Environment-friendly natural latex-carbon fiber reinforced composite mattress material and preparation method thereof

Abstract

The application relates to the technical field of natural rubber, and discloses an environment-friendly natural latex-carbon fiber reinforced composite mattress material and a preparation method thereof; the composite mattress material comprises 100 parts by weight of natural rubber, 0.4-1.5 parts by weight of acrylic acid grafted natural rubber, 1-8 parts by weight of oxidized carbon fiber, 20-50 parts by weight of cationic modified polyurethane, 1.7-2.4 parts by weight of antioxidant, 1.5-1.8 parts by weight of accelerator and the like; the oxidized carbon fiber has a good reinforcing effect, and significantly improves the mechanical properties of the natural rubber composite mattress material; the cationic modified polyurethane contains heat-resistant benzimidazole ring structure, can improve the thermal decomposition temperature of the polyurethane and the natural rubber material, and has better thermal stability; meanwhile, the cationic modified polyurethane contains quaternary ammonium salt antibacterial groups, and the antibacterial properties of the composite mattress material are significantly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of natural rubber, in particular to an environment-friendly natural latex-carbon fiber reinforced composite mattress material and a preparation method thereof. BACKGROUND

[0002] Natural rubber is a non-toxic and environment-friendly natural high molecular compound, and the main component is cis-1,4-polyisoprene, which is the most widely used general-purpose rubber at present. It has important applications in the fields of daily necessities such as latex mattress, pillow, transportation belts, hovercraft, sports goods such as yoga mat and racket, etc. At the same time, natural rubber has high elasticity, mechanical strength and antibacterial properties, which has important significance.

[0003] Carbon fiber is a kind of inorganic fiber material with high strength and high modulus, which is widely used in polymer materials such as plastics and rubbers. Improving the compatibility of carbon fiber and polymer material matrix is a research difficulty, and surface modifiers, compatibilizers, etc. are usually added. Polyurethane is a kind of high-elasticity and high-toughness polymer, which can improve the toughness, strength and other properties of materials such as epoxy resin, polylactic acid and natural rubber. The present application aims to improve the strength, resilience and antibacterial properties of natural rubber material by using oxidized carbon fiber and modified polyurethane. SUMMARY

[0004] The present application aims to provide an environment-friendly natural latex-carbon fiber reinforced composite mattress material and a preparation method thereof. The prepared mattress material has the advantages of high elasticity, excellent mechanical properties and good antibacterial properties.

[0005] To achieve this purpose, the following technical solutions are adopted in the present application:

[0006] An environment-friendly natural latex-carbon fiber reinforced composite mattress material, comprising 100 parts by weight of natural rubber, 0.4-1.5 parts by weight of acrylic acid grafted natural rubber, 1-8 parts by weight of oxidized carbon fiber, 20-50 parts by weight of cationic modified polyurethane, 4-5 parts by weight of additive, 1.5-2.3 parts by weight of auxiliary agent, 1.7-2.4 parts by weight of antioxidant, 1.5-1.8 parts by weight of accelerator, and 1.3-1.6 parts by weight of vulcanizing agent.

[0007] Preferably, the additive is zinc oxide, the auxiliary agent is stearic acid, the antioxidant is antioxidant 4010, the accelerator is accelerator DM or accelerator CZ, and the vulcanizing agent is sulfur.

[0008] Preferably, the preparation method of the cationic modified polyurethane comprises: adding dry polytetrahydrofuran ether diol and isocyanate monomer into a reaction container, purging with nitrogen, heating to 70-80℃, reacting for 2-2.5h, then adding benzimidazole quaternary ammonium salt chain extender and dibutyltin dilaurate, reacting for 1-1.5h, and cooling to obtain the cationic modified polyurethane.

[0009] Preferably, the mass ratio of polytetrahydrofuran ether glycol, isocyanate monomer, benzimidazole quaternary ammonium salt chain extender, dibutyl tin dilaurate is 100:(22-29):(33-36):(0.1-0.12).

[0010] Preferably, the isocyanate monomer is toluene-2,4-diisocyanate or isophorone diisocyanate.

