Preparation method of high-fluidity regenerated polyester functional master batch

Abstract

The application belongs to the technical field of polymer material preparation and recycling, and relates to a preparation method of high-fluidity regenerated polyester functional masterbatch, which comprises the following steps: conveying the melt obtained by melting waste polyester to a closed reactor, introducing superheated mixed alcohol steam into the closed reactor to obtain a mesopolymer by depolymerizing the waste polyester, adding functional powder into the closed reactor to perform in-situ mixing, conveying the mixed melt to a synthesis stage of virgin polyester to perform reaction, and preparing the high-fluidity regenerated functional polyester masterbatch after the reaction is completed; the mixed alcohol steam is mixed steam of dihydric alcohol and polyhydric alcohol, the dihydric alcohol is ethylene glycol, propylene glycol or butanediol, and the polyhydric alcohol is glycerol or pentaerythritol; the polymerization degree of the mesopolymer is 3-30, and the molecular weight distribution PDI is less than 3. The application constructs an efficient alcoholysis functional recycling path, the mesopolymer melt with a certain molecular weight can better disperse the functional powder, and the in-situ polymerization functional recycling is realized in combination with a virgin polyester polymerization route.

Description

[0001] The present application is a divisional application of the patent application "Preparation method of in-situ polymerized regenerated functional polyester", the original application date is November 6, 2024, and the application number is 2024115698575. TECHNICAL FIELD

[0002] The present application belongs to the field of polymer material preparation and recycling, and relates to a preparation method of a high-fluidity regenerated polyester functional master batch. BACKGROUND

[0003] Polyethylene terephthalate (PET) is the most commonly used engineering plastic and fiber raw material. In recent years, with the continuous improvement of people's living standards, the functionalization requirements of PET have also gradually increased. Functionalized PET is mainly prepared by blending, in-situ polymerization and copolymerization, etc. Among them, blending and in-situ polymerization means increase the functionality while ensuring the original physical and chemical properties of PET without changing the main chain structure of PET. However, during blending or in-situ polymerization, dispersion problems often arise, requiring the introduction of many additional dispersants to disperse the powder. For PET in-situ polymerization, functional powder is usually dispersed in PTA and ethylene glycol slurry. Since PTA and functional powder are both small molecular particles, they are easily affected by electrostatic effects and agglomerate during the dispersion process, and further introduction of other dispersants for dispersion may affect the polymerization process.

[0004] For example, patent CN112458568B discloses a preparation method of functionalized graphene intercalation in-situ polymerization polyester composite fiber. Oxidized graphite is added to N,N-dimethylformamide solvent to form a uniform dispersion liquid, and then PTA and ethylene glycol are formed into polymerization raw materials. Patent CN111574698B discloses an organic microcapsule coated zinc borate in-situ polymerization flame-retardant and smoke-suppressing polyester and its preparation method. By treating zinc borate with organic microcapsules, in-situ polymerization can be added without affecting the polymerization reaction during polyester synthesis. Patent CN111269408B discloses a flame-retardant and anti-dripping negative ion health-care polyester based on in-situ polymerization and its preparation method. By dispersing the flame-retardant functional powder and odd ice stone in the PTA and EG slurry, a multifunctional polyester material is prepared.

[0005] From the above patents of in-situ polymerized polyester, it can be seen that in-situ polymerization is currently dispersed with PTA and EG at the initial stage of polymerization, and methods such as increasing dispersants, treating and compounding functional powder are mostly used. These methods not only increase the complexity of the production process, but also increase the additional production cost and production instability.

[0006] Commonly used polyesters also include polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT). The preparation of functional polyesters by functional masterbatch is the main means of functional plastic and fiber preparation, because functional masterbatch has high content characteristics, all functional masterbatch usually requires the base material to have sufficient fluidity to meet the melt processing requirements after functionalization. At present, high fluidity is branched or multi-copolymerized to weaken the intermolecular force, thereby achieving the effect of increasing the melt flowability. However, direct addition of branched copolymerization modification will greatly change the polymerization properties, and the dispersion of inorganic powder in the in-situ polymerization process is still in the small molecule stage, and the melt viscosity is still too low to achieve the dispersion effect.

[0007] Therefore, it is of great significance to study a preparation method of high-fluidity regenerated polyester functional masterbatch to solve the problem of uniform dispersion of functional powder in the polymerization system. SUMMARY

[0008] The purpose of the present application is to solve the problems in the prior art and provide a preparation method of high-fluidity regenerated polyester functional masterbatch.

[0009] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0010] A preparation method of in-situ polymerization regenerated functional polyester, the melt obtained by melting the waste PET by a double screw is transported to a closed reactor, superheated dihydric alcohol vapor is introduced into the closed reactor to depolymerize the waste PET to obtain a mesopolymer, and then the functional powder is added to the closed reactor for in-situ mixing, and the mixed melt is transported to the synthesis stage of virgin polyester for reaction (the synthesis process of virgin polyester is: PTA and EG are mixed to form a slurry, and then subjected to esterification, pre-polycondensation and final polycondensation reactions), and the in-situ polymerization regenerated functional polyester is prepared after the reaction is completed.

[0011] The degree of polymerization of the mesopolymer is 3-30, and the molecular weight distribution PDI is less than 3.

