Preparation method of high-melting-point polyesteramide material capable of being degraded at normal temperature

Abstract

The invention relates to a preparation method of a high-melting-point normal-temperature degradable polyesteramide material, which comprises the following steps: by taking a nylon-66 saline solution and polycaprolactone as raw materials and tetrabutyl titanate as a catalyst, carrying out two-step reaction of low-temperature prepolymerization and high-temperature tackifying, thereby obtaining the high-melting-point normal-temperature degradable polyesteramide material. The melting point of the material prepared by the method is high and can reach 245 DEG C, the mechanical property is good, the tensile strength reaches 23 MPa, and the elongation at break can reach 30%. The material can be degraded at normal temperature, and the mass can be reduced by 53% or above within one month.

Description

Technical Field

[0001] The invention relates to the technical field of polyester amides, and relates to a method for preparing a polyester amide material with a high melting point and degradable at room temperature. Background Art

[0002] Degradable plastics are gaining more and more attention due to their eco-friendly properties. Currently, the more mature degradable plastics include polylactic acid, polycaprolactone, polyglycolide, etc. However, these degradable materials have low melting points, poor mechanical properties and flexibility, which limits the promotion and application of degradable materials.

[0003] Polyamide (PA), commonly known as nylon, refers to a type of polymer containing an amide bond (-NH-C(O)-) in the main chain of the molecule. It has good wear resistance, oil resistance, self-lubricating properties, insulation and mechanical properties, and is widely used. Since its industrialization, polyamide has been widely used in textiles, sports products, automobiles, electronic appliances, packaging, and other fields.

[0004] Combining polyamide and polyester to prepare amide copolymers has both the biodegradability of polyester and the mechanical properties of polyamide, and is expected to develop new degradable polyester amide materials.

[0005] The patent application with the patent application publication number CN115286788A discloses a polyolefin-like bio-based linear polyester amide and a preparation method thereof. The degradation temperature of the obtained polyolefin-like bio-based linear polyester amide is relatively high, which needs to reach 260°C.

[0006] Patent application with patent application publication number CN111019126A discloses a polyester amide and a preparation method thereof, wherein the polyester amide is prepared by using diamine or amino alcohol as an initiator and a macrocyclic lactone based on a diacid diol as a monomer in the presence of a catalyst, and the melting point of the obtained polyester amide material is 137°C.

[0007] At present, some polyester amides still have problems such as low melting point and high environmental requirements for degradation. Summary of the invention

[0008] The main purpose of the present invention is to provide a preparation and properties of a polyester amide with a high melting point and degradable at room temperature, so as to solve the problem that polyamide materials in the prior art are difficult to degrade and have a low melting point.

[0009] In order to achieve the above object, the present invention provides a method for preparing a polyester amide material with a high melting point and degradable at room temperature:

[0010] The product is prepared by using nylon-66 salt solution and polycaprolactone as raw materials and tetrabutyl titanate as catalyst through two steps of low-temperature prepolymerization and high-temperature viscosity enhancement.

[0011] Furthermore, the mass fraction of the aqueous solution of nylon-66 salt is 10%-60%.

[0012] Furthermore, the temperature range of the low-temperature prepolymerization is 190-220° C., and the reaction time is 1-4 hours.

[0013] Furthermore, the temperature range of high temperature viscosity enhancement is 240-280° C., and the reaction time is 2-5 hours.

[0014] Further, the melting point is characterized by DSC.

[0015] Compared with the prior art, the method of the present invention for preparing a high melting point room temperature degradable polyester amide material has the following advantages:

[0016] The material has a high melting point, which can reach 245°C; the material has excellent mechanical properties, with a tensile strength of 23MPa and an elongation at break of 30%; it can degrade at room temperature and achieve a mass reduction of more than 53% within one month. DETAILED DESCRIPTION

[0017] In order to better understand the present invention, the content of the invention is further explained below in conjunction with the embodiments. It should be noted that, in the case of no conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0018] Example 1

[0019] Weigh 35g of 20% nylon-66 salt solution, 15g of polycaprolactone, and 0.5g of tetrabutyl titanate into a reactor, purge with nitrogen for 5 minutes, start stirring, heat to 210°C, and react for 2 hours. Then heat to 240°C, and react for 2 hours. Turn off stirring and take out the product while it is hot.