[0011] Preferably, the preparation method of benzimidazole quaternary ammonium salt chain extender is:

[0012] (1) adding N,N-dimethylformamide, mass ratio of 100:(112-124) of pyromellitic dianhydride, 4-aminobenzyl alcohol into a reaction container, heating to 120-130℃, reacting for 10-15h, pouring the solution into water to precipitate the precipitate, washing with acetone, then adding to thionyl chloride, heating to 65-70℃, reacting for 3-4h, condensing refluxing during reaction, reducing pressure to concentrate, washing with acetone, drying to obtain the precursor. The reaction formula is:

[0013]

[0014] (2) adding acetonitrile, mass ratio of 100:(44-49) of the precursor, 3-dimethylamino-1-propanol into a reaction container, heating to 80-85℃, reacting for 12-18h, condensing refluxing during reaction, reducing pressure to concentrate, recrystallizing the product in a mixed solution of acetone and ethanol to obtain the benzimidazole quaternary ammonium salt chain extender. The reaction formula is:

[0015]

[0016] Preferably, the preparation method of acrylic acid grafted natural rubber comprises: adding water, 100 parts by weight of natural rubber latex, 4-6 parts by weight of fatty alcohol polyoxyethylene ether into a reaction container, stirring, then adding 3-8 parts by weight of acrylic acid, 2.4-4 parts by weight of sodium hydroxide, 0.22-0.32 parts by weight of ammonium persulfate, 0.16-0.24 parts by weight of sodium thiosulfate, heating to 40-50℃, reacting for 1-2h, adding hydrochloric acid solution to adjust pH to 4-5, filtering, drying, extracting the product with acetone in a Soxhlet extractor, drying to obtain the acrylic acid grafted natural rubber.

[0017] Preferably, the preparation method of the environment-friendly natural rubber-carbon fiber reinforced composite mattress material comprises the following steps: plasticizing natural rubber in a rubber mixing mill, then mixing the natural rubber with acrylic acid grafted natural rubber in an open mill, the roller temperature is 50-55 DEG C, after wrapping the roller, adding oxidized carbon fiber, cationic modified polyurethane, additives, adjuvants, anti-aging agents, accelerators, then adding vulcanizing agent after mixing, then sheeting after thin passing, and finally vulcanizing in a vulcanizing instrument, the temperature is 160-170 DEG C, the pressure is 10-12 MPa, discharging, and obtaining the environment-friendly natural rubber-carbon fiber reinforced composite mattress material.

[0018] One of the above technical solutions has the following beneficial effects:

[0019] The application mixes and vulcanizes green and environment-friendly natural rubber, acrylic acid grafted natural rubber, oxidized carbon fiber, cationic modified polyurethane, stearic acid, sulfur and the like, and obtains the environment-friendly natural rubber-carbon fiber reinforced composite mattress material.

[0020] The cationic modified polyurethane contains heat-resistant benzimidazole ring structure, which can improve the thermal decomposition temperature of the polyurethane and the natural rubber material, and exhibits better thermal stability.

[0021] The cationic modified polyurethane contains quaternary ammonium salt antibacterial groups and is uniformly dispersed in the natural rubber composite material matrix, can fully and effectively contact bacteria and microorganisms, and plays a role in inhibition and killing, and significantly improves the antibacterial performance of the composite material. DETAILED DESCRIPTION

[0022] The application will be described in detail below in combination with examples. However, it should be understood that the following examples are only illustrative of the embodiments of the application, and are not a limitation on the scope of the application.

[0023] The natural rubber in the specific embodiment is from Shandong Jinghao Chemical Co., Ltd. The natural rubber latex is from Shandong Jinghao Chemical Co., Ltd. The fatty alcohol polyoxyethylene ether is of model AEO-9 and from Guangzhou Zeyiuan Chemical Co., Ltd. The carbon fiber is 3mm and from Toray New Materials (Guangdong) Co., Ltd.

[0024] Into a reaction vessel, 120 mL of concentrated sulfuric acid (mass fraction 98%), 40 mL of concentrated nitric acid (mass fraction 70%), and 0.5 g of carbon fiber were added, and the mixture was ultrasonically treated at 60°C for 4 h. The solution was poured into water, filtered, washed with water, and dried to obtain oxidized carbon fiber.

[0025] Example 1:

[0026] (1) Into a reaction vessel, 30 mL of N,N-dimethylformamide, 5 g of pyromellitic anhydride, and 5.6 g of 4-aminobenzyl alcohol were added, and the mixture was heated to 120°C and reacted for 15 h. The solution was poured into water, and a precipitate was separated. The precipitate was washed with acetone, added to 10 mL of thionyl chloride, heated to 65°C, and reacted for 3 h while condensing and refluxing. The reaction mixture was concentrated under reduced pressure, washed with acetone, and dried to obtain a precursor.

