A furanyl semi-aromatic polyamide high-strength industrial yarn

Abstract

This invention belongs to the field of polymer materials technology, specifically disclosing a high-strength industrial filament of furan-based semi-aromatic polyamide. The furan-based semi-aromatic polyamide high-strength industrial filament provided by this invention is prepared by one-step melt polymerization of dimethyl 2,5-furandicarboxylate and an aliphatic diamine as monomers to obtain a high molecular weight furan-based semi-aromatic polyamide. The obtained polyamide chips are then dried, melt-spun, and subjected to stretching, heat setting, and winding processes to finally obtain a high-strength bio-based semi-aromatic polyamide industrial filament. The furan-based semi-aromatic polyamide high-strength industrial filament provided by this invention has a high bio-based content, while also exhibiting excellent mechanical strength and heat resistance.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a furan-based semi-aromatic polyamide high-strength industrial filament. Background Technology

[0002] Polyamide, commonly known as nylon, is a general term for thermoplastic resins whose molecular backbone contains repeating amide groups -[NHCO]-. Nylon possesses excellent comprehensive properties, including mechanical properties, heat resistance, wear resistance, chemical resistance, and self-lubricating properties. It also has a low coefficient of friction, some flame retardancy, and is easy to process, making it widely used in synthetic fibers and engineering plastics. There are many varieties of nylon, including aliphatic polyamides, semi-aromatic polyamides, and fully aromatic polyamides (aramid), among many newer varieties. Aliphatic polyamides generally have lower mechanical strength and heat resistance, while semi-aromatic and aramid polymers primarily rely on petroleum-based monomers, lacking the characteristics of low-carbon environmental protection and sustainable development.

[0003] Currently, polyamide industrial yarns are mainly made of nylon 6, nylon 56, nylon 66, and aramid. Among them, the strength of aliphatic polyamide industrial yarns is generally below 10 cN / dtex, while the strength of aramid industrial yarns can reach 20 cN / dtex and above. However, because the melting point of aramid is higher than its decomposition temperature, industrial yarns can only be prepared by solution spinning. The preparation process requires the use of a large amount of organic solvents, making the spinning process more complex, costly, and less environmentally friendly. Patent application CN 111411405 A discloses a high-strength polyamide 56 industrial filament, its preparation method, and its application. The high-strength filament has a breaking strength of 8.7–9.2 cN / dtex and a breaking elongation of 16–24%. The industrial filament has relatively low strength, and the bio-based content of polyamide 56 is <50%. Patent application CN115559012 A discloses a method for preparing high-strength nylon 6 industrial filament. By copolymerizing nylon 6 with 5T, benzene rings are introduced into the macromolecular chain of nylon 6 to obtain copolymerized modified PA6 industrial filament, but its breaking strength is still <9.0 cN / dtex.

[0004] While numerous patents disclose methods for preparing aliphatic polyamide industrial yarns, reports on melt spinning of semi-aromatic polyamides are scarce. Therefore, this invention aims to provide a high-strength furan-based semi-aromatic polyamide industrial yarn to meet application requirements. Summary of the Invention

[0005] The purpose of this invention is to provide a high-strength industrial filament of furan-based semi-aromatic polyamide, which has a high bio-based content and excellent mechanical strength and heat resistance.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] In a first aspect, the present invention provides a high-strength industrial yarn of furanyl semi-aromatic polyamide, the structure of which is shown in general formula I:

[0008]

[0009] m takes the value of an integer from 8 to 14;

[0010] The preparation steps of the raw material furanyl semi-aromatic polyamide include: reacting the reactants 2,5-furandicarboxylic acid dimethyl ester, aliphatic diamine, and catalyst in a nitrogen atmosphere at 90-150°C for 1-1.5 h, then separating the distillate methanol; heating to 230-250°C and reacting for 0.5-1.5 h, then carrying out a polycondensation reaction under negative pressure, with the pressure inside the reactor ≤-50 kPa and the reaction temperature at 280-320°C, to obtain furanyl semi-aromatic polyamide;

[0011] The aliphatic diamine is C8-C. 14 Aliphatic diamines;

[0012] The catalyst is a hexafluorophosphate compound; preferably one or more of tetramethylfluorourea hexafluorophosphate, 6-chlorobenzotriazole-1,1,3,3-tetramethylurea hexafluorophosphate, and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate.

