A polyvinyl chloride mastic modified by bamboo charcoal and a preparation method and application thereof

Abstract

The application belongs to the technical field of polyvinyl chloride mastic, and particularly discloses a polyvinyl chloride mastic modified by bamboo charcoal, a preparation method and application thereof, and the polyvinyl chloride mastic modified by bamboo charcoal is prepared from the following raw materials in parts by weight: 100 parts of coal tar, 12-15 parts of polyvinyl chloride resin, 10-15 parts of plasticizer, 0.5-1.0 parts of stabilizer and 15-36 parts of bamboo charcoal powder. The polyvinyl chloride mastic modified by bamboo charcoal has the advantages that the bamboo charcoal is used as a filler to replace the filler in the original polyvinyl chloride mastic, the specific surface area porosity and surface roughness of the bamboo charcoal (biological carbon) are large, the size is stable, the interface interaction with the high polymer material matrix is strong, the high polymer material melt flows into the pores of the bamboo charcoal to form a firm interface interlocking structure, and therefore the mechanical properties of the modified polyvinyl chloride mastic composite material are improved, the recovery rate, the tensile bonding property and the water immersion tensile rate are improved, and the service life is also prolonged.

Description

Technical Field

[0001] This invention belongs to the field of polyvinyl chloride (PVC) putty technology, specifically relating to a PVC putty modified with bamboo charcoal, its preparation method, and its application. Background Technology

[0002] Adhesive putty is a mud-like plastic solid with certain adhesive properties. This type of plastic solid is generally composed of solid or liquid adhesives with adhesive properties and powder fillers with certain functions, and may also contain appropriate pigments and auxiliary materials. There are many types of adhesive putty, including acid-resistant adhesive putty, corrosion-resistant adhesive putty, and waterproof adhesive putty. Currently, the most widely used type on the market is waterproof adhesive putty. Waterproof adhesive putty is widely used in roofing projects of industrial plants and civil buildings with various slopes due to its advantages such as good waterproof effect, convenient construction, non-flowing at high temperatures, good adhesion, and non-brittleness at low temperatures. It can also be used for connecting and sealing water channels and pipes, as well as joints in multi-story factories and underground oil pipelines.

[0003] Polyvinyl chloride (PVC) sealant, a type of waterproof sealant, has been widely used in roofing projects, water conservancy projects, and flexible waterproof joints in wall panels since its successful development in the 1960s. PVC sealant possesses several unique advantages, primarily reflected in its ease of construction, simple material sources, low cost, convenient storage, minimal impact from climate, good thermal insulation performance, and low technical requirements. Furthermore, it does not contain toxic or harmful substances such as phenol and diisocyanates. Compared to traditional synthetic resins, it has higher mechanical strength and is recyclable, showing promising development prospects in water treatment. However, existing PVC sealants still suffer from drawbacks such as low recovery rate, low tensile strength, susceptibility to cracking, and short service life.

[0004] Therefore, in view of the above situation, there is an urgent need to develop a new modified polyvinyl chloride (PVC) mortar to improve the mechanical properties of PVC mortar. Summary of the Invention

[0005] The purpose of this invention is to provide a bamboo charcoal-modified polyvinyl chloride adhesive, its preparation method, and its application. The aim is to obtain a bamboo charcoal-modified polyvinyl chloride adhesive with high recovery rate, high tensile adhesion, and high water immersion elongation, which can be used as a waterproof joint material.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] The first aspect of the present invention provides a polyvinyl chloride mortar modified with bamboo charcoal, prepared from the following raw materials in parts by weight:

[0008]

