High-molecular high-efficiency nucleating agent as well as preparation method and application thereof

Abstract

The invention relates to a high-molecular high-efficiency nucleating agent as well as a preparation method and application thereof. The polymeric nucleating agent of the present invention comprises a cross-linked polymer comprising a structural unit derived from a photosensitive monomer having a dynamic cross-linking group. The molecular structure of the high-molecular nucleating agent is similar to that of a polymer to be nucleated, the high-molecular nucleating agent further comprises a photosensitive structural unit with a dynamic cross-linking group, cross-linking is performed through ultraviolet irradiation after molecular crystallization of the nucleating agent, so that a topological structure after crystallization of a high-molecular chain is fixed, and the cross-linked polymer is used for the nucleating agent and can remarkably improve the crystallization rate. The nucleating agent provided by the invention has efficient nucleating ability, good dispersibility and thermal stability.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and in particular relates to a polymer-type high-efficiency nucleating agent and a preparation method and application thereof. Background Art

[0002] As an indispensable component of modern industry and daily life, polymer materials have always been the research focus in the field of materials science. Among them, semi-crystalline polymers have attracted extensive attention due to their unique microstructure and excellent comprehensive performance. However, these materials generally have problems such as slow crystallization rate and low crystallinity, which not only affects the final performance of the product, but also significantly reduces production efficiency, restricting its further development in high-performance fields.

[0003] Adding nucleating agents is one of the most effective methods to improve the crystallization properties of semi-crystalline polymer materials. At present, common nucleating agents are mainly divided into two categories: inorganic and organic. Inorganic nucleating agents (such as talc, silica, calcium carbonate, etc.) are inexpensive and widely available, but usually require a higher addition amount (such as 1-5wt%) to achieve significant effects. However, large-scale addition can easily lead to increased material heterogeneity, affecting mechanical and optical properties. Although organic nucleating agents (such as sorbitol derivatives, organic phosphates, benzoates, etc.) can improve crystallization properties at lower addition amounts (such as 0.1-0.5wt%), they generally have problems such as poor thermal stability and poor dispersibility. Especially under high-temperature processing conditions, they are prone to decomposition or migration, resulting in a weakened nucleation effect.

[0004] In recent years, with the continuous development of nanotechnology and supramolecular chemistry, many nucleating agents based on nanotechnology and supramolecular chemistry (such as nanocellulose, graphene, carbon nanotubes and supramolecular self-assemblies, etc.) have been developed. They have higher specific surface area and nucleation ability, and can significantly improve crystallization properties with extremely low addition amounts. However, due to the complex preparation process and high cost, its industrial application still faces huge challenges.

[0005] In addition, the use of polymer substances as nucleating agents has also been reported. For example, Patent Document 1 discloses the use of polyvinyl acetal as a macromolecular nucleating agent for polybutylene succinate and its copolyester. Patent Document 2 discloses a "DBS"-like transparent modified polypropylene macromolecular nucleating agent, which co-grafts functional monomers containing key functional groups of "DBS"-like nucleating agents onto polypropylene molecular chains by means of reactive processing, thereby constructing a molecular structure of a "DBS"-like nucleating agent grafted onto a polypropylene macromolecular chain segment, and obtaining a "DBS"-like substituent as a polypropylene macromolecular link, further improving the dispersion ability of the nucleating agent in the polypropylene matrix. However, this technology is mainly designed for polypropylene, and it is difficult to directly apply it to other types of semi-crystalline polymer materials, lacking universality. Moreover, "DBS"-like nucleating agents generally have poor thermal stability and obvious hygroscopicity, and grafting them onto polypropylene chains may not solve their stability problems under high-temperature processing conditions. In addition, the introduction of a large number of grafted structures may change the properties of polypropylene itself, and ultimately have an adverse effect on the mechanical and rheological properties of the material.

[0006] Citations

[0007] Patent document 1: CN102492248A;

[0008] Patent document 2: CN117304408A. Summary of the invention

[0009] Problem that the invention aims to solve

[0010] In the prior art, the research on the crystallization mechanism is not in-depth enough, so it is difficult to achieve precise control of the crystallization process from a molecular perspective.

[0011] The technical problem to be solved by the present invention is to provide a nucleating agent with high-efficiency nucleating ability, good dispersibility and thermal stability.

[0012] Solutions for solving problems

[0013] In view of the above problems, the inventors conducted long-term and in-depth research, and based on the understanding of the polymer crystallization mechanism, proposed to use photosensitive monomers with dynamic crosslinking groups as comonomers to synthesize polymer nucleating agents, thereby completing the present invention.

[0014] Specifically, the present invention solves the problem of the present invention through the following solutions.

[0015] [1] A polymer nucleating agent comprising a cross-linked polymer comprising a structural unit derived from a photosensitive monomer having a dynamic cross-linking group.

[0016] [2] The polymer nucleating agent according to [1], wherein the photosensitive monomer having a dynamic crosslinking group is one or more monomers selected from monomers having one or more of a cinnamic acid group, a coumarin group, or an azobenzene group;

[0017] Preferably, the photosensitive monomer having a dynamic cross-linking group is selected from one or more of N,N-bis(2-hydroxyethyl)cinnamic acid amide, N,N-bis(3-hydroxypropyl)cinnamic acid amide, N,N-bis(2-hydroxyethyl)-4-methoxycinnamic acid amide, N,N-bis(2-hydroxyethyl)-α-methylcinnamic acid amide, N,N-bis(2,3-dihydroxypropyl)cinnamic acid amide, 5,7-dihydroxy-4-methylcoumarin, 6,7-dihydroxy-4-methylcoumarin, 5,7-dihydroxy-4-propylcoumarin, 7,8-dihydroxy-4-methylcoumarin, 7,8-dihydroxy-3,4-dimethyl-coumarin, 4,4'-dihydroxyazobenzene, 2,2'-dihydroxyazobenzene, 3,3'-dihydroxyazobenzene, and 4,4'-bis(2-hydroxyethoxy)azobenzene;

[0018] Preferably, the content of the structural unit derived from the photosensitive monomer having a dynamic crosslinking group is 10 mol % or less, based on the total moles of the structural units of the crosslinked polymer.

