Hydrophobic polyester elastomers and methods for making the same

Abstract

The application discloses a kind of hydrophobic polyester elastomer and preparation method thereof, belong to polyester elastomer technical field.Its technical scheme is: with aromatic diacid, branched diacid, 1,4-butanediol, long branched diol and polyether diol as raw material, catalyst and other additives are added to carry out esterification and polycondensation and obtain polyester elastomer;Wherein, the addition amount of branched diacid is 5-20% of the total mass of diacid, the addition amount of long branched diol is 5-30% of the total mass of 1,4-butanediol and long branched diol, the ratio of the sum of diacid molar mass and the sum of 1,4-butanediol and long branched diol molar mass is 1:1.2-2, and the mass ratio of diacid and polyether diol is 0.25-4:1.The branched diacid and long branched diol are introduced into the polyester elastomer in the application, which can greatly improve the hydrophobic performance of the polyester elastomer, has synergistic effect, and does not affect the mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of polyester elastomers, and particularly relates to a hydrophobic polyester elastomer and a preparation method thereof. Background Art

[0002] Due to the characteristics of high comprehensive mechanical properties, excellent heat resistance, outstanding chemical resistance and weather resistance, thermoplastic polyester elastomer materials have been widely applied in fields such as automobiles, electronic appliances, industrial products, sports goods, films, medical treatment, and alloy blends. During the use of polyester elastomer plastic products, the presence of water will accelerate aging and degradation. In order to ensure their service life, hydrophobic modification is often required. Research and preparation of hydrophobic polyester elastomers are an important aspect of the functional modification of polyester elastomers.

[0003] The contact angle of hydrophobic plastics is generally greater than 90°. Designing plastics from the molecular structure to improve their hydrophobic properties usually involves introducing substances with low surface energy into their molecules. For example, patents CN114716653A, CN113501948A, US10100159B2, and CN115926131A disclose the introduction of components such as long-chain alkanes, fluoroalkyl groups, and organosilicons to increase the hydrophobicity of plastics. Although fluoroalkyl groups and organosilicons have better hydrophobicity than long-chain alkanes, their costs are high, and the applications of plastics containing fluorine or silicon are limited; while only adding conventional long-chain alkanes, their hydrophobicity is average. Therefore, with the expansion of the application fields of polyester elastomers, it is necessary to develop new hydrophobic polyester elastomers. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art and provide a hydrophobic polyester elastomer and a preparation method thereof. By introducing branched-chain dibasic acids and long branched-chain diols into the polyester elastomer, the hydrophobic property of the polyester elastomer can be greatly improved, with synergy, and at the same time, its mechanical properties will not be affected.

[0005] The technical solution of the present invention is as follows: In the first aspect, the present invention provides a preparation method of a hydrophobic polyester elastomer, using aromatic dibasic acids, branched-chain dibasic acids, 1,4-butanediol, long branched-chain diols, and polyether diols as raw materials, adding a catalyst and other auxiliaries to carry out esterification reaction and polycondensation reaction to obtain a polyester elastomer; wherein, the addition amount of the branched-chain dibasic acid is 5-20% of the total mass of the dibasic acids, the addition amount of the long branched-chain diol is 5-30% of the total mass of 1,4-butanediol and the long branched-chain diol, the ratio of the sum of the molar masses of the dibasic acids to the sum of the molar masses of 1,4-butanediol and the long branched-chain diol is 1:1.2-2, and the mass ratio of the dibasic acid to the polyether diol is 0.25-4:1.

[0006] Preferably, the aromatic dicarboxylic acid is one or more of terephthalic acid, phthalic acid, isophthalic acid, biphenyldicarboxylic acid, and 2,6-naphthalenedicarboxylic acid.

[0007] Preferably, the branched-chain dicarboxylic acid is one or two of the following two compounds: ; .

