Degradable hydrophobic polyurethane and preparation method and application thereof

Abstract

The application provides a degradable hydrophobic polyurethane and a preparation method and application thereof, and relates to the technical field of polyurethane synthesis and modification. Poly-caprolactone, polylactic acid and hydroxyl-terminated polydimethylsiloxane are added into N,N-dimethylformamide to obtain a mixed solution, isophorone diisocyanate and an organic metal catalyst are added, and a prepolymer solution is prepared through catalytic reaction; a polyol chain extender, a polyol crosslinking agent and a non-aqueous polyurethane defoaming agent are added into the prepolymer solution, and stirring is performed until the mixture is uniform, so that a polyurethane emulsion is prepared; and the polyurethane emulsion is subjected to vacuum degassing and curing, so that the degradable hydrophobic polyurethane is prepared. The prepared polyurethane has excellent mechanical properties, degradability and antifouling performance, and can be applied to the surface antifouling of marine materials.

Description

Technical Field

[0001] This invention belongs to the field of polyurethane preparation technology, specifically relating to a biodegradable hydrophobic polyurethane, its preparation method, and its application. Background Technology

[0002] Marine industries and activities inevitably encounter the problems of marine fouling and biofouling, causing significant negative impacts on marine engineering projects such as ships, nuclear power plants, and oil platforms. Humans have limited control over the natural environment in which ships or marine facilities operate. Therefore, applying marine antifouling coatings to modify the surface properties of marine facilities to resist biofouling has become the most economical and feasible method. Acrylic self-polishing antifouling coatings are currently the most widely used materials, but acrylic resins have poor mechanical properties. Polyurethane is a type of material synthesized from polyols, isocyanates, chain extenders, and other raw materials. Ordinary polyurethane has good mechanical properties, but its non-degradability and poor anti-adhesion properties make it difficult to apply in the field of marine antifouling. Therefore, modification is necessary to change its properties and make it biodegradable, which can greatly improve the antifouling performance of polyurethane and better apply it in the field of marine materials.

[0003] Chinese patent document CN112409776A discloses a method for preparing rapidly degradable polyurethane. The method involves synthesizing polyurethane particles, urea-formaldehyde resin, plant starch, polyurethane prepolymer, dioctyl phthalate, polyvinyl butyral, a photodegrading agent, a photosensitizer, and a catalyst. The degradable unit's leading polyol is a block polymer of aliphatic polyester and polyethylene oxide ether. The resulting polyurethane exhibits generally poor mechanical properties (tensile strength 26.18-32.65 MPa, elongation at break 309.5-352.5%), and its degradation conditions are quite demanding, with a degradation rate of 97.63-99.85% only achieved under alkaline conditions.

[0004] Chinese patent document CN118184954A discloses a biodegradable material with added starch. It uses toluene diisocyanate and polytetrahydrofuran diol as base materials. By modifying and compounding amylose into polymer materials, biodegradable polyurethane is obtained. However, its mechanical properties are poor, with a tensile strength of only 4.27-5.13 MPa and an elongation at break of 161-205%. The degradation rate after 120 days is 91.52-94.51%, making it difficult to apply in practical scenarios. Summary of the Invention

[0005] The purpose of this invention is to provide a biodegradable hydrophobic polyurethane with strong mechanical properties and its preparation method, which is suitable for surface antifouling of marine materials.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a biodegradable hydrophobic polyurethane, the general structural formula of which is as follows:

[0008]

[0009] Wherein, 1.2≤m≤31, 1≤n≤20, 1≤y≤26.

[0010] Secondly, the present invention provides a method for preparing the above-mentioned biodegradable hydrophobic polyurethane, comprising the following steps:

[0011] (1) Polycaprolactone, polylactic acid and hydroxyl-terminated polydimethylsiloxane were added to N,N-dimethylformamide and stirred to dissolve, resulting in a mixed solution. Isophorone diisocyanate was added to the mixed solution and stirred until homogeneous. Then an organometallic catalyst was added to catalyze the reaction to obtain a prepolymer solution.

[0012] (2) Add polyol chain extender, polyol crosslinking agent and non-aqueous polyurethane defoamer to the prepolymer solution, stir evenly to obtain polyurethane emulsion, and then vacuum degas and cure the polyurethane emulsion to obtain biodegradable hydrophobic polyurethane.

[0013] Further, in step (1), the mass ratio of hydroxyl-terminated polydimethylsiloxane, polycaprolactone, and polylactic acid is 1:1.5-2:1.2-1.5; the amount of isophorone diisocyanate is 20-50% of the total mass of hydroxyl-terminated polydimethylsiloxane, polycaprolactone, and polylactic acid.