[0012] The in-situ polymerization functional PET in the prior art is mainly realized by means of functional powder modification, addition of dispersants and multi-component compounding in the PTA and EG slurry preparation stage to improve the dispersity, which firstly introduces some components affecting PET reaction and secondly causes unstable production. The superheated dihydric alcohol vapor is introduced into a closed reactor, polyester melt is injected into the closed reactor, depolymerization is carried out at a certain temperature, and the saturated vapor pressure can make the dihydric alcohol content in the melt consistent and uniformly distributed (at a certain temperature, the substance will form a saturated vapor pressure in the gas-liquid coexistence state, and the vapor pressure size can be adjusted with the external temperature change, but not with the container size change), so that the mesopolymer with uniform molecular weight distribution is obtained; the mesopolymer obtained by alcoholysis of waste polyester is used as a functional powder dispersion carrier, compared with the PTA and EG slurry, the mesopolymer with a certain molecular weight has better melt viscosity, which can limit the thermal motion speed of functional molecules, reduce the contact between them, avoid agglomeration caused by static electricity, and the polymerization degree (fluidity) of the mesopolymer produced during depolymerization can be controlled according to different functional components and addition amount, which can be directly introduced into the virgin polyester preparation process after dispersion, without introducing other chemical structures, and has the characteristics of high dispersion, no addition and easy matching, which can realize in-situ functionalization and recycled polyester purposes, and the functional powder can be compounded and added according to actual needs.

[0013] As a preferred technical solution:

[0014] The preparation method of the recycled functional polyester by in-situ polymerization as described above, the melt is pumped into and out of the closed reactor by a melt pump.

[0015] The preparation method of the recycled functional polyester by in-situ polymerization as described above, the waste PET is PET waste bottle pieces, polyester waste silk, polyester waste cloth or polyester-containing waste textiles; the single-component waste PET such as PET waste bottle pieces, polyester waste silk and polyester waste cloth can be directly depolymerized and recycled; the polyester-containing waste textiles include colored polyester textiles and polyester-cotton blended textiles, the colored polyester textiles need to be decolorized before being recycled to prepare recycled PET or blended with color master batches before spinning to prepare dark-colored recycled PET, and the polyester-cotton blended textiles need to be filtered to remove the cotton components (three-stage filtration with filter precision of 500 meshes, 200 meshes and 100 meshes) before being recycled and reused.

[0016] The melting temperature of the waste PET is 250-270℃.

[0017] The preparation method of the recycled functional polyester by in-situ polymerization as described above, the dihydric alcohol is ethylene glycol, propylene glycol, butanediol or pentanediol.

[0018] The preparation method of the regenerated functional polyester by in-situ polymerization as above, wherein the temperature of the superheated dihydric alcohol vapor is 250-270 DEG C, the mass ratio of the superheated dihydric alcohol vapor to the melt is 2-10:1, and the depolymerization time is 10-30 min.

[0019] The preparation method of the regenerated functional polyester by in-situ polymerization as above, wherein the general structure of the mesopolymer is wherein R is (CH2) z , z=2-5, and x=3-30.

[0020] The preparation method of the regenerated functional polyester by in-situ polymerization as above, wherein the functional powder is one or more of carbon black, graphene, carbon nanotube, jade powder, mica powder, tungsten oxide, ferrous oxide, zinc oxide and silver oxide, wherein the carbon black, graphene and carbon nanotube are carbon materials, the jade powder and mica powder are cool materials, the tungsten oxide and ferrous oxide are heat-accumulating and warm-keeping materials, and the zinc oxide and silver oxide are antibacterial materials; the addition amount of the functional powder is 5-10 wt% of the mesopolymer.

[0021] The preparation method of the regenerated functional polyester by in-situ polymerization as above, wherein the synthesis of the virgin polyester adopts a five-kettle polymerization process, and the mixed melt is delivered to one or more of the first esterification kettle, the second esterification kettle, the first pre-polycondensation kettle and the second pre-polycondensation kettle; the polymerization degree of the mesopolymer in the melt delivered to the first esterification kettle, the second esterification kettle, the first pre-polycondensation kettle and the second pre-polycondensation kettle is 3-5, 6-12, 12-25 and 25-30, respectively; and the total addition amount of the mesopolymer is 10-100 wt% of the esterification liquid of the virgin polyester.

[0022] The preparation method of the regenerated functional polyester by in-situ polymerization as above, wherein the temperature of the first esterification kettle and the second esterification kettle is 240-260 DEG C, and the pressure is 0-0.5 MPa; the temperature of the first pre-polycondensation kettle, the second pre-polycondensation kettle and the final polycondensation kettle is 260-280 DEG C, and the pressure is <200 Pa.

[0023] The preparation method of the regenerated functional polyester by in-situ polymerization as above, wherein the polymerization degree of the regenerated functional polyester is 100-150, the intrinsic viscosity is 0.65-0.90 dl / g, and the melting point is 240-260 DEG C; and the regenerated functional polyester can be applied in the fields of plastics and fibers.

[0024] Commonly used polyesters also include polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT). Functional polyester prepared by functional masterbatch is the main means of functional plastic and fiber preparation, because functional masterbatch has high content characteristics, all functional masterbatch usually requires the base material to have sufficient fluidity to meet the melt processing requirements after functionalization. At present, high fluidity is branched or multi-copolymerization to weaken the intermolecular force, so as to achieve the effect of increasing the melt flowability. But direct addition of branched copolymerization modification will greatly change the polymerization property, and the dispersion of inorganic powder in the in-situ polymerization process is still in the small molecule stage, and the melt viscosity is still too low to achieve the dispersion effect.

