Method for synthesizing long carbon chain semi-aromatic nylon

Abstract

The disclosure relates to a synthesis method of long carbon chain semi-aromatic nylon. The synthesis method comprises the following steps: mixing a wet powdery nylon salt, an antioxidant, a catalyst, a surfactant and pellets, and carrying out a one-step solid state polymerization under dynamic mixing to obtain a powdery nylon; under dynamic mixing, enabling the pellets to promote the stirring and mixing of the material and reducing material adhesion to the wall; the one-step solid state polymerization comprises a pre-solid state polymerization and a post-solid state polymerization; in the pre-solid state polymerization, ensuring the nylon salt and the prepolymer not to be molten; in the post-solid state polymerization, gradually reducing the system pressure to vacuum, and keeping the system pressure in vacuum state for at least 1 hour; the temperature of the post-solid state polymerization is not lower than the termination temperature of the pre-solid state polymerization.

Claims

1. A method for synthesizing a long carbon chain semi-aromatic nylon, wherein the method comprises: mixing a wet powdery nylon salt, an antioxidant, a catalyst, a surfactant, and pellets and carrying out a one-step solid state polymerization under dynamic mixing to obtain a powdery nylon, wherein the wet powdery nylon salt has a solvent content of 5-40% wt, and is prepared by salt-forming reaction of terephthalic acid and a long carbon chain diamine with 10-14 carbon atoms in the solvent, wherein the pellets promote stirring and mixing of materials and reduce sticking of materials to a wall under dynamic mixing, wherein the one-step solid state polymerization includes pre-solid state polymerization and post-solid state polymerization; in the pre-solid state polymerization, gradually increasing temperature of the system from 150-190 C. to 180-220 C., ensuring the nylon salt and the prepolymer not to be molten, and increasing the solvent vapor pressure to 1.00-2.20 MPa during the period; in the post-solid state polymerization, gradually reducing the system pressure to vacuum and holding for at least 1 h; the temperature of the post-solid state polymerization should not be lower than the termination temperature of the pre-solid state polymerization; and wherein, in the pre-solid state polymerization, gradually increasing the temperature from 150-190 C. to 180-220 C. includes: holding the temperature at 150-190 C. for 0.5-2 h, then increasing the temperature to 180-220 C. at a rate of 5-10 C. for 0.5-1 h, and holding for 0.5-2 h.

2. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 1, wherein the time of the pre-solid state polymerization is 2-6 h.

3. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 1, wherein gradually reducing the system pressure to vacuum comprises steam releasing and vacuuming after steam releasing, and the stream releasing time is 1-3 h.

4. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 3, wherein the temperature is increased to 200-240 C. at a rate of 3-10 C. for 0.5-1 h after steam releasing for 0.5 h.

5. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 1, wherein the vacuum holding time is 1-6 h.

6. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 2, wherein the vacuum holding time is 1-6 h.

7. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 3, wherein the vacuum holding time is 1-6 h.

8. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 4, wherein the vacuum holding time is 1-6 h.

9. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 1, wherein the catalyst is one or more selected from a group consisting of phosphorous acid, sodium hypophosphite, triphenyl phosphate, and H10, and an amount of the catalyst is 0.1-0.5% of the dry mass of the wet powdery nylon salt.

10. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 1, wherein the antioxidant is one or more selected from a group consisting of sodium hypophosphite, 1010, s9228, SH120, and B215, and an amount of the antioxidant is 0.1-0.5% of the dry mass of the wet powdery nylon salt.

11. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 1, wherein the solvent in the wet powdery nylon salt is one or more selected from a group consisting of water, ethanol, and methanol.

12. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 1, wherein the long carbon chain diamine is one or more selected from a group consisting of decanediamine, undecanediamine, dodecanediamine, tridecanediamine, and tetradecanediamine.

13. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 9, wherein the long carbon chain diamine is one or more selected from a group consisting of decanediamine, undecanediamine, dodecanediamine, tridecanediamine, and tetradecanediamine.

14. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 10, wherein the long carbon chain diamine is one or more selected from a group consisting of decanediamine, undecanediamine, dodecanediamine, tridecanediamine, and tetradecanediamine.

