CN1315912C - Block copolyamide and preparation thereof - Google Patents

Abstract

The invention relates to a copolyamide and a preparation method thereof, in particular to a block copolyamide and a preparation method thereof. The problems of high cost of nylon resin and poor low-temperature resilience and flexibility existing in the prior art are solved. Its structure is shown in the following molecular formula. It is composed of monomers such as 11-aminoundecanoic acid, 12-aminododecanoic acid and 6-aminocaproic acid or caprolactam, aminoacetic acid, aminobutyric acid, 8-aminooctanoic acid or Octane lactam, 9-aminononanoic acid or nonane lactam, 10-aminocapric acid or decanolactam, 11-aminoundecanoic acid, laudecyl lactam or 12-aminododecanoic acid, 14-amino Any one of myristic acid can be made by copolymerization of its corresponding prepolymer. The block copolyamide prepared by the invention and the preparation method thereof diversify the nylon resin products, reduce the cost, improve the performance and make it more practical.

Description

Block copolyamide and its preparation method

technical field

The invention relates to a copolyamide and a preparation method thereof, in particular to a block copolyamide and a preparation method thereof.

Background technique

Polyamide, commonly known as nylon, has excellent properties and is widely used in automobiles, electronics and other fields. In particular, nylon 11 based on 11-aminoundecanoic acid or nylon 12 based on dodecyl lactam or 12-aminododecanoic acid has the general generality and good comprehensive properties of polyamides, and has unique physical and chemical properties, such as relative The density is small, the mechanical properties are less affected by water absorption, and the impact strength is good at low temperature. But nylon 11 or nylon 12 is expensive, and more importantly, it cannot be made into a hose without adding plasticizers, and gasoline is a good solvent for plasticizers, so once nylon encounters gasoline, it will denature and cannot be used normally . Commercial nylons are usually alloys or copolymers of several different nylons. The purpose of preparing these mixed nylon resins is to improve the performance of one of the nylons as the main component, but usually at the expense of other properties. CN1214349 discloses a method for preparing copolyamide by polycondensation of a mixture of lauryl lactam or 12-aminododecanoic acid and 11-aminoundecanoic acid (different from the present invention in performance), and US4507465 describes a Lactam/polyhydroxyl block polymer and its preparation method, US4485213 has described a kind of preparation method of high-impact block copolyamide, and it is that under the condition that a kind of prepolymer polymerization accelerator exists, ω-lactam passes through obtained by anionic polymerization. An improved method for the preparation of block copolyamides is disclosed in EP1141023. EP355017A2 describes a method for preparing block copolyamide, that is, polycondensation of diamine and dibasic fatty acid to obtain a prepolymer, and then adding a polyamide monomer to prepare a block copolymer.

Contents of the invention

The invention provides a block copolyamide and a preparation method thereof in order to solve the problems of high cost of nylon resin and poor low-temperature resilience and flexibility in the prior art.

The molecular formula of block copolyamide of the present invention is as follows:

Among them, a=2, 4, 6, 8, 9, 10, 11, 12, 14; b=11 or 12; c=2, 4, 6, 8, 9, 10, 11, 12, 14; x ₁ =1-100, y ₁ =0-200, x ₂ =1-100, y ₂ =1-100, x ₃ =1-100, y ₃ =0-200, where a≠b≠c; y ₁ , _y3 is not zero at the same time.

The preparation method of block copolyamide of the present invention comprises the preparation of prepolymer and block copolymer,

①. Preparation of nylon prepolymer: Add a monomer and 5-50% deionized water by weight into the autoclave, exhaust the air, and heat it to 170-190°C in a closed manner, and then keep the reactant under heat and pressure 0.5-3 hours, then depressurized to ambient pressure, then heated to 220-230°C, vacuumed for 0.5-2 hours, supplemented with nitrogen or inert gas when discharging, to obtain a prepolymer. The number average molecular weight of nylon prepolymer is between 500-10000.