[0025] Further, to solve the problem of uniform dispersion of functional powder in the polymerization system, and to develop a new flowability adjustment strategy to optimize the performance of functional masterbatch, it is of great significance to promote the functionalization process of polyester materials. Therefore, the present application provides a preparation method of high flowability regenerated polyester functional masterbatch, which adopts the technical scheme as follows:

[0026] A preparation method of high flowability regenerated polyester functional masterbatch, the melt obtained by melting waste polyester is transported to a closed reactor, overheat mixed alcohol vapor is introduced into the closed reactor to depolymerize the waste polyester to obtain a mesopolymer, then overheat mixed alcohol vapor is introduced to realize depolymerization in a homogeneous state, avoid the process of gradually depolymerizing from the surface to the inner layer in solid phase depolymerization, realize the control of the degree of polymerization of the depolymerization product (mesopolymer), and introduce branched molecular chain structure, functional powder is added to the closed reactor for in-situ mixing, and the mixed melt is transported to the synthesis stage of virgin polyester for reaction, and high flowability regenerated functional polyester masterbatch is prepared after the reaction is completed;

[0027] The mixed alcohol vapor is a mixed vapor of dihydric alcohol and polyhydric alcohol, the dihydric alcohol is ethylene glycol, propylene glycol or butanediol, and the polyhydric alcohol is glycerol or pentaerythritol;

[0028] The degree of polymerization of the mesopolymer is 3-30, and the molecular weight distribution PDI is less than 3; the mesopolymer has a certain degree of polymerization, which can limit the thermal motion speed of the functional powder, reduce the contact between each other, avoid the agglomeration caused by static effect, and match different degrees of polymerization of mesopolymer according to the polarity and compounding form of different functional powder, realize the blending addition of high proportion of functional powder.

[0029] The existing high flowability polyester preparation technology is to add one or more branched or to realize branched flowability improvement through reactive blending in the polyester chip processing stage. The flowability improvement method of the present application is to introduce mixed alcohol steam into the depolymerization of waste polyester, and the multi-functional groups are linked at both ends of the mesopolymer after depolymerization, and then mixed with functional powder. First, the mesopolymer with a certain degree of polymerization has high melt viscosity when mixed with functional powder, which increases the adhesion capacity of the functional powder and avoids the agglomeration of the powder to realize high dispersibility; second, the branched end group structure after polycondensation will make the macromolecular chain branched to increase the melt flowability, and finally a high flowability masterbatch is prepared. Since the source is waste polyester, the process can also realize the functional regeneration of polyester, and the mesopolymer with different degrees of polymerization can be combined with the original polymerization process to realize regeneration.

[0030] In the prior art, alcoholysis recovery PET also uses one or more diols and polyols as solvents for depolymerization of waste PET; among them, PET is solid phase depolymerization, and the depolymerization occurs from the surface layer, and the polymerization degree of the alcoholysis solution is difficult to control, and the molecular weight distribution is wide; and the present application introduces superheated mixed alcohol steam into the sealed container, so that every part of the polymer is superheated mixed alcohol steam, so that the depolymerization effect of every part of the polymer is the same, therefore, even if the present application uses mixed alcohol steam, the molecular weight distribution is still very narrow.

[0031] As a preferred technical solution:

[0032] The preparation method of the high flowability regenerated polyester functional masterbatch as described above, the proportion of polyhydric alcohol in the mixed alcohol steam is 50-80wt%.

[0033] The preparation method of the high flowability regenerated polyester functional masterbatch as described above, the waste polyester is waste polyethylene terephthalate (PET), waste polytrimethylene terephthalate (PTT) or waste polybutylene terephthalate (PBT), and the form of the waste polyester is bottle pieces, foam material, friction material or textiles;

[0034] The melting temperature of the waste PET is 160-270℃.

[0035] The preparation method of the high flowability regenerated polyester functional masterbatch as described above, the temperature of the superheated mixed alcohol steam is 250-270℃ (the boiling point of the system will be reduced by blending different alcohols to form azeotrope), the mass ratio of superheated mixed alcohol steam to melt is 2-7:1, and the depolymerization time is 10-30min.

[0036] The preparation method of the high flowability regenerated polyester functional masterbatch as described above, the structure of the mesopolymer is In the formula, R is (CH2) z, z = 2 ~ 4, x = 3 ~ 30, R0 is glycerol or pentaerythritol structure, R1 is ethylene glycol, propylene glycol or butanediol structure.

[0037] The preparation method of the regenerated functional polyester in situ polymerization as described above, the functional powder is one or more of carbon black, graphene, carbon nanotube, jade powder, mica powder, tungsten oxide, ferrous oxide, zinc oxide and silver oxide, wherein the carbon black, graphene and carbon nanotube are carbon materials, the jade powder and mica powder are cool materials, the tungsten oxide and ferrous oxide are heat storage and warm-keeping materials, and the zinc oxide and silver oxide are antibacterial materials; the functional powder is added in an amount of 30-40wt% of the mesopolymer.

[0038] The preparation method of the regenerated functional polyester in situ polymerization as described above, the synthesis of the virgin polyester adopts a five-kettle polymerization process, and the mixed melt is delivered to one or more of the first esterification kettle, the second esterification kettle, the first pre-polycondensation kettle and the second pre-polycondensation kettle; the polymerization degree of the mesopolymer in the melt delivered to the first esterification kettle, the second esterification kettle, the first pre-polycondensation kettle and the second pre-polycondensation kettle is 3-5, 6-12, 12-25 and 25-30, respectively; and the total amount of the mesopolymer added is 30-100wt% of the esterification liquid of the virgin polyester.

