An omega-pentadecalactone / crosslinked polyester autodiffusive lubricating material, and a preparation method and application thereof

Abstract

The present application provides a kind of omega-pentadecalactone / crosslinking polyester autocrine lubricating material and its preparation method and application, belong to organic gel technical field.The present application is prepared by photo-curing reaction omega-pentadecalactone / crosslinking polyester autocrine lubricating material, wherein matrix is the crosslinking polyester containing poly (omega-pentadecalactone), and small molecule is omega-pentadecalactone;Utilize the crystallization-melting of crosslinking polyester network to obtain reversible release omega-pentadecalactone;Due to the time-temperature dependence of polyester network crystallization / melting, further obtain the dynamic control of secretion amount and secretion speed;Omega-pentadecalactone is as crystalline small molecule, control its crystallization-melting phase change and further obtain the condensate state of controllable release;Due to the lubricating effect of omega-pentadecalactone / crosslinking polyester autocrine lubricating material secretion omega-pentadecalactone, controllable friction coefficient and droplet sliding, debonding and other properties are shown.

Description

Technical Field

[0001] The invention belongs to the technical field of organic gels, and in particular relates to an ω-pentadecalactone / cross-linked polyester autocrine lubricating material, a preparation method and an application thereof. Background Art

[0002] Achieving self-protection of material surfaces and active regulation of surface properties are beneficial to the development of intelligent devices. Based on the exocrine effect of biomimetic plants and animals, achieving reversible migration of functional substances between the material interface and the bulk phase, and then creating smart materials with release effects, has become an important method for protecting material surfaces (e.g., lubrication and anti-adhesion) and regulating surface properties (e.g., friction coefficient and wettability). This holds broad application prospects in fields such as microfluidic chips, anti-adhesion, and intelligent lubrication.

[0003] However, there are currently no reports on intelligent reversible release strategies with controllable release condensate state (solid or liquid), release amount, and release rate. Summary of the Invention

[0004] In light of this, the present invention aims to provide an ω-pentadecalactone / cross-linked polyester autocrine lubricating material, its preparation method, and application. The ω-pentadecalactone / cross-linked polyester autocrine lubricating material provided by the present invention can achieve a controllable condensed state of released substances that can be stably present on the surface, and can achieve dynamically regulated secretion volume and rate.

[0005] In order to achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a method for preparing an ω-pentadecalactone / cross-linked polyester autocrine lubricating material, comprising the following steps:

[0007] Mixing 1,8-octanediol, a first ω-pentadecalactone, and a first catalyst, and performing a ring-opening polymerization reaction to obtain poly(ω-pentadecalactone)diol;

[0008] The poly(ω-pentadecalactone) diol, the first allyl isocyanate, the first organic solvent and the second catalyst are mixed, and a first end-capping reaction is performed under the protection of a first inert gas to obtain poly(ω-pentadecalactone) diallylformamide;

[0009] Mixing the first polymer with the poly(ω-pentadecalactone) diallylformamide, a trithiol crosslinking agent, a photoinitiator, a second ω-pentadecalactone and a third organic solvent, and performing a photocuring reaction to obtain the ω-pentadecalactone / crosslinked polyester autocrystallizing lubricating material;

[0010] The first polymer is poly(ε-caprolactone) diallylformamide, polyethylene glycol diacrylate or poly(ε-caprolactone) diacrylate;

[0011] The preparation method of the poly (ε-caprolactone) diallylformamide comprises the following steps:

[0012] The poly(ε-caprolactone) diol, the second allyl isocyanate, the second organic solvent and the third catalyst are mixed, and a second end-capping reaction is carried out under the protection of a second inert gas to obtain the poly(ε-caprolactone) diallyl formamide.

[0013] Preferably, the mass of the poly(ω-pentadecalactone) diallylformamide is 10 to 90% of the total mass of the first polymer and the poly(ω-pentadecalactone) diallylformamide.

[0014] Preferably, the molar ratio of the mercapto group in the trithiol crosslinking agent to the double bond functional groups in the first polymer and poly(ω-pentadecalactone) diallylformamide is (1-4):(2-3).

[0015] Preferably, the mass of the second ω-pentadecalactone is 30 to 65% of the total mass of the second ω-pentadecalactone, the first polymer and poly(ω-pentadecalactone) diallylformamide.

[0016] Preferably, the photocuring reaction is carried out under ultraviolet light; the power of the ultraviolet light is 250W, and the main wavelength range is 315-450nm.

[0017] Preferably, the temperature of the ring-opening polymerization reaction is 100-140° C., and the time is 36-72 hours.