[0019] [3] The polymer nucleating agent according to [1] or [2], wherein the cross-linked polymer is at least one selected from polyester, polyamide, polyolefin, and polyether.

[0020] [4] The method for preparing a polymer nucleating agent according to any one of [1] to [3], comprising the following steps:

[0021] (a) polymerizing a monomer composition comprising a photosensitive monomer having a dynamic crosslinking group to obtain a precursor polymer;

[0022] (b) preparing a film from the precursor polymer obtained in step (a) and crystallizing the precursor polymer;

[0023] (c) photochemically crosslinking the precursor polymer in the film obtained in step (b) to form the crosslinked polymer.

[0024] [5] The preparation method according to [4], wherein the monomer composition comprises one or more selected from diols, dicarboxylic acids, lactones, lactides, compounds containing carboxyl and hydroxyl groups, diamines, compounds containing amino and carboxyl groups, lactams, olefins, and oxacycloalkanes;

[0025] Preferably, the monomer composition comprises at least one of the following (i) to (ix):

[0026] (i) diols and dicarboxylic acids,

[0027] (ii) lactone,

[0028] (iii) lactide,

[0029] (iv) compounds containing carboxyl and hydroxyl groups,

[0030] (v) dicarboxylic acids and diamines,

[0031] (vi) compounds containing amino groups and carboxyl groups,

[0032] (vii) lactams,

[0033] (viii) olefins,

[0034] (ix) oxacycloalkanes;

[0035] The polymerization reaction in step (a) is carried out by melt polycondensation, coordination polymerization or ring-opening polymerization;

[0036] The number average molecular weight of the precursor polymer is 1,000 to 100,000 g / mol, preferably 2,000 to 80,000 g / mol.

[0037] [6] The preparation method according to [4] or [5], wherein in step (b), the precursor polymer obtained in step (a) is prepared into a film by solvent evaporation film forming or hot melt film forming;

[0038] Preferably, the precursor polymer obtained in step (a) is prepared into a film by solvent evaporation film forming;

[0039] More preferably, the precursor polymer obtained in step (a) is dissolved in a solvent to obtain a precursor polymer solution, and then the solvent is evaporated to allow the precursor polymer to crystallize and form a film; preferably, the precursor polymer is evaporated at a temperature of 0.040°C above the glass transition temperature T g To melting point T m The solvent is evaporated at a temperature in the range of .

[0040] [7] A composition comprising the polymer nucleating agent described in any one of [1] to [3] and a matrix polymer;

[0041] Preferably, the content of the polymer nucleating agent is 100 to 50000 ppm;

[0042] Preferably, the matrix polymer is a semi-crystalline polymer, more preferably at least one selected from polyester, polyamide, polyolefin, and polyether.

[0043] [8] The composition according to [7], wherein the base polymer and the cross-linked polymer in the polymeric nucleating agent have substantially the same structural unit composition except for the structural unit derived from the photosensitive monomer having a dynamic cross-linking group.

[0044] [9] Use of a cross-linked polymer as a polymer nucleating agent, wherein the cross-linked polymer comprises a structural unit derived from a photosensitive monomer having a dynamic cross-linking group;

[0045] Preferably, the polymer is a semi-crystalline polymer, more preferably at least one selected from polyester, polyamide, polyolefin, and polyether.

[0046]

[10] The use according to [9], wherein the polymer and the cross-linked polymer have substantially the same structural unit composition except for the structural unit derived from the photosensitive monomer having a dynamic cross-linking group.

[0047] Effects of the Invention

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] 1. "Crystallization before cross-linking" strategy: By introducing dynamic cross-linking groups and conducting cross-linking reactions, the topological structure of the polymer after crystallization is effectively fixed; the core advantage of this strategy is that even after heating and melting, the polymer chain transforms into an amorphous conformation, but because the relative positions of the molecular chain segments have been fixed by the cross-linking reaction, the difference between its conformation and that in the crystallized state is still small, thereby reducing the entropy barrier for crystallization nucleation and increasing the crystallization nucleation rate.

[0050] 2. Excellent dispersibility and interfacial compatibility: The polymer nucleating agent of the present invention has a similar chemical structure to the matrix polymer, which can significantly improve the dispersibility and interfacial compatibility of the nucleating agent in the polymer matrix, solving the problem of easy agglomeration and poor interfacial compatibility of traditional inorganic nucleating agents.

[0051] 3. Good thermal stability and migration resistance: The present invention endows the nucleating agent with good thermal stability and migration resistance through cross-linking treatment. This cross-linking structure ensures that the nucleating agent remains stable under high-temperature processing conditions and effectively inhibits loss and migration during processing, thereby ensuring the persistence of the nucleating effect.

[0052] 4. Comprehensively optimized crystallization performance: The polymer nucleating agent prepared by the present invention can significantly improve the crystallization rate, crystallization temperature and relative crystallinity of the polymer, which can not only improve the comprehensive performance of the material, but also greatly improve the production efficiency.

[0053] 5. Wide adaptability: The polymer nucleating agent of the present invention can be applied to various semi-crystalline polymers, including but not limited to polyesters, polyamides, polyolefins, polyethers, etc.

[0054] 6. Significant cost-effectiveness: The raw materials required for the preparation method of the nucleating agent of the present invention are easily available, the process is simple, and it has significant cost advantages, which is conducive to industrial large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 Schematic diagram of cross-linking of the nucleating agent of the present invention.

