Environment-friendly polyurethane composite material for underwater sound absorption and preparation method thereof

Abstract

The invention discloses an environment-friendly underwater sound absorption polyurethane composite material and a preparation method thereof, the environment-friendly underwater sound absorption polyurethane composite material comprises a prepolymer, a chain extender and a filler, the prepolymer is a polymer obtained by polymerizing polyether and diphenylmethane diisocyanate, and the NCO value of the polymer is 12-18%; the chain extender takes butanediol as a hard segment and polyether and polyether polyol as soft segments; the environment-friendly polyurethane composite material for underwater sound absorption is a sound absorption material which does not contain ricinoleic acid, oleic acid and linoleic acid, can avoid water body pollution caused by explosive propagation of ricinoleic acid, oleic acid and linoleic acid, is used for replacing an existing sound absorption material, and has the advantages that the environment-friendly polyurethane composite material for underwater sound absorption is good in sound absorption effect and good in sound absorption effect. And water pollution is prevented while sound is absorbed.

Description

Technical Field

[0001] The present application relates to the technical field of polyurethane composite materials for underwater sound absorption, and specifically to an environmentally friendly polyurethane composite material for underwater sound absorption and a method for manufacturing the same. Background Art

[0002] Castor oil is neither a synthetic condensation polymer nor an oligomer polyol, but its molecular weight and hydroxyl equivalent weight are similar to those of oligomer polyols. Its molecular structure contains fewer ester groups than polyesters and no ether groups. Its primary component is a fatty acid triglyceride, composed of 90% ricinoleic acid (9-enyl-12-hydroxyoctadecanoic acid) and 10% oleic and linoleic acids, which do not contain hydroxyl groups.

[0003] The molecular formula of ricinoleic acid is: 18 H 34 O3, the structural formula is:

[0004]

[0005] Ricinoleic acid is a non-drying oil, a nearly colorless or pale yellow, transparent, viscous, flammable liquid with a distinctive odor. It is soluble in ethanol, acetone, ether, and chloroform. It can be used in the manufacture of Turkish red oil, soap, plastics, lubricants, and other products. It is also used in the production of daily cosmetics, shoe polish, and medical ointments, and is a raw material for the production of 12-hydroxystearic acid. It is also used in the production of sebacic acid, cold-resistant plasticizers, lubricants, fragrances, penetrants and emulsifiers for the textile industry, and in the manufacture of laxatives and zinc preparations. It is also used in the production of sulfated castor oil. It is also used as a molding agent and brightener for leather finishing and in the manufacture of plasticizers, dibasic acids, polyurethane coatings, rubber, adhesives, fatty acids, surfactants, insulating oils, hydraulic oils, lubricants, Turkish red oil, soaps, and polyamide-11 fibers.

[0006] The molecular formula of oleic acid is: C 18 H 34 O2, the structural formula is:

[0007]

[0008] Pure oleic acid is a colorless oily liquid with the smell of animal oil or vegetable oil. The color gradually darkens when it is exposed to air for a long time. The industrial product is a yellow to red oily liquid with the smell of lard. It is easily soluble in organic solvents such as ethanol, ether, and chloroform, but insoluble in water. It is flammable. It is easily saponified when it comes into contact with alkali, and forms a white soft solid after solidification. It is very easy to oxidize, polymerize or decompose under high heat. It is non-toxic. Because oleic acid contains double bonds, it can undergo self-oxidation when left in the air for a long time, and partially transform into carbonyl-containing substances with a rancid smell. This is the reason why the oil deteriorates. Commercial oleic acid generally contains 7% to 12% of saturated fatty acids, such as palmitic acid and stearic acid. Linoleic acid: The molecular formula is: C 18 H 32O2, the structural formula is:

[0009]

[0010] Linoleic acid is a colorless oily liquid that is insoluble in water but soluble in organic solvents such as ether and chloroform. It is prone to self-oxidation in the air to produce peroxides and aldehydes.