15. The method for synthesizing the long carbon chain semi-aromatic nylon according to claim 11, wherein the long carbon chain diamine is one or more selected from a group consisting of decanediamine, undecanediamine, dodecanediamine, tridecanediamine, and tetradecanediamine.

16. A method for synthesizing a long carbon chain semi-aromatic nylon, wherein the method comprises: mixing a wet powdery nylon salt, an antioxidant, a catalyst, a surfactant, and pellets and carrying out a one-step solid state polymerization under dynamic mixing to obtain a powdery nylon, wherein the wet powdery nylon salt has a solvent content of 5-40% wt, and is prepared by salt-forming reaction of terephthalic acid and a long carbon chain diamine with 10-14 carbon atoms in the solvent, wherein the pellets promote stirring and mixing of materials and reduce sticking of materials to a wall under dynamic mixing, wherein the one-step solid state polymerization includes pre-solid state polymerization and post-solid state polymerization; in the pre-solid state polymerization, gradually increasing temperature of the system from 150-190 C. to 180-220 C., ensuring the nylon salt and the prepolymer not to be molten, and increasing the solvent vapor pressure to 1.00-2.20 MPa during the period; in the post-solid state polymerization, gradually reducing the system pressure to vacuum and holding for at least 1 h; the temperature of the post-solid state polymerization should not be lower than the termination temperature of the pre-solid state polymerization; wherein gradually reducing the system pressure to vacuum comprises steam releasing and vacuuming after stream releasing, and the steam releasing time is 1-3 h; and wherein the temperature of the post-solid state polymerization is increased to 200-240 C. at a rate of 3-10 C. for 0.5-1 h after steam releasing for 0.5 h.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a structural schematic diagram of the synthesis device for long carbon chain semi-aromatic nylon used in an embodiment of the present disclosure;

(2) FIG. 2 is the FT-IR image of the semi-aromatic nylon PA12T obtained in Example 1 of the present disclosure;

(3) FIG. 3 is the .sup.1H-NMR image of the semi-aromatic nylon PA12T obtained in Example 1 of the present disclosure;

(4) wherein, 1rack, 2rotary drum reactor, 3circulation heat medium temperature control system, 4gas release system, 5gas replacement system, 6vibrating screen, 7baffle plate, 8temperature sensor, 9filter cover, 10filter, 11cyclone separator, 12vacuum buffer tank, 13vacuum pump, 14material port.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(5) The implementation of the present disclosure will be further described below in conjunction with specific examples.

(6) The following example uses the long carbon chain semi-aromatic nylon synthesis device as shown in FIG. 1 to efficiently synthesize long carbon chain semi-aromatic nylon.

(7) Specifically, the volume of the device used in this experiment is 30 L, including the rack 1, the rotary drum reactor 2, the circulating heat medium temperature control system 3, the steam release system 4, the vacuum system, the gas replacement system 5 and the vibrating screen 6.

(8) The rotary drum reactor includes a cylinder and left and right heads, and a baffle plate 7 is provided on the inner wall of the cylinder.

(9) The rotary drum reactor 2 is rotatably assembled on the rack 1 with an included angle between the rotation axis and the central axis of the cylindrical side wall, and the included angle is 0-90, such as 30-60. The driving device drives the drum reactor to rotate along the axis of rotation.

(10) The rotary drum reactor is also connected with a circulating heat medium temperature control system 3, a temperature sensor 8, a vacuuming system, a steam release system 4, and a gas replacement system 5. The vacuuming system, the stream release system 4, and the gas replacement system 5 are connected to the rotary drum reactor through the same connecting pipeline, a filter cover 9 is provided at the connection position of the rotary drum reactor and the connecting pipeline, the filter cover 9 can prevent powdery material from rushing out and blocking the pipeline.

(11) The steam release system 4 includes a steam release pipe and a vent valve installed on the steam release pipe. The gas replacement system 5 includes a gas source and a gas replacement pipeline. The vacuuming system includes a filter 10, a cyclone separator 11, a vacuum buffer tank 12 and a vacuum pump 13 which are connected in sequence.

(12) The rotary drum reactor is provided with a material port 14. When discharging, a vibrating screen is installed downstream of the material port 14. The vibrating screen is used to receive the discharge from the rotary drum reactor and screen the pellets and powdery materials.