[0039] The preparation method of the regenerated functional polyester in situ polymerization as described above, the temperature of the first esterification kettle and the second esterification kettle is 240-260℃, and the pressure is 0-0.5MPa; the temperature of the first pre-polycondensation kettle, the second pre-polycondensation kettle and the final polycondensation kettle is 260-280℃, and the pressure is <200Pa.

[0040] The preparation method of the regenerated functional polyester in situ polymerization as described above, the polymerization degree of the high-fluidity regenerated functional polyester master batch is 100-150, the intrinsic viscosity is 0.60-0.80dl / g, and the melting point is 200-230℃.

[0041] Advantages:

[0042] (1) The preparation method of the regenerated functional polyester in situ polymerization, first melts the waste PET and then delivers it to the reactor, and then passes the superheated dihydric alcohol into the melt, so that the depolymerization can be realized in a homogeneous state, avoiding the process of gradually depolymerizing from the surface layer to the inner layer in the solid phase, and the polymerization degree of the depolymerization product (mesopolymer) can be controlled.

[0043] (2) The preparation method of the regenerated functional polyester in situ polymerization, the dihydric alcohol as the depolymerizing agent does not affect the molecular chain structure, and the mesopolymer has a certain polymerization degree, which can limit the thermal motion speed of the functional powder, reduce the contact between them, avoid the agglomeration caused by the electrostatic effect, and match the mesopolymer with different polymerization degrees according to the polarity and compounding form of different functional powders.

[0044] (3) The preparation method of the in-situ polymerization regenerated functional polyester of the application constructs an efficient PET alcoholysis functional recycling path. After the mesopolymer disperses the functional powder, the mesopolymer can be directly added to the preparation process of the virgin polyester according to the polymerization degree of the mesopolymer, and has the characteristics of high process matching degree and strong adaptability, and the addition proportion of the functional component and the regeneration proportion can be flexibly adjusted in the polymerization stage. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 It is a schematic diagram of the preparation method of the in-situ polymerization regenerated functional polyester;

[0046] Figure 2 It is a schematic diagram of the preparation method of the high-fluidity regenerated polyester functional master batch. DETAILED DESCRIPTION

[0047] The application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the application. Furthermore, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content taught by the application, and these equivalent forms also fall within the scope defined by the appended claims of the application.

[0048] The performance indicators in the examples and comparative examples of the application involve the following test methods:

[0049] Polymerization degree: calculated by the method of calculating the viscosity average molecular weight; the calculation formula is: [η]=KM α , x=M / 228; wherein K and a are solvent constants; the test solvent is phenol / tetrachloroethane with a mass ratio of 1:1; K=2.1×10 -4 at 25℃, a=0.82), [η] is the relative viscosity of the test, and M is the viscosity average molecular weight of the mesopolymer. When the relative viscosity of the mesopolymer is 0.0545, correspondingly, x=3.86, and the polymerization degree of the mesopolymer is 4; when the relative viscosity of the mesopolymer is 0.0996, correspondingly, x=8.04, and the polymerization degree of the mesopolymer is 8; when the relative viscosity of the mesopolymer is 0.2392, correspondingly, x=23.42, and the polymerization degree of the mesopolymer is 23. Intrinsic viscosity: tested by using an Ubbelohde viscometer with a capillary diameter of 0.7-0.8mm. 0.25g of the sample to be tested is weighed on an electronic balance, dissolved in a phenol-tetrachloroethane solvent with a mass ratio of 1:1, and a 50ml volumetric flask is used to configure a solution with a concentration of 0.005g / ml. The solution is completely dissolved in a 60-70℃ water bath, and then the configured solution is placed in a 25℃ constant temperature water bath for 10 minutes. The temperature of the constant temperature water bath is 25±0.1℃. The solution is observed and recorded as it flows through the upper and lower two scale lines of the Ubbelohde viscometer, and the average value of three tests for each sample is taken as the final result, and the calculation process is according to the following formula.

[0050]

[0051] wherein: η r - relative viscosity; t1- solution flow time (s); t0- solvent flow time (s); η sp - specific viscosity; [η] - intrinsic viscosity.

[0052] The number average molecular weight and the molecular weight distribution (PDI) of the sample were tested by using a GPC-50 type gel permeation chromatograph of British PL Company, which was equipped with a differential refractive detector and a PL gel column (5 μm mixed-C), 1,1,1,3,3,3-hexafluoro-2-propanol was used as an eluent, and the flow rate was 1 mL / min; when the column temperature reached 40±1℃, the sample was dried and dissolved in hexafluoroisopropanol to prepare a 1.0 mg / mL solution, and then the test was performed.

[0053] Example 1

[0054] A preparation method of a regenerated functional polyester polymerized in situ, as shown in the following specific steps: Figure 1

[0055] (1) Preparation of raw materials:

[0056] Waste PET: PET waste bottle pieces;

[0057] Diol: ethylene glycol;

[0058] Functional powder: carbon black;

[0059] (2) The waste PET was melted at a temperature of 250℃, and the obtained melt was pumped into a closed reactor through a melt pump;

[0060] (3) The waste PET was depolymerized for 30 min by introducing superheated diol vapor with a temperature of 250℃ into the closed reactor to obtain a mesomer with a polymerization degree of 3 and a molecular weight distribution PDI of 1.3, then the functional powder was added to the closed reactor for in-situ mixing, and the mixed melt was pumped out to the first esterification kettle of the virgin polyester through a melt pump for reaction, the synthesis of the virgin polyester adopted a five-kettle polymerization process, the temperature of the first esterification kettle and the second esterification kettle was 240℃, and the pressure was 0.5 MPa; the temperature of the first pre-polycondensation kettle, the second pre-polycondensation kettle and the final polycondensation kettle was 260℃, and the pressure was 100 Pa, and the regenerated functional polyester polymerized in situ was prepared after the reaction was completed;

[0061] The mass ratio of the superheated diol vapor to the melt was 10:1; the addition amount of the functional powder was 10 wt% of the mesomer; the structural formula of the mesomer was The addition amount of the mesomer was 10 wt% of the esterification liquid of the virgin polyester. ​

[0062] The final prepared recycled functional polyester has a polymerization degree of 100, an intrinsic viscosity of 0.65 dl / g, and a melting point of 257℃.