[0011] For castor oil component, owing to there is the ricinoleic acid of incomplete reaction in the finished material, and the oleic acid and linoleic acid that do not participate in reaction, its free ricinoleic acid, oleic acid and linoleic acid content account for approximately 3-4% in the finished material.Due to the water-absorbing property of polyurethane material, these ricinoleic acids, oleic acid, linoleic acid can migrate and diffuse among the water body under the effect of water molecules (process analysis is complicated), and its migration speed can not be determined, i.e. effective soak time.Oleic acid can take place autoxidation when long-term placement in air owing to containing double bond simultaneously, and local transformation is carbonyl-containing material, has corrupt rancid smell, and linoleic acid can take place autoxidation and produce the aldehydes with bad taste, and this is one of reason that water body produces peculiar smell.

[0012] The apparent phenomenon of the water turning black and smelling bad in the pool can be directly explained as organic pollution of the water. The reason is that there are too many organic matter in the water. At first, heterotrophic aerobic microorganisms decompose the organic matter, and then they multiply in large numbers to cause water hypoxia. Then, heterotrophic anaerobic microorganisms multiply in large numbers and decompose the organic matter into H2S, CH4, etc., making the water turn black and smelly.

[0013] Analysis of the materials and synthesis of the previous product revealed the presence of aniline and urea products produced by the reaction of free MDI with water, hydrolysis products of castor oil-based polyurethanes, and unreacted oleic and linoleic acids from castor oil components. These products and components all migrate and precipitate into the water after the product absorbs water. Since the pool is open to the air, where a wide range of microbial species may exist, the composition of the water is a primary factor contributing to subsequent changes in the water during microbial growth and outbreaks.

[0014] The reproduction conditions of chemoheterotrophic microorganisms must be met under the conditions of pH, oxygen, nutrition, temperature, etc. in order to reproduce rapidly. Under normal temperature conditions, microorganisms can basically reproduce within a certain pH value. The dissolved oxygen concentration and carbon dioxide concentration in the water determine the reproduction of anaerobic and aerobic groups. The types of nutrients are starch, sugars, cellulose, organic acids, etc.

[0015] Therefore, ricinoleic acid, oleic acid, and linoleic acid are the main nutrients in water bodies. Under appropriate pH, dissolved oxygen concentration and carbon dioxide in water, temperature and other conditions, microorganisms will multiply explosively and cause water pollution.

[0016] Based on the above, a sound-absorbing material that does not contain ricinoleic acid, oleic acid and linoleic acid and can avoid their explosive growth and water pollution is needed to replace the existing sound-absorbing material and prevent water pollution.

[0017] Application Contents

[0018] The purpose of this application is to provide an environmentally friendly underwater sound-absorbing polyurethane composite material and its production method. The polyurethane composite material does not contain ricinoleic acid, oleic acid, and linoleic acid, and can avoid the explosive growth of ricinoleic acid, oleic acid, and linoleic acid, which can cause water pollution. It can be used to replace existing sound-absorbing materials to prevent water pollution. To achieve the above purpose, this application provides the following technical solutions: The environmentally friendly underwater sound-absorbing polyurethane composite material includes a prepolymer, a chain extender, and a filler.

[0019] The prepolymer is a polymer obtained by polymerization of polyether and diphenylmethane diisocyanate with an NCO value of 12-18%;

[0020] The chain extender has butanediol as the hard segment and polyether and polyether polyol as the soft segment;

[0021] The fillers include foamed acrylic microspheres, foamed styrene microspheres and ultrafine mica powder. The three fillers are mainly used to improve the overall strength of the material and change the overall density and sonic velocity adaptation of the composite material.

[0022] Preferably, the polyether includes polytetramethylene ether PTMG650, polytetramethylene ether PTMG1000 and / or polytetramethylene ether PTMG2000.

[0023] A method for preparing an environmentally friendly polyurethane composite material for underwater sound absorption, comprising:

[0024] S1: Add the prepolymer into the reactor and stir;

[0025] S2: Add expanded acrylic microspheres and stir for 5-10 minutes to make them uniform, add expanded styrene microspheres and stir for 5-10 minutes to make them uniform, then add ultrafine mica powder and stir for 5-10 minutes to make them uniform;

[0026] S3: After adding the chain extender, vacuum the mixture and stir for 1-5 minutes to degas.