[0018] Preferably, the molar ratio of the poly(ω-pentadecalactone) diol to the first allyl isocyanate is 1:(2-3).

[0019] Preferably, the temperature of the first end-capping reaction is 75-95° C., and the time is 4-6 hours.

[0020] The present invention provides an ω-pentadecalactone / cross-linked polyester autocrine lubricating material prepared by the preparation method described in the above scheme, comprising a cross-linked polyester matrix and ω-pentadecalactone embedded in the cross-linked polyester matrix; the cross-linked polyester matrix is ​​a cross-linked polyester containing poly(ω-pentadecalactone).

[0021] The present invention provides the application of the ω-pentadecalactone / cross-linked polyester autocrine lubricating material described in the above scheme in the fields of intelligent lubrication, anti-adhesion or microfluidic chips.

[0022] The present invention provides a preparation method of an ω-pentadecalactone / cross-linked polyester autocrine lubricating material, comprising the following steps: mixing 1,8-octanediol, a first ω-pentadecalactone and a first catalyst, performing a ring-opening polymerization reaction to obtain poly(ω-pentadecalactone) diol; mixing the poly(ω-pentadecalactone) diol, a first allyl isocyanate, a first organic solvent and a second catalyst, and performing a first end-capping reaction under the protection of a first inert gas to obtain poly(ω-pentadecalactone) diallylformamide; and reacting the first polymer with the poly(ω-pentadecalactone) diallylformamide, a trithiol cross-linking agent and a photoinitiator. The invention relates to a method for preparing a self-secreting lubricating material of ω-pentadecalactone / cross-linked polyester by mixing a first polymer, a second ω-pentadecalactone and a third organic solvent, and performing a photocuring reaction to obtain the ω-pentadecalactone / cross-linked polyester autocrine lubricating material; the first polymer is poly(ε-caprolactone) diallylformamide, polyethylene glycol diacrylate or poly(ε-caprolactone) diacrylate; and the method for preparing the poly(ε-caprolactone) diallylformamide comprises the following steps: mixing poly(ε-caprolactone) glycol, a second allyl isocyanate, a second organic solvent and a third catalyst, and performing a second end-capping reaction under the protection of a second inert gas to obtain the poly(ε-caprolactone) diallylformamide.

[0023] The present invention prepares an ω-pentadecalactone / cross-linked polyester autocrystallized lubricating material through a photocuring reaction. The matrix is ​​a cross-linked polyester containing poly(ω-pentadecalactone) and the embedded small molecule is ω-pentadecalactone. The ω-pentadecalactone is reversibly released by the crystallization-melting process of the cross-linked polyester network. Due to the time-temperature dependence of the crystallization / melting of the polyester network, the secretion volume and rate can be dynamically controlled. The ω-pentadecalactone, as a crystalline small molecule, is controlled by its crystallization-melting phase transition to achieve a controllable condensed state of released material. Because the melting point of ω-pentadecalactone (34°C) is much lower than the melting point of the poly(ω-pentadecalactone) chains within the polyester network (75-85°C), liquid ω-pentadecalactone is hindered by unmelted polymer crystals (poly(ω-pentadecalactone) chains) and is not resorbed, remaining relatively stable at the interface to achieve interfacial functional applications of different condensed states. Due to the lubricating effect of the ω-pentadecalactone secreted by the ω-pentadecalactone / cross-linked polyester autocrystallized lubricating material, the material exhibits controllable friction coefficient, droplet sliding, and de-adhesion properties.

[0024] Therefore, the present invention exploits three types of surfaces that appear during reversible secretion: polymer networks ( 80℃ polyester surface ) Controllable friction coefficients were achieved on both solid ω-pentadecalactone surfaces at room temperature and liquid ω-pentadecalactone surfaces at 40°C. Furthermore, the system exhibited intelligent anti-adhesion properties and controlled water droplet sliding. Therefore, the unique reversible secretion properties and controllable surface properties of ω-pentadecalactone / cross-linked polyester autocrine lubricants are expected to provide new insights into practical applications such as intelligent lubrication, anti-adhesion, and microfluidic chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is a diagram demonstrating the reversible release of the sample in Example 1;

[0027] Figure 2 The graph showing the change of the internal polyester network structure during the release of the sample of Example 1 (top graph) and the XRD monitoring graph during the release process (bottom graph);

[0028] Figure 3 The secretion efficiency of the samples in Example 1 at different release temperatures;

[0029] Figure 4 is the peak area ratio (PAR) of the sample in Example 1 at different release temperatures;

[0030] Figure 5 The nano-CT three-dimensional and two-dimensional images of the sample in Example 1;