[0013] In one embodiment of the present invention, the aliphatic diamine is selected from 1,8-octanediamine, 1,10-decanediamine, and 1,12-dodecanediamine.

[0014] Preferably, the aliphatic diamine is 1,10-decanediamine.

[0015] In one embodiment of the present invention, the value of m is 8, 10, or 12, preferably 10.

[0016] In one embodiment of the present invention, an antioxidant is further added to the reaction raw materials. Preferably, the antioxidant is selected from one or more of antioxidants 1010, SEED, and B215. More preferably, the antioxidant is antioxidant B215.

[0017] As one embodiment of the present invention, the molar ratio of dimethyl 2,5-furandicarboxylate to the aliphatic diamine is 1:(1.02-1.08), preferably, the molar ratio of dimethyl 2,5-furandicarboxylate to the aliphatic diamine is 1:1.05.

[0018] As one embodiment of the present invention, the amount of catalyst used is 0.1 to 0.3% of the mass of dimethyl 2,5-furandicarboxylate; preferably, the amount of catalyst used is 0.1% of the mass of dimethyl 2,5-furandicarboxylate.

[0019] In one embodiment of the present invention, the amount of antioxidant is 0.05-0.1% of the total mass of dimethyl 2,5-furandicarboxylate and the aliphatic diamine; preferably, the amount of antioxidant is 0.06-0.08% of the total mass of dimethyl 2,5-furandicarboxylate and the aliphatic diamine; more preferably, the amount of antioxidant is 0.07% of the total mass of dimethyl 2,5-furandicarboxylate and the aliphatic diamine.

[0020] In one embodiment of the present invention, during the preparation of the raw material furanyl semi-aromatic polyamide, the reaction raw material is stirred during the process of heating to 90-150°C and during the reaction at 90-150°C, with a stirring speed of 100-200 r / min, preferably 120 r / min.

[0021] In one embodiment of the present invention, during the negative compression polymerization reaction, the stirring speed is 20-60 r / min and the reaction time is 1-4 h; preferably, during the negative compression polymerization reaction, the stirring speed is 50 r / min and the reaction time is 1-2 h; more preferably, during the negative compression polymerization reaction, the reaction time is 1.5 h.

[0022] As one embodiment of the present invention, the furanyl semi-aromatic polyamide high-strength industrial yarn is made from furanyl semi-aromatic polyamide using a method comprising the following steps:

[0023] Furan-based semi-aromatic polyamide chips were melt-spun at a temperature of 270–310℃ and a spinning speed of 500–1500 m / min. A three-stage stretching and setting process was employed, with a total stretch ratio of 4.0–6.5. The tension heat setting temperature was 150–230℃, and the relaxation heat setting temperature was 100–200℃. The stretching and winding speed was 2500–4000 m / min, yielding high-strength industrial filaments of furan-based semi-aromatic polyamide.

[0024] As one embodiment of the present invention, the three-stage stretching and shaping includes a first-stage pre-stretching, a second-stage main stretching, and a third-stage secondary stretching. The stretching ratio of the first-stage pre-stretching is 1.0 to 1.2, the stretching ratio of the second-stage main stretching is 2.0 to 2.5, and the stretching ratio of the third-stage secondary stretching is 2.0 to 2.5.

[0025] In one embodiment of the present invention, tension heat setting is performed during the second-stage main stretching process, and relaxation heat setting is performed during the third-stage secondary stretching process.

[0026] In one embodiment of the present invention, the temperature of the first-stage pre-stretching is 110-150°C; the temperature of the tension heat setting is 180-230°C, preferably 180-200°C; and the temperature of the relaxation heat setting is 100-140°C, preferably 120-140°C.