[0009] Coal tar, also known as coal paste, coal tar oil, or coal tar solution, is a black or dark brown viscous liquid obtained during coal coking. It is denser than water, has some solubility and a distinctive odor, and is flammable and corrosive. Coal tar is one of the products of the crude coal gas generated during the pyrolysis of coal in the coking industry, accounting for approximately 3%-4% of the coal charged into the furnace. At room temperature and pressure, it is a black, viscous liquid. Coal tar is an important raw material for the production of plastics, synthetic fibers, dyes, rubber, pharmaceuticals, and high-temperature resistant materials. In this invention, coal tar is used as the main raw material, polyvinyl chloride resin is used as a modifier, and plasticizers and stabilizers are added. Bamboo charcoal is used as a filler to replace... A new type of modified polyvinyl chloride (PVC) mortar was prepared using bamboo charcoal (biochar) as the filler. Bamboo charcoal (biochar) has a large specific surface area, porosity, and surface roughness, and is dimensionally stable. It has strong interfacial interaction with the polymer matrix, and the polymer melt flows into the pores of the bamboo charcoal to form a strong interfacial interlocking structure. This improves the mechanical properties of the composite material, significantly enhances the recovery rate, tensile adhesion, and water immersion elongation of the PVC mortar, improves the low-temperature flexibility of the PVC mortar, and extends the service life of the PVC mortar.

[0010] Furthermore, the particle size of the bamboo charcoal powder is 100-3000 mesh.

[0011] In this invention, the bamboo charcoal powder used as a filler material cannot have a large particle size. The filler particles are hard, and the larger the particles are, the worse the bonding effect with polyvinyl chloride mortar, and the easier it is to break. Generally, the smaller the particle size, the better. However, the smaller the particle size, the higher the preparation cost. Taking into account both performance and cost, the particle size is controlled within the range of 100-3000 mesh.

[0012] Furthermore, the bamboo charcoal powder has a particle size of 200-300 mesh, resulting in a good bonding effect between the bamboo charcoal powder and polyvinyl chloride mortar, and the preparation cost is not too high.

[0013] Furthermore, the specific surface area of ​​the bamboo charcoal powder is not less than 500 m² / g.

[0014] In this invention, bamboo charcoal powder with a specific surface area of ​​not less than 500 m² / g is selected. Its large specific surface area and high porosity allow the polymer melt to flow fully into the pores of the bamboo charcoal powder, thereby enhancing the strength of interfacial interactions.

[0015] Furthermore, the bamboo charcoal powder accounts for 10.5-25% of the total mass of the raw materials used.

[0016] In this invention, if there is too much bamboo charcoal powder, the polyvinyl chloride (PVC) mortar will be hard, compacted, and lack elasticity. If there is too little bamboo charcoal powder, the PVC mortar will not be able to increase the tensile strength. By setting the bamboo charcoal powder to account for 10.5-25% of the total mass, and further, by setting the bamboo charcoal powder to account for 15%-19% of the total mass, the elasticity and tensile strength of the modified PVC mortar can be better balanced.

[0017] Existing polyvinyl chloride (PVC) sealant is prone to cracking, mainly due to thermal expansion and contraction. This invention, by setting a specific content of bamboo charcoal powder, allows the polymer melt to flow entirely into the pores of the bamboo charcoal powder, thereby forming a more robust interlocking structure. This improves the mechanical properties of the composite material, further enhancing the elasticity, tensile strength, and low-temperature flexibility of the PVC sealant. Within this range, the PVC sealant is made more uniform, and other components are fully dispersed and dissolved.

[0018] Furthermore, the mass ratio of the polyvinyl chloride resin to the bamboo charcoal powder is 1:(1:3).

[0019] In this invention, the mass ratio of polyvinyl chloride resin to bamboo charcoal powder in the above-mentioned polyvinyl chloride mortar is 1:(1:3). When the mass ratio of polyvinyl chloride resin to bamboo charcoal powder is within this range, the produced polyvinyl chloride mortar can improve in terms of high recovery rate, high tensile adhesion, and high water immersion elongation.

[0020] Furthermore, the plasticizer is either dibutyl phthalate or dioctyl phthalate.

[0021] Dibutyl phthalate is the most commonly used and important plasticizer for polyvinyl chloride (PVC), which gives the product good flexibility. Dioctyl phthalate is also an excellent plasticizer, widely used in PVC and other plastics, which can enhance the flexibility and plasticity of the material. Therefore, in this invention, either dibutyl phthalate or dioctyl phthalate is selected as the plasticizer to increase the flexibility and plasticity of the modified PVC putty.

[0022] Further, the stabilizer is at least one of lead stearate, tribasic lead sulfate, or calcium stearate. Preferably, the stabilizer is calcium stearate.

[0023] Calcium stearate is inexpensive, readily available, has low toxicity, good processability, and excellent lubricity. Therefore, calcium stearate is preferred as a heat stabilizer for polyvinyl chloride resin in this invention.