[0031] Figure 6 The rheological test diagram of the sample of Example 1 at different temperatures;

[0032] Figure 7 Graph showing the variation of friction coefficients of three surfaces with speed when the sample of Example 1 is not released (80°C) and released;

[0033] Figure 8 This is a diagram demonstrating the debonding test of the sample in Example 1;

[0034] Figure 9 This is a diagram showing the control of water droplet sliding by the sample in Example 1. DETAILED DESCRIPTION

[0035] The present invention provides a method for preparing an ω-pentadecalactone / cross-linked polyester autocrine lubricating material, comprising the following steps:

[0036] Mixing 1,8-octanediol, a first ω-pentadecalactone, and a first catalyst, and performing a ring-opening polymerization reaction to obtain poly(ω-pentadecalactone)diol;

[0037] The poly(ω-pentadecalactone) diol, the first allyl isocyanate, the first organic solvent and the second catalyst are mixed, and a first end-capping reaction is performed under the protection of a first inert gas to obtain poly(ω-pentadecalactone) diallylformamide;

[0038] Mixing the first polymer with the poly(ω-pentadecalactone) diallylformamide, a trithiol crosslinking agent, a photoinitiator, a second ω-pentadecalactone and a third organic solvent, and performing a photocuring reaction to obtain the ω-pentadecalactone / crosslinked polyester autocrystallizing lubricating material;

[0039] The first polymer is poly(ε-caprolactone) diallylformamide, polyethylene glycol diacrylate or poly(ε-caprolactone) diacrylate;

[0040] The preparation method of the poly (ε-caprolactone) diallylformamide comprises the following steps:

[0041] The poly(ε-caprolactone) diol, the second allyl isocyanate, the second organic solvent and the third catalyst are mixed, and a second end-capping reaction is carried out under the protection of a second inert gas to obtain the poly(ε-caprolactone) diallyl formamide.

[0042] Unless otherwise specified, the materials and equipment used in the present invention are all commercially available products.

[0043] The present invention mixes 1,8-octanediol, a first ω-pentadecalactone and a first catalyst, and performs a ring-opening polymerization reaction to obtain poly(ω-pentadecalactone)diol.

[0044] In the present invention, the mass of the 1,8-octanediol is preferably 2 to 3.5% of the total mass of the 1,8-octanediol, the first ω-pentadecalactone and the first catalyst, and more preferably 2.5 to 3.3%.

[0045] In the present invention, the first catalyst preferably includes 1,5,7-triazidobicyclo(4.4.0)dec-5-ene; the mass of the first catalyst is preferably 1 to 5% of the total mass of 1,8-octanediol, the first ω-pentadecalactone and the first catalyst, and more preferably 2 to 3.5%.

[0046] In the present invention, the temperature of the ring-opening polymerization reaction is preferably 100-140°C, more preferably 100°C; the time of the ring-opening polymerization reaction is preferably 36-72 hours, more preferably 40-60 hours. In the present invention, the ring-opening polymerization reaction is preferably carried out under stirring. The present invention has no particular requirements for stirring, and the requirements known in the art can be adopted.

[0047] After completing the ring-opening polymerization reaction, the present invention preferably purifies the obtained product. The present invention has no particular requirements for the process of product purification, as long as the poly (ω-pentadecalactone) diol can be obtained. In an embodiment of the present invention, the reaction solution after the ring-opening polymerization reaction is dissolved in chloroform, then precipitated in n-hexane and filtered, and dried to obtain the poly (ω-pentadecalactone) diol.

[0048] After obtaining the poly(ω-pentadecalactone) diol, the present invention mixes the poly(ω-pentadecalactone) diol, a first allyl isocyanate, a first organic solvent, and a second catalyst, and performs a first end-capping reaction under the protection of a first inert gas to obtain poly(ω-pentadecalactone) diallylformamide.

[0049] In the present invention, the first organic solvent preferably includes N,N-dimethylformamide (DMF). The present invention has no particular requirements for the amount of the first organic solvent, as long as it can dissolve the poly(ω-pentadecalactone) diol and the first allyl isocyanate.

[0050] In the present invention, the molar ratio of the poly(ω-pentadecalactone) diol to the first allyl isocyanate is preferably 1:(2-3), and more preferably 1:2.5.

[0051] In the present invention, the second catalyst is preferably dibutyltin dilaurate (DBTDL). In the present invention, the mass of the second catalyst is preferably 0.5-2% of the total mass of the poly(ω-pentadecalactone) diol and the first allyl isocyanate, and more preferably 1-1.5%.

