Omega-pentadecanolide / cross-linked polyester autocrine lubricating material as well as preparation method and application thereof

Abstract

The invention provides an omega-pentadecanolide / cross-linked polyester autocrine lubricating material as well as a preparation method and application thereof, and belongs to the technical field of organic gel. The omega-pentadecalactone / crosslinked polyester self-secretion lubricating material is prepared through a photocuring reaction, a matrix is poly (omega-pentadecalactone)-containing crosslinked polyester, and an embedded small molecule is omega-pentadecalactone; reversible release omega-pentadecanolide is obtained by utilizing crystallization-melting of a cross-linked polyester network; due to the time-temperature dependence of crystallization / melting of the polyester network, the secretion volume and the secretion speed which are dynamically regulated and controlled are further obtained; the alpha, omega-pentadecalactone is used as a crystalline micromolecule, and crystallization-melting phase change of the alpha, omega-pentadecalactone is controlled, so that a controllable released substance condensed state is obtained. Due to the lubricating effect of omega-pentadecanolide secreted by the omega-pentadecanolide / cross-linked polyester self-secretion lubricating material, controllable friction coefficient and liquid drop sliding, deadhesion 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 and a preparation method and application thereof. Background Art

[0002] Obtaining self-protection of material surfaces and active regulation of surface properties is conducive to the development of intelligent devices. Based on the exocrine effect of bionic plants and animals, achieving reversible migration of functional substances between the material interface and the bulk phase, and then creating intelligent materials with release effects has become an important way to protect material surfaces (such as lubrication and anti-adhesion) and regulate surface properties (such as friction coefficient and wettability). It has broad application prospects in the fields of microfluidic chips, anti-adhesion, and intelligent lubrication.

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

[0004] In view of this, the object of the present invention is to provide an ω-pentadecalactone / cross-linked polyester autocrine lubricating material and a preparation method and application thereof. The ω-pentadecalactone / cross-linked polyester autocrine lubricating material provided by the present invention can obtain a regulated release condensed state and can stably exist on the surface, and can obtain a dynamically regulated secretion amount and secretion speed.

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

[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) diallyl formamide;

[0009] The first polymer and the poly(ω-pentadecalactone) diallylformamide, a trithiol crosslinking agent, a photoinitiator, a second ω-pentadecalactone and a third organic solvent are mixed to perform a photocuring reaction to obtain the ω-pentadecalactone / crosslinked polyester self-secreting 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) diallylcarboxamide is 10 to 90% of the total mass of the first polymer and the poly(ω-pentadecalactone) diallylcarboxamide.

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

[0015] Preferably, the mass of the second ω-pentadecalactone is 30-65% 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 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 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 chip.

[0022] The invention provides a method for preparing an ω-pentadecalactone / cross-linked polyester autosecreting lubricating material, comprising the following steps: 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; 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; wherein the first polymer is poly(ε-caprolactone) diallylformamide, polyethylene glycol diacrylate or poly(ε-caprolactone) diacrylate; and wherein the preparation method of the poly(ε-caprolactone) diallylformamide comprises the following steps: mixing poly(ε-caprolactone) diol, 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 ω-pentadecalactone / cross-linked polyester autosecreting lubricating material by photocuring reaction, wherein the matrix is ​​cross-linked polyester containing poly(ω-pentadecalactone), and the embedded small molecule is ω-pentadecalactone; the reversible release of ω-pentadecalactone is obtained by crystallization-melting of the cross-linked polyester network; due to the time-temperature dependence of crystallization / melting of the polyester network, the secretion amount and secretion speed of dynamic regulation are obtained; ω-pentadecalactone is used as a crystalline small molecule, and its crystallization-melting phase transition is controlled 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) chain in the polyester network (75-85°C), the liquid ω-pentadecalactone can be hindered by the unmelted polymer crystals (poly(ω-pentadecalactone) chain) without being reabsorbed, and can be relatively stable at the interface to obtain interface functional applications of different condensed states. Due to the lubricating effect of ω-pentadecalactone secreted by the ω-pentadecalactone / cross-linked polyester autosecreting lubricating material, controllable friction coefficient and droplet sliding, de-adhesion and other properties are demonstrated.