[0027] (2) Into a reaction vessel, 200 mL of acetonitrile, 20 g of the precursor, and 8.8 g of 3-dimethylamino-1-propanol were added, and the mixture was heated to 85°C and reacted for 12 h while condensing and refluxing. The reaction mixture was concentrated under reduced pressure, and the product was recrystallized from a mixed solution of acetone and ethanol to obtain a benzoimide quaternary ammonium salt chain extender.

[0028] (3) Into a reaction vessel, 100 g of dried polytetrahydrofuran ether glycol 2000 and 29 g of isophorone diisocyanate were added, and the mixture was heated to 70°C and reacted for 2.5 h while purging with nitrogen. Then, 33.6 g (50 mmol) of the benzoimide quaternary ammonium salt chain extender and 0.12 g of dibutyltin dilaurate were added, and the mixture was reacted for 1 h. The reaction mixture was cooled to obtain a cation-modified polyurethane.

[0029] (4) Into a reaction vessel, 60 mL of water, 10 g of natural rubber latex, and 0.6 g of a fatty alcohol polyoxyethylene ether were added, and the mixture was stirred. Then, 0.5 g of acrylic acid, 0.3 g of sodium hydroxide, 26 mg of ammonium persulfate, and 20 mg of sodium thiosulfate were added, and the mixture was heated to 40°C and reacted for 2 h. The pH was adjusted to 4 by adding a 20% mass fraction hydrochloric acid solution. The reaction mixture was filtered and dried. The product was extracted with acetone in a Soxhlet extractor, and dried to obtain an acrylic acid grafted natural rubber.

[0030] (5) 1000 g of natural rubber was plasticized in a rubber mill, and then mixed with 4 g of the acrylic acid grafted natural rubber in an open mill at a roll temperature of 55°C. After the mixing, 10 g of oxidized carbon fiber, 200 g of the cation-modified polyurethane, 50 g of zinc oxide, 15 g of stearic acid, 17 g of antioxidant 4010, and 15 g of accelerator DM were added. After the mixing, 13 g of sulfur was added, and the mixture was thin passed and sheeted. Finally, the mixture was vulcanized in a vulcanizer at a temperature of 170°C and a pressure of 10 MPa to obtain an environmentally friendly natural rubber-carbon fiber reinforced composite mattress material.

[0031] Example 2:

[0032] (1) Into a reaction vessel, 35 mL of N,N-dimethylformamide, 5 g of pyromellitic dianhydride, 6.2 g of 4-aminobenzyl alcohol were added, heated to 130°C, and reacted for 10 h. The solution was poured into water, and a precipitate was separated. After washing with acetone, it was added to 8 mL of sulfoxide chloride, heated to 70°C, and reacted for 4 h while condensing and refluxing. After concentration under reduced pressure, washing with acetone, and drying, a precursor was obtained.

[0033] (2) Into a reaction vessel, 200 mL of acetonitrile, 20 g of the precursor, and 9.8 g of 3-dimethylamino-1-propanol were added, heated to 80°C, and reacted for 18 h while condensing and refluxing. After concentration under reduced pressure, the product was recrystallized in a mixed solution of acetone and ethanol, and a benzoimide quaternary ammonium salt chain extender was obtained.

[0034] (3) Into a reaction vessel, 100 g of dry polytetrahydrofuran ether glycol 2000, 22 g of toluene-2,4-diisocyanate were added, nitrogen was introduced, and the temperature was raised to 80°C. After reacting for 2 h, 36 g of the benzoimide quaternary ammonium salt chain extender and 0.1 g of dibutyltin dilaurate were added, and reacted for 1.5 h. After cooling, a cation-modified polyurethane was obtained.

[0035] (4) Into a reaction vessel, 60 mL of water, 10 g of natural rubber latex, and 0.4 g of fatty alcohol polyoxyethylene ether were added, stirred, and then 0.8 g of acrylic acid, 0.4 g of sodium hydroxide, 32 mg of ammonium persulfate, and 24 mg of sodium thiosulfate were added. After heating to 40°C and reacting for 2 h, the pH was adjusted to 4 by adding a 20% hydrochloric acid solution. After filtering and drying, the product was extracted with acetone in a Soxhlet extractor, and dried to obtain an acrylic acid grafted natural rubber.