[0052] In the present invention, the first inert gas is preferably nitrogen. In the present invention, the temperature of the first end-capping reaction is preferably 75 to 95°C, more preferably 80 to 93°C, and the time is preferably 4 to 6 hours, more preferably 5 hours. In the present invention, the first end-capping reaction is preferably carried out under stirring. The present invention has no particular requirements for stirring, and the requirements well known in the art can be adopted.

[0053] After completing the first end-capping reaction, the present invention preferably purifies the obtained product. The present invention has no particular requirements for the process of product purification, as long as the poly (ω-pentadecalactone) diallylformamide can be obtained. In an embodiment of the present invention, the reaction solution after the first end-capping reaction is precipitated in n-heptane, filtered, washed, and dried to obtain the poly (ω-pentadecalactone) diol.

[0054] In the first end-capping reaction of the present invention, the double bond of poly(ω-pentadecalactone) diol is end-capped by an addition reaction.

[0055] After obtaining the poly(ω-pentadecalactone) diol, the present invention mixes the first polymer with the poly(ω-pentadecalactone) diallylformamide, a trithiol crosslinking agent, a photoinitiator, a second ω-pentadecalactone, and a third organic solvent, and performs a photocuring reaction to obtain the ω-pentadecalactone / crosslinked polyester autocrystallizing lubricating material;

[0056] The first polymer is poly(ε-caprolactone) diallylformamide, polyethylene glycol diacrylate or poly(ε-caprolactone) diacrylate;

[0057] The preparation method of the poly (ε-caprolactone) diallylformamide comprises the following steps:

[0058] The poly(ε-caprolactone) diol, the second allyl isocyanate, the second organic solvent and the third catalyst are mixed, and a second end-capping reaction is carried out under the protection of a second inert gas to obtain the poly(ε-caprolactone) diallyl formamide.

[0059] In the present invention, the molar ratio of the poly(ε-caprolactone) diol and the second allyl isocyanate is preferably 1:(2-3), more preferably 1:2.5. In the present invention, the mass of the third catalyst is preferably 0.5-2% of the total mass of the poly(ε-caprolactone) diol and the second allyl isocyanate, more preferably 1-1.5%.

[0060] In the present invention, the types of the second organic solvent and the third catalyst, the type of the second inert gas, and the conditions of the second end-capping reaction are the same as those of the first end-capping reaction and are not described in detail herein.

[0061] In the present invention, the trithiol crosslinking agent preferably includes trimethylolpropane tris(3-mercaptopropionate); the photoinitiator preferably includes photoinitiator 651; and the third organic solvent preferably includes trichloroethane.

[0062] In the present invention, the amount of the third organic solvent is preferably 2 to 4 times the total mass of the poly(ε-caprolactone) diallylformamide and the poly(ω-pentadecalactone) diallylformamide.

[0063] In the present invention, the mass of the poly(ω-pentadecalactone) diallylcarboxamide is preferably 10 to 90% of the total mass of the first polymer and the poly(ω-pentadecalactone) diallylcarboxamide, and more preferably 50 to 85%.

[0064] In the present invention, the molar ratio of the thiol group in the trithiol crosslinking agent to the double bond functional group in the first polymer and poly(ω-pentadecalactone) diallylformamide is preferably (1-4):(2-3), and more preferably (1.5-2.5):2.5.

[0065] In the present invention, the mass of the photoinitiator is preferably 1 to 5% of the total mass of the first polymer and poly(ω-pentadecalactone) diallylformamide, and more preferably 2.5 to 4.5%.

[0066] In the present invention, the mass of the second ω-pentadecalactone is preferably 30-65% of the total mass of the second ω-pentadecalactone, the first polymer and poly(ω-pentadecalactone) diallylformamide, and more preferably 40-55%.

[0067] In the present invention, the photocuring reaction is preferably carried out under ultraviolet light; the power of the ultraviolet light is preferably 250W, the main wavelength is preferably 315-450nm, and the main wavelength is preferably 365nm. In the present invention, the photocuring reaction time is preferably 2-8 minutes, more preferably 3-6 minutes.

[0068] During the photocuring reaction, the obtained photocurable solution is preferably poured into a culture dish as a mold. The open surface of the culture dish is then placed under a UV lamp for a first photocuring step, and then the culture dish is inverted for a second photocuring step to minimize the crosslinking gradient. In the present invention, the time for the first and second photocuring steps is preferably 1 to 4 minutes, respectively.

[0069] After the photocuring reaction is completed, the present invention preferably removes the solvent from the obtained reaction solution, and then performs demoulding to obtain the ω-pentadecalactone / cross-linked polyester autocrine lubricating material.