[0014] Further, in step (1), the amount of isophorone diisocyanate used is 30% of the total mass of hydroxyl-terminated polydimethylsiloxane, polycaprolactone and polylactic acid.

[0015] Further, in step (1), the organometallic catalyst is dibutyltin dilaurate or stannous octoate, and its amount is 0.1-1% of the mass of isophorone diisocyanate.

[0016] Furthermore, in step (1), the catalytic reaction temperature is controlled at 50-90℃; the catalytic reaction time is controlled at 2-4h.

[0017] Further, in step (2), the polyol chain extender is any one of 1,4-butanediol, propylene glycol, dimethylene phenyl glycol, and triethanolamine, and its amount is 10-15% of the mass of isophorone diisocyanate; the polyol crosslinking agent is any one of trimethylpropane, pentaerythritol, and trihydroxymethylethane; the non-aqueous polyurethane defoamer is any one of YRXP-02, YRXP-07, and YRXP-07B; and the mass ratio of the polyol chain extender to the polyol crosslinking agent and the non-aqueous polyurethane defoamer is 1:0.4-0.6:0.03-0.05.

[0018] Thirdly, the present invention provides an application of the biodegradable hydrophobic polyurethane material prepared by the above preparation method, which is applied to the surface antifouling of marine materials.

[0019] Compared with the prior art, the technical solution of the present invention has the following beneficial effects.

[0020] The biodegradable hydrophobic polyurethane material provided by this invention has soft and hard segments. The soft segments are hydroxyl-terminated polydimethylsiloxane, polycaprolactone, and polylactic acid segments, while the hard segment is isophorone diisocyanate. Due to the high crystallinity and high ester bond content of the polylactic acid segments, coupled with the large number of isocyanate groups provided by isophorone diisocyanate, the hardness and tensile strength of the material are improved. The hydroxyl-terminated polydimethylsiloxane contains a large number of silicon-oxygen bonds, resulting in weak intermolecular forces and allowing the segments to have a certain degree of fluidity. The polycaprolactone molecular chain contains highly flexible aliphatic segments composed of carbon atoms, which have great flexibility and can move freely. Therefore, the hydroxyl-terminated polydimethylsiloxane and polycaprolactone segments mainly provide good flexibility for the material and enhance its elongation at break.

[0021] Polylactic acid and polycaprolactone segments contain a large number of hydrolyzable ester bonds. These ester bonds are easily hydrolyzed and broken under conditions containing water and microorganisms, which gives polyurethane materials excellent degradation properties.

[0022] Hydroxyl-terminated polydimethylsiloxane provides a large number of silicon-oxygen bonds, while polycaprolactone segments provide a large number of long-chain alkyl groups and ester bonds. These groups are all high-performance hydrophobic groups, and their synergistic effect gives polyurethane materials excellent hydrophobic properties.

[0023] The preparation method disclosed in this invention uses polycaprolactone, polylactic acid, hydroxyl-terminated polydimethylsiloxane, and isophorone diisocyanate as raw materials to prepare a biodegradable hydrophobic polyurethane material. Compared with the prior art, the preparation process is simple and the manufacturing cost is low, making it suitable for large-scale industrial production. The prepared polyurethane material has excellent mechanical properties, hydrophobic properties, and degradation properties. Its tensile strength exceeds 40 MPa, its elongation at break exceeds 400%, and its water contact angle exceeds 130°. Under conditions of 58°C and 50° humidity, the material degradation rate exceeds 99% after 120 days, and under seawater conditions of 25°C, the material degradation rate exceeds 30% after 120 days. In the scraper test, it still has good antifouling performance after 600 days, meeting practicality. Moreover, compared with existing antifouling coatings, the polyurethane raw materials prepared by this invention are green and environmentally friendly, and suitable for surface antifouling of marine materials. Attached Figure Description

[0024] Figure 1 The image shows the infrared spectrum of the biodegradable polyurethane material obtained in Example 1; in the image, Transmittance represents infrared transmittance, and Wavenumber represents the infrared spectral wavenumber. Detailed Implementation

[0025] The present invention is described in detail below through specific embodiments, but this does not limit the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used are all commercially available. Through these descriptions, the features and advantages of the present invention will become clearer and more explicit. Example 1

[0026] 76g of hydroxyl-terminated polydimethylsiloxane, 114g of polycaprolactone, and 91.2g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 100mL of N,N-dimethylformamide and stirred until completely dissolved to obtain a mixed solution. 84.36g of isophorone diisocyanate was added to the mixed solution, and the mixture was heated to 85°C while stirring. Simultaneously, 0.8436g of stannous octoate catalyst was added. After reacting for 2 hours, a prepolymer solution was obtained. Liquid; Add 8.436g of chain extender 1,4-butanediol (BDO), 3.3744g of crosslinking agent trimethylpropane (TMP), and 0.253g of defoamer YRXP-02 (produced by Guangzhou Yourun New Materials Co., Ltd.) to the prepolymer solution, stir evenly at 60℃, then pour into a polytetrafluoroethylene mold, place in a vacuum oven at -0.1MPa to remove bubbles, and cure at room temperature for 3 days to obtain a biodegradable hydrophobic polyurethane, denoted as PDMS-PCL. 1.5 -PLA 1.2 -PU.