[0027] As one embodiment of the present invention, the furanyl semi-aromatic polyamide high-strength industrial yarn has a yarn strength of 9.0-12.0 cN / dtex, a breaking elongation of 15-27%, and a heat shrinkage rate of 4-7%.

[0028] Secondly, this invention provides an application of furanyl semi-aromatic polyamide high-strength industrial yarn for use in the manufacture of tire cord, airbag yarn, waterproof cloth, canvas, seat belt, rope, fishing net, industrial filter cloth, conveyor belt, parachute, tent, and luggage, as a preparation material.

[0029] The furanyl semi-aromatic polyamide high-strength industrial yarn provided by this invention is prepared by one-step melt polymerization of dimethyl 2,5-furandicarboxylate and aliphatic diamine as monomers to obtain high molecular weight furanyl semi-aromatic polyamide. The resulting polyamide chips are then dried, melt-spun, and subjected to stretching, heat setting, and winding processes to finally obtain high-strength bio-based semi-aromatic polyamide industrial yarn. The furanyl semi-aromatic polyamide high-strength industrial yarn provided by this invention has a high bio-based content, while also exhibiting excellent mechanical strength and heat resistance. It can be applied to tire cord, airbag yarn, waterproof fabric, canvas, seat belts, ropes, fishing nets, industrial filter cloth, conveyor belts, parachutes, tents, bags, and other fields.

[0030] This invention enables the one-step melt polymerization of high-molecular-weight furanyl semi-aromatic polyamides by selecting a suitable catalyst and controlling appropriate reaction conditions, such as negative compression polymerization. The resulting polyamide chips are then subjected to tertiary stretching and heat setting to obtain high-strength furanyl semi-aromatic polyamide industrial yarns. The furanyl semi-aromatic polyamide high-strength industrial yarns prepared by this invention differ from other petroleum-based polymers, reducing dependence on and consumption of petroleum resources, reducing carbon dioxide emissions, and minimizing carbon footprint, thus being low-carbon and environmentally friendly. Furthermore, dimethyl 2,5-furandicarboxylate has a low melting point and does not require salt formation with aliphatic diamines, allowing for one-step melt polymerization to prepare polyamides with low requirements for reaction equipment. The furanyl semi-aromatic polyamide industrial yarns prepared using this invention exhibit excellent mechanical strength and heat resistance.

[0031] This invention prepares furan-based semi-aromatic polyamides by melt polymerization using dimethyl 2,5-furandicarboxylate as the main raw material, which are then used to produce industrial fibers. This process has advantages such as low environmental pollution, low carbon emissions, simple process, and stable product performance. At the same time, with the addition of a suitable catalyst, a high reaction rate is ensured, resulting in polymers with large molecular weights and excellent heat resistance and mechanical properties. Attached Figure Description

[0032] Figure 1 This is a photograph of the poly(2,5-furandicarboxylate) slice (PA10F) obtained in Example 1 of the present invention.

[0033] Figure 2 This is the GPC spectrum of the poly(2,5-furandicarboxylate) slice (PA10F) obtained in Example 1 of the present invention. Detailed Implementation

[0034] The technical solution of the present invention will be further described in detail below. Those skilled in the art should understand that the specific embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof.

[0035] It should be noted that, unless otherwise specified, the technical means used in the following examples are conventional means well known to those skilled in the art, and the raw materials used are all commercially available conventional products.