Example 1

(13) The synthesis method of long carbon chain semi-aromatic nylon of this embodiment includes the following steps:

(14) 1) 15 kg of pure water was added to the salt-forming autoclave, 2.76 kg of dodecanediamine and 2.27 kg of terephthalic acid (the molar ratio of 1.01:1) were added, the autoclave was sealed, the gas in the autoclave was replaced with N.sub.2 for three times and the pressure inside the autoclave was kept at 0.01 MPa. The stirring motor was turned on and the stirring speed was adjusted to 150 r/min. The autoclave was heated, when the temperature in the autoclave was increased to 140 C., the pH value was 7.2, and the temperature and the pressure were kept for 1 h. The temperature was lowered to obtain a mixed solution of nylon PA12T salt. The mixed solution was dehydrated to prepare a wet powdery nylon PA12T salt with a water content of 10 wt %.

(15) 2) 4 kg of the wet powdery nylon PA12T salt obtained in step 1), 12 g of catalyst phosphorous acid, 8 g of antioxidant SH120, 20 g of surfactant heavy alkylbenzene sulfonate and 50 polyether-ether-ketones pellets with a diameter of 40 mm were weighed and placed into the above rotary drum reactor, the reactor was sealed, the gas inside the reactor was replaced with N.sub.2 for three times and the pressure in the reactor was maintained at 0.01 MPa. The rotary drum motor was turned on and the rotary drum speed was adjusted to 4 r/min. The reactor was heated, the internal temperature of the reactor was firstly increased to 180 C. and kept for 0.5 h; then the temperature was increased to 210 C. at a rate of 10 C. for 0.5 h, at this time, the internal pressure of the reactor was 1.73 MPa; the temperature and pressure were hold for 1 h; the steam was released, after the steam was released for 0.5 h, the temperature was increased to 220 C. at a rate of 3-4 C. for 0.5 h, the steam release time was 2 h; then vacuum was applied for 2 h. The temperature was reduced and the material was discharged to obtain a white powdery semi-aromatic nylon PA12T.

Example 2

(16) The synthesis method of long carbon chain semi-aromatic nylon of this embodiment includes the following steps:

(17) 1) 15 kg of pure water was added to the salt-forming autoclave, 2.57 kg of decanediamine and 2.46 kg of terephthalic acid (the molar ratio of 1.01:1) were added, the autoclave was sealed, the gas in the autoclave was replaced with CO.sub.2 for three times and the pressure inside the autoclave was kept at 0.01 MPa. The stirring motor was turned on and the stirring speed was adjusted to 200 r/min. The autoclave was heated, when the temperature in the autoclave was increased to 140 C., the pH value was 7.5, and the temperature and the pressure were kept for 1 h. The temperature was lowered to obtain a mixed solution of nylon PA10T salt. The mixed solution was dehydrated to prepare a wet powdery nylon PA10T salt with a water content of 10 wt %.

(18) 2) 4 kg of the wet powdery nylon PA10T salt obtained in step 1), 12 g of catalyst sodium hypophosphite, 8 g of antioxidant s9228, 20 g of surfactant fatty alcohol polyoxyethylene ether sodium sulfate and 40 stainless steel pellets with a diameter of 50 mm were weighed and placed into a homemade rotary drum reactor, the reactor was sealed, the gas inside was replaced with N.sub.2 for three times and the pressure in the reactor was maintained at 0.01 MPa. The rotary drum motor was turned on and the rotary drum speed was adjusted to 3 r/min. The reactor was heated, the internal temperature of the reactor was firstly increased to 180 C. and kept for 0.5 h; then the temperature was increased to 210 C. at a rate of 10 C. for 0.5 h, at this time the internal pressure of the reactor was 1.76 MPa; the temperature and pressure were hold for 1 h; the steam was released, after the steam was released for 0.5 h, the temperature was increased to 220 C. at a rate of 3-4 C. for 0.5 h, the steam release time was 2 h; then vacuum was applied for 2 h. The temperature was reduced and the material was discharged to obtain a white powdery semi-aromatic nylon PA10T.