[0056] Figure 2 The DSC curves of the compositions of Example 1, Comparative Example 1, and PBS without adding a nucleating agent are shown in FIG.

[0057] Figure 3 The DSC curves of the compositions of Example 2, Comparative Example 2, and PLLA without adding a nucleating agent. DETAILED DESCRIPTION

[0058] The following is a detailed description of the present invention. The technical features described below are described based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples.

[0059] <Terms and Definitions>

[0060] In this specification, "macromolecule" and "polymer" have the same meaning.

[0061] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints numerical values ​​A and B.

[0062] In the present specification, a numerical range expressed using "above" or "below" means a numerical range including the number.

[0063] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0064] In this specification, the use of "optionally" or "optional" indicates that certain substances, components, execution steps, application conditions and other factors are used or not used.

[0065] In this specification, the unit names used are all international standard unit names, and unless otherwise stated, the "%" used indicates weight or mass percentage.

[0066] In this specification, the references to "preferred embodiments", "embodiments", etc., mean that the specific elements (e.g., features, structures, properties and / or characteristics) described in connection with the embodiments are included in at least one embodiment described herein, and may or may not exist in other embodiments. In addition, it should be understood that the elements may be combined in various embodiments in any suitable manner.

[0067] <Polymer nucleating agent and preparation method thereof>

[0068] An object of the present invention is to provide a polymeric nucleating agent comprising a cross-linked polymer comprising a structural unit derived from a photosensitive monomer having a dynamic cross-linking group.

[0069] The “structural unit derived from a photosensitive monomer having a dynamic crosslinking group” refers to a structural unit formed by a polymerization reaction of a photosensitive monomer having a dynamic crosslinking group, and may also be referred to as a “photosensitive structural unit having a dynamic crosslinking group”.

[0070] The present invention uses a photosensitive monomer with a dynamic cross-linking group to give the cross-linked polymer a dynamic cross-linking property, and can easily fix the molecular chain topology (such as a folded conformation) corresponding to the crystallization state through a photochemical cross-linking reaction, thereby reducing the activation energy of the nucleation process and improving the nucleation efficiency of the polymer crystallization.

[0071] Preferably, the photosensitive monomer having a dynamic cross-linking group is one or more monomers selected from monomers having one or more of a cinnamic acid group, a coumarin group, or an azobenzene group.

[0072] Examples of monomers having a cinnamic acid group include N,N-bis(2-hydroxyethyl)cinnamic amide (BHECA), N,N-bis(2-hydroxyethyl)cinnamic amide, N,N-bis(3-hydroxypropyl)cinnamic amide, N,N-bis(2-hydroxyethyl)-4-methoxycinnamic amide, N,N-bis(2-hydroxyethyl)-α-methylcinnamic amide, and N,N-bis(2,3-dihydroxypropyl)cinnamic amide.

[0073] Examples of the monomer having a coumarin group include 5,7-dihydroxy-4-methylcoumarin, 6,7-dihydroxy-4-methylcoumarin, 5,7-dihydroxy-4-propylcoumarin, 7,8-dihydroxy-4-methylcoumarin, and 7,8-dihydroxy-3,4-dimethylcoumarin.

[0074] Examples of the monomer having an azobenzene group include 4,4′-dihydroxyazobenzene, 2,2′-dihydroxyazobenzene, 3,3′-dihydroxyazobenzene, and 4,4′-bis(2-hydroxyethoxy)azobenzene.

[0075] In some embodiments, the structural unit derived from the photosensitive monomer having a dynamic crosslinking group is located on the main chain of the crosslinked polymer. Herein, the main chain of the crosslinked polymer refers to its main chain in a non-crosslinked state.

[0076] In some embodiments, the dynamic cross-linking groups in the cross-linked polymer are in a cross-linked state.

[0077] In some embodiments, the cross-linked polymer only comprises cross-linked structures formed by dynamic cross-linking groups.

[0078] Preferably, based on the total molar number of the structural units of the cross-linked polymer, the content of the structural units derived from the photosensitive monomer having a dynamic cross-linking group is 10 mol% or less, preferably 8 mol% or less, more preferably 6 mol% or less, further preferably 4 mol% or less, and even preferably 2 mol% or less. The present invention has no particular limitation on the lower limit of the content of the structural units derived from the photosensitive monomer having a dynamic cross-linking group, for example, it may be 0.01 mol% or more, preferably 0.1 mol% or more, further preferably 0.2 mol% or more, and more preferably 0.3 mol% or more. For example, 0.4 mol%, 0.5 mol%, 0.6 mol%, 0.7 mol%, 0.8 mol%, 0.9 mol%, 1 mol%, 1.5 mol%, etc.

[0079] Preferably, the cross-linked polymer is at least one selected from polyester, polyamide, polyolefin, and polyether. The polymer type described for the cross-linked polymer here means that the cross-linked polymer contains structural units that form the described type of polymer, and the proportion in the total structural units is preferably 80 mol% or more, more preferably 90 mol% or more. For example, when the cross-linked polymer is polyester, it contains structural units that form polyester, that is, monomers derived from diols, dicarboxylic acids, etc.

[0080] The polyester may be an aliphatic polyester or an aromatic polyester, for example, a polymer obtained by polycondensation of a diol and a dicarboxylic acid, a polymer obtained by ring-opening polymerization of a lactone or a lactide, and a polymer obtained by polycondensation of a carboxyl group- and hydroxyl group-containing compound.

[0081] The diols include, but are not limited to, aliphatic diols having 2 to 20 carbon atoms and aromatic diols having 6 to 20 carbon atoms, such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-benzenedimethanol, 1,4-benzenediethanol, 1,4-benzenedipropanol, 1,3-benzenedimethanol, 1,3-benzenediethanol, 1,3-benzenedipropanol, and the like, as well as derivatives of these diols substituted with one or more substituents, wherein the substituents may be F, Cl, Br, CN, C 1～6 Alkyl, etc.