[0024] Therefore, the present invention exploits three types of surfaces that occur during reversible secretion: polymer networks ( 80℃ polyester surface ) The solid ω-pentadecalactone surface at room temperature and the liquid ω-pentadecalactone surface at 40°C obtained a controllable friction coefficient; further, the system showed intelligent anti-adhesion performance and controlled sliding of water droplets. Therefore, the unique reversible secretion performance of ω-pentadecalactone / cross-linked polyester autocrine lubricating material and the regulation of surface properties are expected to provide new ideas for 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 drawings required for use in the embodiments will be briefly introduced below. 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 creative labor.

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

[0027] Figure 2 The graph of the change of the internal polyester network structure during the release XRD monitoring of the sample of Example 1 (upper graph) and the XRD monitoring graph of the release process (lower 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 samples 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 The graphs of the friction coefficients of the three surfaces of the sample in Example 1 before release (80°C) and after release as a function of speed are shown;

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

[0034] Fig. 9 This is a diagram showing the control of the sliding of a water droplet 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) diallyl formamide;

[0038] The first polymer and the poly(ω-pentadecalactone) diallylformamide, a trithiol crosslinking agent, a photoinitiator, a second ω-pentadecalactone and a third organic solvent are mixed to perform a photocuring reaction to obtain the ω-pentadecalactone / crosslinked polyester self-secreting 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 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-triazidebicyclo(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 to 140° C., more preferably 100° C.; the time of the ring-opening polymerization reaction is preferably 36 to 72 hours, more preferably 40 to 60 hours. In the present invention, the ring-opening polymerization reaction is preferably carried out under stirring. The present invention has no special requirements for the stirring, and the requirements known in the art can be adopted.

[0047] After the ring-opening polymerization reaction is completed, the present invention preferably purifies the obtained product. The present invention has no special requirements for the process of purifying the product, 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 specifically 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) diallyl formamide.

[0049] In the present invention, the first organic solvent preferably includes N,N-dimethylformamide (DMF). The present invention has no particular requirement on 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 special requirements for the stirring, and the requirements known in the art can be used.

[0053] After completing the first end-capping reaction, the present invention preferably purifies the obtained product. The present invention has no special requirements for the process of purifying the product, 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 bonds of poly(ω-pentadecalactone) diol are end-capped by 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 self-secreting 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 to 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 usage 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 to 65% of the total mass of the second ω-pentadecalactone, the first polymer and poly(ω-pentadecalactone) diallylformamide, and more preferably 40 to 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 waveband is preferably 315-450nm, and the main wavelength is preferably 365nm. In the present invention, the photocuring reaction time is preferably 2-8min, and more preferably 3-6min.

[0068] In the present invention, when performing the photocuring reaction, it is preferred to use a culture dish as a mold to pour the obtained photocurable solution, then place the open surface of the culture dish under an ultraviolet lamp for the first photocuring, and then invert the culture dish for the second photocuring to minimize the crosslinking gradient. In the present invention, the time of the first photocuring and the second photocuring is preferably 1 to 4 minutes independently.

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

[0070] The present invention prepares the ω-pentadecalactone / cross-linked polyester self-secreting lubricating material by photocuring reaction, wherein the matrix is ​​a cross-linked polyester containing poly (ω-pentadecalactone), and the embedded small molecule is ω-pentadecalactone; the crystallization-melting of the cross-linked polyester network is used to obtain the reversible release of ω-pentadecalactone; due to the time-temperature dependence of the crystallization / melting of the polyester network, the secretion amount and secretion speed that are dynamically regulated are obtained; ω-pentadecalactone is used as a crystalline small molecule, and its crystallization-melting phase transition is controlled 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) chain in the polyester network (75-85° C.), the liquid ω-pentadecalactone can be hindered by the unmelted polymer crystals (poly (ω-pentadecalactone) chain) without being reabsorbed, and can be relatively stable at the interface to obtain interface functional applications of different condensed states.