[0008] Preferably, the long branched-chain diol is one or more of 1,2-octanediol, 1,2-nonanediol, 1,2-decanediol, 1,2-dihydroxydodecane, 1,2-dihydroxytetradecane, 1,2-dihydroxyhexadecane, and 1,2-dihydroxyoctadecane.

[0009] Preferably, the polyether diol is one or more of polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol.

[0010] Preferably, the number-average molecular weight of the polyether diol is 200 - 2000.

[0011] Preferably, the catalyst is one or more of zinc acetate, magnesium acetate, calcium acetate, titanium dioxide, germanium dioxide, antimony trioxide, antimony acetate, ethylene glycol antimony, polyethylene glycol antimony, triisobutylaluminum, dibutyltin oxide, stannous octoate, monobutyltin triisooctoate, dioctyltin oxide, tetrabutyl titanate, and isopropyl titanate.

[0012] Preferably, the other additives are one or more of antioxidants, anti-aging agents, light stabilizers, heat stabilizers, branching agents, mold release agents, pigments, lubricants, and matting agents.

[0013] Preferably, the temperature of the esterification reaction is 180 - 230 °C, and the reaction time is 0.5 - 2 h; the temperature of the polycondensation reaction is 240 - 280 °C, the reaction time is 2 - 4 h, and the vacuum degree < 100 Pa.

[0014] In the second aspect, the present invention also provides a hydrophobic polyester elastomer prepared by the above preparation method.

[0015] Compared with the prior art, the present invention has the following beneficial effects: By introducing branched-chain dicarboxylic acid and long branched-chain diol into the polyester elastomer, the hydrophobic property of the polyester elastomer can be greatly improved, which has synergy and does not affect its mechanical properties at the same time. Specific Embodiments

[0016] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions of the present invention will be clearly and completely described below in combination with the embodiments of the present invention.

[0017] Unless otherwise specified, all the chemical reagents and supplies mentioned in the present invention are well-known and commonly used chemical reagents and supplies in the prior art. For the experimental methods without specific conditions in the embodiments of the present invention, they are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0018] The test methods in the embodiments of the present invention are as follows: Hardness: According to the standard GB / T 531.1-2008, the thickness of the specimen is 4 mm, and the residence time is 3 s.

[0019] Tensile strength: According to the standard GB / T 1040.2-2022, it is measured at a test speed of 50 mm / min.

[0020] Hydrophobicity detection: The static droplet method is used to characterize the water contact angle of the material surface with a contact angle goniometer at ambient temperature. The volume of the water droplet used is 5 μL. During the test, five different positions of the sample are selected, and the average value of the contact angles at the five different positions is taken as the test result.

[0021] Example 1 The preparation method of the hydrophobic polyester elastomer in this example is as follows: 0.9 kg of terephthalic acid, 0.1 kg of branched dibasic acid, 0.7 kg of 1,4-butanediol, 0.1 kg of 1,2-decanediol, 1 kg of polytetramethylene ether glycol (M n =1000), 2 g of stannous octoate, 5 g of antioxidant 1010, and 5 g of antioxidant 168 are added to the reaction kettle. Under nitrogen protection, the temperature is raised to 180 °C for esterification reaction for 1.5 h, then the polymerization temperature is raised to 240 °C and polycondensation is carried out under a high vacuum of less than 100 Pa for 2.5 h to obtain the polyester elastomer. The structural formula of the branched dibasic acid is as follows: .

[0022] Example 2 The preparation method of the hydrophobic polyester elastomer in this example is as follows: 0.7 kg of terephthalic acid, 0.1 kg of 2,6-naphthalenedicarboxylic acid, 0.2 kg of branched dibasic acid, 0.6 kg of 1,4-butanediol, 0.04 kg of 1,2-decanediol, 1 kg of polytetramethylene ether glycol (Mn = 2000), 1.4 g of ethylene glycol antimonate, 5 g of antioxidant 1010, and 5 g of antioxidant 168 are added to the reaction kettle. Under nitrogen protection, the temperature is raised to 190 °C for esterification reaction for 1 h, then the polymerization temperature is raised to 250 °C and polycondensation is carried out under a high vacuum of less than 100 Pa for 2 h to obtain the polyester elastomer. Among them, the structural formula of the branched dibasic acid is as follows: .