[0082] The dicarboxylic acids include, but are not limited to, aliphatic dicarboxylic acids having 3 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms, such as malonic acid, succinic acid, 1,5-pentanedioic acid, 1,6-hexanedioic acid, 1,7-heptanedioic acid, 1,8-octanedioic acid, 1,9-zelaic acid, 1,10-decanedioic acid, terephthalic acid, isophthalic acid, and the like, as well as derivatives of these dicarboxylic acids substituted with one or more substituents, wherein the substituents may be F, Cl, Br, CN, C 1～6 Alkyl, etc.

[0083] Lactones include, but are not limited to, aliphatic lactones having 4 to 10 carbon atoms, such as caprolactone, valerolactone, and the like.

[0084] Lactide includes but is not limited to glycolide, lactide and the like.

[0085] Compounds containing carboxyl and hydroxyl groups include, but are not limited to, lactic acid, β-hydroxybutyric acid, and the like.

[0086] Examples of polyesters include polybutylene succinate (PBS), polybutylene fumarate (PBF), polybutylene adipate (PBA), polycaprolactone (PCL), polyhydroxybutyrate (PHB), polyhydroxyvalerate (PHV), polyethylene succinate (PES), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polylactic acid (PLA), and polybutylene terephthalate-adipate (PBAT).

[0087] Polyamides may be aliphatic polyamides and aromatic polyamides. For example, polymers obtained by polycondensation of dicarboxylic acids and diamines, polymers obtained by polycondensation of compounds containing amino groups and carboxyl groups, and polymers obtained by ring-opening polymerization of lactams. The dicarboxylic acids may be the dicarboxylic acids described above. Diamines may be aliphatic diamines having 2 to 20 carbon atoms and aromatic diamines having 6 to 20 carbon atoms, such as ethylenediamine, propylenediamine, 1,4-butylenediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, p-phenylenediamine, m-phenylenediamine, and derivatives of these diamines substituted by one or more substituents, wherein the substituents may be F, Cl, Br, CN, C 1～6 Alkyl, etc. Amino and carboxyl group-containing compounds such as 6-aminocaproic acid, 12-aminododecanoic acid, etc. Lactams such as ε-caprolactam, ω-laurolactam, etc.

[0088] Examples of the polyamide include polyamide 6 (Nylon 6), polyamide 66 (Nylon 66), polyamide 46, polyamide 12, polyamide 69, and polyamide 6-10.

[0089] The polyolefin may be a polymer obtained by polymerizing an olefin, such as an olefin having 2 to 20 carbon atoms, such as ethylene, propylene, butene, pentene, hexene, octene, styrene, etc., and derivatives of these olefins substituted with one or more substituents, such as F, Cl, Br, CN, C 1～6 Alkyl, etc.

[0090] Examples of the polyolefin include one or more of polyethylene (PE), polypropylene (PP) and polystyrene (PS).

[0091] The polyether may be a polymer obtained by polymerization of oxacycloalkanes, such as ethylene oxide, propylene oxide, oxetane, tetrahydrofuran, and the like.

[0092] Examples of the polyether include polyethylene oxide, polypropylene oxide, polyoxetane, and polytetramethylene oxide.

[0093] An object of the present invention is to provide a method for preparing a polymer nucleating agent, characterized in that it comprises the following steps:

[0094] (a) polymerizing a monomer composition comprising a photosensitive monomer having a dynamic crosslinking group to obtain a precursor polymer;

[0095] (b) preparing a film from the precursor polymer obtained in step (a) and crystallizing the precursor polymer;

[0096] (c) photochemically crosslinking the precursor polymer in the film obtained in step (b) to form the crosslinked polymer.

[0097] The various steps of the preparation method of the present invention are described below.

[0098] Step (a)

[0099] In step (a), a monomer composition comprising a photosensitive monomer having a dynamic crosslinking group is polymerized to obtain a precursor polymer.

[0100] The photosensitive monomer having a dynamic cross-linking group is as described above.

[0101] Preferably, the monomer composition further comprises other monomers for forming the cross-linked polymer, including but not limited to one or more selected from diols, dicarboxylic acids, lactones, lactides, compounds containing carboxyl and hydroxyl groups, diamines, compounds containing amino and carboxyl groups, lactams, olefins, and oxacycloalkanes.

[0102] Preferably, the monomer composition comprises a monomer or a combination of monomers described in at least one of the following (i) to (ix):

[0103] (i) diols and dicarboxylic acids,

[0104] (ii) lactone,

[0105] (iii) lactide,

[0106] (iv) compounds containing carboxyl and hydroxyl groups,

[0107] (v) dicarboxylic acids and diamines,

[0108] (vi) compounds containing amino groups and carboxyl groups,

[0109] (vii) lactams,

[0110] (viii) olefins,

[0111] (ix) Oxycycloalkanes.

[0112] When the cross-linked polymer is a polyester, the monomer composition includes at least one monomer or a combination of monomers described in (i) to (iv).

[0113] When the cross-linked polymer is a polyamide, the monomer composition contains at least one monomer or a combination of monomers described in (v) to (vii).

[0114] Where the crosslinked polymer is a polyolefin, the monomer composition comprises one or more (viii) olefins.

[0115] When the crosslinked polymer is a polyether, the monomer composition contains (ix) an oxacycloalkane.

[0116] Among them, the diols, dicarboxylic acids, lactones, lactides, compounds containing carboxyl and hydroxyl groups, diamines, compounds containing amino and carboxyl groups, lactams, olefins, and oxacycloalkanes may be those described above.