[0070] The present invention prepares an ω-pentadecalactone / cross-linked polyester autosecreting lubricating material through a photocuring reaction, wherein the matrix is ​​a cross-linked polyester containing poly(ω-pentadecalactone) and the embedded small molecule is ω-pentadecalactone. The ω-pentadecalactone is reversibly released by the crystallization-melting process of the cross-linked polyester network. Due to the time-temperature dependence of the crystallization / melting of the polyester network, the secretion volume and speed can be dynamically controlled. The ω-pentadecalactone, as a crystalline small molecule, is controlled by controlling its crystallization-melting phase transition to obtain a controllable condensed state of the released material. Because the melting point of ω-pentadecalactone (34°C) is much lower than the melting point of the poly(ω-pentadecalactone) chains in the polyester network (75-85°C), the liquid ω-pentadecalactone is hindered by unmelted polymer crystals (poly(ω-pentadecalactone) chains) and is not resorbed, and can remain relatively stable at the interface to obtain different interfacial functional applications.

[0071] The present invention provides an ω-pentadecalactone / cross-linked polyester autocrine lubricating material prepared by the preparation method described in the above scheme, comprising a cross-linked polyester matrix and ω-pentadecalactone embedded in the cross-linked polyester matrix; the cross-linked polyester matrix is ​​a cross-linked polyester containing poly(ω-pentadecalactone).

[0072] The present invention provides the application of the ω-pentadecalactone / cross-linked polyester autocrine lubricating material described in the above scheme in the fields of intelligent lubrication, anti-adhesion or microfluidic chips.

[0073] The present invention utilizes three types of surfaces that appear during reversible secretion: polymer networks (80℃ polyester surface ) Controllable friction coefficients were achieved on both solid ω-pentadecalactone surfaces at room temperature and liquid ω-pentadecalactone surfaces at 40°C. Furthermore, the system exhibited intelligent anti-adhesion properties and controlled water droplet sliding. Therefore, the unique reversible secretion properties and controllable surface properties of ω-pentadecalactone / cross-linked polyester autocrine lubricants are expected to provide new insights into practical applications such as intelligent lubrication, anti-adhesion, and microfluidic chips.

[0074] To further illustrate the present invention, the ω-pentadecalactone / cross-linked polyester autocrine lubricating material provided by the present invention, its preparation method and application are described in detail below with reference to the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present invention.

[0075] Example 1

[0076] Synthesis of poly(ω-pentadecalactone) diol: 102 g of ω-pentadecalactone, 3.59 g of 1,8-octanediol, and 3.41 g of 1,5,7-triazidobicyclo(4.4.0)dec-5-ene (TBD) were placed in a three-necked flask, connected to a condenser, and magnetically stirred at 100°C for 48 h. After the reaction, the mixture was dissolved in 400 mL of chloroform and precipitated in 500 mL of n-hexane. The precipitate was filtered and dried to obtain poly(ω-pentadecalactone) diol powder.

[0077] Synthesis of poly(ω-pentadecalactone) diallylformamide: 8.5 g of the poly(ω-pentadecalactone) diol was weighed and dissolved in 18 g of DMF solvent in a three-necked flask. 0.79 mL of allyl isocyanate and 3 g of dibutyltin dilaurate (DBTDL) were added. Nitrogen was passed through a condenser and the mixture was stirred under magnetic stirring at 95° C. for 5 h. The reaction mixture was precipitated in n-heptane, washed, and dried to obtain poly(ω-pentadecalactone) diallylformamide.

[0078] Synthesis of poly(ε-caprolactone) diallylformamide: 20 g of poly(ε-caprolactone) diol (Mn=2000) and 1.63 mL of allyl isocyanate were dissolved in 30 g of DMF, and 3 g of DBTDL was added. The mixture was purged with nitrogen and placed in a condenser. The reaction was stirred magnetically at 95°C for 5 h. The reaction solution was precipitated in n-heptane, filtered, washed, and dried to obtain poly(ε-caprolactone) diallylformamide.

[0079] Synthesis of an ω-pentadecalactone / cross-linked polyester autocrystallized lubricating material: 1.7 g of poly(ω-pentadecalactone) diallylformamide, 0.3 g of poly(ε-caprolactone) diallylformamide, 0.2016 g of trimethylolpropane tris(3-mercaptopropionate) (TMPMP), 0.1 g of photoinitiator 651, and 2 g of ω-pentadecalactone (PDL) were dissolved in 4.67 g of trichloroethane. The resulting mixed solution was poured into an open Petri dish, and the open side was placed under an ultraviolet lamp (main band 315-450 nm, main wavelength 365 nm, light intensity 250 W) for photocuring reaction for 3 minutes. The dish was then inverted and the other side was photocured for 3 minutes. The trichloroethane was then removed at 50°C to obtain the ω-pentadecalactone / cross-linked polyester autocrystallized lubricating material.