[0027] Figure 1 For PDMS-PCL1.5 -PLA 1.2 -Infrared spectrum of PU material, from which it can be seen that 3383cm -1 A mixed peak attributable to stretching vibrations of amides and hydroxyl groups; 2954 cm⁻¹ -1 The peak attributable to the methyl-CH3 stretching vibration in the chain segment; 2838 cm⁻¹ -1 The peak is attributed to the methylene-CH2 stretching vibration in the chain segment; 1750 cm⁻¹ -1 Absorption peak attributable to the carbonyl C=O stretching vibration of amides; 1513 cm⁻¹ -1 Absorption peak attributable to the NH deformation vibration of the urea group; 1139 cm⁻¹ -1 Attributable to Si-O in the chain segment; 1082 cm -1 Attributable to Si-C peak, 936 cm⁻¹ -1 The peak attributable to the out-of-plane bending vibration of the benzene ring CH in the chain segment should be located at 2200-2280 cm⁻¹. -1 The disappearance of the representative N=C=O stretching vibration peak in the wavenumber range indicates that the polyurethane segments synthesized by this method simultaneously contain hydroxyl-terminated polydimethylsiloxane, polylactic acid, and polycaprolactone segments, proving its successful synthesis. Based on this, its general structural formula is: Example 2

[0028] 740g of hydroxyl-terminated polydimethylsiloxane, 1295g of polycaprolactone, and 962g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 1000mL of N,N-dimethylformamide and stirred at room temperature until completely dissolved. Next, 1215g of isophorone diisocyanate was added, and the mixture was heated to 85°C while stirring. Simultaneously, 1.2g of stannous octoate catalyst was added, and the reaction was stopped after 4 hours to obtain a prepolymer solution. 182.2g of chain extender propylene glycol, 109.32g of crosslinking agent trimethylpropane (TMP), and 9.11g of defoamer YRXP-07 (produced by Guangzhou Yourun New Materials Co., Ltd.) were added to the prepolymer solution and stirred evenly at 60°C. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum oven at -0.1MPa to remove bubbles. After curing at room temperature for 3 days, a biodegradable hydrophobic polyurethane PDMS-PCL was obtained. 1.75 -PLA 1.3 -PU; its structural formula is: Example 3

[0029] 1482 g of hydroxyl-terminated polydimethylsiloxane, 2964 g of polycaprolactone, and 1926.6 g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 2000 mL of N,N-dimethylformamide and stirred at room temperature until completely dissolved. Next, 1911.78 g of isophorone diisocyanate was added, and the mixture was heated to 85°C while stirring. Simultaneously, 11.86 g of stannous octoate catalyst was added. After reacting for 3 hours, the reaction was stopped to obtain the prepolymer. Solution: Add 237.12g of chain extender dimethylene phenyl glycol, 132.7872g of crosslinking agent trihydroxymethyl ethane, and 11.1446g of defoamer YRXP-07 (produced by Guangzhou Yourun New Materials Co., Ltd.) to the prepolymer solution. Stir evenly at 60℃, then pour into a polytetrafluoroethylene mold, place in a vacuum oven at -0.1MPa to remove bubbles, and cure at room temperature for 3 days to obtain biodegradable hydrophobic polyurethane PDMS-PCL2-PLA. 1.3 -PU; its structural formula is: Example 4

[0030] Weigh out 1485g of hydroxyl-terminated polydimethylsiloxane, 2598.75g of polycaprolactone, and 2227.5g of polylactic acid, and dry them in a vacuum oven for 1 hour. Then, add them to a three-necked flask and add 2000mL of N,N-dimethylformamide. Stir at room temperature until completely dissolved, then add 1893.375g of isophorone diisocyanate. While stirring, raise the temperature to 85°C, and simultaneously add 11.9283g of stannous octoate catalyst. After reacting for 3 hours, stop the reaction. A prepolymer solution should be obtained. Add 227.205g of chain extender 1,4-butanediol, 127.2348g of crosslinking agent trihydroxymethyl ethane, and 9.0882g of defoamer YRXP-07 (produced by Guangzhou Yourun New Materials Co., Ltd.) to the prepolymer solution. Stir evenly at 60℃, then pour into a polytetrafluoroethylene mold, place in a vacuum oven at -0.1MPa to remove bubbles, and cure at room temperature for 3 days to obtain biodegradable hydrophobic polyurethane PDMS-PCL. 1.75 -PLA 1.5 -PU; its structural formula is: Example 5