[0117] Preferably, the content of the photosensitive monomer having a dynamic crosslinking group in the monomer composition is 10 mol% or less, preferably 8 mol% or less, more preferably 6 mol% or less, further preferably 4 mol% or less, and even preferably 2 mol% or less. The present invention has no particular limitation on the lower limit of the content of the photosensitive monomer having a dynamic crosslinking group, for example, it may be 0.01 mol% or more, preferably 0.1 mol% or more, further preferably 0.2 mol% or more, and more preferably 0.3 mol% or more. For example, 0.4 mol%, 0.5 mol%, 0.6 mol%, 0.7 mol%, 0.8 mol%, 0.9 mol%, 1 mol%, 1.5 mol%, etc.

[0118] The present invention has no particular limitation on the method for carrying out the polymerization reaction in step (a), and may be, for example, a conventional polymerization method in the art such as melt polycondensation, coordination polymerization or ring-opening polymerization. In particular, a person skilled in the art may select a suitable polymerization method according to the type of the cross-linked polymer. For example, when the cross-linked polymer is polyester or polyamide, a melt polycondensation method may be used; when the cross-linked polymer is polyolefin, a coordination polymerization method may be used; and when the cross-linked polymer is polyether, a ring-opening polymerization method may be used.

[0119] The polymerization reaction in step (a) can be carried out under conventional conditions in the art. For example, the polymerization reaction temperature can be 40 to 260° C.; the polymerization reaction time can be 1 to 8 hours. Specifically, in the case of melt polycondensation, the reaction temperature is 150 to 260° C. and the reaction time is 2 to 8 hours; in the case of coordination polymerization, the reaction temperature is 180 to 200° C. and the reaction time is 1 to 4 hours; in the case of ring-opening polymerization, the reaction temperature is 40 to 120° C. and the reaction time is 1 to 8 hours.

[0120] The number average molecular weight of the polymer obtained in step (a) is 1,000 to 100,000 g / mol, preferably 2,000 to 80,000 g / mol.

[0121] Step (b)

[0122] In step (b), the precursor polymer obtained in step (a) is prepared into a film and the precursor polymer is crystallized.

[0123] Preferably, in step (b), the precursor polymer obtained in step (a) is prepared into a film by solvent evaporation film forming or hot melt film forming.

[0124] In some embodiments, the precursor polymer obtained in step (a) is prepared into a film by hot melt film forming and the precursor polymer is crystallized. Specifically, the precursor polymer can be melted by heating, then formed into a film (for example, by extrusion), and then cooled to crystallize the precursor polymer.

[0125] The present invention has no particular limitation on the melting temperature, and a temperature higher than the melting point of the precursor polymer may be selected according to the type of the precursor polymer. g To melting point T m Temperature range (T g ~T m ).

[0126] In a preferred embodiment, the precursor polymer obtained in step (a) is prepared into a film by solvent volatilization. Specifically, the precursor polymer obtained in step (a) is dissolved in a solvent to obtain a precursor polymer solution, the precursor polymer solution is coated into a film, and then the solvent is evaporated to crystallize the precursor polymer and form a film.

[0127] The solvent may be an organic solvent or water. The organic solvent is preferably one or more selected from hydrocarbons, halogenated hydrocarbons, ethers, esters, ketones, amides, sulfoxides, and nitrile solvents, and more preferably one or more selected from chloroform, dichloromethane, tetrachloroethane, tetrahydrofuran, N,N-dimethylformamide, o-dichlorobenzene, toluene, xylene, trichloroethylene, tetrachloroethylene, ethyl acetate, acetone, cyclohexanone, dimethyl sulfoxide, n-hexane, acetonitrile, cyclohexane, and dimethylacetamide.

[0128] Preferably, the content of the precursor polymer in the precursor polymer solution is 0.1 to 10 mass %, preferably 0.2 to 8 mass %, more preferably 0.3 to 6 mass %, further preferably 0.4 to 4 mass %, and for example 0.5 to 3 mass %, 0.6 to 2 mass %.

[0129] Preferably, the precursor polymer is dissolved in the solvent under stirring conditions, and the stirring time is preferably 0.5 to 5 hours, preferably 0.5 to 4 hours, and more preferably 1 to 3 hours.

[0130] The present invention has no particular limitation on the method of coating the precursor polymer solution into a film, and for example, methods such as spin coating, spray coating, printing, and casting may be used.

[0131] Preferably, the glass transition temperature T g To melting point T m Within the temperature range (T g ~T m ) to evaporate the solvent and simultaneously crystallize the polymer. For example, the solvent evaporation temperature may be 40 to 100°C, preferably 40 to 80°C.

[0132] Preferably, the time for evaporating the solvent may be 1 to 10 hours, preferably 2 to 8 hours, more preferably 3 to 7 hours.

[0133] Step (c)

[0134] In step (c), the precursor polymer in the film obtained in step (b) is photochemically cross-linked to form the cross-linked polymer.

[0135] Preferably, the film obtained in step (b) is irradiated with light so as to cause a photochemical cross-linking reaction of the precursor polymer therein.

[0136] More preferably, the light irradiation is performed using ultraviolet light, and the wavelength of the ultraviolet light is preferably 200-400 nm, such as 365 nm.

[0137] More preferably, the light irradiation time is 0.1 to 5 hours, preferably 0.5 to 3 hours.

[0138] Additional Steps

[0139] In some embodiments, the method of the present invention further comprises the step of preparing a photosensitive monomer having a dynamic crosslinking group.

[0140] For example, a monomer having a cinnamamide group can be prepared by subjecting a cinnamic acid ester to an ester exchange reaction with a diolamine (e.g., diethanolamine, dipropanolamine, etc.). The ester exchange reaction can be carried out under suitable conditions known in the art, such as vacuum, heating (e.g., 80 to 120° C.), and the presence of a catalyst (e.g., sodium alkoxide, sodium carbonate, tetrabutyl titanate).

[0141] In some embodiments, the preparation method of the present invention further comprises other steps such as cutting and crushing the cross-linked film obtained in step (c).