[0036] The furanyl semi-aromatic polyamide high-strength industrial yarn provided by this invention is obtained by a method comprising the following preparation steps:

[0037] (1) Preparation of raw material furanyl semi-aromatic polyamide

[0038] Dimethyl 2,5-furandicarboxylate, aliphatic diamine, catalyst, and antioxidant were added to a reactor according to the specified ratio. After the addition was complete, the air inside the reactor was purged with nitrogen, and stirring was started to raise the temperature for reaction. Once the temperature inside the reactor reached 90–150°C, the reaction was maintained at this temperature for 1–2 hours. The stirring speed during the heating and holding processes was 100–200 r / min. After the holding reaction was completed, the pressure inside the reactor was reduced to atmospheric pressure within 0.5–1 hour, while the reaction temperature was raised to 230–250°C. The reaction was continued at atmospheric pressure for 0.5–1.5 hours. Then, negative compression polymerization was carried out by vacuuming, controlling the pressure inside the reactor to ≤-50 kPa, the reaction temperature to 280–320°C, and the stirring speed to 20–60 r / min for 1–2 hours. Finally, the melt was extruded by purging with nitrogen, cooled, and granulated to prepare furan-based semi-aromatic polyamide chips.

[0039] The structure of furanyl semi-aromatic polyamide is shown in general formula I:

[0040]

[0041] m takes the value of an integer from 8 to 14;

[0042] Aliphatic diamines are C8-C 14 The aliphatic diamine can be selected from 1,8-octanediamine, 1,10-decanediamine, and 1,12-dodecanediamine, with 1,10-decanediamine being the preferred aliphatic diamine.

[0043] The catalyst is a hexafluorophosphate compound, preferably one or more of tetramethylfluorourea hexafluorophosphate, 6-chlorobenzotriazole-1,1,3,3-tetramethylurea hexafluorophosphate, and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate.

[0044] The antioxidant is selected from one or more of antioxidants 1010, SEED, and B215, with antioxidant B215 being preferred.

[0045] The molar ratio of dimethyl 2,5-furandicarboxylate to aliphatic diamine is 1:(1.02–1.08); the amount of catalyst used is 0.1–0.3% of the mass of dimethyl 2,5-furandicarboxylate; and the amount of antioxidant used is 0.05–0.1% of the total mass of dimethyl 2,5-furandicarboxylate and aliphatic diamine.

[0046] (2) Preparation of furanyl semi-aromatic polyamide high-strength industrial yarn

[0047] Furanyl semi-aromatic polyamide chips were melt-spun at a temperature of 270–310℃ and a spinning speed of 500–1500 m / min. A three-stage stretching and setting process was employed, with a total stretch ratio of 4.0–6.5. The tension heat setting temperature was 150–230℃, and the relaxation heat setting temperature was 100–200℃. The stretching and winding speed was 2500–4000 m / min, yielding high-strength industrial filaments of furanyl semi-aromatic polyamide.

[0048] The three-stage stretching and setting process includes a first-stage pre-stretching, a second-stage main stretching, and a third-stage secondary stretching. The stretching ratio of the first-stage pre-stretching is 1.0–1.2, the stretching ratio of the second-stage main stretching is 2.0–2.5, and the stretching ratio of the third-stage secondary stretching is 2.0–2.5. Tension heat setting is performed during the second-stage main stretching, and relaxation heat setting is performed during the third-stage secondary stretching. Four pairs of hot rollers are used in the stretching process. The second-stage main stretching and tension heat setting are performed between the second and third pairs of hot rollers, followed by the third-stage secondary stretching and relaxation heat setting between the third and fourth pairs of hot rollers. The temperature of the first-stage pre-stretching is 110–150°C; the temperature of the tension heat setting is 180–230°C, preferably 180–200°C; and the temperature of the relaxation heat setting is 100–140°C, preferably 120–140°C.

[0049] The following detailed explanation will be provided through specific examples.