[0027] S4: After preheating the mold, the material is poured into the mold under vacuum;

[0028] S5: Encapsulating the mold, moving the mold into an oven, curing at 70-80° C. for 1-2 hours, and then demoulding to obtain an environmentally friendly polyurethane composite material for underwater sound absorption.

[0029] Preferably, the preparation of the prepolymer comprises: dehydrating the polyether at 100-110° C. while stirring under vacuum, adding liquefied diphenylmethane diisocyanate after dehydration, mixing, and reacting at 70-80° C. with stirring under vacuum for a certain period of time to synthesize a prepolymer with an NCO value of 12-18%, and after the prepolymer is synthesized, filling with nitrogen or vacuuming and stirring at a low speed for storage for use.

[0030] Preferably, the chain extender is prepared by using polytetramethylene glycol PTMG650, polytetramethylene glycol PTMG1000 and / or polytetramethylene glycol PTMG2000, polyether polyol 330N and butanediol BDO as raw materials, adding a defoamer and a catalyst. The chain extender is prepared by mixing butanediol BDO as a hard segment, polytetramethylene glycol PTMG650, polytetramethylene glycol PTMG1000 and / or polytetramethylene glycol PTMG2000 and polyether polyol 330N as a soft segment for chain extension. The mass percentage of the defoamer in the chain extender is 0.5-1%, and the mass percentage of the catalyst in the chain extender is 0.2-0.5%.

[0031] Compared with the existing technology, the beneficial effects of this application are: this environmentally friendly polyurethane composite material for underwater sound absorption does not contain components such as ricinoleic acid, oleic acid, linoleic acid, etc. that may cause water pollution, and the sound absorption effect is significant after testing. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0033] Based on literature and relevant experimental data, liquefied isocyanate, polytetramethylene glycol ether, polyether polyol, and butanediol are selected as the main raw materials. The prepolymer is synthesized with isocyanate as the hard segment and PTMG (PTMG is a long linear molecule) as the soft segment. The chain extender uses small molecule BDO as the hard segment, and PTMG and polyether 330N as the soft segments for mixed chain extension. The overall hard segment ratio of the composite material is controlled to be around 25-35%.

[0034] Polytetrahydrofuran (PTMG) is the primary raw material and serves as the primary soft segment of this polyurethane composite. PTMG ether is typically a white, waxy solid that becomes a transparent liquid when heated above room temperature. It is readily soluble in alcohols, esters, ketones, aromatic hydrocarbons, and chlorinated hydrocarbons, but insoluble in aliphatic hydrocarbons and water. Solubility decreases as molecular weight increases. At room temperature, PTMG is hygroscopic. Its hygroscopicity depends on its molecular weight, reaching a maximum of 2% water absorption. Compared to other elastomers, elastomers made from hydroxyl-terminated polytetrahydrofuran exhibit excellent hydrolytic stability, air permeability, and wear resistance, while also exhibiting good elasticity, flexibility, and impact resistance even at low temperatures.

[0035] Based on the above, an environmentally friendly polyurethane composite material for underwater sound absorption is proposed, which includes: a prepolymer, a chain extender and a filler.

[0036] The prepolymer formula is as follows: polytetramethylene ether PTMG650, polytetramethylene ether 1000 and polytetramethylene ether 2000 are dehydrated at 105° C. while being vacuumed and stirred; after the dehydration is completed, diphenylmethane diisocyanate in a liquefied state is added; after mixing, the mixture is vacuumed and stirred at 70-80° C. for 2-2.5 hours to synthesize a prepolymer with an NCO value (isocyanate content) of 12-18%; after the reaction is completed, 0.5‰ of a special polyurethane color paste is added according to demand for coloring; after the coloring of the prepolymer is completed, it is filled with nitrogen or vacuumed and stirred at a low speed for storage for use.

[0037] The chain extender is composed primarily of polytetramethylene glycol PTMG650, polytetramethylene glycol 1000, and polytetramethylene glycol 2000, polyether polyol 330N, and butanediol (BDO). 0.7% defoamer and 0.33% catalyst are added. The chain extender utilizes a low-molecule BDO hard segment, while PTMG and polyether 330N serve as soft segments.