[0142] <Composition>

[0143] An object of the present invention is to provide a composition comprising the polymeric nucleating agent of the present invention and a matrix polymer.

[0144] Preferably, the mass content of the polymer nucleating agent in the composition of the present invention is 100 to 50000 ppm, preferably 1000 ppm to 20000 ppm, more preferably 2000 ppm to 10000 ppm. By making the content of the polymer nucleating agent within the above range, it is beneficial to improve the crystallization performance of the composition.

[0145] The matrix polymer is preferably a semi-crystalline polymer, for example, at least one selected from polyester, polyamide, polyolefin, and polyether.

[0146] The polyester may be an aliphatic polyester or an aromatic polyester, for example, a polymer obtained by polycondensation of a diol and a dicarboxylic acid, a polymer obtained by ring-opening polymerization of a lactone or a lactide, and a polymer obtained by polycondensation of a carboxyl group- and hydroxyl group-containing compound.

[0147] The diols include, but are not limited to, aliphatic diols having 2 to 20 carbon atoms and aromatic diols having 6 to 20 carbon atoms, such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-benzenedimethanol, 1,4-benzenediethanol, 1,4-benzenedipropanol, 1,3-benzenedimethanol, 1,3-benzenediethanol, 1,3-benzenedipropanol, and the like, as well as derivatives of these diols substituted with one or more substituents, wherein the substituents may be F, Cl, Br, CN, C 1～6 Alkyl, etc.

[0148] The dicarboxylic acids include, but are not limited to, aliphatic dicarboxylic acids having 3 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms, such as malonic acid, succinic acid, 1,5-pentanedioic acid, 1,6-hexanedioic acid, 1,7-heptanedioic acid, 1,8-octanedioic acid, 1,9-zelaic acid, 1,10-decanedioic acid, terephthalic acid, isophthalic acid, and the like, as well as derivatives of these dicarboxylic acids substituted with one or more substituents, wherein the substituents may be F, Cl, Br, CN, C 1～6 Alkyl, etc.

[0149] Lactones include, but are not limited to, aliphatic lactones having 4 to 10 carbon atoms, such as caprolactone, valerolactone, and the like.

[0150] Lactide includes but is not limited to glycolide, lactide and the like.

[0151] Compounds containing carboxyl and hydroxyl groups include, but are not limited to, lactic acid, β-hydroxybutyric acid, and the like.

[0152] Examples of polyesters include polybutylene succinate (PBS), polybutylene fumarate (PBF), polybutylene adipate (PBA), polycaprolactone (PCL), polyhydroxybutyrate (PHB), polyhydroxyvalerate (PHV), polyethylene succinate (PES), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polylactic acid (PLA), and polybutylene terephthalate-adipate (PBAT).

[0153] Polyamides may be aliphatic polyamides and aromatic polyamides. For example, polymers obtained by polycondensation of dicarboxylic acids and diamines, polymers obtained by polycondensation of compounds containing amino groups and carboxyl groups, and polymers obtained by ring-opening polymerization of lactams. The dicarboxylic acids may be the dicarboxylic acids described above. Diamines may be aliphatic diamines having 2 to 20 carbon atoms and aromatic diamines having 6 to 20 carbon atoms, such as ethylenediamine, propylenediamine, 1,4-butylenediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, and derivatives of these diamines substituted by one or more substituents, wherein the substituents may be F, Cl, Br, CN, C 1～6 Alkyl, etc. Amino and carboxyl group-containing compounds such as 6-aminocaproic acid, 12-aminododecanoic acid, etc. Lactams such as ε-caprolactam, ω-laurolactam, etc.

[0154] Examples of the polyamide include polyamide 6 (Nylon 6), polyamide 66 (Nylon 66), polyamide 46, polyamide 12, polyamide 69, and polyamide 6-10.

[0155] The polyolefin may be a polymer obtained by polymerizing an olefin, such as an olefin having 2 to 20 carbon atoms, such as ethylene, propylene, butene, pentene, hexene, octene, styrene, etc., and derivatives of these olefins substituted with one or more substituents, such as F, Cl, Br, CN, C 1～6 Alkyl, etc.

[0156] Examples of the polyolefin include one or more of polyethylene (PE), polypropylene (PP) and polystyrene (PS).

[0157] The polyether may be a polymer obtained by polymerization of oxacycloalkanes, such as ethylene oxide, propylene oxide, oxetane, tetrahydrofuran, and the like.

[0158] Examples of the polyether include polyethylene oxide, polypropylene oxide, polyoxetane, and polytetramethylene oxide.

[0159] Preferably, the content of the base polymer in the composition of the present invention is 80 mass % or more, preferably 90 mass % or more, more preferably 95 mass % or more, further preferably 97 mass % or more, and also preferably 98 mass % or more, for example 99 mass %, 99.2 mass %, 99.4 mass %, 99.6 mass %, 99.8 mass %, etc.

[0160] Preferably, the matrix polymer and the cross-linked polymer in the polymer nucleating agent are the same type of polymer, for example, polyester, polyamide, polyolefin or polyether.

[0161] More preferably, the matrix polymer and the crosslinked polymer in the polymeric nucleating agent have substantially the same structural unit composition, except for the structural unit derived from the photosensitive monomer having a dynamic crosslinking group. Substantially the same means 90 mol% or more, preferably 95 mol% or more, more preferably 98 mol% or more, further preferably 99 mol% or more, for example 100 mol% or more.

[0162] The composition of the present invention can be prepared by conventional methods in the art, such as melt blending or solvent blending of the polymer nucleating agent of the present invention with the matrix polymer.

[0163] <Purpose>

[0164] One object of the present invention is to provide the use of a crosslinked polymer as a polymer nucleating agent, wherein the crosslinked polymer comprises structural units derived from a photosensitive monomer having a dynamic crosslinking group.

