107] Preparation of Polyethylene Naphthalate Composite Material with High Impact Strength: 100 g of polyethylene naphthalate, 5 g of low-crosslinked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder for melt extrusion. The temperatures of the first, second, third, fourth, fifth zones and the die head of the extruder were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, and 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0108] Comparative Example 8

[0109] Preparation of Low-Crosslinked Polyacrylate Elastomer: 40 g of butyl acrylate (BA), 40 g of methyl methacrylate (MMA), 20 g of 2-hydroxyethyl methacrylate (HEMA), 20 g of glycidyl methacrylate (GMA), 1.0 g of azobisisobutyronitrile (AIBN), and 200 g of toluene were put into a four-necked flask, heated to 100 °C and reacted for 4 h, and then cooled to obtain a polyacrylate solution; the solution was baked at 260 °C for 1 h to cause self-crosslinking reaction to obtain a low-crosslinked polyacrylate elastomer.

[0110] Preparation of high impact strength polyethylene naphthalate composite material: 100 g of polyethylene naphthalate, 50 g of low cross-linked polyacrylate elastomer, 1 g of triphenyl phosphite, and 0.5 g of distearyl disulfide were mixed in a mixer for 5 min; the mixed material was added to a twin-screw extruder for melt extrusion. The temperatures of the first, second, third, fourth, fifth zones and the die head of the extruder were 275 °C, 280 °C, 280 °C, 280 °C, 280 °C, 275 °C in sequence; the screw speed of the extruder was 40 rpm; the feeding speed of the feeder was 3 rpm.

[0111] For the raw materials and conditions in Examples 1-13 and Comparative Examples 1-8 in the present invention, see Table 1, and for the performance comparison, see Table 2.

[0112] Table 1 Synthesis data of examples and comparative examples

[0113]

[0114] Table 2 Performance comparison of PEN resins obtained from examples and comparative examples

[0115]

[0116] According to Examples 1-13 and Comparative Examples 1-8, in Comparative Examples 1 and 2, the amounts of the synthetic polyacrylate elastomer monomers BA and GMA exceeded the dosage ratio range in the present invention, resulting in an increase in the glass transition temperature of the synthesized polyacrylate resin and the inability to exhibit the elastomer characteristics, leading to poor toughening effect. In Comparative Example 3, the polycondensation reaction temperature was lower than the reaction temperature range in the present invention. The too low polycondensation temperature led to a slow polycondensation reaction rate and the formation of an oligomer solution, which could not play a toughening role. The polycondensation reaction time in Comparative Example 4 was too short, which also led to a low molecular weight of the polyacrylate and the formation of an oligomer solution, unable to play a toughening role. The post-crosslinking temperatures of the polyacrylate solutions in Comparative Examples 5 and 6 exceeded the temperature range in the present invention. In Comparative Example 5, it was too low to form a cross-linked structure; in Comparative Example 6, the cross-linking temperature was too high, resulting in too high a cross-linking degree and unable to be melt-processed. In Comparative Examples 7 and 8, the contents of the low cross-linked polyacrylate elastomer melt-blended with PEN both exceeded the dosage range in the present invention. In Comparative Example 7, the amount of the elastomer was too small to promote the plastic deformation of the matrix; in Comparative Example 8, the amount of the elastomer was too large, forming larger particle sizes in the resin, resulting in poor toughening effect.

[0117] Referring to Table 2, the high impact polyethylene naphthalate composite material prepared by the present invention has excellent impact performance, which is 80-135 kJ / m 2 , which can reach more than 40-62.5 times that of pure PEN resin (the pure PEN resin is 2.0 kJ / m 2). Meanwhile, the PEN composite material also has good mechanical properties, with a tensile strength of 70 - 90 MPa and a Young's modulus of 1.8 - 2.5 GPa, meeting the performance requirements of engineering plastics in most application scenarios. In addition, the composite material also has good thermal stability, with a 2% mass loss temperature greater than 300 °C, which further broadens its application scenarios.