[0036] (5) 1000 g of natural rubber was plasticized in a rubber mixer, and then 10 g of the acrylic acid grafted natural rubber was added to a two-roll mill and mixed at a roll temperature of 55°C. After wrapping, 45 g of carbon fiber, 350 g of the cation-modified polyurethane, 40 g of zinc oxide, 23 g of stearic acid, 24 g of antioxidant 4010, and 15 g of accelerator CZ were added, and mixed. After adding 16 g of sulfur, thin passing, and finally placing in a vulcanizer at a temperature of 160°C and a pressure of 12 MPa, the product was discharged to obtain an environmentally friendly natural rubber-carbon fiber reinforced composite mattress material.

[0037] Example 3:

[0038] (1) 50 mL of water, 10 g of natural rubber latex, 0.4 g of fatty alcohol polyoxyethylene ether were added into a reaction vessel, after stirring, 0.3 g of acrylic acid, 0.24 g of sodium hydroxide, 22 mg of ammonium persulfate, 16 mg of sodium thiosulfate were added, heated to 50°C, reacted for 1 h, 20% mass fraction of hydrochloric acid solution was added to adjust pH to 5, after filtration and drying, the product was extracted with acetone in a Soxhlet extractor, dried to obtain acrylic acid grafted natural rubber.

[0039] (2) 1000 g of natural rubber was plasticized in a rubber mill, then 15 g of acrylic acid grafted natural rubber was added to the open mill for mixing, the roller temperature was 50°C, after wrapping, 80 g of oxidized carbon fiber, 500 g of cationic modified polyurethane (the same as the preparation method of Example 1), 40 g of zinc oxide, 20 g of stearic acid, 17 g of antioxidant 4010, 18 g of accelerator DM were added, after mixing, 16 g of sulfur was added, after thinning, the sheet was taken out, and finally placed in a vulcanizing instrument for vulcanization, the temperature was 160°C, the pressure was 12 MPa, and the material was discharged to obtain an environmentally friendly natural latex-carbon fiber reinforced composite mattress material.

[0040] The difference between Comparative Example 1 and Example 1 is that carbon fiber is used instead of oxidized carbon fiber.

[0041] (1) 1000 g of natural rubber was plasticized in a rubber mill, then 4 g of acrylic acid grafted natural rubber was added to the open mill for mixing, the roller temperature was 55°C, after wrapping, 10 g of carbon fiber, 200 g of cationic modified polyurethane, 50 g of zinc oxide, 15 g of stearic acid, 17 g of antioxidant 4010, 15 g of accelerator DM were added, after mixing, 13 g of sulfur was added, after thinning, the sheet was taken out, and finally placed in a vulcanizing instrument for vulcanization, the temperature was 170°C, the pressure was 10 MPa, and the material was discharged to obtain an environmentally friendly natural latex-carbon fiber reinforced composite mattress material.

[0042] The difference between Comparative Example 2 and Example 1 is that no acrylic acid grafted natural rubber is added.

[0043] (1) 1000 g of natural rubber was plasticized in a rubber mill, then added to the open mill for mixing, the roller temperature was 55°C, after wrapping, 10 g of oxidized carbon fiber, 200 g of cationic modified polyurethane, 50 g of zinc oxide, 15 g of stearic acid, 17 g of antioxidant 4010, 15 g of accelerator DM were added, after mixing, 13 g of sulfur was added, after thinning, the sheet was taken out, and finally placed in a vulcanizing instrument for vulcanization, the temperature was 170°C, the pressure was 10 MPa, and the material was discharged to obtain an environmentally friendly natural latex-carbon fiber reinforced composite mattress material.

[0044] The difference between Comparative Example 3 and Example 1 is that no cationic modified polyurethane is added.

[0045] (1) 1000 g of natural rubber was plasticized in a rubber mill, then 4 g of acrylic acid grafted natural rubber was added to the open mill for mixing, the roller temperature was 55°C, after wrapping, 10 g of oxidized carbon fiber, 50 g of zinc oxide, 15 g of stearic acid, 17 g of antioxidant 4010, 15 g of accelerator DM were added, after mixing, 13 g of sulfur was added, after thinning, the sheet was placed in a vulcanizing instrument for vulcanization, the temperature was 170°C, the pressure was 10 MPa, the material was discharged, and an environmentally friendly natural latex-carbon fiber reinforced composite mattress material was obtained.