[0080] Example 2

[0081] The synthesis of poly(ω-pentadecalactone) diol and poly(ω-pentadecalactone) diallylformamide was the same as in Example 1.

[0082] The synthesis of the ω-pentadecalactone / cross-linked polyester autocrine lubricating material was the same as that in Example 1, except that poly(ε-caprolactone) diallylformamide was replaced by polyethylene glycol diacrylate.

[0083] Specifically, 1.7 g of poly(ω-pentadecalactone) diallylformamide, 0.3 g of polyethylene glycol diacrylate, 0.2016 g of TMPMP, 0.1 g of photoinitiator 651 and 2 g of ω-pentadecalactone were dissolved in 4.67 g of trichloroethane, and the resulting mixed solution was poured into an open culture dish. The open surface was placed under an ultraviolet lamp (main band 315-450 nm, main wavelength 365 nm, light intensity 250 W) for photocuring reaction for 3 minutes, and then the dish was inverted and the other side was photocured for 3 minutes; then the trichloroethane was removed at 50°C to obtain the ω-pentadecalactone / cross-linked polyester autocrystallizing lubricating material.

[0084] Example 3

[0085] The synthesis of poly(ω-pentadecalactone) diol and poly(ω-pentadecalactone) diallylformamide was the same as in Example 1.

[0086] The synthesis of the ω-pentadecalactone / cross-linked polyester autocrine lubricating material was the same as that in Example 1, except that poly(ε-caprolactone) diallylformamide was replaced by poly(ε-caprolactone) diacrylate.

[0087] Specifically, 1.7 g of poly(ω-pentadecalactone) diallylformamide, 0.3 g of poly(ε-caprolactone) diacrylate, 0.2016 g of TMPMP, 0.1 g of photoinitiator 651 and 2 g of ω-pentadecalactone were dissolved in 4.67 g of trichloroethane, and the resulting mixed solution was poured into an open culture dish. The open surface was placed under an ultraviolet lamp (main band 315-450 nm, main wavelength 365 nm, light intensity 250 W) for photocuring reaction for 3 minutes, and then the dish was inverted and the other side was photocured for 3 minutes; then the trichloroethane was removed at 50°C to obtain the ω-pentadecalactone / cross-linked polyester autocrystallizing lubricating material.

[0088] Comparative Example 1

[0089] The preparation steps are the same as those in Example 1, except that no photocuring reaction is performed when synthesizing the ω-pentadecalactone / cross-linked polyester autocrystallized lubricating material.

[0090] Comparative Example 2

[0091] The preparation steps are the same as those in Example 1, except that the crystalline small molecule ω-pentadecalactone is replaced with castor oil (a non-crystalline small molecule) when synthesizing the ω-pentadecalactone / cross-linked polyester autocrine lubricating material.

[0092] Performance Testing

[0093] Figure 1 This is a demonstration diagram of the reversible release of the sample in Example 1. At 80°C, the sample has an amorphous polyester network morphology. When cooled to room temperature and placed (S1-S2), the polyester network undergoes isothermal crystallization, and a solid ω-pentadecalactone layer appears on the surface of the sample. The temperature is further raised to 40°C (S2-S3), and the ω-pentadecalactone layer on the surface of the sample melts into a liquid state, soaking the surface filter paper. Because the polyester network is not completely melted at this time, the liquid layer is not completely reabsorbed and exists at the interface. Further heating to 80°C, the surface reabsorbs the ω-pentadecalactone and exposes the polyester network interface again. The effects of Examples 2 to 3 are similar.

[0094] The release process was monitored by XRD (EMPYREAN, PANalytical, The Netherlands). Figure 2 The above figure shows the changes in the internal polyester network structure of the sample of Example 1 monitored by XRD during release. It can be seen that the relative crystallinity (ε) of the internal network gradually increases with the increase in release time, indicating the release effect induced by the crystallization of the polyester network. Figure 2 The figure below shows the XRD monitoring pattern of the sample release process in Example 1. The peak marked on the left is the main diffraction peak of the polyester network, and the peak marked on the right is the main diffraction peak of ω-pentadecalactone (PDL). The peak area ratio (PAR, ω-pentadecalactone main diffraction peak area to polyester network main diffraction peak area) gradually increases with release, indicating the release process. Examples 2 and 3 have similar effects.