[0165] See above for a description of the cross-linked polymer.

[0166] The polymer is preferably a semi-crystalline polymer, for example, at least one selected from polyester, polyamide, polyolefin, and polyether. For the description of the polymer, refer to the description of the base polymer above.

[0167] Preferably, the polymer and the cross-linked polymer have substantially the same structural unit composition, except for the structural unit derived from the photosensitive monomer having a dynamic cross-linking group, wherein substantially the same means 90 mol% or more, preferably 95 mol% or more, more preferably 98 mol% or more, further preferably 99 mol% or more, for example 100 mol% or more.

[0168] Example

[0169] The present invention is further described by enumerating specific embodiments below. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content recorded in the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the present invention equally.

[0170] Example 1

[0171] <Preparation of polymer nucleating agent>

[0172] (1) Synthesis of N,N-bis(2-hydroxyethyl)cinnamamide containing a photosensitive group: 8.11 g of methyl cinnamate and 10.51 g of diethanolamine were added to a 100 mL flask, and the mixed solution was heated to 110°C under stirring, followed by the addition of 0.05 g of sodium methoxide. The mixture was reacted for 2 hours under vacuum, and precipitated with a mixture of 150 mL of ice water and 0.1 ml of hydrochloric acid. The mixture was recrystallized from ethyl acetate to obtain a white powdery substance, which was vacuum dried at 80°C for 48 hours to obtain N,N-bis(2-hydroxyethyl)cinnamamide (BHECA);

[0173] (2) reacting the dried BHECA (0.5 mol %) obtained in step (1) as the third comonomer with 1,4-butanediol (49.5 mol %) and succinic acid (50 mol %) to prepare a copolymer PBS-co-BHECA by multi-step melt polycondensation. The polymerization temperature was controlled at 215° C., the reaction time was controlled at 5 hours, and the final molecular weight was 7500 g / mol;

[0174] (3) Dissolve 0.1 g of PBS-co-BHECA obtained in step (2) in 10 ml of chloroform to prepare a 1 wt % solution, and stir for 2 hours;

[0175] (4) pouring the solution of step (3) into a culture dish and placing it on a hot plate at 65° C. for 4 hours to allow the solvent to evaporate and completely crystallize to form a film;

[0176] (5) The film obtained in step (4) is photocrosslinked under 365 nm ultraviolet light for 2 hours to obtain the final polymer nucleating agent.

[0177] <Preparation of Composition>

[0178] (6) adding the polymer nucleating agent obtained in step (5) to PBS at a ratio of 0.5 wt % to obtain a mixture;

[0179] (7) 0.1 g of the mixture obtained in (6) above was dissolved in 10 ml of chloroform (1 wt%) and stirred for 2 hours. The solution was then placed on a hot plate at 65°C to evaporate the solvent, thereby preparing a PBS / nucleating agent composition.

[0180] Example 2

[0181] <Preparation of polymer nucleating agent>

[0182] (1) synthesizing N,N-bis(2-hydroxyethyl)cinnamamide containing a photosensitive group in the same manner as step (1) in Example 1;

[0183] (2) The dried BHECA obtained in step (1) was used as an initiator (0.1 mol %) to initiate the ring-opening polymerization of L-lactide (99.9 mol %) to prepare linear PLLA-BHECA. The polymerization reaction temperature was controlled at 170° C. and the reaction time was controlled at 3 hours. The final molecular weight was 30,000 g / mol.

[0184] (3) Dissolve 0.1 g of PLLA-BHECA obtained in step (2) in 10 ml of chloroform to prepare a 1 wt % solution, and stir for 2 hours;

[0185] (4) pouring the solution of step (3) into a culture dish and placing it on a hot plate at 40° C. for 10 hours to allow the solvent to evaporate and fully crystallize to form a film;

[0186] (5) The film obtained in step (4) is photocrosslinked under 365 nm ultraviolet light for 2 hours to obtain a polymer nucleating agent.

[0187] <Preparation of Composition>

[0188] (6) adding the polymer nucleating agent obtained in step (5) to PLLA at a ratio of 0.5 wt % to obtain a mixture;

[0189] (7) 0.1 g of the mixture obtained in (6) above was dissolved in 10 ml of chloroform (1 wt%) and stirred for 2 hours. The solution was then placed on a hot plate at 65°C to evaporate the solvent, thereby preparing a PLLA / nucleating agent composition.

[0190] Comparative Example 1

[0191] In the same manner as steps (6) and (7) in Example 1, the precursor polymer PBS-co-BHECA obtained in step (2) of Example 1 without UV treatment was added to PBS at a ratio of 0.5 wt % to prepare a composition.

[0192] Comparative Example 2

[0193] In the same manner as steps (6) and (7) in Example 2, the precursor polymer PLLA-BHECA obtained in step (2) of Example 2 without UV treatment was added to PLLA at a ratio of 0.5 wt % to prepare a composition.

[0194] <Evaluation>

[0195] The crystallization behavior of PBS, PLLA without adding nucleating agent, and the compositions obtained in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 were tested by differential scanning calorimetry (DSC). For PBS without adding nucleating agent, Comparative Example 1 and Example 1, the temperature was increased to 160°C at a constant rate, then cooled, and then heated twice, and the first cooling (a) and second heating (b) curves were collected, and the heating and cooling rate was 10°C / min. For PLLA without adding nucleating agent, Comparative Example 2 and Example 2, the temperature was increased to 210°C at a constant rate, then cooled, and then heated twice, and the first cooling (a) and second heating (b) curves were collected, and the heating and cooling rate was 10°C / min. The results are listed in Tables 1 and 2. The DSC curves are shown in Tables 1 and 2. Figure 2 and 3 shown.