[0046] Comparative Example 4: The difference from Example 1 is that 1,4-butanediol is used instead of the benzimidazole quaternary ammonium salt chain extender in the preparation of the polyurethane.

[0047] (1) 1000 g of natural rubber was plasticized in a rubber mill, then 4 g of acrylic acid grafted natural rubber was added to the open mill for mixing, the roller temperature was 55°C, after wrapping, 10 g of oxidized carbon fiber, 50 g of zinc oxide, 15 g of stearic acid, 17 g of antioxidant 4010, 15 g of accelerator DM were added, after mixing, 13 g of sulfur was added, after thinning, the sheet was placed in a vulcanizing instrument for vulcanization, the temperature was 170°C, the pressure was 10 MPa, the material was discharged, and an environmentally friendly natural latex-carbon fiber reinforced composite mattress material was obtained.

[0048] (2) 1000 g of natural rubber was plasticized in a rubber mill, then 4 g of acrylic acid grafted natural rubber was added to the open mill for mixing, the roller temperature was 55°C, after wrapping, 10 g of oxidized carbon fiber, 200 g of polyurethane, 50 g of zinc oxide, 15 g of stearic acid, 17 g of antioxidant 4010, 15 g of accelerator DM were added, after mixing, 13 g of sulfur was added, after thinning, the sheet was placed in a vulcanizing instrument for vulcanization, the temperature was 170°C, the pressure was 10 MPa, the material was discharged, and an environmentally friendly natural latex-carbon fiber reinforced composite mattress material was obtained.

[0049] Comparative Example 5: The difference from Example 1 is that benzimidazole chain extender is used instead of benzimidazole quaternary ammonium salt chain extender in the preparation of the polyurethane.

[0050] (1) 30 mL of N,N-dimethylformamide, 5 g of pyromellitic dianhydride, and 5.6 g of 4-aminobenzyl alcohol were added to a reaction vessel, heated to 120°C, and reacted for 15 h. The solution was poured into water, and the precipitate was separated and washed with acetone and dried to obtain a benzimidazole chain extender. The structure is:

[0051] (2) 1000 g of natural rubber was plasticized in a rubber mill, then 4 g of acrylic acid grafted natural rubber was added to the open mill for mixing, the roller temperature was 55°C, after wrapping, 10 g of oxidized carbon fiber, 200 g of polyurethane, 50 g of zinc oxide, 15 g of stearic acid, 17 g of antioxidant 4010, 15 g of accelerator DM were added, after mixing, 13 g of sulfur was added, after thinning, the sheet was placed in a vulcanizing instrument for vulcanization, the temperature was 170°C, the pressure was 10 MPa, the material was discharged, and an environmentally friendly natural latex-carbon fiber reinforced composite mattress material was obtained.

[0052] (3) 1000 g of natural rubber was plasticized in a rubber mill, then 4 g of acrylic acid grafted natural rubber was added to the open mill for mixing, the roller temperature was 55 °C, after wrapping, 10 g of oxidized carbon fiber, 200 g of modified polyurethane, 50 g of zinc oxide, 15 g of stearic acid, 17 g of antioxidant 4010, 15 g of accelerator DM were added, after mixing, 13 g of sulfur was added, after thinning, the sheet was placed, and finally placed in a vulcanizing instrument for vulcanization, the temperature was 170 °C, the pressure was 10 MPa, and the material was discharged, to obtain an environmentally friendly natural latex-carbon fiber reinforced composite mattress material.

[0053] The tear strength of the natural latex-carbon fiber reinforced composite mattress material was tested according to the national standard GB / T 529-2008. The rebound value was tested according to the national standard GB / T 1681-2009.

[0054] 5 mg of the composite mattress material was weighed and placed in a thermogravimetric analyzer for thermal gravimetric performance analysis in a nitrogen atmosphere, with a heating rate of 10 °C / min.

[0055] Table 1 Performance test of the composite mattress material

[0056]

[0057] After testing, the composite mattress materials of Examples 1-3 have higher tear strength, rebound value and initial thermal decomposition temperature, showing higher elasticity, mechanical properties and thermal stability. Mainly because of the addition of oxidized carbon fiber, cationic modified polyurethane and acrylic acid grafted natural rubber. The modified polyurethane contains cationic groups which can interact with the carboxyl groups on the surface of the oxidized carbon fiber and the carboxyl groups of the acrylic acid grafted natural rubber, enhancing the interfacial bonding strength and compatibility between the three, so that the acrylic acid grafted natural rubber acts as a compatibilizer, improving the compatibility between the oxidized carbon fiber, the cationic modified polyurethane and the natural rubber, making the carbon fiber play a better reinforcing effect, significantly improving the mechanical properties of the natural rubber composite mattress material. At the same time, the cationic modified polyurethane is uniformly distributed in the natural rubber material, playing a good toughening effect, which is conducive to improving the elasticity of the composite mattress material, and the modified polyurethane contains heat-resistant benzimidazole ring structure, which can improve the thermal decomposition temperature of the polyurethane and natural rubber material, showing better thermal stability.