[0095] Figure 3 The secretion efficiency of the sample of Example 1 at different release temperatures was quantified by the weight method to quantify the release amount, which illustrates the change of the secretion efficiency with temperature. The secretion efficiency is the mass fraction of the PDL mass released on the surface to the total PDL mass in the system. It can be seen that the secretion efficiency first increases and then decreases with the decrease of temperature. Because, we can realize the regulation of the surface PDL amount by controlling the temperature of the material.

[0096] Figure 4 The peak area ratio (PAR) of the sample of Example 1 at different release temperatures illustrates the regulation of the release amount at different release temperatures. With the decrease of the release temperature from 25℃ to 17℃ to 10℃ to 0℃, the peak area ratio gradually decreases from 5.226 to 4.47 to 0.59 to 0.16, which illustrates that the release amount gradually decreases, and the regulation of the release temperature has a controllable release amount. In Examples 2-3, similar effects are also obtained.

[0097] Figure 5 The Nano-CT three-dimensional and two-dimensional graphs of the sample of Example 1 at different release temperatures illustrate the reversible release effect and the release layer thickness at different temperatures. It can be seen that with the decrease of the release temperature from 20℃ to 10℃ to 0℃, the surface release layer thickness decreases from 87.2μm to 67.8μm and finally to 13μm. It further illustrates that the regulation of the release temperature can obtain a controllable release amount.

[0098] The rheological test (TA, DHR-2, USA) monitors the release process to illustrate the release speed. The crystallization of the polyester network increases the storage modulus, and with the gradual covering of the polyester network by the release of the small molecule ω-pentadecalactone, the storage modulus of the sample will decrease. The time to reach the highest storage modulus is defined as the highest modulus time to evaluate the release rate. It is known that the smaller the highest modulus time, the faster the release, and the greater the release rate.

[0099] Figure 6 The rheological test graph of the sample of Example at different temperatures. Figure 6 The upper graph is the change of the storage (G ’ ) and loss modulus (G ” ) with time at 10℃, with the release of ω-pentadecalactone, the surface properties of the sample change from the storage modulus being greater than the loss modulus to the loss modulus being greater than the storage modulus. The storage modulus increases due to the crystallization of the polyester network, and decreases due to the release effect, so it shows a trend of first increasing and then decreasing. The time of the highest point of the storage modulus is defined as the maximum storage modulus time to evaluate the release rate. Figure 6The figure below shows the change of storage modulus over time at different temperatures. The storage modulus at 36.5°C remains stable over time. At this time, there is no isothermal crystallization and no release effect. When the temperature is lowered to 25°C, the storage modulus first increases and then decreases. At this time, isothermal crystallization is sufficient to induce secretion. Continue to lower the temperature to 20°C and 10°C, the maximum modulus time gradually decreases, and the release rate gradually accelerates. By regulating the release temperature, a controllable release rate can be obtained. In Examples 2 to 3, rheological tests also showed similar effects.

[0100] The friction coefficient of the material was measured using a CSM friction and wear testing machine in reciprocating mode. Figure 7 The friction coefficient of three surfaces (polyester surface at 80°C, solid ω-pentadecalactone surface at room temperature, liquid ω-pentadecalactone surface at 40°C) that appeared when the sample of Example 1 was not released (80°C) and released varies with speed, where RT represents room temperature. It can be seen that the friction coefficient is regulated between approximately 1.3, 0.5, and 0.03. The friction coefficient of the polyester surface at 80°C is greater than 2 when the speed is too high, which exceeds the detection range of the instrument. For the solid ω-pentadecalactone surface and the liquid ω-pentadecalactone surface, the friction coefficient is relatively stable when the speed changes. In Examples 2 to 3, the friction coefficient test also showed similar effects.

[0101] The sample was adhered to a steel block using high-temperature glue to demonstrate its intelligent anti-adhesion performance. Figure 8 This image shows the debonding test of the sample from Example 1, illustrating the intelligent anti-adhesion capabilities of the ω-pentadecalactone / cross-linked polyester autocrine lubricant. RT represents room temperature. The sample was adhered to a steel block using a high-temperature adhesive. As the ω-pentadecalactone was released at the adhesive-sample interface, the sample was heated to 40°C to melt the ω-pentadecalactone, breaking the adhesive-sample interface and ultimately debonding the sample. Similar results were obtained in Examples 2 and 3.