[0063] Example 2

[0064] A preparation method of in-situ polymerization recycled functional polyester, the specific steps are as follows:

[0065] (1) Preparation of raw materials:

[0066] Waste PET: polyester waste silk;

[0067] Diol: propylene glycol;

[0068] Functional powder: jade powder;

[0069] (2) The waste PET is melted at a temperature of 255℃, and the obtained melt is pumped into a closed reactor through a melt pump;

[0070] (3) The overheat diol vapor with a temperature of 255℃ is introduced into the closed reactor to depolymerize the waste PET for 25 min to obtain a mesomer with a polymerization degree of 8 and a molecular weight distribution PDI of 1.6, then the functional powder is added into the closed reactor for in-situ mixing, and the mixed melt is pumped out to the second esterification kettle of the virgin polyester through a melt pump for reaction, the synthesis of the virgin polyester adopts a five-kettle polymerization process, the temperature of the first esterification kettle and the second esterification kettle is 245℃, and the pressure is 0.5 MPa; the temperature of the first pre-polycondensation kettle, the second pre-polycondensation kettle and the final polycondensation kettle is 265℃, and the pressure is 100 Pa, and the in-situ polymerization recycled functional polyester is prepared after the reaction is completed;

[0071] The mass ratio of the overheat diol vapor to the melt is 6:1; the addition amount of the functional powder is 8wt% of the mesomer; the structural formula of the mesomer is The addition amount of the mesomer is 30wt% of the esterification liquid of the virgin polyester.

[0072] The final prepared recycled functional polyester has a polymerization degree of 115, an intrinsic viscosity of 0.75 dl / g, and a melting point of 250℃.

[0073] Example 3

[0074] A preparation method of in-situ polymerization recycled functional polyester, the specific steps are as follows:

[0075] (1) Preparation of raw materials:

[0076] Waste PET: polyester waste cloth;

[0077] Diol: butanediol;

[0078] Functional powder: tungsten oxide;

[0079] (2) the waste PET is melted at a temperature of 260°C, and the obtained melt is pumped into a closed reactor by a melt pump;

[0080] (3) superheated dihydric alcohol vapor at a temperature of 260°C is introduced into the closed reactor to depolymerize the waste PET for 20 min to obtain a mesopolymer with a polymerization degree of 21 and a molecular weight distribution PDI of 2.4, then the functional powder is added into the closed reactor for in-situ mixing, and the mixed melt is pumped out to a first pre-condensation kettle of virgin polyester by a melt pump for reaction, the synthesis of the virgin polyester adopts a five-kettle polymerization process, the temperature of the first esterification kettle and the second esterification kettle is 250°C, and the pressure is 0.3 MPa; the temperature of the first pre-condensation kettle, the second pre-condensation kettle and the final condensation kettle is 270°C, and the pressure is 100 Pa, and the in-situ polymerization regenerated functional polyester is prepared after the reaction is completed;

[0081] wherein the mass ratio of the superheated dihydric alcohol vapor to the melt is 4:1; the addition amount of the functional powder is 7wt% of the mesopolymer; and the structural formula of the mesopolymer is The addition amount of the mesopolymer is 50wt% of the esterification liquid of the virgin polyester.

[0082] The finally prepared regenerated functional polyester has a polymerization degree of 125, an intrinsic viscosity of 0.8 dl / g, and a melting point of 245°C.

[0083] Example 4

[0084] A preparation method of in-situ polymerization regenerated functional polyester, and the specific steps are as follows:

[0085] (1) preparation of raw materials:

[0086] waste PET: colored polyester waste textiles;

[0087] dihydric alcohol: pentanediol;

[0088] functional powder: zinc oxide;

[0089] (2) the waste PET is melted at a temperature of 265°C, and the obtained melt is pumped into a closed reactor by a melt pump;

[0090] (3) the functional powder is added to the closed reactor for in-situ mixing, and the mixed melt is pumped out to the second pre-polycondensation kettle of the virgin polyester for reaction, the synthesis of the virgin polyester adopts a five-kettle polymerization process, the temperature of the first esterification kettle and the second esterification kettle is 255 DEG C, and the pressure is 0.1 MPa; the temperature of the first pre-polycondensation kettle, the second pre-polycondensation kettle and the final polycondensation kettle is 275 DEG C, and the pressure is 150 Pa, and the regenerated functional polyester is prepared after reaction;

[0091] wherein the mass ratio of the superheated dihydric alcohol vapor to the melt is 2:1; the addition amount of the functional powder is 6 wt% of the mesopolymer; and the structural formula of the mesopolymer is The addition amount of the mesopolymer is 100 wt% of the esterification liquid of the virgin polyester.

[0092] The finally prepared regenerated functional polyester has a polymerization degree of 140, an intrinsic viscosity of 0.85 dl / g and a melting point of 240 DEG C.