②, the preparation of block copolymer, mix one prepolymer prepared in the above steps with another or several prepolymers and add deionized water with 5-50% of the weight of the mixture into the stirred polymerization reactor During the process, exhaust the air 3 to 5 times, heat the reactor to 170 to 240 ° C, keep the temperature and pressure of the reactant under the condition of self-generated pressure for 0.5 to 4 hours, release the air and depressurize to the ambient pressure, and then heat to 210 to 210 ° C. Further react at 270°C, and then vacuumize for 0.5 to 5 hours to complete the reaction. Supplement nitrogen or inert gas when discharging as needed. Nitrogen or inert gas can be used to exhaust the air before the reaction, mainly to exhaust the air and prevent side reactions. The main purpose of vacuuming is to dry up the added deionized water, so as to avoid the presence of water in the product and affect the performance of the product. Its melting point ranges from 170 to 230°C, and its intrinsic viscosity is between 1.1 and 2.5.

The monomer selected in the above step ① can be aminoacetic acid, aminobutyric acid, 6-aminocaproic acid or caprolactam, 8-aminocaprylic acid or octane lactam, 9-aminononanoic acid or nonanelactam, 10-aminocaproic acid Acid or decanolactam, 11-aminoundecanoic acid, lauryl lactam or any one of 12-aminododecanoic acid, 14-aminotetradecanoic acid and its corresponding prepolymer.

The preparation method of block copolyamide of the present invention preferably follows the steps:

①. Preparation of nylon prepolymer: Add a monomer and 5-50% deionized water by weight into the autoclave, exhaust the air, and heat it to 170-190°C in a closed manner, and then keep the reactant under heat and pressure 0.5 to 3 hours, then depressurized to ambient pressure, then heated to 220 to 230°C, vacuumed for 0.5 to 2 hours, and nitrogen or inert gas was added when discharging. to obtain a prepolymer.

The monomers selected in the above step ① can be 11-aminoundecanoic acid, lauryl lactam or 12-aminododecanoic acid (PA12) and caprolactam or 6-aminocaproic acid (PA6), aminoacetic acid, aminobutyric acid , 8-aminocaprylic acid or octane lactam, 9-aminononanoic acid or nonanolactam, 10-aminocapric acid or decanolactam, 14-aminotetradecanoic acid and its corresponding pre-prepared Polymer nylon 11 (PA11), prepolymer nylon 12 (PA12), prepolymer nylon 6 (PA6), prepolymer nylon 2 (PA2), prepolymer nylon 4 (PA4), prepolymer nylon 8 ( PA8), prepolymer nylon 9 (PA9), prepolymer nylon 10 (PA10).

②, the preparation of block copolymer, the prepolymer nylon 11 or prepolymer nylon 12 of 1%～99% of the total weight after mixing prepared by the above steps is mixed with 99～1% of other prepolymer nylons and mixed Add deionized water with 5-50% weight of the mixture and put it into the stirred polymerization reactor, exhaust the air 4-5 times, heat the reactor to 180-190°C in an airtight manner, and keep the reactants warm under the condition of self-generated pressure Keep the pressure for 1-2 hours, release the gas and reduce the pressure to the ambient pressure, then heat to 230-240°C for further reaction, and then vacuumize for 2-3 hours to complete the reaction. Supplement nitrogen or inert gas when discharging as needed.

The block copolyamide of the present invention is a block copolyamide formed by copolymerization of two or more polyamides, and the melting point range is 180-220°C. The intrinsic viscosity is between 1.1 and 2.5.

The above studies have been carried out on block copolyamides. Compared with the prior art, the preparation process and block copolyamide products provided by the present invention have the following advantages:

1. The preparation process is sufficiently simple, and it fully utilizes the polymerization kettle for polymerization. The polymerization operation is convenient, easy to overhaul, and can fully reach the required polymerization temperature. The capacity of polymerization is large, which is convenient for mass production, and can integrate polymerization and granulation, which is convenient for the realization of its industrialization.

2. The raw material we use is 11-aminoundecanoic acid monomer of nylon 11, and the main raw material for producing 11-aminoundecanoic acid is castor oil, which reacts with methanol to form castor oil methyl ester, which is then cracked, reduced Fractional distillation of undecylenic acid and heptanal. Undecylenic acid is added to hydrobromic acid in the presence of hydrogen peroxide to generate 11 brominated undecanoic acid, which is then converted into aminoundecylic acid by reacting with ammonia. And our country is a big producer of castor oil, so it is ideal and easy to use 11-aminoundecanoic acid.

3. The present invention does not add any additives during the preparation process, and antioxidants, coupling agents, etc. can also be added during the preparation to make the physical properties of the block polymer more excellent.