[0058] Comparative Example 1 uses carbon fiber instead of oxidized carbon fiber, the content of carboxyl groups on the surface of carbon fiber is very low, which cannot interact with cationic modified polyurethane, resulting in low interfacial bonding strength and compatibility between carbon fiber and composite mattress material matrix, poor compatibility and poor reinforcing effect, resulting in low tear strength and rebound value of the composite material.

[0059] Comparative Example 2 does not add acrylic grafted natural rubber, the interfacial bonding strength and compatibility between oxidized carbon fiber and cationic modified polyurethane and natural rubber is low, the compatibility is poor, resulting in low tear strength and resilience of the composite material.

[0060] Comparative Example 3 does not add cationic modified polyurethane, the resilience of the composite material is very low, and the thermal decomposition temperature is low, and the thermal stability is poor.

[0061] Comparative Example 4 uses 1,4-butanediol instead of benzimidazole quaternary ammonium salt chain extender, and the obtained polyurethane does not contain benzimidazole ring structure, and the thermal decomposition temperature of the composite material is low, and the thermal stability is poor.

[0062] Comparative Example 5 uses benzimidazole chain extender instead of benzimidazole quaternary ammonium salt chain extender, and the obtained polyurethane does not contain quaternary ammonium salt cation, and cannot occur electrostatic interaction with the carboxyl group on the surface of the oxidized carbon fiber and the carboxyl group of the acrylic grafted natural rubber, the interfacial bonding strength and compatibility between the three is low, resulting in low tear strength and resilience of the material.

[0063] The antibacterial performance of the composite mattress material is tested by film pasting method. The composite mattress material is sterilized by ultraviolet light, 0.2 mL of c test bacteria liquid (concentration of 10 5 cfu / mL) is taken and dropped on the surface of the composite mattress material, then a sterilized polyethylene film is covered on the surface of the composite mattress material, and placed in a sterile culture dish in a constant temperature and humidity incubator at 37°C for 24h, then 20 mL of 0.8% sodium chloride solution is used to elute the composite mattress material and the polyethylene film, 0.2 mL of eluate is inoculated in agar medium and cultured at 37°C for 48h, and the viable bacteria count is carried out. Calculate the antibacterial rate R. R=(B-C) / B x 100%. C is the average number of recovered bacteria of the experimental sample. B is the average number of recovered bacteria of the blank control sample. The natural latex-carbon fiber reinforced composite mattress material of Comparative Example 3 is used as the blank control sample.

[0064] Table 2 Antibacterial performance test of composite mattress material

[0065]

[0066] After testing, the composite mattress materials of Examples 1-3 show very high antibacterial rate to Escherichia coli and Staphylococcus aureus, mainly because the cationic modified polyurethane added contains quaternary ammonium salt antibacterial groups and is uniformly dispersed in the natural rubber composite material matrix, which can effectively contact bacteria and microorganisms and play a role in inhibition and killing, significantly improving the antibacterial performance of the composite material.

[0067] The antibacterial rate of Comparative Example 2 is slightly lower than that of Example 1, mainly because no acrylic grafted natural rubber is added, the cationic modified polyurethane is not well compatible with the natural rubber, and is not uniformly dispersed in the natural rubber composite material matrix, so as to not fully and effectively contact the bacterial microorganisms, resulting in a lower antibacterial rate.

[0068] Comparative Example 4 and Comparative Example 5 add polyurethane without quaternary ammonium salt antibacterial groups, and the antibacterial rate of the composite mattress material is very low, and the antibacterial performance is poor.