[0093] Example 5

[0094] A preparation method of a regenerated functional polyester prepared by in-situ polymerization, and the specific steps are as follows:

[0095] (1) preparation of raw materials:

[0096] Waste PET: polyester-cotton blended waste textiles (the ratio of polyester / cotton is 80 / 20);

[0097] Dihydric alcohol: ethylene glycol;

[0098] Functional powder: tungsten oxide and silver oxide with a mass ratio of 1:1;

[0099] (2) the waste PET is melted at a temperature of 270 DEG C, and the obtained melt is pumped into a closed reactor by a melt pump;

[0100] (3) mesopolymer a and mesopolymer b are respectively prepared;

[0101] (3.1) superheated dihydric alcohol vapor with a temperature of 250 DEG C is introduced into the closed reactor I to depolymerize the waste PET for 30 min to obtain mesopolymer a with a polymerization degree of 4 and a molecular weight distribution PDI of 1.4;

[0102] (3.2) superheated dihydric alcohol vapor with a temperature of 250 DEG C is introduced into the closed reactor II to depolymerize the waste PET for 15 min to obtain mesopolymer b with a polymerization degree of 9 and a molecular weight distribution PDI of 1.6;

[0103] (4) a part of the functional powder is added into the closed reactor I for in-situ mixing, the added amount of the functional powder is 5wt% of the intermediate a, the mixed melt is pumped out to the first esterification kettle of the virgin polyester by a melt pump for reaction; another part of the functional powder is added into the closed reactor II for in-situ mixing, the added amount of the functional powder is 5wt% of the intermediate b, the mixed melt is pumped out to the second esterification kettle of the virgin polyester by a melt pump for reaction, to prepare the in-situ polymerization regenerated functional polyester; the synthesis of the virgin polyester adopts a five-kettle polymerization process, the temperature of the first esterification kettle and the second esterification kettle is 260℃, and the pressure is 0MPa; the temperature of the first pre-polycondensation kettle, the second pre-polycondensation kettle and the final polycondensation kettle is 280℃, and the pressure is 150Pa, to prepare the in-situ polymerization regenerated functional polyester;

[0104] wherein the mass ratio of the superheated dihydric alcohol vapor to the melt is 9:1; the structural formula of the intermediate a and the intermediate b is The added amount of the intermediate a and the intermediate b is 25wt% and 50wt% of the esterification liquid of the virgin polyester respectively.

[0105] The finally prepared regenerated functional polyester has a polymerization degree of 150, an intrinsic viscosity of 0.9dl / g and a melting point of 260℃.

[0106] Example 6

[0107] A preparation method of a high-fluidity regenerated polyester functional master batch, as shown in Figure 2 The specific steps are as follows:

[0108] (1) Preparation of raw materials:

[0109] Waste polyester: waste polyethylene terephthalate bottle pieces;

[0110] Mixed alcohol vapor: mixed vapor of dihydric alcohol and polyhydric alcohol, the dihydric alcohol is ethylene glycol, the polyhydric alcohol is glycerol, and the volume ratio of the dihydric alcohol to the polyhydric alcohol is 1:5;

[0111] Functional powder: carbon black;

[0112] (2) The waste polyester is melted at a temperature of 250℃, and the obtained melt is pumped into a closed reactor by a melt pump;

[0113] (3) the functional powder is added to the closed reactor for in-situ mixing after the waste polyester is depolymerized for 30 min by introducing the superheated mixed alcohol vapor with a temperature of 260℃ to obtain a mesopolymer with a polymerization degree of 4 and a molecular weight distribution PDI of 1.6, and the mixed melt is transported to the first esterification kettle of the virgin polyester for reaction, the synthesis of the virgin polyester adopts a five-kettle polymerization process, the temperature of the first esterification kettle and the second esterification kettle is 240℃, and the pressure is 0.5 MPa; the temperature of the first pre-polycondensation kettle, the second pre-polycondensation kettle and the final polycondensation kettle is 260℃, and the pressure is 150 Pa, and the high-fluidity regenerated polyester functional masterbatch is prepared after the reaction is completed;

[0114] wherein the mass ratio of the superheated mixed alcohol vapor to the melt is 10:1; the addition amount of the functional powder is 10 wt% of the mesopolymer; and the structural formula of the mesopolymer is The addition amount of the mesopolymer is 100 wt% of the esterification liquid of the virgin polyester.

[0115] The finally prepared regenerated functional polyester has a polymerization degree of 150, an intrinsic viscosity of 0.8 dl / g and a melting point of 230℃.

[0116] Example 7

[0117] A preparation method of a high-fluidity regenerated polyester functional masterbatch, and the specific steps are as follows:

[0118] (1) Preparation of raw materials:

[0119] Waste polyester: waste polytrimethylene terephthalate foam;

[0120] Mixed alcohol vapor: mixed vapor of dihydric alcohol and polyhydric alcohol, the dihydric alcohol is propylene glycol, the polyhydric alcohol is pentaerythritol, and the volume ratio of the dihydric alcohol to the polyhydric alcohol is 1:3;

[0121] Functional powder: graphene;

[0122] (2) The waste polyester is melted at a temperature of 260℃, and the obtained melt is pumped into a closed reactor by a melt pump;