[0023] Example 3 The preparation method of the hydrophobic polyester elastomer in this embodiment is as follows: Add 0.9 kg of terephthalic acid, 0.08 kg of isophthalic acid, 0.06 kg of branched-chain dibasic acid, 0.6 kg of 1,4-butanediol, 0.2 kg of 1,2-octanediol, 0.1 kg of polypropylene glycol (Mn = 1000), 1.2 kg of polytetramethylene ether glycol (Mn = 一千), 0.8 g of antimony trioxide, 1.2 g of tetrabutyl titanate, and 6 g of antioxidant 1098 into the reaction kettle. After raising the temperature to 185 °C under nitrogen protection and carrying out the esterification reaction for 1 h, raise the polymerization temperature to 250 °C and carry out polycondensation for 2 h under a high vacuum of less than 100 Pa to obtain the polyester elastomer. Among them, the structural formula of the branched-chain dibasic acid is as follows: .

[0024] Example 4 The difference from Example 1 is that the structural formula of the branched-chain dibasic acid is as follows: .

[0025] Example 5 The difference from Example 1 is that the addition amount of terephthalic acid is 0.8 kg, and the addition amount of the branched-chain dibasic acid is 0.2 kg.

[0026] Example 6 The difference from Example 1 is that 1,2-decanediol is replaced by 1,2-dihydroxyoctadecane.

[0027] Example 7 The difference from Example 1 is that the addition amount of 1,4-butanediol is 0.6 kg, and the addition amount of 1,2-decanediol is 0.2 kg.

[0028] Comparative Example 1 The difference from Example 1 is that the branched-chain dibasic acid is not added, and the addition amount of terephthalic acid is adjusted to 1 kg.

[0029] Comparative Example 2 The difference from Example 1 is that the addition amount of terephthalic acid is 0.6 kg, and the addition amount of the branched-chain dibasic acid is 0.4 kg.

[0030] Comparative Example 3 The difference from Example 1 is that the branched-chain dibasic acid is replaced by butylmalonic acid.

[0031] Comparative Example 4 The difference from Example 1 is that 1,2-decanediol is not added, and the addition amount of 1,4-butanediol is adjusted to 0.8 kg.

[0032] Comparative Example 5 The differences from Example 1 are as follows: the addition amount of 1,4-butanediol is 0.5 kg, and the addition amount of 1,2-decanediol is 0.3 kg.

[0033] The tensile strength, elongation at break and contact angle of the polyester elastomers prepared in Examples 1-7 and Comparative Examples 1-5 were tested, and the test results are shown in Table 1: Table 1 As can be seen from Table 1, the water contact angle of the polyester elastomer prepared in the embodiment of the present invention is 136-150°, the Shore hardness is 44-50 HD, and the tensile strength is 22-34 Mpa.

[0034] By comparing the data of Examples 1-5 and Comparative Examples 1 and 3, it can be found that adding a specific branched-chain dibasic acid can greatly increase the hydrophobicity of the polyester elastomer. The water contact angle increases from 112° (Comparative Example 1) without branched-chain dibasic acid to 142°, and the Shore hardness and mechanical properties are almost not lost; while using butylmalonic acid instead of the branched-chain dibasic acid of the present invention, the water contact angle of the prepared polyester elastomer is only 123°, which is greatly reduced. At the same time, it can be seen from Comparative Example 2 that when the addition amount of the branched-chain dibasic acid is too high, although the water contact angle of the prepared polyester elastomer increases, the Shore hardness and tensile strength decrease significantly.