[0050] Example 1

[0051] This embodiment provides a furanyl semi-aromatic polyamide, the preparation method of which includes the following steps:

[0052] 700g of dimethyl 2,5-furandicarboxylate (3.8mol, 1eq) and 690g of... 1,10-Decanediamine (4.0 mol, 1.05 eq), 1.0 g antioxidant B215, and 0.7 g tetramethylfluorourea hexafluorophosphate were added to a reactor. Nitrogen gas was purged to replace the air in the reactor, and this process was repeated three times. The reactor temperature was raised to 100°C using a circulating heat medium, and stirring was started simultaneously at 120 r / min. The reaction was maintained at this temperature for 1.5 h. After the reaction was completed, the pressure inside the reactor was slowly reduced to atmospheric pressure over 1 h, and the distilled methanol was collected. The reactor temperature was then raised to 230°C using a circulating heat medium, and the reaction continued for 1 h under atmospheric pressure. Next, negative compression polymerization was performed under vacuum, controlling the reactor pressure to ≤-50 kPa, the reaction temperature to 280°C, and the stirring speed to 50 r / min for 1.5 h. The melt was then extruded using nitrogen gas, cooled, and granulated to prepare poly(2,5-furandicarboxylated decanediamine) chips (PA10F). A photograph of the polyamide chips is shown below. Figure 1 As shown. Its molecular weight is Mn: 22000, Mw: 72000, and the GPC spectrum is shown below. Figure 2 As shown; the relative viscosity is 3.17 (the relative viscosity in this invention is measured with reference to standard GB / T12006.1-2009).

[0053] Example 2

[0054] This embodiment provides a furanyl semi-aromatic polyamide. The preparation method differs from Example 1 only in that the amount of 1,10-decanediamine is adjusted from 690g to 667g (3.88mol, 1.02eq). Poly(2,5-furandicarboxydecanediamine) chips (PA10F) are prepared. The molecular weight of this polyamide chip is: Mn: 19000, Mw: 59000; the relative viscosity is: 2.92.

[0055] Example 3

[0056] This embodiment provides a furanyl semi-aromatic polyamide. The preparation method differs from Example 1 only in that the amount of 1,10-decanediamine is adjusted from 690g to 720g (4.19mol, 1.10eq). Poly(2,5-furandicarboxydecanediamine) chips (PA10F) are prepared. The molecular weight of this polyamide chip is: Mn: 18000, Mw: 55000; the relative viscosity is: 2.85.

[0057] Example 4

[0058] This embodiment provides a furanyl semi-aromatic polyamide. The preparation method differs from Example 1 only in that the catalyst is changed from tetramethylfluorourea hexafluorophosphate to benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate, while the amount remains the same at 0.7g. Poly(2,5-furandicarboxylate decanediamine) chips (PA10F) are obtained. The molecular weight of this polyamide chip is: Mn: 21000, Mw: 70000; the relative viscosity is 3.08.

[0059] Example 5

[0060] This embodiment provides a high-strength industrial yarn made of furanyl semi-aromatic polyamide. The preparation method of the raw material furanyl semi-aromatic polyamide is the same as that in Example 1, and it is a scaled-up experiment of Example 1. The preparation method specifically includes the following steps:

[0061] 7000g of dimethyl 2,5-furandicarboxylate (38mol, 1eq) and 6900g of... 1,10-Decanediamine (40 mol, 1.05 eq), 10 g antioxidant B215, and 7 g tetramethylfluorourea hexafluorophosphate were added to a reactor. Nitrogen gas was purged to replace the air in the reactor, and this process was repeated three times. The reactor temperature was raised to 100°C using a circulating heat medium, and stirring was started at 120 r / min. The reaction was maintained at this temperature for 1.5 h. After the reaction was completed, the pressure in the reactor was slowly reduced to atmospheric pressure within 1 h, and the distilled methanol was collected. The reactor temperature was raised to 230°C using a circulating heat medium, and the reaction was continued at atmospheric pressure for 1 h. Then, negative compression polymerization was carried out by vacuuming, controlling the reactor pressure to ≤-50 kPa, the reaction temperature to 280°C, the stirring speed to 50 r / min, and the reaction was carried out for 1.5 h. Afterward, the melt was extruded by purging nitrogen gas, cooled, and granulated to prepare poly(2,5-furandicarboxydecanediamine) chips (PA10F). The polyamide chips have the following molecular weights: Mn: 22000, Mw: 72000; and a relative viscosity of 3.15.