[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 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 chip.

[0073] The present invention exploits three types of surfaces that occur during reversible secretion: polymer networks (80℃ polyester surface ) The solid ω-pentadecalactone surface at room temperature and the liquid ω-pentadecalactone surface at 40°C obtained a controllable friction coefficient; further, the system showed intelligent anti-adhesion performance and controlled sliding of water droplets. Therefore, the unique reversible secretion performance of ω-pentadecalactone / cross-linked polyester autocrine lubricating material and the regulation of surface properties are expected to provide new ideas for 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 and its preparation method and application are described in detail below in conjunction with 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 into a three-necked flask, dissolved in 18 g of DMF solvent, 0.79 mL of allyl isocyanate and 3 g of dibutyltin dilaurate (DBTDL) were added, nitrogen was passed through a condenser, and the reaction was carried out under magnetic stirring at 95° C. for 5 h; the reaction liquid after the reaction 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 to a condenser under nitrogen flow, and the mixture was stirred under magnetic stirring 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 ω-pentadecalactone / cross-linked polyester autosecreting lubricating material: 1.7g of poly(ω-pentadecalactone) diallylformamide, 0.3g of poly(ε-caprolactone) diallylformamide, 0.2016g of trimethylolpropane tris(3-mercaptopropionate) (TMPMP), 0.1g of photoinitiator 651 and 2g of ω-pentadecalactone (PDL) were dissolved in 4.67g of trichloroethane, and the resulting mixed solution was poured into an open culture dish, and the open surface was placed under an ultraviolet lamp (main band 315-450nm, main wavelength 365nm, light intensity 250w) for photocuring reaction for 3min, and then the dish was inverted and the other side was photocured for 3min; then the trichloroethane was removed at 50°C to obtain the ω-pentadecalactone / cross-linked polyester autosecreting 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 the 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 are dissolved in 4.67 g of trichloroethane, and the resulting mixed solution is poured into an open culture dish, and the open surface is 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 is inverted to perform photocuring reaction on the other side for 3 minutes; and then the trichloroethane is removed at 50° C. to obtain the ω-pentadecalactone / cross-linked polyester self-secreting 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 autocrystallized lubricating material was the same as that in Example 1, except that the 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 are dissolved in 4.67 g of trichloroethane, and the resulting mixed solution is poured into an open culture dish, and the open surface is 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 is inverted to perform photocuring reaction on the other side for 3 minutes; and then the trichloroethane is removed at 50° C. to obtain the ω-pentadecalactone / cross-linked polyester self-secreting 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 when synthesizing the ω-pentadecalactone / cross-linked polyester autocrine lubricating material, the crystalline small molecule ω-pentadecalactone is replaced by castor oil (non-crystalline small molecule).

[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 (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. At this time, the polyester network is not completely melted, and the liquid layer is not completely resorbed and exists at the interface. The temperature is further raised to 80°C, and the surface resorbs the ω-pentadecalactone, exposing 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 as it is released by XRD monitoring. 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 is an XRD monitoring diagram of the sample release process of Example 1. The peak marked by the left line is the main diffraction peak of the polyester network, and the peak marked by the right line 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 to 3 have similar effects.

[0095] Figure 3 The secretion efficiency of the samples in Example 1 at different release temperatures is obtained by weighing the secretion efficiency (release efficiency) to quantify the release amount, which illustrates the change of 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 as the temperature decreases, the secretion efficiency increases first and then decreases. Because we can achieve 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 indicates the regulation of the release amount at different release temperatures. As the release temperature decreases from 25°C to 17°C to 10°C to 0°C, the peak area ratio gradually decreases from 5.226 to 4.47 to 0.59 to 0.16, indicating that the release amount gradually decreases, and regulating the release temperature means that the release amount can be regulated. Examples 2 to 3 also have similar effects.