[0031] 1480g of hydroxyl-terminated polydimethylsiloxane, 2960g of polycaprolactone, and 2220g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 2000mL of N,N-dimethylformamide and stirred at room temperature until completely dissolved. Next, 1998g of isophorone diisocyanate was added, and the mixture was heated to 85°C while stirring. Simultaneously, 14.7852g of stannous octoate catalyst was added. After reacting for 3 hours, the reaction was stopped to obtain the prepolymer. Bulk solution; Add 299.7g of chain extender 1,4-butanediol, 149.85g of crosslinking agent trimethylpropane, and 13.4865g of defoamer YRXP-07B (produced by Guangzhou Yourun New Materials Co., Ltd.) to the prepolymer solution, stir evenly at 60℃, then pour into a polytetrafluoroethylene mold, place in a vacuum oven at -0.1MPa to remove bubbles, and cure at room temperature for 3 days to obtain biodegradable hydrophobic polyurethane PDMS-PCL2-PLA. 1.5 -PU; its structural formula is: Example 6

[0032] 740g of hydroxyl-terminated polydimethylsiloxane, 1110g of polycaprolactone, and 888g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 1000mL of N,N-dimethylformamide and stirred at room temperature until completely dissolved. 547.6g of isophorone diisocyanate was added, and the mixture was heated to 85°C while stirring. Simultaneously, 5.476g of stannous octoate catalyst was added, and the reaction was allowed to proceed for 3 hours to obtain a prepolymer solution. 82.14g of chain extender 1,4-butanediol (BDO), 32.856g of crosslinking agent trimethylpropane (TMP), and 2.4642g of defoamer YRXP-02 (produced by Guangzhou Yourun New Materials Co., Ltd.) were added to the prepolymer solution and stirred evenly at 60°C. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum oven at -0.1MPa to remove bubbles. After curing at room temperature for 3 days, a biodegradable hydrophobic polyurethane, denoted as PDMS-PCL, was obtained. 1.5 -PLA 1.2 -PU1; its structural formula is: Example 7

[0033] 100g of hydroxyl-terminated polydimethylsiloxane, 150g of polycaprolactone, and 120g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 100mL of N,N-dimethylformamide and stirred at room temperature until completely dissolved. 185g of isophorone diisocyanate was added, and the mixture was heated to 85°C while stirring. Simultaneously, 1.48g of stannous octoate catalyst was added, and the reaction was allowed to proceed for 4 hours to obtain a prepolymer solution. 20.35g of chain extender 1,4-butanediol (BDO), 12.21g of crosslinking agent trimethylpropane (TMP), and 0.814g of defoamer YRXP-02 (produced by Guangzhou Yourun New Materials Co., Ltd.) were added to the prepolymer solution and stirred evenly at 60°C. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum oven at -0.1MPa to remove bubbles. After curing at room temperature for 3 days, a biodegradable hydrophobic polyurethane, denoted as PDMS-PCL, was obtained. 1.5 -PLA 1.2 -PU2; its structural formula is: Comparative Example 1

[0034] Weigh 150g of polycaprolactone and 150g of polylactic acid and dry them in a vacuum oven for 1 hour. Then, add them to a three-necked flask and add 100mL of N,N-dimethylformamide. Stir at room temperature until completely dissolved, then add 90g of isophorone diisocyanate. While stirring, raise the temperature to 85℃ and add 0.504g of catalyst stannous octoate. After the prepolymerization reaction is stopped after 3 hours, the prepolymer is obtained. Add 10.8g of chain extender 1,4-butanediol (BDO), 6.156g of crosslinking agent trimethylpropane (TMP), and 0.5184g of defoamer YRXP-02 (produced by Guangzhou Yourun New Materials Co., Ltd.) to the prepolymer solution. Stir evenly at 60℃, then pour into a polytetrafluoroethylene mold and place in a vacuum oven at -0.1MPa to remove bubbles. Cure at room temperature for 3 days to obtain biodegradable hydrophobic polyurethane PCL-PLA-PU. Comparative Example 2

[0035] 100g of hydroxyl-terminated polydimethylsiloxane and 150g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 100mL of N,N-dimethylformamide and stirred at room temperature until completely dissolved. Next, 75g of isophorone diisocyanate was added, and the mixture was heated to 85°C while stirring. Simultaneously, 0.5025g of stannous octoate catalyst was added. The prepolymer reaction was stopped after 3 hours to obtain a prepolymer. 10.5g of chain extender 1,4-butanediol (BDO), 5.985g of crosslinking agent trimethylpropane (TMP), and 0.504g of defoamer YRXP-02 (produced by Guangzhou Yourun New Materials Co., Ltd.) were added to the prepolymer solution and stirred evenly at 60°C. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum oven at -0.1MPa to remove bubbles. After curing at room temperature for 3 days, biodegradable hydrophobic polyurethane PDMS-PLA was obtained. 1.5 -PU. Comparative Example 3