[0062] High-strength industrial yarn was prepared using poly(2,5-furandicarboxylate) chips as raw material. The chips were first vacuum-dried, then melt-spun at 290℃ with a total draw ratio of 6.0. The drawing process employed four pairs of hot rollers in three stages: a pre-stretch with a draw ratio of 1.2; a main stretch followed by tension heat setting with a draw ratio of 2.5; and a secondary stretch with a draw ratio of 2.0. The pre-stretch temperature was 110–130℃; the tension heat setting temperature was 180–200℃; and the relaxation heat setting followed by... The temperature is 120-140℃. Tension heat setting is performed during the second-stage main stretching process, and relaxation heat setting is performed during the third-stage stretching process. The second-stage main stretching and tension heat setting are performed between the second pair of hot rollers and the third pair of hot rollers. Then, the third-stage stretching and relaxation heat setting are performed between the third pair of hot rollers and the fourth pair of hot rollers. The spinning speed is 500m / min, the stretching and winding speed is 3000m / min, and the nascent yarn is fully stretched and set before winding. A furan-based semi-aromatic polyamide high-strength industrial yarn was successfully obtained.

[0063] Comparative Example 1

[0064] This comparative example provides a polyamide, the preparation method of which includes the following steps:

[0065] 700g of 2,5-furandicarboxylic acid (4.49mol, 1eq), 812g of decanediamine (4.72mol, 1.05eq), 150g of deionized water, 1.0g of antioxidant 1010, and 0.7g of tetramethylfluorourea hexafluorophosphate were added to the reactor. Nitrogen gas was purged to replace the air in the reactor, and this process was repeated three times. The reactor temperature was raised to 250℃ using a circulating heat medium, and the stirring was started at 120r / min. The reaction was maintained at this temperature for 2h. After the reaction was completed, the pressure in the reactor was slowly reduced to atmospheric pressure within 1h. The reactor temperature was then raised to 290℃ using a circulating heat medium, and the reaction was continued at atmospheric pressure for 1h. Then, negative compression polymerization was carried out by vacuuming, controlling the reactor pressure to ≤-50kPa, the reaction temperature to 310℃, the stirring speed to 50r / min, and the reaction time to 3h. Since the melt viscosity did not increase significantly, granulation could not be successfully carried out, and only blocky poly(2,5-furandicarboxylate) (PA10F) could be obtained.

[0066] Comparative Example 2

[0067] This comparative example provides a polyamide, the preparation method of which includes the following steps:

[0068] 700g of dimethyl 2,5-furandicarboxylate (3.8mol, 1eq), 690g of 1,10-decanediamine (4.0mol, 1.05eq), 1.0g of antioxidant B215, and 0.7g of hypophosphoric acid were added to a reactor. Nitrogen gas was purged to replace the air in the reactor, and this process was repeated three times. The reactor temperature was raised to 100℃ using a circulating heat medium, and stirring was started at 120r / min. The reaction was maintained at this temperature for 1.5h. After the reaction was completed, the pressure in the reactor was slowly reduced to atmospheric pressure within 1h, and the distilled methanol was collected. The reactor temperature was raised to 230℃ using a circulating heat medium, and the reaction was continued at atmospheric pressure for 1h. Then, negative compression polymerization was carried out by vacuuming, controlling the reactor pressure to ≤-50kPa, the reaction temperature to 280℃, the stirring speed to 50r / min, and the reaction time to 3h. Since the melt viscosity did not increase significantly, granulation could not be successfully carried out, and only blocky poly(2,5-furandicarboxylate) (PA10F) could be obtained.