Example 3

(19) The synthesis method of long carbon chain semi-aromatic nylon of this embodiment includes the following steps:

(20) 1) 15 kg of pure water was added to the salt-forming autoclave, 2.92 kg of tetradecanediamine and 2.11 kg of terephthalic acid (the molar ratio of 1.01:1) were added, the autoclave was sealed, the gas in the autoclave was replaced with N.sub.2 for three times and the pressure inside the autoclave was kept at 0.01 MPa. The stirring motor was turned on and the stirring speed was adjusted to 100 r/min. The autoclave was heated, when the temperature in the autoclave was increased to 140 C., the pH value was 6.7, 36 g of tetradecanediamine was added, the pH value was 7.2 and the condition was kept for 1 h. The temperature was lowered to obtain a mixed solution of nylon PA14T salt. The mixed solution was dehydrated to prepare a wet powdery nylon PA14T salt with a water content of 10 wt %.

(21) 2) 4 kg of the wet powdery nylon PA14T salt obtained in step 1), 12 g of catalyst H10, 8 g of antioxidant B215, 20 g of surfactant (para-position) linear sodium dodecyl benzene sulfonate and 50 polytetrafluoroethylene pellets with a diameter of 35 mm were weighed and placed into a homemade rotary drum reactor, the reactor was sealed, the gas inside the reactor was replaced with N.sub.2 for three times and the pressure in the reactor was maintained at 0.01 MPa. The rotary drum motor was turned on and the rotary drum speed was adjusted to 5 r/min. The reactor was heated, the internal temperature of the reactor was firstly increased to 180 C. and kept for 0.5 h; then the temperature was stepwise increased to 210 C. at a rate of 10 C. for 0.5 h, at this time the internal pressure of the reactor was 1.69 MPa; the temperature and pressure were hold for 1 h; the steam was released, after the steam was released for 0.5 h, the temperature was increased to 220 C. at a rate of 3-4 C. for 0.5 h, the steam release time was 2 h; then vacuum was applied for 2 h. The temperature was reduced and the material was discharged to obtain a white powdery semi-aromatic nylon PA14T.

Example 4

(22) The new method for synthesizing long carbon chain semi-aromatic nylon in this example is different from Example 1 only in that the vacuum time at the end of the polymerization is different, other formulas and process parameters are the same as those in Example 1. In this example, the vacuum time was 1 h.

Example 5

(23) The new method for synthesizing long carbon chain semi-aromatic nylon in this example is different from Example 1 only in that the vacuum time at the end of the polymerization is different, other formulas and process parameters are the same as those in Example 1. In this example, the vacuum time was 4 h.

Example 6

(24) The new method for synthesizing long carbon chain semi-aromatic nylon in this example is different from Example 1 only in that the vacuum time at the end of the polymerization is different, other formulas and process parameters are the same as those in Example 1. In this example, the vacuum time was 6 h.

Example 7

(25) The new method for synthesizing long carbon chain semi-aromatic nylon in this example is different from Example 1 only in that the final reaction temperature of the steam release stage during the polymerization is different, and other formulas and process parameters are the same as in Example 1. In the example, the final reaction temperature was 210 C., that is, there is no need to increase the temperature during the steam release and vacuum stages.

Example 8

(26) The new method for synthesizing long carbon chain semi-aromatic nylon in this example is different from Example 1 only in that the final reaction temperature of the steam release stage during the polymerization is different, and other formulas and process parameters are the same as in Example 1. In the example, the final reaction temperature was 230 C., that is, after 0.5 h of steam release, the temperature was increased to 230 C. at a rate of (6-7) C. for 0.5 h.

Example 9

(27) The new method for synthesizing long carbon chain semi-aromatic nylon in this example is different from Example 1 only in that the water content of the nylon salt is different, and other formulas and process parameters are the same as in Example 1. In this example, the water content of the nylon salt was 8 wt % (320 g water in the rotary drum reactor).

Example 10

(28) The new method for synthesizing long carbon chain semi-aromatic nylon in this example is different from Example 1 only in that the water content of the nylon salt is different, and other formulas and process parameters are the same as in Example 1. In this example, the water content of the nylon salt was 12 wt % (480 g water in the rotary drum reactor).

Example 11

(29) The new method for synthesizing long carbon chain semi-aromatic nylon in this example is different from Example 1 only in that the amount of catalyst is different, and other formulations and process parameters are the same as in Example 1. In this example, the amount of catalyst was 5 g.