[0118] The PEN composite material prepared by the method of the present invention avoids the defect of poor impact performance of pure PEN resin and significantly improves the impact toughness while maintaining good mechanical properties. In addition, it has excellent thermal stability and processing performance and has great application value in the field of engineering plastics.

[0119] In the present invention, a polyacrylate elastomer with a low crosslinking density is dispersed into the PEN resin to form a phase morphology with the characteristic of a low matrix ligament thickness. This morphology can effectively increase the ductility of PEN, enabling it to exhibit better energy absorption and deformation ability under impact, thereby avoiding brittle fracture. The composite material of the present invention avoids the defect of poor impact performance of pure PEN resin and significantly improves the impact toughness while maintaining good mechanical properties. In addition, it has excellent thermal stability and processing performance, with excellent comprehensive performance, a simple preparation process, and easily available raw materials, and has broad industrial application prospects.

[0120] The above is only an illustration of the best embodiments of the present invention and should not be construed as a limitation of the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to vary. Any changes made within the protection scope of the independent claims of the present invention are within the protection scope of the present invention.

[0121] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

Claims

1. A preparation method of a polyethylene naphthalate composite material with high impact strength, characterized in that, It includes the following steps: By mass parts, 100 parts of polyethylene naphthalate, 10 - 40 parts of polyacrylate elastomer, 0.5 - 1.5 parts of heat stabilizer and 0.5 - 1 part of antioxidant additive are mixed evenly and melt-extruded to obtain a polyethylene naphthalate composite material with high impact strength; the impact strength of the composite material is 80 - 135 kJ / m 2 , the tensile strength is 70 - 90 MPa, the Young's modulus is 1.8 - 2.5 GPa, and the 2% mass loss temperature > 300 °C; The heat stabilizer is one of triphenyl phosphate, triphenyl phosphite and diphenyl phosphate; the antioxidant auxiliary is one of tris(2,4-di-tert-butylphenyl) phosphite, distearyl disulfide, didecyl disulfide and antioxidant 1010; The polyacrylate elastomer is prepared through the following process: by mass parts, 30 - 50 parts of butyl acrylate, 30 - 50 parts of methyl methacrylate, 5 - 30 parts of 2-hydroxyethyl methacrylate, 1 - 30 parts of glycidyl methacrylate, 0.5 - 1.5 parts of oil-soluble initiator and 200 parts of solvent are subjected to a polymerization reaction to obtain a polyacrylate solution; the polyacrylate solution is subjected to a self-crosslinking reaction under heating to obtain the polyacrylate elastomer; The temperature of the polymerization reaction is 70 - 130 °C and the time is 2 - 6 h; The temperature of the self-crosslinking reaction is 200 - 300 °C and the time is 0.2 - 2 h.

2. The preparation method of the polyethylene naphthalate composite material with high impact strength according to claim 1, characterized in that, The oil-soluble initiator is one of azobisisobutyronitrile, benzoyl peroxide and di-tert-butyl peroxide.

3. The preparation method of the polyethylene naphthalate composite material with high impact strength according to claim 1, characterized in that, The solvent is one of toluene, xylene, mesitylene, ethyl acetate and butyl acetate or a mixture of one or two of them.

4. The preparation method of the polyethylene naphthalate composite material with high impact strength according to claim 1, characterized in that, The melt extrusion is carried out in a twin-screw extruder. The temperatures of the first zone, second zone, third zone, fourth zone, fifth zone and die head of the twin-screw extruder are 275 °C, 280 °C, 280 °C, 280 °C, 280 °C and 275 °C in sequence; the screw rotation speed of the extruder is 10 - 60 rpm; the rotation speed of the feeder is 1 - 6 rpm.

5. A polyethylene naphthalate composite material with high impact strength prepared by the method according to any one of claims 1-4, characterized in that, The impact strength of the composite material is 80 - 135 kJ / m 2 , the tensile strength is 70 - 90 MPa, the Young's modulus is 1.8 - 2.5 GPa, and the temperature at 2% mass loss is > 300 °C.

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