[0020] Example 2

[0021] The difference between Example 2 and Example 1 is that 30 g of 20% by mass nylon-66 saline solution and 20 g of polycaprolactone are weighed to finally prepare polyester amide-40.

[0022] Example 3

[0023] The difference between Example 3 and Example 1 is that 25 g of 20% by mass nylon-66 salt solution and 25 g of polycaprolactone are weighed to finally prepare polyester amide-50.

[0024] Example 4

[0025] The difference between Example 4 and Example 1 is that 20 g of 20% by mass nylon-66 salt solution and 30 g of polycaprolactone are weighed to finally prepare polyester amide-60.

[0026] Example 5

[0027] The difference between Example 5 and Example 1 is that 15 g of 20% by mass nylon-66 salt solution and 35 g of polycaprolactone are weighed to finally prepare polyester amide-70.

[0028] Example 6

[0029] The difference between Example 6 and Example 1 is that 10 g of 20% by mass nylon-66 saline solution and 40 g of polycaprolactone are weighed to finally prepare polyester amide-80.

[0030] Example 7

[0031] The difference between Example 7 and Example 1 is that 7.5 g of 20% by mass nylon-66 salt solution and 42.5 g of polycaprolactone are weighed to finally prepare polyester amide-85.

[0032] Comparative Example 1

[0033] The difference between Comparative Example 1 and Example 1 is that 5 g of 20% by mass nylon-66 salt solution and 45 g of polycaprolactone are weighed.

[0034] The melting point results of the samples of Examples 1 to 7 and Comparative Example 1 are as follows:

[0035] Example No. Melting point / ℃ Example 1 248.2 Example 2 246.9 Example 3 246.3 Example 4 245.9 Example 5 245.7 Example 6 245.4 Example 7 244.6 Comparative Example 1 170.4

[0036] Mechanical properties test:

[0037] The samples of Examples 1 to 7 and Comparative Example 1 were used to prepare mechanical test samples. The mechanical test method was in accordance with GB / T1040.1-2018, and the film was tested. During the mechanical test sample preparation process, the film pressing temperature needed to reach above 265°C, but not higher than 310°C. The mechanical property test results of the prepared mechanical test samples are as follows:

[0038] Example No. Tensile strength / MPa Elongation at break / % Example 1 34 38 Example 2 32 37 Example 3 29 37 Example 4 28 36 Example 5 25 31 Example 6 23 32 Example 7 23 30 Comparative Example 1 9 12

[0039] Degradation performance test:

[0040] The degradation liquid of the degradation environment adopts sodium hydroxide aqueous solution or hydrochloric acid aqueous solution, and the pH value is 1-12.

[0041] The samples of Examples 1 to 7 and Comparative Example 1 were weighed, and the mass was recorded as M0. At 25°C, they were placed in a 1 mol / L NaOH aqueous solution for immersion, and taken out and weighed after 30 days, and the mass was recorded as M 30 , calculate △M=(M 30-M0) / M0 x 100%, and the data are as follows.

[0042]

[0043]

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations, such as changing the concentration of nylon-66 salt, degradation environment, mechanical test sample morphology, etc. Any modification, equivalent replacement, improvement, etc. (such as using KOH solution, etc.) made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a polyester amide material with a high melting point and degradable at room temperature, characterized in that: The product is prepared by using nylon-66 salt solution and polycaprolactone as raw materials and tetrabutyl titanate as catalyst through two steps of low-temperature prepolymerization and high-temperature viscosity enhancement.

2. The preparation method according to claim 1, characterized in that: The mass fraction of the aqueous solution of nylon-66 salt is 10%-60%.

3. The preparation method according to claim 1, characterized in that: The mass fraction of tetrabutyl titanate in the reaction system is 1%-1.5%.

4. The preparation method according to claim 1, characterized in that: The temperature range of low-temperature prepolymerization is 190-220°C, and the reaction time is 1-4 hours.

5. The preparation method according to claim 1, characterized in that: The temperature range of high temperature viscosity enhancement is 240-280°C, and the reaction time is 2-5 hours.

6. The preparation method according to claim 1, characterized in that: The mass ratio of polycaprolactone to nylon-66 salt is 0.25-4:1.

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