4. The block copolyamide prepared by the present invention and its preparation method can modify a single nylon 11 or 12, diversify the products of nylon 11 or 12 through copolymerization, reduce costs, improve performance, and make it more Practical (wherein the performance measurement of some products is shown in specific examples).

The prepared block copolymerized PA6/11, block copolymerized PA11/12, block copolymerized PA6/11/12, etc., the performance of the product will be improved in different aspects, such as tensile strength or impact strength, water absorption sex, and so on. At present, single-component nylon is far from meeting the needs of applications, and the most effective way to develop new products and broaden the application field of nylon is to modify product properties and reduce production costs through copolymerization. Block copolymerization modification diversifies nylon products, reduces production costs, and broadens the application of nylon to meet people's daily needs.

The prepared block copolyamide can be used to manufacture various hoses and spiral tubes for oil delivery systems, brake systems, clutches, air conditioners and other devices in automobiles; in addition, it can also be widely used as oil delivery pipelines and gas pipelines.

Detailed ways

Example 1,

Preparation of block copolymerized PA611:

Using caprolactam (PA6) as raw material, adding monomer and 5-50wt% (calculated by monomer weight) deionized water into a stirring autoclave, the amount of feed to the polymerization tank does not exceed 2/3 of the volume of the tank. Replace the air in the polymerization kettle with nitrogen for 4-5 times, heat it, and keep the reactant under the condition of self-generated pressure for 2 hours when the temperature reaches 190°C, exhaust and depressurize to ambient pressure, heat to 220°C and vacuum for 60 Minutes, according to the actual viscosity of the reaction product, fill it with nitrogen and discharge it, cool it in a water tank, and cut it into pellets to obtain a PA6 prepolymer.

For the treatment of PA6 prepolymer, since the caprolactam monomer is soluble in water, boiling water can be used to remove the unreacted caprolactam monomer, that is, put the product into a certain amount of water, boil it, keep it for 30 minutes, and then take out the PA6 prepolymer. The remaining aqueous solution can be used to continue to extract the caprolactam monomer.

The reaction formula of nylon 6 prepolymer is as follows (including caprolactam hydrolysis ring-opening process and polycondensation process):

(1) open loop

(2) condensation

(3) Addition

Using 11-aminoundecanoic acid (PA11) as a raw material, add monomers and 5-50wt% (by monomer weight) of deionized water into a stirred autoclave, the same experimental steps as the preparation of PA6 prepolymer , wait until the temperature rises to 230°C and vacuumize for 60 minutes, and then discharge to obtain PA11 prepolymer. Purify PA11 prepolymer with the same treatment method as PA6 prepolymer.

The polycondensation reaction formula of PA11 prepolymer is as follows:

Add the PA6 prepolymer and the PA11 prepolymer according to the ratio shown in Table 1 and 5-50wt% (by weight of the mixture) of deionized water into a stirred autoclave, and replace it with nitrogen for 4-5 times. Heat to 190°C, keep the pressure for 2 hours under self-generated pressure, exhaust and reduce the pressure to ambient pressure, heat to 230°C and evacuate for 2 hours for co-condensation, fill with nitrogen and discharge according to the actual situation, cool in a water tank, and pelletize The block copolymerized PA6/11 was prepared.

The polycondensation reaction formula of block copolymerization PA611 is as follows:

The preparation process and physical properties of block copolyamide are listed in Table 2.

Table 1

Continued Table 1

Table 2

Continued Table 2

Comparative example 1

Nylon 6 prepolymer was also prepared by adding caprolactam monomer according to the preparation process of Example 1, but the vacuuming time was 80 minutes and 100 minutes respectively.

The preparation of the nylon 11 prepolymer, the ratio of the two prepolymers, the polymerization process and the process are the same as in Example 1, and the physical property test results of the prepared block copolyamide are shown in Table 2.

Example 2,

Preparation of block copolymerized PA11/12:

With 11-aminoundecanoic acid (PA11), 12-aminododecanoic acid (PA12) and deionized water as raw materials, with a stirring autoclave of 10L, the polymerization of the oligomer can be carried out smoothly according to the preparation process of Example 1 Implementation, the proportioning of the prepolymer in the block copolyamide, the polymerization conditions and the process are the same as in Example 1.