[0035] By comparing the data of Example 1, Examples 6-7 and Comparative Example 4, it can be found that adding a long-chain branched diol can improve the hydrophobicity of the polyester elastomer, and the water contact angle increases significantly; and the hydrophobicity increases with the increase of the content of the long-chain branched diol and the methylene chain of the long-chain branched diol, and the water contact angle can increase to 145°, and the Shore hardness and mechanical strength are almost not lost; similarly, it can be seen from Comparative Example 5 that when the content of the long-chain branched diol exceeds 30%, although the hydrophobicity increases, the Shore hardness and tensile strength of the polyester elastomer decrease significantly. The Shore hardness of Comparative Example 5 decreases to 35 D, and the tensile strength decreases to 18 Mpa.

[0036] In summary, by compounding the branched-chain dibasic acid and the long-chain branched diol, the present invention can better improve the hydrophobic performance of the polyester elastomer, and its Shore hardness and mechanical strength hardly change.

Claims

1. A method for preparing a hydrophobic polyester elastomer, characterized in that, A polyester elastomer is obtained by using aromatic diacids, branched diacids, 1,4-butanediol, long-branched diols, and polyether diols as raw materials, and adding catalysts and other auxiliaries to carry out esterification and polycondensation reactions. The amount of branched diacid added is 5-20% of the total mass of the diacids, the amount of long-branched diol added is 5-30% of the total mass of 1,4-butanediol and long-branched diols, the ratio of the sum of the molar masses of the diacids to the sum of the molar masses of 1,4-butanediol and long-branched diols is 1:1.2-2, and the mass ratio of the diacids to the polyether diols is 0.25-4:

1. The branched dicarboxylic acid is one or both of the following two compounds: ； ； The long-branched diol is one or more of 1,2-octanediol, 1,2-nonanediol, 1,2-decanediol, 1,2-dihydroxydodecane, 1,2-dihydroxytetradecane, 1,2-dihydroxyhexadecane, and 1,2-dihydroxyoctadecane.

2. The method for preparing the hydrophobic polyester elastomer according to claim 1, characterized in that, The aromatic dicarboxylic acid is one or more of terephthalic acid, phthalic acid, isophthalic acid, biphenyl acid, and 2,6-naphthalenedicarboxylic acid.

3. The method for preparing the hydrophobic polyester elastomer according to claim 1, characterized in that, The polyether diol is one or more of polyethylene glycol, polypropylene glycol, and polytetramethylene ether diol.

4. The method for preparing the hydrophobic polyester elastomer as described in claim 1 or 3, characterized in that, The number average molecular weight of the polyether diol is 200-2000.

5. The method for preparing the hydrophobic polyester elastomer according to claim 1, characterized in that, The catalyst is one or more of the following: zinc acetate, magnesium acetate, calcium acetate, titanium dioxide, germanium dioxide, antimony trioxide, antimony acetate, antimony glycol, antimony polyethylene glycol, triisobutylaluminum, dibutyltin oxide, stannous octoate, monobutyltriisooctanoate, dioctyltin oxide, tetrabutyl titanate, and isopropyl titanate.

6. The method for preparing the hydrophobic polyester elastomer according to claim 1, characterized in that, The other additives are one or more of the following: anti-aging agents, branching agents, release agents, pigments, lubricants, and matting agents.

7. The method for preparing the hydrophobic polyester elastomer according to claim 1, characterized in that, The other additives are one or more of antioxidants, light stabilizers, and heat stabilizers.

8. The method for preparing the hydrophobic polyester elastomer according to claim 1, characterized in that, The esterification reaction is carried out at a temperature of 180-230℃ for a reaction time of 0.5-2h; the polycondensation reaction is carried out at a temperature of 240-280℃ for a reaction time of 2-4h, with a vacuum degree of <100Pa.

9. The hydrophobic polyester elastomer prepared by the preparation method according to any one of claims 1-7.

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