[0069] Comparative Example 3

[0070] This comparative example provides a nylon 6 industrial filament, the preparation method of which includes the following steps:

[0071] 10 kg of caprolactam, 300 g of deionized water, 10 g of antioxidant 1010, and 25 g of terephthalic acid were added to a reaction vessel. Nitrogen gas was purged to replace the air in the vessel, and this process was repeated three times. The temperature inside the vessel was raised to 240°C using a circulating heat medium, and stirring was started at 120 r / min for 2 hours for the hydrolysis ring-opening reaction. After the reaction, the pressure inside the vessel was slowly reduced to atmospheric pressure within 1 hour. The temperature inside the vessel was then raised to 265°C using a circulating heat medium, and negative compression polymerization was performed under vacuum, with the pressure inside the vessel ≤ -90 kPa, stirring speed 50 r / min, and reaction time 2.5 hours. Finally, the melt was extruded through nitrogen gas, cooled, and granulated to obtain nylon 6 chips.

[0072] The chips were vacuum dried and melt-spun at a spinning temperature of 260–270℃ with a total draw ratio of 6.0. The drawing process used four pairs of hot rollers and consisted of three stages of drawing and setting: the first stage was pre-drawing with a draw ratio of 1.2; the second stage was main drawing followed by tension heat setting with a draw ratio of 2.5; and the third stage was secondary drawing with a draw ratio of 2.0. The temperature for the first stage pre-drawing was 110–130℃; the temperature for tension heat setting was 180–200℃; and the temperature for relaxation heat setting was 120–140℃. The spinning speed was 1200 m / min, and the drawing and winding speed was 3000 m / min. After the nascent yarn was fully drawn and set, it was wound to successfully obtain nylon 6 industrial yarn.

[0073] The industrial yarns obtained in Example 5 and Comparative Example 3 were subjected to performance tests using the following methods:

[0074] (1) Fracture strength, coefficient of variation of fracture strength (CV): determined in accordance with GB / T 14344-2008;

[0075] (2) Elongation at break, coefficient of variation of elongation at break (CV): determined in accordance with GB / T 14344-2008;

[0076] (3) Heat shrinkage rate (boiling water shrinkage or dry shrinkage) shall be determined in accordance with the standard GB / T6505-2017.

[0077] The performance test results are shown in Table 1 below.

[0078] Table 1

[0079]

[0080] As can be seen from Examples 1-3 above, 2,5-furandicarboxylic acid decanediamine (PA10F) was synthesized in Examples 1-3 respectively. In Examples 2-3, the molar ratio of decanediamine to dimethyl 2,5-furandicarboxylic acid was adjusted. In Example 1, the molar ratio of decanediamine to dimethyl 2,5-furandicarboxylic acid was 1.05:1; in Example 2, the molar ratio of decanediamine to dimethyl 2,5-furandicarboxylic acid was 1.02:1; and in Example 3, the molar ratio of decanediamine to dimethyl 2,5-furandicarboxylic acid was 1.10:1. The test results show that the molar ratio of monomers has a great influence on the increase of molecular weight. The molar ratio of decanediamine to dimethyl 2,5-furandicarboxylic acid is preferably in the range of (1.03 to 1.08):1, and is especially preferred to be 1.05:1.

[0081] In Example 4, benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate was selected as the catalyst, which can also be used to prepare PA10F, which has good catalytic effect.

[0082] Compared with Comparative Example 1, in the melt polymerization system, dimethyl 2,5-furandicarboxylate has better reactivity than 2,5-furandicarboxylic acid. The direct reaction of the diacid monomer with the diamine cannot obtain polyamide with a high molecular weight. Meanwhile, in Comparative Example 2, a common hypophosphite catalyst was selected, but its catalytic effect was poor.

[0083] The industrial yarn prepared in Example 5 has a tensile strength (i.e. breaking strength) > 9.0 cN / dtex. In Comparative Example 3, nylon 6 chips with similar molecular weight were synthesized and spun, but the yarn prepared from them had lower strength. This shows that the furan-based semi-aromatic polyamide high-strength yarn of the present invention has great application potential.