The molecular weight of the prepolymer and the physical properties of the obtained block copolymerized PA11/12 are shown in Table 3.

table 3

Example 3,

Preparation of block copolymerized PA6/11/12:

With caprolactam (PA6), 11-aminoundecanoic acid (PA11), 12-aminododecanoic acid 9 (PA12) and deionized water as raw materials, with a 10L agitated autoclave, the polymerization of oligomers is according to the examples The preparation process of 1 can be implemented smoothly, the polymerization conditions and process of the block copolyamide are the same as in Example 1, and the proportioning ratio of the prepolymer in the block copolyamide is shown in Table 4.

Table 4

The physical properties of the obtained block copolymerized PA6/11/12 and the molecular weight of the prepolymer are shown in Table 5.

table 5

Example 4,

Preparation of block copolymerized PA6/12:

With caprolactam (PA6), 12-aminododecanoic acid 9 (PA12) and deionized water as raw materials, with a 10L agitated autoclave, the polymerization of the oligomer can be carried out smoothly according to the preparation process of Example 1, and the block The polymerization conditions and process of the copolyamide are the same as in Example 1, and the proportioning ratio of the prepolymer in the block copolyamide is shown in Table 6.

The physical property test result of prepared block copolyamide is as shown in continued table 7

Table 6

Table 7

Claims (5)

1, a kind of preparation method of block copolyamide is characterized in that it comprises the steps:

1., the preparation of nylon prepolymer: in a kind of monomer and deionized water adding autoclave by its weight 5～50%, emptying gas, and airtightly be heated to 170～190 ℃ again to reactant heat-insulation pressure keeping 0.5～3 hour, environmental stress again reduces pressure, post-heating to 220～230 ℃, vacuumized 0.5～2 hour, and replenished nitrogen or rare gas element during discharging.Obtain prepolymer;

2., the preparation of segmented copolymer, a kind of prepolymer of above-mentioned steps preparation is added in the stirring-type polymerization reactor with the deionized water that another kind of or several prepolymers mix and add described mixture weight 5～50%, emptying gas 3～5 times, be heated to 170～240 ℃ to reactor is airtight, to reactant heat-insulation pressure keeping 0.5～4 hour, venting was decompressed to environmental stress under the condition of autogenous pressure, reheat to 210～270 ℃ further reaction, after vacuumized 0.5～5 hour, reaction is finished.When discharging, replenish nitrogen or rare gas element as required.

2, the preparation method of block copolyamide according to claim 1 is characterized in that it comprises the steps:

1., the preparation of nylon prepolymer: in a kind of monomer and deionized water adding autoclave by its weight 5～50%, emptying gas, and airtightly be heated to 170～190 ℃ again to reactant heat-insulation pressure keeping 0.5～3 hour, environmental stress again reduces pressure, post-heating to 220～230 ℃, vacuumized 0.5～2 hour, and replenished nitrogen or rare gas element during discharging.Obtain prepolymer;

Monomer is its corresponding prepolymer Ni Long11, prepolymer nylon 12, prepolymer nylon 6, prepolymer nylon 2, prepolymer nylon 4, prepolymer nylon 8, prepolymer nylon 9, the prepolymer nylon 10 of any system in 11-aminoundecanoic acid, 12 and 6-aminocaprolc acid, Padil, aminobutyric acid, 8-aminocaprylic acid or octane lactan, 9 aminononanoic acid or nonane lactan, 10-amino certain herbaceous plants with big flowers acid or certain herbaceous plants with big flowers alkane lactan, the amino TETRADECONIC ACID of 14-

2., the preparation of segmented copolymer, the deionized water that mixes and add described mixture weight 5～50% by the prepolymer Ni Long11 that mixes back gross weight 99%～1% or prepolymer nylon 12 and other prepolymer nylon of 99%～1% that above-mentioned steps is prepared into is put into the stirring-type polymerization reactor, emptying gas 4～5 times, be heated to 180～190 ℃ to reactor is airtight, under the condition of autogenous pressure to reactant heat-insulation pressure keeping 1～2 hour, venting is decompressed to environmental stress, reheat to 230～240 ℃ further reaction, after vacuumized 2～3 hours, reaction is finished.When discharging, replenish nitrogen or rare gas element as required.

3, block copolyamide according to claim 1 is characterized in that: the number-average molecular weight of nylon prepolymer is between 500-10000.

4, block copolyamide according to claim 1 is characterized in that: the limiting viscosity of block copolyamide is between 1.1-2.5.

5, block copolyamide according to claim 1 is characterized in that: the fusing point of block copolyamide is between 170-230 ℃.