Example 12

(30) The new method for synthesizing long carbon chain semi-aromatic nylon in this example is different from Example 1 only in that the amount of catalyst is different, and other formulas and process parameters are the same as in Example 1. In this example, the amount of catalyst was 25 g.

Example 13

(31) The synthesis method of long carbon chain semi-aromatic nylon of this embodiment includes the following steps:

(32) 1) 15 kg of ethanol was added to the salt-forming autoclave, 2.76 kg of dodecanediamine and 2.27 kg of terephthalic acid (the molar ratio of 1.01:1) were added, the autoclave was sealed, the gas in the autoclave was replaced with N.sub.2 three times, and the pressure inside the autoclave was kept at 0.01 MPa. The stirring motor was turned on and the stirring speed was adjusted to 150 r/min. The autoclave was heated, when the temperature in the autoclave was increased to 120 C., the pH value was 7.2, and the temperature and the pressure were kept for 1 h. The temperature was lowered to obtain a mixed solution of nylon PA12T salt. The mixed solution was subjected to ethanol removal to prepare a wet powdery nylon PA12T salt with an ethanol content of 10 wt %.

(33) 2) 4 kg of the wet powdery nylon PA12T salt obtained in step 1), 12 g of catalyst triphenyl phosphate, 8 g of antioxidant s9228, 20 g of surfactant sodium lauryl sulfate and 40 agate balls with a diameter of 40 mm were weighed and placed into a homemade rotary drum reactor, the reactor was sealed, the gas inside the reactor was replaced with Ar three times and the pressure in the reactor was maintained at 0.01 MPa. The rotary drum motor was turned on and the rotary drum speed was adjusted to 4 r/min. The reactor was heated, the internal temperature of the reactor was firstly increased to 160 C. and kept for 0.5 h; then the temperature was stepwise increased to 190 C. at a rate of 10 C. for 0.5 h, at this time the internal pressure of the reactor was 2.06 MPa; the temperature and pressure were hold for 1 h; the steam was released, after the steam was released for 0.5 h, the temperature was increased to 220 C. at a rate of 10 C. for 0.5 h, the steam release time was 2 h; then vacuum was applied for 2 h. The temperature was reduced and the material was discharged to obtain a white powdery semi-aromatic nylon PA12T.

Example 14

(34) The synthesis method of long carbon chain semi-aromatic nylon of this embodiment includes the following steps:

(35) 1) 15 kg of pure water was added to the salt-forming autoclave, 0.30 kg of dodecanediamine, 2.29 kg of decanediamine and 2.43 kg of terephthalic acid (the molar ratio of diamine to diacid of 1.01:1, the molar ratio of PA10T salt to PA12T salt of 9:1) were added, the autoclave was sealed, the gas in the autoclave was replaced with N.sub.2 three times, and the pressure inside the autoclave was kept at 0.01 MPa. The stirring motor was turned on and the stirring speed was adjusted to 150 r/min. The autoclave was heated, when the temperature in the autoclave was increased to 140 C., the pH value was 7.2, and the temperature and the pressure were kept for 1 h. The temperature was lowered to obtain a mixed solution of nylon PA10T/12T salt. The mixed solution was dehydrated to prepare a wet powdery nylon PA10T/12T salt with a water content of 10 wt %.

(36) 2) 4 kg of the wet powdery nylon PA10T/12T salt obtained in step 1), 12 g of catalyst sodium hypophosphite, 8 g of antioxidant SH120, 20 g of surfactant heavy alkylbenzene sulfonate and 50 polyether-ether-ketone pellets with a diameter of 40 mm were weighed and placed into a homemade rotary drum reactor, the reactor was sealed, and the gas inside the reactor was replaced with N.sub.2 three times and the pressure in the reactor was maintained at 0.01 MPa. The rotary drum motor was turned on and the rotary drum speed was adjusted to 4 r/min. The reactor was heated, the internal temperature of the reactor was firstly increased to 180 C. and kept for 0.5 h; then the temperature was increased to 220 C. at a rate of 10 C. for 0.5 h, at this time the internal pressure of the reactor was 1.75 MPa; the temperature and pressure were hold for 1 h; the steam was released, after the steam was released for 0.5 h, the temperature was increased to 230 C. at a rate of 3-4 C. for 0.5 h, the steam release time was 2 h; then vacuum was applied for 2 h. The temperature was reduced and the material was discharged to obtain a white powdery semi-aromatic nylon PA10T/12T.