[0123] (3) the functional powder is added to the closed reactor for in-situ mixing after the waste polyester is depolymerized for 25 min by introducing the superheated mixed alcohol vapor with a temperature of 250℃ to obtain a mesopolymer with a polymerization degree of 9 and a molecular weight distribution PDI of 1.8, and the mixed melt is transported to the second esterification kettle of the virgin polyester for reaction, the synthesis of the virgin polyester adopts a five-kettle polymerization process, the temperature of the first esterification kettle and the second esterification kettle is 250℃, and the pressure is 0.2 MPa; the temperature of the first pre-polycondensation kettle, the second pre-polycondensation kettle and the final polycondensation kettle is 265℃, and the pressure is 100 Pa, and the high-fluidity regenerated polyester functional masterbatch is prepared after the reaction is completed;

[0124] The mass ratio of the superheated mixed alcohol vapor to the melt is 8:1; the functional powder is added in an amount of 9wt% of the mesopolymer; and the mesopolymer has the structural formula The mesopolymer is added in an amount of 60wt% of the original polyester esterification liquid.

[0125] The final prepared regenerated functional polyester has a polymerization degree of 100, an intrinsic viscosity of 0.6dl / g, and a melting point of 200℃.

[0126] Example 8

[0127] A preparation method of a high-fluidity regenerated polyester functional masterbatch, and the specific steps are as follows:

[0128] (1) Preparation of raw materials:

[0129] Waste polyester: waste polybutylene terephthalate friction material;

[0130] Mixed alcohol vapor: mixed vapor of dihydric alcohol and polyhydric alcohol, the dihydric alcohol is butanediol, the polyhydric alcohol is glycerol, and the volume ratio of the dihydric alcohol to the polyhydric alcohol is 1:4.5;

[0131] Functional powder: carbon nanotube;

[0132] (2) The waste polyester is melted at a temperature of 270℃, and the obtained melt is pumped into a closed reactor by a melt pump;

[0133] (3) The superheated mixed alcohol vapor at a temperature of 260℃ is introduced into the closed reactor to depolymerize the waste polyester for 20min to obtain a mesopolymer with a polymerization degree of 17 and a molecular weight distribution PDI of 2.0, then the functional powder is added into the closed reactor for in-situ mixing, and the mixed melt is transported to the first pre-polycondensation kettle of the original polyester for reaction. The synthesis of the original polyester adopts a five-kettle polymerization process, the temperature of the first esterification kettle and the second esterification kettle is 260℃, and the pressure is 0MPa; the temperature of the first pre-polycondensation kettle, the second pre-polycondensation kettle and the final polycondensation kettle is 270℃, and the pressure is 150Pa. The reaction is ended to prepare the high-fluidity regenerated polyester functional masterbatch;

[0134] The mass ratio of the superheated mixed alcohol vapor to the melt is 6:1; the functional powder is added in an amount of 7wt% of the mesopolymer; and the mesopolymer has the structural formula The mesopolymer is added in an amount of 40wt% of the original polyester esterification liquid.

[0135] The final prepared regenerated functional polyester has a polymerization degree of 135, an intrinsic viscosity of 0.76dl / g, and a melting point of 225℃.

[0136] Example 9

[0137] A preparation method of a high-fluidity regenerated polyester functional masterbatch, and the specific steps are as follows:

[0138] (1) Preparation of raw materials:

[0139] Waste polyester: waste polyethylene terephthalate textiles;

[0140] Mixed alcohol steam: mixed steam of diol and polyol, the diol is ethylene glycol, the polyol is pentaerythritol, and the volume ratio of diol to polyol is 1:3.5;

[0141] Functional powder: jade powder;

[0142] (2) melting the waste polyester at a temperature of 255° C., and pumping the melt obtained by the melting into a closed reactor through a melt pump;

[0143] (3) Superheated mixed alcohol steam at a temperature of 270° C. is introduced into a closed reactor to depolymerize the waste polyester for 20 minutes to obtain a polymer with a degree of polymerization of 26 and a molecular weight distribution (PDI) of 2.9, and then the functional powder is added to the closed reactor for in-situ mixing. The mixed melt is transported to the second pre-condensation kettle of the original polyester for reaction. The synthesis of the original polyester adopts a five-kettle polymerization process. The temperature of the first esterification kettle and the second esterification kettle is 245° C. and the pressure is 0.4 MPa; the temperature of the first pre-condensation kettle, the second pre-condensation kettle and the final condensation kettle is 275° C. and the pressure is 100 Pa. After the reaction is completed, a high-flowability recycled polyester functional masterbatch is prepared;

[0144] The mass ratio of superheated mixed alcohol vapor to melt is 2:1; the amount of functional powder added is 6wt% of the intermediate polymer; the structural formula of the intermediate polymer is The amount of the intermediate polymer added is 10 wt% of the original polyester esterification liquid.

[0145] The final recycled functional polyester has a degree of polymerization of 130, an intrinsic viscosity of 0.71 dl / g, and a melting point of 205°C.