[0196] The crystallinity (X) in Table 1 and Table 2 c ) is calculated by the following formula:

[0197]

[0198] Where ΔH m is the melting enthalpy; ΔH cc is the cold crystallization enthalpy; is the standard melting enthalpy; the standard melting enthalpy of PBS and PLLA are 133.5 J / g and 93.0 J / g respectively.

[0199] Table 1

[0200]

[0201] From Table 1 and Figure 2 It can be seen that compared with PBS without adding a nucleating agent, the crystallization temperature of PBS using the polymer nucleating agent of the present invention is increased by 12.1°C, the relative crystallinity is increased by 11%, and the half-crystallization time of 92°C isothermal crystallization is shortened by 88%.

[0202] Table 2

[0203]

[0204] From Table 2 and Figure 3 It can be seen that compared with PLLA without adding a nucleating agent, the crystallization temperature of PLLA using the polymer nucleating agent of the present invention is increased by 1.1° C., the cold crystallization temperature is reduced by 11.8° C., and the relative crystallinity is increased by 4.1%.

[0205] Industrial Applicability

[0206] The polymer nucleating agent of the present invention can be widely used as a nucleating agent for semi-crystalline polymers.

Claims

1. A polymer nucleating agent, characterized in that: A cross-linked polymer is included, wherein the cross-linked polymer includes a structural unit derived from a photosensitive monomer having a dynamic cross-linking group.

2. The polymer nucleating agent according to claim 1, characterized in that: The photosensitive monomer having a dynamic cross-linking group is one or more monomers selected from monomers having one or more of a cinnamic acid group, a coumarin group, or an azobenzene group; Preferably, the photosensitive monomer having a dynamic cross-linking group is selected from one or more of N,N-bis(2-hydroxyethyl)cinnamic acid amide, N,N-bis(3-hydroxypropyl)cinnamic acid amide, N,N-bis(2-hydroxyethyl)-4-methoxycinnamic acid amide, N,N-bis(2-hydroxyethyl)-α-methylcinnamic acid amide, N,N-bis(2,3-dihydroxypropyl)cinnamic acid amide, 5,7-dihydroxy-4-methylcoumarin, 6,7-dihydroxy-4-methylcoumarin, 5,7-dihydroxy-4-propylcoumarin, 7,8-dihydroxy-4-methylcoumarin, 7,8-dihydroxy-3,4-dimethyl-coumarin, 4,4'-dihydroxyazobenzene, 2,2'-dihydroxyazobenzene, 3,3'-dihydroxyazobenzene, and 4,4'-bis(2-hydroxyethoxy)azobenzene; Preferably, the content of the structural unit derived from the photosensitive monomer having a dynamic crosslinking group is 10 mol % or less, based on the total moles of the structural units of the crosslinked polymer.

3. The polymer nucleating agent according to claim 1 or 2, characterized in that: The cross-linked polymer is at least one selected from polyester, polyamide, polyolefin and polyether.

4. The method for preparing a polymer nucleating agent according to any one of claims 1 to 3, characterized in that: The following steps are involved: (a) polymerizing a monomer composition comprising a photosensitive monomer having a dynamic crosslinking group to obtain a precursor polymer; (b) preparing a film from the precursor polymer obtained in step (a) and crystallizing the precursor polymer; (c) photochemically crosslinking the precursor polymer in the film obtained in step (b) to form the crosslinked polymer.

5. The preparation method according to claim 4, characterized in that: The monomer composition comprises one or more selected from diols, dicarboxylic acids, lactones, lactides, compounds containing carboxyl and hydroxyl groups, diamines, compounds containing amino and carboxyl groups, lactams, olefins, and oxacycloalkanes; Preferably, the monomer composition comprises at least one of the following (i) to (ix): (i) diols and dicarboxylic acids, (ii) lactone, (iii) lactide, (iv) compounds containing carboxyl and hydroxyl groups, (v) dicarboxylic acids and diamines, (vi) compounds containing amino groups and carboxyl groups, (vii) lactams, (viii) olefins, (ix) oxacycloalkanes; The polymerization reaction in step (a) is carried out by melt polycondensation, coordination polymerization or ring-opening polymerization; The number average molecular weight of the precursor polymer is 1,000 to 100,000 g / mol, preferably 2,000 to 80,000 g / mol.

6. The preparation method according to claim 4 or 5, characterized in that: In step (b), the precursor polymer obtained in step (a) is prepared into a film by solvent evaporation film forming or hot melt film forming; Preferably, the precursor polymer obtained in step (a) is prepared into a film by solvent evaporation film forming; More preferably, the precursor polymer obtained in step (a) is dissolved in a solvent to obtain a precursor polymer solution, and then the solvent is evaporated to allow the precursor polymer to crystallize and form a film; preferably, the precursor polymer is evaporated at a temperature of 0.040°C above the glass transition temperature T g To melting point T m The solvent is evaporated at a temperature in the range of .

7. A composition, characterized in that A polymer nucleating agent and a matrix polymer according to any one of claims 1 to 3; Preferably, the content of the polymer nucleating agent is 100 to 50000 ppm; Preferably, the matrix polymer is a semi-crystalline polymer, more preferably at least one selected from polyester, polyamide, polyolefin, and polyether.

8. The composition according to claim 7, characterized in that The matrix polymer and the cross-linked polymer in the polymeric nucleating agent have substantially the same structural unit composition except for the structural unit derived from the photosensitive monomer having a dynamic cross-linking group.

9. Use of a cross-linked polymer as a polymer nucleating agent, characterized in that The cross-linked polymer comprises structural units derived from a photosensitive monomer having a dynamic cross-linking group; Preferably, the polymer is a semi-crystalline polymer, more preferably at least one selected from polyester, polyamide, polyolefin, and polyether.

10. The use according to claim 9, characterized in that The polymer has substantially the same structural unit composition as the cross-linked polymer, except for the structural unit derived from the photosensitive monomer having a dynamic cross-linking group.

Images