2. Explanation of the Comparative Example

Comparative Example 1

(37) The new method for synthesizing long carbon chain semi-aromatic nylon in this comparative example is different from Example 1 only in that the water content of the nylon salt is different, and other formulas and process parameters are the same as in Example 1. In this comparative example, the water content of the nylon salt is zero.

Comparative Example 2

(38) The new method for synthesizing long carbon chain semi-aromatic nylon in this comparative example is different from Example 1 only in that the vacuum time in the late polymerization stage is different. Other formulas and process parameters are the same as in Example 1. In this comparative example, the vacuum time is zero.

3. Experimental Example

Experimental Example 1

(39) The semi-aromatic nylon PA12T obtained in Example 1 was tested by FT-IR and .sup.1H-NMR test, the results are shown in FIG. 2 and FIG. 3.

(40) In FIG. 2, 3313 cm.sup.1 is the stretching vibration peak of NH, 2919 cm.sup.1 and 2848 cm.sup.1 is the stretching vibration peak of CH.sub.2, 1630 cm.sup.1 is the stretching vibration peak of CO (amide I band), 1534 cm.sup.1 is the in-plane bending vibration peak of NH (amide II band), 1276 cm.sup.1 is the stretching vibration peak of CN(amide III band), 854 cm.sup.1 is the out-of-plane bending vibration peak of CH on the benzene ring.

(41) FIG. 3 shows the chemical shift of each H.

(42) From the results of FIG. 2 and FIG. 3, it can be seen that the white powdery product obtained in Example 1 is a semi-aromatic nylon PA12T.

Experimental Example 2

(43) The melting point, intrinsic viscosity, melt index, mechanical properties, and thermal deformation temperature of the products obtained in each example were characterized. The test equipment and test standards used for each characterization are shown in Table 1.

(44) TABLE-US-00001 TABLE 1 Product test items, test equipment and test standards Test items Test equipment Test standard Melting point DSC (PE-8500) 10 C./min Intrinsic viscosity Ubbelohde viscometer GB/T 12006.1-2009 Melt flow rate Melt flow rate tester GB/T 3682-2000 (ZRZ2452) Tensile strength Microcomputer controlled GB/T 1040.2-2006 Elongation at break electronic universal tester Bending strength (CMT4204) GB/T 9341-2008 Bending modulus Notched impact Pendulum impact tester GB/T 1043.1-2008 strength (ZBC8400-B) Thermal deformation Thermal deformation GB/T 1634.2-2004 temperature VEKA softening point tester (ZWK 1302-A)

(45) The performance test results of the long carbon chain semi-aromatic nylon of Examples 1-3 are shown in Table 2.

(46) TABLE-US-00002 TABLE 2 Properties of long carbon chain semi-aromatic nylon obtained in Example 1-3. Items Example 1 Example 2 Example 3 Product status powdery powdery powdery Color white white white Melting point ( C.) 318 334 302 Intrinsic viscosity (dL/g) 0.72 0.64 0.97 Melt flow rate (g/10 min) 29 20 34 Tensile strength (MPa) 73 86 58 Elongation at break (%) 56 34 72 Bending strength (MPa) 48 55 42 Bending modulus (GPa) 1.52 1.74 1.27 Notched impact strength 9.3 8.1 11.7 (kJ/m.sup.2) Thermal deformation 118 123 112 temperature (1.8 MPa, C.)

(47) In Table 2, three long carbon chain semi-aromatic nylons PA12T, PA10T and PA14T are all discharged in powdery form, which indicates that solid state polymerization has occurred during this process, there is basically no melting phenomenon, and the color of the product is white. As the number of carbon atoms in the diamine increases, the melting point, tensile strength, bending strength, bending modulus, and thermal deformation temperature of the corresponding nylon product gradually decrease, and the elongation at break and notched impact strength gradually increase, which is also in accordance with the theory.