[0069] Based on the above ideal embodiments according to the present application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. An environmentally friendly natural latex-carbon fiber reinforced composite mattress material, characterized in that, The composite mattress material comprises 100 parts by weight of natural rubber, 0.4-1.5 parts by weight of acrylic-grafted natural rubber, 1-8 parts by weight of oxidized carbon fiber, 20-50 parts by weight of cationic modified polyurethane, 4-5 parts by weight of additives, 1.5-2.3 parts by weight of auxiliaries, 1.7-2.4 parts by weight of antioxidants, 1.5-1.8 parts by weight of accelerators, and 1.3-1.6 parts by weight of vulcanizing agents; The preparation method of the cationic modified polyurethane includes: adding dry polytetrahydrofuran ether diol and isocyanate monomer to a reaction vessel, introducing nitrogen gas, heating to 70-80℃, reacting for 2-2.5 hours, and then adding the following: The chain extender of benzoimide quaternary ammonium salt, dibutyltin dilaurate, was reacted for 1-1.5 h, and then cooled to obtain cationic modified polyurethane.

2. The environmentally friendly natural latex-carbon fiber reinforced composite mattress material according to claim 1, characterized in that, The additive is zinc oxide; the auxiliary agent is stearic acid; the antioxidant is antioxidant 4010; the accelerator is accelerator DM or accelerator CZ; and the vulcanizing agent is sulfur.

3. The environmentally friendly natural latex-carbon fiber reinforced composite mattress material according to claim 1, characterized in that, The preparation method of acrylic-grafted natural rubber includes: adding water, 100 parts by weight of natural rubber latex, and 4-6 parts by weight of fatty alcohol polyoxyethylene ether to a reaction vessel; stirring and then adding 3-8 parts by weight of acrylic acid, 2.4-4 parts by weight of sodium hydroxide, 0.22-0.32 parts by weight of ammonium persulfate, and 0.16-0.24 parts by weight of sodium thiosulfate; heating to 40-50°C and reacting for 1-2 hours; adjusting the pH to 4-5 with hydrochloric acid solution; filtering and drying; and extraction to obtain acrylic-grafted natural rubber.

4. The environmentally friendly natural latex-carbon fiber reinforced composite mattress material according to claim 1, characterized in that, The mass ratio of polytetrahydrofuran ether diol, isocyanate monomer, benzoimide quaternary ammonium salt chain extender, and dibutyltin dilaurate is 100:(22-29):(33-36):(0.1-0.12).

5. The environmentally friendly natural latex-carbon fiber reinforced composite mattress material according to claim 4, characterized in that, The isocyanate monomer is toluene-2,4-diisocyanate or isophorone diisocyanate.

6. The environmentally friendly natural latex-carbon fiber reinforced composite mattress material according to claim 4, characterized in that, The preparation method of the benzoimide quaternary ammonium salt chain extender includes: (1) Add N,N-dimethylformamide, pyromellitic anhydride and 4-aminobenzyl alcohol to the reaction vessel, heat to 120-130℃, react for 10-15h, pour the solution into water, precipitate out, wash and add to thionyl chloride, heat to 65-70℃, react for 3-4h, reflux during the reaction, concentrate under reduced pressure, wash and dry to obtain the precursor; (2) Add acetonitrile, precursor and 3-dimethylamino-1-propanol to the reaction vessel, heat to 80-85℃, react for 12-18h, reflux during the reaction, concentrate under reduced pressure, recrystallize the product to obtain benzoimide quaternary ammonium salt chain extender.

7. The environmentally friendly natural latex-carbon fiber reinforced composite mattress material according to claim 6, characterized in that, The mass ratio of pyromellitic anhydride and 4-aminobenzyl alcohol in (1) is 100:(112-124).

8. The environmentally friendly natural latex-carbon fiber reinforced composite mattress material according to claim 6, characterized in that, The mass ratio of the precursor to 3-dimethylamino-1-propanol in (2) is 100:(44-49).

9. A method for preparing an environmentally friendly natural latex-carbon fiber reinforced composite mattress material as described in any one of claims 1-8, characterized in that, The preparation method is as follows: natural rubber is plasticized in a rubber mixing mill, and then it is mixed with acrylic-grafted natural rubber in an open mill. The roller temperature is 50-55℃. After wrapping the rollers, carbon fiber oxide, cationic modified polyurethane, additives, auxiliaries, antioxidants, and accelerators are added. After mixing, a vulcanizing agent is added. After thinning, the mixture is sheeted and finally placed in a vulcanizing apparatus for vulcanization at a temperature of 160℃-170℃ and a pressure of 10-12MPa. The material is then discharged to obtain an environmentally friendly natural latex-carbon fiber reinforced composite mattress material.

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