[0024] A second aspect of the present invention provides a method for preparing the above-mentioned polyvinyl chloride mortar modified with bamboo charcoal, comprising the following steps:

[0025] S1. Take coal tar, dehydrate it at 120-140℃, and then cool it down to 40-60℃ for later use.

[0026] S2. According to the formula, add the stabilizer to the coal tar and stir evenly to obtain the first mixture;

[0027] S3. Mix the polyvinyl chloride resin and plasticizer according to the specified ratio to form a paste, then add it to the first mixture and stir evenly to obtain the second mixture;

[0028] S4. Heat the second mixture to 130-140℃. While stirring, add bamboo charcoal powder and maintain for 5-10 minutes. The resulting adhesive is the polyvinyl chloride mortar modified with bamboo charcoal.

[0029] In step S1 of the above preparation method, the dehydration temperature of the coal tar is maintained between 120-140℃ so that the coal tar can be dehydrated effectively.

[0030] In step S2 of the above preparation method, the dehydrated coal tar is cooled and maintained between 40-60°C so that the stabilizer can be evenly dispersed in the coal tar.

[0031] In step S4 of the above preparation method, the temperature of the second mixture is maintained between 100-130°C, and bamboo charcoal powder is added while stirring for 5-10 minutes to ensure that the second mixture can flow into the pores of the bamboo charcoal powder, thereby forming a more robust interlocking structure and improving the mechanical properties of the polyvinyl chloride mortar composite material modified with bamboo charcoal.

[0032] The third aspect of the present invention provides that the above-mentioned bamboo charcoal-modified polyvinyl chloride mortar is used as a waterproof joint material. The bamboo charcoal-modified polyvinyl chloride mortar prepared by the above-mentioned preparation method has good waterproof performance when used as a waterproof joint material.

[0033] Compared with the prior art, the present invention has the following technical effects:

[0034] (1) In this invention, bamboo charcoal is used as a filler to replace the original filler (talc) in polyvinyl chloride mortar. Because bamboo charcoal (biochar) has a large specific surface area, porosity and surface roughness, and is dimensionally stable, it can have a strong interfacial interaction with the polymer matrix. The polymer melt flows into the pores of bamboo charcoal to form a strong interfacial interlocking structure, thereby improving the mechanical properties of the modified polyvinyl chloride mortar composite material, such as increased recovery rate, improved tensile adhesion and increased water immersion elongation. At the same time, it improves the low-temperature flexibility of polyvinyl chloride mortar.

[0035] (2) By setting a specific amount of bamboo charcoal powder, the present invention can make the polymer material melt flow into the pores of the bamboo charcoal powder, thereby forming a more solid interlocking structure, which further improves the mechanical properties of the polyvinyl chloride mortar composite material modified by bamboo charcoal. Detailed Implementation

[0036] To enable those skilled in the art to better understand this solution, the following detailed description is provided in conjunction with specific embodiments. Unless otherwise specified, the process methods used in the embodiments are conventional methods; the materials used, unless otherwise specified, are commercially available. The bamboo charcoal powder used in this embodiment has a specific surface area of ​​600 m² / g and a particle size of 200 mesh.

[0037] Preparation Examples

[0038] Preparation Example 1

[0039] The specific composition of each raw material in polyvinyl chloride (PVC) putty is shown in Table 1 below, and its preparation method includes the following steps:

[0040] S1. Dehydrate the coal tar at 120℃, and then cool it to 40℃ for later use.

[0041] S2. Add calcium stearate to coal tar and stir until homogeneous to obtain the first mixture;

[0042] S3. Mix polyvinyl chloride resin and dibutyl phthalate to form a paste, then add it to the first mixture and stir until homogeneous to obtain the second mixture;

[0043] S4. Heat the second mixture to 130°C. While stirring, add bamboo charcoal powder and maintain for 5 minutes. The resulting adhesive is the polyvinyl chloride mortar modified with bamboo charcoal, denoted as A1.

[0044] Preparation Example 2

[0045] The specific composition of each raw material in polyvinyl chloride (PVC) putty is shown in Table 1 below, and its preparation method includes the following steps:

[0046] S1. Dehydrate the coal tar at 130℃, and then cool it down to 50℃ for later use.