[0036] 100g of hydroxyl-terminated polydimethylsiloxane and 150g of polycaprolactone were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 100mL of N,N-dimethylformamide and stirred at room temperature until completely dissolved. Next, 75g of isophorone diisocyanate was added, and the mixture was heated to 85°C while stirring. Simultaneously, 0.5025g of stannous octoate catalyst was added. The prepolymer reaction was stopped after 3 hours to obtain the prepolymer. 10.5g of chain extender 1,4-butanediol (BDO), 5.985g of crosslinking agent trimethylpropane (TMP), and 0.504g of defoamer YRXP-02 (produced by Guangzhou Yourun New Materials Co., Ltd.) were added to the prepolymer solution and stirred evenly at 60°C. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum oven at -0.1MPa to remove bubbles. After curing at room temperature for 3 days, a biodegradable hydrophobic polyurethane PDMS-PCL was obtained. 1.5 -PU. Comparative Example 4

[0037] 200g of hydroxyl-terminated polydimethylsiloxane, 150g of polycaprolactone, and 120g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 100mL of N,N-dimethylformamide and stirred at room temperature until completely dissolved. 141g of isophorone diisocyanate was added, and the mixture was heated to 85°C while stirring. At the same time, 1.41g of stannous octoate catalyst was added, and the reaction was stopped after 2 hours to obtain a prepolymer solution. 15.51g of chain extender 1,4-butanediol, 7.755g of crosslinking agent trihydroxymethyl ethane, and 0.6049g of defoamer YRXP-07 (produced by Guangzhou Yourun New Materials Co., Ltd.) were added to the prepolymer solution and stirred evenly at 60°C. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum oven at -0.1MPa to remove bubbles. After curing at room temperature for 3 days, a biodegradable hydrophobic polyurethane PDMS-PCL-PLA-PU was obtained. Comparative Example 5

[0038] 100g of hydroxyl-terminated polydimethylsiloxane, 300g of polycaprolactone, and 120g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 100mL of N,N-dimethylformamide and stirred at room temperature until completely dissolved. Next, 156g of isophorone diisocyanate was added, and the mixture was heated to 85°C while stirring. Simultaneously, 1.56g of stannous octoate catalyst was added, and the reaction was stopped after 2 hours to obtain a prepolymer solution. 23.4g of chain extender 1,4-butanediol, 11.7g of crosslinking agent trihydroxymethyl ethane, and 1.17g of defoamer YRXP-07 (produced by Guangzhou Yourun New Materials Co., Ltd.) were added to the prepolymer solution and stirred evenly at 60°C. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum oven at -0.1MPa to remove bubbles. After curing at room temperature for 3 days, a biodegradable hydrophobic polyurethane PDMS-PCL3-PLA was obtained. 1.5 -PU. Comparative Example 6

[0039] 100g of hydroxyl-terminated polydimethylsiloxane, 150g of polycaprolactone, and 200g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 100mL of N,N-dimethylformamide and stirred at room temperature until completely dissolved. 135g of isophorone diisocyanate was added, and the mixture was heated to 85°C while stirring. At the same time, 1.35g of stannous octoate catalyst was added, and the reaction was stopped after 2 hours to obtain a prepolymer solution. 19.98g of chain extender 1,4-butanediol, 11.988g of crosslinking agent trihydroxymethyl ethane, and 0.999g of defoamer YRXP-07B (produced by Guangzhou Yourun New Materials Co., Ltd.) were added to the prepolymer solution and stirred evenly at 60°C. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum oven at -0.1MPa to remove bubbles. After curing at room temperature for 3 days, a biodegradable hydrophobic polyurethane PDMS-PCL2-PLA2-PU was obtained. Comparative Example 7

[0040] 100g of hydroxyl-terminated polydimethylsiloxane, 150g of polycaprolactone, and 120g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 100mL of N,N-dimethylformamide and stirred at room temperature until completely dissolved. Next, 37g of isophorone diisocyanate was added, and the mixture was heated to 85°C while stirring. Simultaneously, 1.11g of stannous octoate catalyst was added, and the reaction was stopped after 2 hours to obtain a prepolymer solution. 11.1g of chain extender 1,4-butanediol (BDO), 4.44g of crosslinking agent trimethylpropane (TMP), and 0.333g of defoamer YRXP-02 (produced by Guangzhou Yourun New Materials Co., Ltd.) were added to the prepolymer solution and stirred evenly at 60°C. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum oven at -0.1MPa to remove bubbles. After curing at room temperature for 3 days, a biodegradable hydrophobic polyurethane PDMS-PCL was obtained. 1.5 -PLA 1.2 -PU-1. Comparative Example 8