[0038] Fillers mainly include: expanded acrylic microspheres, expanded styrene microspheres, and ultra-fine mica powder. These three fillers are mainly used to improve the overall strength of the material, change the overall density of the composite material, and adjust the sound velocity.

[0039] The preparation method of the above-mentioned environmentally friendly underwater sound-absorbing polyurethane composite material comprises:

[0040] S1: Add the synthesized prepolymer into the reactor and stir;

[0041] S2: Add foaming acrylic microspheres and stir for 5-10 minutes until uniform;

[0042] S3: Add styrene microspheres and stir for 5-10 minutes until uniform;

[0043] S4: Add mica powder and stir for 5-10 minutes until uniform;

[0044] S5: Add chain extender, immediately evacuate and stir for 1-5 minutes to degas;

[0045] S6: Pour the material into the mold under vacuum (the mold needs to be preheated);

[0046] S7: After the blanking is completed, the mold is packaged and placed in an oven and kept at 70-80°C for 1-2 hours (the time can be increased or decreased appropriately according to the curing conditions);

[0047] S8: After the material is solidified, demoulding is performed to obtain a finished sound-absorbing material.

[0048] Example 1

[0049] A 330 sound-absorbing cone environmentally friendly underwater sound-absorbing polyurethane composite material, the formula of which is:

[0050] Serial number name Single root dosage (g) 1 Isocyanate MDI-100LL 37.16 2 Polyether PTMG650 24.27 3 Polyether PTMG1000 53.23 4 Polyether PTMG2000 14.86 5 Polyether 330N 7.43 6 Butanediol BDO 4.59 7 Acrylic microspheres 0.27 8 Styrene microspheres 1.17 9 Ultrafine mica powder 41.73 10 Color paste 0.1 11 Additives (defoaming agents, catalysts) 0.19 total 185 .

[0051] Example 2

[0052] A 470 sound-absorbing cone environmentally friendly underwater sound-absorbing polyurethane composite material, the formula of which is:

[0053] Serial number name Single root dosage (g) 1 Isocyanate MDI-100LL 92.4 2 Polyether PTMG650 58.4 3 Polyether PTMG1000 127.5 4 Polyether PTMG2000 28 5 Polyether 330N 18 6 Butanediol BDO 10.4 7 Acrylic microspheres 0.68 8 Styrene microspheres 2.9 9 Ultrafine mica powder 126 10 Color paste 0.25 11 Additives (defoaming agents, catalysts) 0.47 total 465 .

[0054] Example 3

[0055] A 100 sound-absorbing wedge-shaped, environment-friendly, underwater sound-absorbing polyurethane composite material, the formula of which is:

[0056] Serial number name Single piece dosage (g) 1 Isocyanate MDI-100LL 2373.80 2 Polyether PTMG1000 3974.60 3 Polyether PTMG2000 737.90 4 Polyether 330N 440.50 5 Butanediol BDO 311.60 6 Acrylic microspheres 19.70 7 Ultrafine barium sulfate 4422.30 8 Color paste 9.80 9 Additives (defoaming agents, catalysts) 9.80 total 12300.00 .

[0057] Example 4

[0058] A 50 sound-absorbing wedge-shaped environmentally friendly underwater sound-absorbing polyurethane composite material, the formula of which is:

[0059] Serial number name Single piece dosage (g) 1 Isocyanate MDI-100LL 796.00 2 Polyether PTMG1000 1346.00 3 Polyether PTMG2000 247.50 4 Polyether 330N 146.30 5 Butanediol BDO 104.50 6 Acrylic microspheres 6.60 7 Ultrafine barium sulfate 1471.50 8 Color paste 3.30 9 Additives (defoaming agents, catalysts) 3.30 total 4125.00 After testing, the sound absorption coefficient of the sound-absorbing material of Example 1 of the present application at a frequency of 3kHz-100kHz is ≥99%; the sound absorption coefficient of the sound-absorbing material of Example 2 at a frequency of 1kHz (inclusive)-2kHz is ≥90%, and the sound absorption coefficient at a frequency of 2kHz (inclusive)-100kHz is ≥99%; the sound absorption coefficient of the sound-absorbing material of Example 3 at a frequency of 5kHz (inclusive)-10kHz is ≥90%, and the sound absorption coefficient at a frequency of 10kHz (inclusive)-100kHz is ≥99%; the sound absorption coefficient of the sound-absorbing material of Example 4 at a frequency of 10kHz (inclusive)-15kHz is ≥90%, the sound absorption coefficient at a frequency of 15kHz (inclusive)-20kHz is ≥95%, and the sound absorption coefficient at a frequency of 20kHz (inclusive)-100kHz is ≥99%.