[0097] Figure 5 The Nano-CT 3D and 2D images of the sample of Example 1 at different release temperatures illustrate the reversible release effect and the thickness of the release layer at different temperatures. It can be seen that as the release temperature increases from 20°C to 10°C to 0°C, the thickness of the surface release layer decreases from 87.2μm to 67.8μm and finally to 13μm. This further illustrates that the release amount can be controlled by regulating the release temperature.

[0098] Rheological testing (TA, DHR-2, USA) monitors the release process to illustrate the release rate. The crystallization of the polyester network increases the storage modulus, and as the small molecule ω-pentadecalactone is released and gradually covers the polyester network, the storage modulus of the sample decreases. The time to reach the highest storage modulus is defined as the highest modulus time to evaluate the release rate. It is easy to know that the smaller the highest modulus time, the faster the release and the greater the release rate.

[0099] Figure 6 These are rheological test diagrams of the samples in the examples at different temperatures. Figure 6 The figure above shows the energy storage at 10℃ (G ’ ) and loss modulus (G ” ) Changes with time, as ω-pentadecalactone is released, the surface characteristics of the sample change from storage modulus greater than loss modulus to loss modulus greater than storage modulus. The storage modulus increases due to the crystallization of the polyester network, but due to the reduction of the release effect, it shows a trend of first increasing and then decreasing. The time of the highest 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 is stable over time at 36.5°C. There is no isothermal crystallization at this time, so there is 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. Then, a controllable release rate can be obtained by regulating the release temperature. 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. At 80°C, the friction coefficient of the polyester surface is greater than 2 when the speed is too high, which exceeds the detection range of the instrument. With the solid ω-pentadecalactone surface and the liquid ω-pentadecalactone surface as the 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 the steel block with high temperature glue to illustrate its intelligent anti-adhesion performance. Figure 8 The debonding test diagram of the sample in Example 1 illustrates the intelligent anti-adhesion ability of the ω-pentadecalactone / cross-linked polyester autocrine lubricating material, where RT represents room temperature. The sample is adhered to a steel block with a high-temperature glue, and as the ω-pentadecalactone is released at the interface between the glue and the sample, the temperature is applied to 40°C to melt the ω-pentadecalactone to destroy the interface between the glue and the sample, thereby debonding. The debonding test results of Examples 2 to 3 are similar.

[0102] The state of the water droplet on the sample surface was photographed using a contact angle meter (DSA100, KRUSS, Germany) to illustrate the system's control over the sliding of the water droplet. Fig. 9 The control diagram of the sample in Example 1 on the sliding of water droplets 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 that melts the interface ω-pentadecalactone after release. Water droplets have different adhesion behaviors at the above 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 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 angle of 10°. Therefore, the sliding of water droplets can be controlled by controlling the condensed state of the released substance. Examples 2 to 3 have similar effects.

[0103] The performance test methods of Examples 2 to 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 will have a reversible secretion effect, but no controllable surface condensation state, which shows the importance of the crystalline small molecule ω-pentadecalactone in the system to achieve a controllable condensation state.

[0106] Although the above embodiment describes the present invention in detail, 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 protection scope of the present invention.

Claims

1. A method for preparing an ω-pentadecalactone / cross-linked polyester autosecreting 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) diallyl formamide; The first polymer and the poly(ω-pentadecalactone) diallylformamide, a trithiol crosslinking agent, a photoinitiator, a second ω-pentadecalactone and a third organic solvent are mixed to perform a photocuring reaction to obtain the ω-pentadecalactone / crosslinked polyester self-secreting 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 group 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 30-65% 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 autosecreting 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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