[0041] 100g of hydroxyl-terminated polydimethylsiloxane, 150g of polycaprolactone, and 120g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 100mL of N,N-dimethylformamide and stirred at room temperature until completely dissolved. Next, 240.5g of isophorone diisocyanate was added, and the mixture was heated to 85°C while stirring. Simultaneously, 1.1063g of stannous octoate catalyst was added, and the reaction was stopped after 2 hours to obtain a prepolymer solution. 11.063g of chain extender 1,4-butanediol (BDO), 4.4252g of crosslinking agent trimethylpropane (TMP), and 0.3319g of defoamer YRXP-02 (produced by Guangzhou Yourun New Materials Co., Ltd.) were added to the prepolymer solution and stirred evenly at 60°C. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum oven at -0.1MPa to remove bubbles. After curing at room temperature for 3 days, a biodegradable hydrophobic polyurethane PDMS-PCL was obtained. 1.5 -PLA 1.2 -PU-2. Comparative Example 9

[0042] 100g of hydroxyl-terminated polydimethylsiloxane, 150g of polycaprolactone, and 120g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask and 100mL of N,N-dimethylformamide were added. The mixture was stirred at room temperature until completely dissolved. 1.11g of stannous octoate catalyst was added first, followed by 111g of isophorone diisocyanate. Subsequently, explosive polymerization occurred, generating a large amount of foam and yellowing, making it impossible to conduct subsequent experiments. Comparative Example 10

[0043] 100g of hydroxyl-terminated polydimethylsiloxane, 150g of polycaprolactone, and 120g of polylactic acid were weighed and dried in a vacuum oven for 1 hour. Then, they were added to a three-necked flask along with 100mL of N,N-dimethylformamide and stirred at room temperature until completely dissolved. Next, 111g of isophorone diisocyanate was added, and the mixture was heated to 85°C while stirring. Simultaneously, 1.11g of stannous octoate catalyst was added, and the reaction was stopped after 2 hours to obtain a prepolymer solution. 29.97g of chain extender 1,4-butanediol (BDO), 20.0799g of crosslinking agent trimethylpropane (TMP), and 2.997g of defoamer YRXP-02 (produced by Guangzhou Yourun New Materials Co., Ltd.) were added to the prepolymer solution and stirred evenly at 60°C. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum oven at -0.1MPa to remove bubbles. After curing at room temperature for 3 days, a biodegradable hydrophobic polyurethane PDMS-PCL was obtained. 1.5 -PLA 1.2 -PU-3. Comparative Example 11

[0044] Biodegradable polyurethane prepared according to the method described in Chinese patent document CN112409776A. Comparative Example 12

[0045] Biodegradable polyurethane prepared according to the method described in Chinese patent document CN118184954A.

[0046] To verify the technical effects of the present invention, the polyurethane films prepared in the examples and comparative examples were tested for mechanical properties, water contact angle, and degradability. Mechanical properties were tested using a universal tensile testing machine according to GB / T1040-92, and the results are shown in Table 1. Water contact angle was tested using a water contact angle measuring instrument according to GB / T30693, and the results are shown in Table 1. Degradability was tested using a controlled composting degradation device and a controlled seawater degradation device, according to GB / T19277 and ISO19679, respectively. The controlled composting degradation environment was set at 58°C and 50% humidity, while the seawater degradation environment was set at 25°C. The polyurethane samples from the examples and comparative examples were cultured in different environments, and the degree of degradation was recorded. The results are shown in Table 2.

[0047]

[0048] As can be seen from Table 1, the polyurethane materials obtained using Examples 1-7 have tensile strength and elongation at break of 40.11-48.19 MPa and 402-482%, respectively. Compared with Comparative Examples 1-3, the tensile strength, elongation at break, and hydrophobic properties of Examples 1-7 are significantly enhanced. This indicates that the performance of the three-component polyurethane prepared using polydimethylsiloxane, polycaprolactone, and polylactic acid is significantly better than that of the two-component polyurethane. Furthermore, as can be seen from Comparative Examples 1-3, hydroxyl-terminated polydimethylsiloxane mainly provides silicon-oxygen bonds, which increases the flexibility and hydrophobic properties of the material. Polylactic acid and polycaprolactone contain a large number of ester bonds, which can increase the tensile strength of the material. In addition, the long-chain alkyl groups in polycaprolactone can also form a synergistic effect with silicon-oxygen bonds to enhance the hydrophobic properties of the material.