[0060] Unless otherwise specified, the methods used in the present invention are all conventional methods in the art.

[0061] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. An environmentally friendly polyurethane composite material for underwater sound absorption, characterized in that: Including prepolymer, chain extender and filler, The prepolymer is a polymer obtained by polymerization of polyether and diphenylmethane diisocyanate with an NCO value of 12-18%; The chain extender has butanediol as the hard segment and polyether and polyether polyol as the soft segment; The filler comprises foamed acrylic microspheres, foamed styrene microspheres and ultrafine mica powder.

2. The environmentally friendly underwater sound-absorbing polyurethane composite material according to claim 1, characterized in that: The polyether includes polytetramethylene ether PTMG650, polytetramethylene ether PTMG1000 and / or polytetramethylene ether PTMG2000.

3. A method for preparing an environmentally friendly polyurethane composite material for underwater sound absorption, for preparing the environmentally friendly polyurethane composite material for underwater sound absorption according to claim 1 or 2, characterized in that: include, S1: Add the prepolymer into the reactor and stir; S2: Add expanded acrylic microspheres, expanded styrene microspheres and ultrafine mica powder in sequence and stir evenly; S3: After adding the chain extender, vacuum and stir to degas; S4: After preheating the mold, the material is poured into the mold under vacuum; S5: Encapsulating the mold, moving the mold into an oven for curing, and then demoulding to obtain an environmentally friendly polyurethane composite material for underwater sound absorption.

4. The method for preparing an environmentally friendly underwater sound-absorbing polyurethane composite material according to claim 3, characterized in that: The preparation of the prepolymer includes: dehydrating the polyether while stirring and vacuuming at a certain temperature, adding liquefied diphenylmethane diisocyanate after dehydration, and then reacting at a certain temperature and vacuuming and stirring for a certain period of time to synthesize a prepolymer with an NCO value of 12-18%.

5. The method for preparing an environmentally friendly underwater sound-absorbing polyurethane composite material according to claim 4, characterized in that: After the prepolymer is synthesized, it is filled with nitrogen or vacuumed and stirred at a low speed for storage.

6. The method for preparing an environmentally friendly underwater sound-absorbing polyurethane composite material according to claim 4, characterized in that: The polyether is dehydrated at 100-110° C. while being vacuumed and stirred. After dehydration, liquefied diphenylmethane diisocyanate is added. After mixing, the mixture is vacuumed and stirred at 70-80° C. for a certain period of time to synthesize a prepolymer with an NCO value of 12-18%.

7. The method for preparing the environmentally friendly underwater sound-absorbing polyurethane composite material according to claim 3, characterized in that: The chain extender is prepared by using polytetramethylene glycol PTMG650, polytetramethylene glycol PTMG1000 and / or polytetramethylene glycol PTMG2000, polyether polyol 330N and butanediol BDO as raw materials, and adding a defoamer and a catalyst. The chain extender uses butanediol BDO as a hard segment and polytetramethylene glycol PTMG650, polytetramethylene glycol PTMG1000 and / or polytetramethylene glycol PTMG2000 and polyether polyol 330N as a soft segment for mixed chain extension.

8. The method for preparing the environmentally friendly underwater sound-absorbing polyurethane composite material according to claim 7, characterized in that: The mass percentage of the defoamer to the chain extender is 0.5-1%, and the mass percentage of the catalyst to the chain extender is 0.2-0.5%.

9. The method for preparing the environmentally friendly underwater sound-absorbing polyurethane composite material according to claim 3, characterized in that: The mold is cured in an oven at a temperature of 70-80°C.

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