[0102] The state of the water droplet on the sample surface was photographed using a contact angle meter (DSA100, KRUSS, Germany) to illustrate the control of the system on the sliding of the water droplet. Figure 9 The diagram showing the control of the sliding of water droplets by the sample in Example 1 is shown, where RT represents room temperature. Depending on whether ω-pentadecalactone is released or not, the sample can present three different surfaces, namely the polyester surface when not released, the solid ω-pentadecalactone surface after release, and the liquid surface in which the interface ω-pentadecalactone is melted after release. Water droplets have different adhesion behaviors at the above-mentioned different interfaces. The two vertically placed sample images on the left are divided into a polyester surface and a solid ω-pentadecalactone surface. It can be seen that the water droplets are pinned to the above-mentioned surfaces and do not slide even when placed vertically at 90°. However, the water droplets slide on the liquid ω-pentadecalactone surface sample placed on the right at an inclination of 10°. Therefore, the control of water droplet sliding can be achieved by controlling the condensed state of the released substance. Examples 2 to 3 have similar effects.

[0103] The performance testing methods of Examples 2-3 are similar to those of Example 1. They also demonstrate controllable release condensation state, release amount, and release rate; and also demonstrate adjustable friction coefficient, intelligent anti-adhesion, and regulated water droplet sliding behavior.

[0104] The system of Comparative Example 1 has no reversible secretion effect, which further illustrates the importance of the cross-linked polyester network for the system to achieve a reversible secretion effect.

[0105] The system of Comparative Example 2 exhibits a reversible secretion effect but no controllable surface condensed state, which illustrates the importance of achieving a controllable condensed state of the crystalline small molecule ω-pentadecalactone in the system.

[0106] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A method for preparing an ω-pentadecalactone / cross-linked polyester autocrine lubricating material, characterized in that: The following steps are involved: Mixing 1,8-octanediol, a first ω-pentadecalactone, and a first catalyst, and performing a ring-opening polymerization reaction to obtain poly(ω-pentadecalactone)diol; The poly(ω-pentadecalactone) diol, the first allyl isocyanate, the first organic solvent and the second catalyst are mixed, and a first end-capping reaction is performed under the protection of a first inert gas to obtain poly(ω-pentadecalactone) diallylformamide; Mixing the first polymer with the poly(ω-pentadecalactone) diallylformamide, a trithiol crosslinking agent, a photoinitiator, a second ω-pentadecalactone and a third organic solvent, and performing a photocuring reaction to obtain the ω-pentadecalactone / crosslinked polyester autocrystallizing lubricating material; The first polymer is poly(ε-caprolactone) diallylformamide, polyethylene glycol diacrylate or poly(ε-caprolactone) diacrylate; The preparation method of the poly (ε-caprolactone) diallylformamide comprises the following steps: The poly(ε-caprolactone) diol, the second allyl isocyanate, the second organic solvent and the third catalyst are mixed, and a second end-capping reaction is carried out under the protection of a second inert gas to obtain the poly(ε-caprolactone) diallyl formamide.

2. The preparation method according to claim 1, characterized in that The mass of the poly(ω-pentadecalactone) diallylformamide is 10 to 90% of the total mass of the first polymer and the poly(ω-pentadecalactone) diallylformamide.

3. The preparation method according to claim 1, characterized in that The molar ratio of the mercapto group in the trithiol crosslinking agent to the double bond functional groups in the first polymer and poly(ω-pentadecalactone) diallylformamide is (1-4):(2-3).

4. The preparation method according to claim 1, characterized in that The mass of the second ω-pentadecalactone is 30 to 65% of the total mass of the second ω-pentadecalactone, the first polymer and poly(ω-pentadecalactone) diallylformamide.

5. The preparation method according to any one of claims 1 to 4, characterized in that The photocuring reaction is carried out under ultraviolet light; the power of the ultraviolet light is 250W, and the main wavelength is 315-450nm.

6. The preparation method according to claim 1, characterized in that The temperature of the ring-opening polymerization reaction is 100-140° C., and the time is 36-72 hours.

7. The preparation method according to claim 1, characterized in that The molar ratio of the poly(ω-pentadecalactone) diol to the first allyl isocyanate is 1:(2-3).

8. The preparation method according to claim 1 or 7, characterized in that The temperature of the first end-capping reaction is 75-95° C., and the time is 4-6 hours.

9. The ω-pentadecalactone / cross-linked polyester autocrine lubricating material prepared by the preparation method according to any one of claims 1 to 8 comprises a cross-linked polyester matrix and ω-pentadecalactone embedded in the cross-linked polyester matrix; the cross-linked polyester matrix is ​​a cross-linked polyester containing poly(ω-pentadecalactone).

10. Use of the ω-pentadecalactone / cross-linked polyester autocrine lubricating material according to claim 9 in the fields of intelligent lubrication, anti-adhesion or microfluidic chips.

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