[0049] Compared to Example 1, Comparative Example 4 showed a significant decrease in tensile strength and elongation at break, while the hydrophobic properties remained essentially the same. This indicates that as the amount of polydimethylsiloxane exceeds 1:1.5-2:1.2-1.5, the silicon-oxygen content increases, weakening the intermolecular forces between chain segments and thus reducing the mechanical properties of the material. In Comparative Example 5, it can be seen that as the excess of polycaprolactone exceeds 1:1.5-2:1.2-1.5, the alkyl chains within the material lengthen, and the crosslinking ratio between the long alkyl chains decreases, resulting in a decrease in the material's mechanical properties. The mechanical properties of the material are reduced, and the increase in alkyl chain content reduces the synergistic effect between alkyl chains and silicon-oxygen bonds, thus reducing the hydrophobicity of the material. In Comparative Example 6, as the polylactic acid content exceeds 1:1.5-2:1.2-1.5, the content of short-chain polylactic acid segments in the polyurethane increases, which increases the crystallinity of the molecular chain, resulting in poor molecular chain flexibility and a significant decrease in its elongation at break. In addition, the increase in polylactic acid content increases the ester bond content in the chain segments, making it easier to form hydrogen bonds with water, thereby reducing the hydrophobicity of the material.

[0050] Compared with Example 1, it can be seen from Comparative Examples 7 and 8 that since isocyanate segments are hard segments in polyurethane, their content exceeding 1:0.2-0.5 will significantly affect the mechanical properties of the material. Their content exceeding 1:0.5 will make the material too hard and significantly reduce the elongation at break. Their content below 1:0.2 will result in insufficient tensile strength of the material.

[0051] Compared with Example 1, it can be seen from Comparative Example 10 that when the ratio of isophorone diisocyanate to chain extender exceeds 1:0.1-0.15, the material flexibility will also be reduced and the elongation at break will be decreased.

[0052] Compared with existing technologies, Comparative Examples 11 and 12, the material prepared by this invention is significantly superior to other existing patents in terms of mechanical properties and hydrophobic properties.

[0053]

[0054] As can be seen from Table 2, in Examples 1-5 obtained using the preparation method of the present invention, the degradation performance of Examples 1-5 and Comparative Examples 5 and 6 under biocomposting conditions is excellent, reaching over 99% after 120 days. Similarly, the degradation effect under simulated seawater degradation conditions, which are difficult to degrade, is also over 30%. This indicates that the degradation performance of the material is mainly affected by the polycaprolactone and polylactic acid segments in the material. However, even if the content of polycaprolactone and polylactic acid segments exceeds 1:1.5-2:1.2-1.5, it will not further increase the degradation performance of the material.

[0055] Compared with Example 1, the degradation rate in Comparative Example 4 after 120 days was significantly reduced. This is because the amount of hydroxyl-terminated polydimethylsiloxane used exceeded 1:1.5-2:1.2-1.5, which significantly reduced the proportion of ester bonds in the chain segments and decreased the hydrolysis performance.

[0056] Moreover, compared with Comparative Examples 11 and 12, the materials prepared in Examples 1-5 have excellent degradation performance, indicating that compared with existing patents, the biodegradable hydrophobic polyurethane materials prepared in this invention also have significant degradation effects. Furthermore, the preparation method is simple, the process equipment requirements are low, and it can be widely used in the environmental protection field, with extremely strong application value and application prospects.

[0057] Application examples

[0058] Considering mechanical properties, water contact angle, and degradation effect, the material prepared in Example 5 was selected as an application example. A 40cm*40cm*4.5cm low-carbon steel plate was selected as the base layer. After sandblasting, cleaning, and drying, a layer of Laoren Brand Pioneer Shield epoxy zinc-rich primer 750 was brushed onto its surface. After drying, the polyurethane film prepared in Example 1 was bonded to the base layer with epoxy zinc-rich primer 750. After curing for 24 hours, a polyurethane modified base composite material was obtained. The above-prepared composite material was placed in seawater. After 120 days, the composite base was taken out and compared with the marine organism attachment on the original base. The results are shown in Table 3.

[0059] Application Comparative Example 1

[0060] A seawater scraping experiment was conducted using the original low-carbon steel plate as the substrate. The plate was placed in seawater, and after 120 days, the composite substrate was removed and compared with the original substrate to show the attachment of marine organisms. The results are shown in Table 3.