[0146] Example 10

[0147] A method for preparing a high-flowability recycled polyester functional masterbatch, comprising the following steps:

[0148] (1) Preparation of raw materials:

[0149] Waste polyester: waste polytrimethylene terephthalate bottle flakes;

[0150] Mixed alcohol steam: mixed steam of diol and polyol, the diol is propylene glycol, the polyol is glycerol, and the volume ratio of diol to polyol is 1:5;

[0151] Functional powder: tungsten oxide and silver oxide in a mass ratio of 1:1;

[0152] (2) melt the waste polyester at a temperature of 265℃, and pump the obtained melt into a closed reactor through a melt pump;

[0153] (3) prepare mesopolymer a and mesopolymer b respectively;

[0154] (3.1) introduce superheated mixed alcohol steam at a temperature of 270℃ into the closed reactor I to depolymerize the waste polyester for 30 min to obtain mesopolymer a with a degree of polymerization of 4 and a molecular weight distribution PDI of 1.5;

[0155] (3.1) introduce superheated dihydric alcohol steam at a temperature of 260℃ into the closed reactor II to depolymerize the waste PET for 25 min to obtain mesopolymer b with a degree of polymerization of 8 and a molecular weight distribution PDI of 1.8;

[0156] (4) add a part of the functional powder to the closed reactor I for in-situ mixing, the addition amount of the functional powder being 5wt% of the mesopolymer a, and then transport the mixed melt to the first esterification kettle of the virgin polyester for reaction; add another part of the functional powder to the closed reactor II for in-situ mixing, the addition amount of the functional powder being 5wt% of the mesopolymer b, and then transport the mixed melt to the second esterification kettle of the virgin polyester for reaction, the synthesis of the virgin polyester adopting a five-kettle polymerization process, the temperature of the first esterification kettle and the second esterification kettle being 255℃, and the pressure being 0.1MPa; the temperature of the first pre-polycondensation kettle, the second pre-polycondensation kettle and the final polycondensation kettle being 280℃, and the pressure being 100Pa, and the reaction ends to prepare the high-fluidity regenerated polyester functional masterbatch;

[0157] wherein the mass ratio of the superheated mixed alcohol steam to the melt is 6:1; the structural formula of the mesopolymer a and the mesopolymer b is The addition amount of the mesopolymer a and the mesopolymer b is 10wt% and 15wt% of the esterification liquid of the virgin polyester respectively.

[0158] The finally prepared regenerated functional polyester has a degree of polymerization of 115, an intrinsic viscosity of 0.64dl / g, and a melting point of 220℃.

Claims

1. A process for the preparation of a high flow renewable polyester functional masterbatch, characterized by: The melt obtained by melting the waste polyester is transported to a closed reactor, superheated mixed alcohol vapor is introduced into the closed reactor to depolymerize the waste polyester to obtain a mesopolymer, and then a functional powder is added to the closed reactor for in-situ mixing, the mixed melt is transported to the synthesis stage of the virgin polyester for reaction, and the high-flow regenerated functional polyester masterbatch is prepared after the reaction is completed. The mixed alcohol vapor is a mixture of dihydric alcohol and polyhydric alcohol, the dihydric alcohol is ethylene glycol, propylene glycol or butanediol, and the polyhydric alcohol is glycerol or pentaerythritol. The temperature of the superheated mixed alcohol vapor is 250-270℃, the mass ratio of the superheated mixed alcohol vapor to the melt is 2-7:1, and the depolymerization time is 10-30min. The polymerization degree of the mesopolymer is 3-30, and the molecular weight distribution PDI is less than 3. The functional powder is one or more of carbon black, graphene, carbon nanotube, jade powder, mica powder, tungsten oxide, ferrous oxide, zinc oxide and silver oxide, wherein the carbon black, graphene and carbon nanotube are carbon materials, the jade powder and mica powder are cool materials, the tungsten oxide and ferrous oxide are heat-accumulating and warm-keeping materials, and the zinc oxide and silver oxide are antibacterial materials.

2. The method of preparing a high flow renewable polyester functional masterbatch according to claim 1, characterized in that, The proportion of polyhydric alcohol in the mixed alcohol vapor is 50-80wt%.

3. The method for preparing a high-fluidity recycled polyester functional masterbatch according to claim 1, characterized in that: The waste polyester is waste polyethylene terephthalate, waste polypropylene terephthalate or waste polybutylene terephthalate, and the form of the waste polyester is bottle pieces, foam, friction material or textiles. The melting temperature of the waste PET is 160-270℃.

4. The method for preparing a high flow renewable polyester functional masterbatch according to claim 1, wherein the polymeric structure has a general formula of ###0001### wherein R is (CH2)z, z = 2-4, x = 3-30, R0 is a glycerol or pentaerythritol structure, and R1 is an ethylene glycol, propylene glycol or butylene glycol structure. z , z = 2-4, x = 3-30, R0 is a glycerol or pentaerythritol structure, and R1 is an ethylene glycol, propylene glycol or butylene glycol structure.​ 5. The method according to claim 1, wherein the amount of the functional powder added is 30-40wt% of the mesopolymer.

6. The method according to claim 1, wherein the synthesis of the virgin polyester adopts a five-kettle polymerization process, and the mixed melt is transported to one or more of the first esterification kettle, the second esterification kettle, the first pre-polycondensation kettle and the second pre-polycondensation kettle, the polymerization degree of the mesopolymer in the melt transported to the first esterification kettle, the second esterification kettle, the first pre-polycondensation kettle and the second pre-polycondensation kettle is 3-5, 6-12, 12-25 and 25-30 respectively, and the total amount of the mesopolymer added is 30-100wt% of the virgin polyester esterification liquid.

7. The method according to claim 6, wherein the temperature of the first esterification kettle and the second esterification kettle is 240-260℃, and the pressure is 0-0.5MPa; the temperature of the first pre-polycondensation kettle, the second pre-polycondensation kettle and the final polycondensation kettle is 260-280℃, and the pressure is less than 200Pa.

8. The method according to claim 1, wherein the polymerization degree of the high-flow regenerated functional polyester masterbatch is 100-150, the intrinsic viscosity is 0.60-0.80dl / g, and the melting point is 200-230℃.

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