[0084] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A furanyl semi-aromatic polyamide high-strength industrial yarn, characterized in that, The structure of its raw material, furanyl semi-aromatic polyamide, is shown in general formula I: I m takes the value of an integer from 8 to 14; The preparation steps of the raw material furanyl semi-aromatic polyamide include: reacting the reactants 2,5-furandicarboxylic acid dimethyl ester, aliphatic diamine, and catalyst in a nitrogen atmosphere at 90~150℃ for 1~1.5h, then separating the distillate methanol; heating to 230~250℃ and reacting for 0.5~1.5h, then carrying out a polycondensation reaction under negative pressure, with the pressure inside the reactor ≤-50kpa and the reaction temperature at 280~320℃, to obtain furanyl semi-aromatic polyamide; The aliphatic diamine is selected from one or more of 1,8-octanediamine, 1,10-decanediamine, and 1,12-dodecanediamine; the catalyst is selected from one or more of tetramethylfluorourea hexafluorophosphate, 6-chlorobenzotriazole-1,1,3,3-tetramethylurea hexafluorophosphate, and benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate. The furanyl semi-aromatic polyamide high-strength industrial yarn is made from furanyl semi-aromatic polyamide using a method comprising the following steps: Furanyl semi-aromatic polyamide chips were melt-spun at a temperature of 270-310℃ and a spinning speed of 500-1500 m / min. A three-stage stretching and setting process was employed, with a total stretch ratio of 4.0-6.

5. The tension heat setting temperature was 150-230℃, and the relaxation heat setting temperature was 100-200℃. The stretching and winding speed was 2500-4000 m / min, yielding high-strength industrial filaments of furanyl semi-aromatic polyamide. The three-stage stretching and setting process includes a first-stage pre-stretch, a second-stage main stretch, and a third-stage secondary stretch. The stretching ratio of the first-stage pre-stretch is 1.0 to 1.2, the stretching ratio of the second-stage main stretch is 2.0 to 2.5, and the stretching ratio of the third-stage secondary stretch is 2.0 to 2.

5. Tension heat setting is performed during the second-stage main stretch, and relaxation heat setting is performed during the third-stage secondary stretch.

2. The industrial filament according to claim 1, characterized in that, The aliphatic diamine is 1,10-decanediamine; and / or, the value of m is 8, 10, or 12.

3. The industrial filament according to claim 1 or 2, characterized in that, The reaction raw materials also contain antioxidants, which are selected from one or more of antioxidants 1010, SEED, and B215.

4. The industrial filament according to claim 3, characterized in that, The molar ratio of the dimethyl 2,5-furandicarboxylate to the aliphatic diamine is 1:(1.02~1.08); and / or, the amount of the catalyst is 0.1~0.3% of the mass of the dimethyl 2,5-furandicarboxylate; and / or, the amount of the antioxidant is 0.05~0.1% of the total mass of the dimethyl 2,5-furandicarboxylate and the aliphatic diamine.

5. The industrial filament according to claim 1, characterized in that, During the preparation of the raw material furanyl semi-aromatic polyamide, the reaction raw material is stirred during the heating process to 90~150℃ and during the reaction process at 90~150℃, with a stirring speed of 100~200r / min.

6. The industrial filament according to claim 5, characterized in that, During the negative compression polymerization process, the stirring speed is 20~60 r / min and the reaction time is 1~4 h.

7. The industrial filament according to claim 6, characterized in that, During the negative compression polymerization process, the stirring speed is 50 r / min and the reaction time is 1~2 h.

8. The industrial filament according to claim 1, characterized in that, The temperature of the first stage of pre-stretching is 110~150℃; the temperature of tension heat setting is 180~230℃; and the temperature of relaxation heat setting is 100~140℃.

9. The industrial filament according to claim 1, characterized in that, The furanyl semi-aromatic polyamide high-strength industrial yarn has a yarn strength of 9.0~12.0 cN / dtex, a breaking elongation of 15~27%, and a heat shrinkage rate of 4~7%.

10. The application of the furanyl semi-aromatic polyamide high-strength industrial yarn according to any one of claims 1-9, for use in the manufacture of tire cord, airbag yarn, waterproof cloth, canvas, seat belt, rope, fishing net, industrial filter cloth, conveyor belt, parachute, tent, and luggage.

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