(48) The melting point of the obtained PA12T and PA1 OT is higher than that of the product obtained by traditional two-step method (Synthesis and characterization of PA10T and its copolymer (319 C.) and Synthesis, characterization and performance of semi-aromatic high-temperature nylon PA12T (293 C.)), which is related to the polymerization method and product structure.

(49) The above analysis shows that the new one-step solid state polymerization is very suitable for the production of long carbon chain semi-aromatic nylon, and the product quality is very good.

(50) The properties of long carbon chain semi-aromatic nylon obtained in Example 1 and Example 4-6 with vacuum time of 2 h, 1 h, 4 h and 6 h respectively, as shown in Table 3.

(51) TABLE-US-00003 TABLE 3 Properties of long carbon chain semi-aromatic nylon obtained in Example 1 and Examples 4-6 Items Example 4 Example 1 Example 5 Example 6 Product status powdery powdery powdery powdery Color white white white white Melting point ( C.) 319 318 318 320 Intrinsic viscosity (dL/g) 0.55 0.72 1.02 1.21 Melt flow rate (g/10 min) 43 29 17 8 Tensile strength (MPa) 58 73 75 74 Elongation at break (%) 13 56 53 55 Bending strength (MPa) 36 48 49 51 Bending modulus (GPa) 1.17 1.52 1.58 1.63 Notched impact strength 4.6 9.3 9.1 9.0 (kJ/m.sup.2) Thermal deformation 117 118 119 122 temperature (1.8 MPa, C.)

(52) It can be seen from Table 3 that with the extension of the vacuum time, the intrinsic viscosity of PA12T gradually increases and the melt index gradually decreases, but other properties remain basically unchanged.

(53) Example 1, Example 7, and Example 8 reflect the effect of the final reaction temperature of postsolid state polymerization on the product performance. Example 1 is that the temperature is increased to 220 C. at a rate of 3-4 C. for 0.5 h after the steam is released for 0.5 h, and the final reaction temperature is kept at 220 C.; Example 7 is that there is no temperature rise during the steam release and vacuuming stages, and the final reaction temperature is maintained at 210 C.; Example 8 is that the temperature is increased to 230 C. at a rate of (6-7) C. for 0.5 h after the steam is released for 0.5 h, and the final reaction temperature is kept at 230 C., and the specific results are shown in Table 4.

(54) TABLE-US-00004 TABLE 4 Properties of long carbon chain semi-aromatic nylon obtained in Example 1 and Examples 7-8 Items Example 7 Example 1 Example 8 Product status powdery powdery powdery Color white white white Melting point ( C.) 319 318 317 Intrinsic viscosity (dL/g) 0.51 0.72 1.12 Melt flow rate (g/10 min) 47 29 22 Tensile strength (MPa) 66 73 74 Elongation at break (%) 43 56 51 Bending strength (MPa) 42 48 48 Bending modulus (GPa) 1.31 1.52 1.55 Notched impact strength 8.4 9.3 9.3 (kJ/m.sup.2) Thermal deformation 116 118 121 temperature (1.8 MPa, C.)

(55) It can be seen from Table 4 that as the reaction temperature increases, the intrinsic viscosity of PA12T gradually increases and the melt index gradually decreases, but other properties remain basically unchanged.

(56) Example 1 and Examples 9-10 reflect the influence of the solvent content in the wet powdery nylon salt on the product performance. The solvent content of the wet powdery nylon salt in Example 1, Example 9 and Example 10 are 10 wt %, 8 wt %, 12 wt %, respectively, the specific results are shown in Table 5.

(57) TABLE-US-00005 TABLE 5 Properties of long carbon chain semi-aromatic nylons in Example 1 and Examples 9-10 Items Example 9 Example 1 Example 10 Product status powdery powdery powdery Color white white white Melting point ( C.) 318 318 319 Intrinsic viscosity (dL/g) 0.60 0.72 0.95 Melt flow rate (g/10 min) 42 29 20 Tensile strength (MPa) 69 73 74 Elongation at break (%) 48 56 53 Bending strength (MPa) 44 48 49 Bending modulus (GPa) 1.42 1.52 1.52 Notched impact strength 8.6 9.3 9.2 (kJ/m.sup.2) Thermal deformation 117 118 120 temperature (1.8 MPa, C.)