[0061] Application Comparative Example 2

[0062] The material prepared in Comparative Example 11 was selected as Application Comparative Example 2. A 40cm*40cm*4.5cm low-carbon steel plate was selected as the base layer. After sandblasting, cleaning and drying, a layer of Laoren Brand Pioneer Shield epoxy zinc-rich primer 750 was brushed on its surface. After drying, the polyurethane film prepared in Comparative Example 11 was applied on the epoxy zinc-rich primer 750. After curing for 24 hours, a polyurethane modified base composite material was obtained. The above-prepared composite material was placed in seawater. After 120 days, the composite base was taken out and compared with the marine organism attachment on the original base. The results are shown in Table 3.

[0063] Application Comparative Example 3

[0064] The material prepared in Comparative Example 12 was selected as Application Comparative Example 3. A 40cm*40cm*4.5cm low-carbon steel plate was selected as the base layer. After sandblasting, cleaning and drying, a layer of Laoren Brand Pioneer Shield epoxy zinc-rich primer 750 was brushed on its surface. After drying, the polyurethane film prepared in Comparative Example 12 was applied on the epoxy zinc-rich primer 750. After curing for 24 hours, a polyurethane modified base composite material was obtained. The above-prepared composite material was placed in seawater. After 120 days, the composite base was taken out and compared with the marine organism attachment on the original base. The results are shown in Table 3.

[0065]

[0066] As shown in Table 3, after 120 days of natural seawater and biological corrosion, the mass of both the original steel plate and the modified steel plates increased. This increased mass is due to the adhesion of marine biofouling. Compared with the original steel plate, the modified steel plates all achieved a certain antifouling effect. The most significant effect was seen in the application example, where the mass increase rate after 120 days was less than 10%, which was significantly better than application comparison examples 2 and 3. To verify the service life of the material, the application example was further subjected to the hanging plate experiment for up to 600 days. The experimental data, compared with the original substrate of application comparison example 1, are shown in Table 4, indicating that the material obtained using this method has excellent practical application effects.

[0067]

[0068] The present invention has been described in detail above with reference to preferred embodiments and normative examples. However, it should be noted that these specific embodiments are illustrative explanations of the present invention and do not constitute any limitation on the scope of protection of the present invention. Various improvements, equivalent substitutions, or modifications can be made to the technical content and embodiments of the present invention without departing from the spirit and scope of protection of the present invention, and all such modifications fall within the scope of protection of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A biodegradable hydrophobic polyurethane, characterized in that, The method for preparing the biodegradable hydrophobic polyurethane includes the following steps: (1) Polycaprolactone, polylactic acid and hydroxyl-terminated polydimethylsiloxane were dissolved in N,N-dimethylformamide to obtain a mixed solution. Isophorone diisocyanate was added to the mixed solution and stirred evenly. Then an organometallic catalyst was added to catalyze the reaction to obtain a prepolymer solution. (2) Add polyol chain extender, polyol crosslinking agent and non-aqueous polyurethane defoamer to the prepolymer solution, stir and react to obtain polyurethane emulsion, and then vacuum degas and cure the polyurethane emulsion to obtain biodegradable hydrophobic polyurethane. In step (1), the mass ratio of hydroxyl-terminated polydimethylsiloxane, polycaprolactone, and polylactic acid is 1:1.5-2:1.2-1.5; the amount of isophorone diisocyanate used is 20-50% of the total mass of hydroxyl-terminated polydimethylsiloxane, polycaprolactone, and polylactic acid. In step (2), the polyol chain extender is any one of 1,4-butanediol, propylene glycol, dimethylene phenyl glycol, and triethanolamine, and its dosage is 10-15% of the mass of isophorone diisocyanate; the polyol crosslinking agent is any one of trimethylolpropane, pentaerythritol, and trimethylolethane; the non-aqueous polyurethane defoamer is any one of YRXP-02, YRXP-07, and YRXP-07B; and the mass ratio of the polyol chain extender to the polyol crosslinking agent and the non-aqueous polyurethane defoamer is 1:0.4-0.6:0.03-0.

05. The biodegradable hydrophobic polyurethane has a tensile strength exceeding 40 MPa and a water contact angle exceeding 130°. Under conditions of 58°C, 50° humidity, and biocomposting, the material degradation rate exceeds 99% after 120 days, and under seawater conditions of 25°C, the material degradation rate exceeds 30% after 120 days.

2. The biodegradable hydrophobic polyurethane according to claim 1, characterized in that, In step (1), the organometallic catalyst is dibutyltin dilaurate or stannous octoate, and its amount is 0.1-1% of the mass of isophorone diisocyanate.

3. The biodegradable hydrophobic polyurethane according to claim 1, characterized in that, In step (1), the catalytic reaction temperature is controlled at 50-90℃ and the catalytic reaction time is controlled at 2-4h.

4. An application of the biodegradable hydrophobic polyurethane as described in claim 1, characterized in that, The biodegradable hydrophobic polyurethane is applied to the surface antifouling of marine materials.

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