(58) It can be seen from Table 5 that when the solvent (water) content of the wet powdery nylon salt is not less than 8 wt %, PA12T salt can react to form PA12T, and as the water content increases, the intrinsic viscosity of PA12T gradually increases, and the melt flow rate gradually decreases, but other properties remain basically unchanged.

(59) Example 1 and Examples 11-12 reflect the effects of different catalyst dosages on product performance, wherein, the catalyst dosages of Example 11, Example 1, and Example 12 are 5 g, 12 g, and 25 g, respectively. The specific results are shown in Table 6.

(60) TABLE-US-00006 TABLE 6 Properties of long carbon chain semi-aromatic nylon obtained in Example 1 and Examples 11-12 Items Example 11 Example 1 Example 12 Product status powdery powdery powdery Color white white white Melting point ( C.) 318 318 319 Intrinsic viscosity (dL/g) 0.61 0.72 1.02 Melt flow rate (g/10 min) 40 29 22 Tensile strength (MPa) 69 73 74 Elongation at break (%) 51 56 53 Bending strength (MPa) 46 48 49 Bending modulus (GPa) 1.82 1.52 1.52 Notched impact strength 8.8 9.3 9.2 (kJ/m.sup.2) Thermal deformation 118 118 120 temperature (1.8 MPa, C.)

(61) It can be seen from Table 6 that as the amount of catalyst increases, the intrinsic viscosity of PA12T gradually increases and the melt flow rate gradually decreases, but other properties remain basically unchanged.

(62) The solvent of the PA12T salt used in Example 13 is ethanol, and the properties of the obtained semi-aromatic nylon PA12T are shown in Table 7.

(63) TABLE-US-00007 TABLE 7 Properties of long carbon chain semi-aromatic nylon obtained in Examples 1 and 13 Items Example 1 Example 13 Product status powdery powdery Color white white Melting point ( C.) 318 319 Intrinsic viscosity (dL/g) 0.72 0.74 Melt flow rate (g/10 min) 29 29 Tensile strength (MPa) 73 72 Elongation at break (%) 56 54 Bending strength (MPa) 48 49 Bending modulus (GPa) 1.52 1.55 Notched impact strength 9.3 9.6 (kJ/m.sup.2) Thermal deformation 118 121 temperature (1.8 MPa, C.)

(64) It can be seen from Table 7 that the change of solvent type has little effect on the performance of PA12T.

(65) TABLE-US-00008 TABLE 8 Properties of long carbon chain semi-aromatic nylon obtained in Examples 1 and 14 Items Example 1 Example 14 Product status powdery powdery Color white white Melting point ( C.) 318 319 Intrinsic viscosity (dL/g) 0.72 0.76 Melt flow rate (g/10 min) 29 27 Tensile strength (MPa) 73 76 Elongation at break (%) 56 47 Bending strength (MPa) 48 51 Bending modulus (GPa) 1.52 1.69 Notched impact strength 9.3 8.5 (kJ/m.sup.2) Thermal deformation 118 122 temperature (1.8 MPa, C.)

(66) It can be seen from Table 8 that the device and experimental scheme are also suitable for the synthesis of copolymerized long carbon chain semi-aromatic nylon, and the performance of product is excellent.

(67) In Comparative Example 1, the water content of the nylon salt is 0, and in Comparative Example 2, the vacuum time is 0. The properties of the long carbon chain semi-aromatic nylon obtained in Example 1, Comparative Example 1, and Comparative Example 2 are shown in Table 9.

(68) TABLE-US-00009 TABLE 9 Properties of long carbon chain semi-aromatic nylon obtained in Example 1, Comparative Examples 1-2 Comparative Comparative Items Example 1 Example 1 Example 2 Product status powdery powdery powdery Color white white white Melting point ( C.) 318 273 318 Intrinsic viscosity (dL/g) 0.72 0.04 0.25 Comment no low molecular polymerization weight, cannot be occurred injection molded

(69) It can be seen from the results in Table 9 that in Comparative Example 1, when the water content of the nylon salt is 0, no polymerization reaction occurs; in Comparative Example 2, the intrinsic viscosity is only 0.25 dL/g without vacuuming, which is much lower than that of Example 1 and cannot be injection molded.