[0047] S2. Add calcium stearate to coal tar and stir until homogeneous to obtain the first mixture;

[0048] S3. Mix polyvinyl chloride resin and dibutyl phthalate to form a paste, then add it to the first mixture and stir until homogeneous to obtain the second mixture;

[0049] S4. Heat the second mixture to 135°C. While stirring, add bamboo charcoal powder and maintain for 8 minutes. The resulting adhesive is the polyvinyl chloride mortar modified with bamboo charcoal, denoted as A2.

[0050] Preparation Example 3

[0051] The specific composition of each raw material in polyvinyl chloride (PVC) putty is shown in Table 1 below, and its preparation method includes the following steps:

[0052] S1. Dehydrate the coal tar at 130℃, and then cool it down to 60℃ for later use.

[0053] S2. Add calcium stearate to coal tar and stir until homogeneous to obtain the first mixture;

[0054] S3. Mix polyvinyl chloride resin and dioctyl phthalate to form a paste, then add it to the first mixture and stir until homogeneous to obtain the second mixture;

[0055] S4. Heat the second mixture to 135°C. While stirring, add 29 parts of bamboo charcoal powder and maintain for 8 minutes. The resulting adhesive is the polyvinyl chloride mortar modified with bamboo charcoal, denoted as A3.

[0056] Preparation Example 4

[0057] The specific composition of each raw material in polyvinyl chloride (PVC) putty is shown in Table 1 below, and its preparation method includes the following steps:

[0058] S1. Dehydrate the coal tar at 140℃, and then cool it down to 40℃ for later use.

[0059] S2. Add calcium stearate to coal tar and stir until homogeneous to obtain the first mixture;

[0060] S3. Mix polyvinyl chloride resin and dibutyl phthalate to form a paste, then add it to the first mixture and stir until homogeneous to obtain the second mixture;

[0061] S4. Heat the second mixture to 140°C. While stirring, add charcoal powder and maintain for 8 minutes. The resulting adhesive is polyvinyl chloride mortar modified with bamboo charcoal, denoted as A4.

[0062] Preparation of comparative examples

[0063] Preparation of Comparative Example 1

[0064] The specific composition of each raw material in polyvinyl chloride (PVC) putty is shown in Table 1 below, and its preparation method includes the following steps:

[0065] S1. Dehydrate the coal tar at 120℃, and then cool it down to 50℃ for later use.

[0066] S2. Add calcium stearate to coal tar and stir until homogeneous to obtain the first mixture;

[0067] S3. Mix polyvinyl chloride resin and dibutyl phthalate to form a paste, then add it to the first mixture and stir until homogeneous to obtain the second mixture;

[0068] S4. Heat the second mixture to 135°C. While stirring, add talc powder and maintain for 8 minutes. The resulting adhesive is polyvinyl chloride putty, denoted as B1.

[0069] Preparation of Comparative Example 2

[0070] The specific composition of each raw material in polyvinyl chloride (PVC) putty is shown in Table 1 below, and its preparation method includes the following steps:

[0071] S1. Dehydrate the coal tar at 120℃, and then cool it down to 50℃ for later use.

[0072] S2. Add calcium stearate to coal tar and stir until homogeneous to obtain the first mixture;

[0073] S3. Mix polyvinyl chloride resin and dibutyl phthalate to form a paste, then add it to the first mixture and stir until homogeneous to obtain the second mixture;

[0074] S4. Heat the second mixture to 135°C. While stirring, add bamboo charcoal powder and talc powder and maintain for 8 minutes. The resulting adhesive is the polyvinyl chloride mortar modified with bamboo charcoal, denoted as B2.

[0075] Preparation of Comparative Example 3

[0076] The specific composition of each raw material in polyvinyl chloride (PVC) putty is shown in Table 1 below, and its preparation method includes the following steps:

[0077] S1. Dehydrate the coal tar at 120℃, and then cool it down to 50℃ for later use.

[0078] S2. Add calcium stearate to coal tar and stir until homogeneous to obtain the first mixture;

[0079] S3. Mix polyvinyl chloride resin and dibutyl phthalate to form a paste, then add it to the first mixture and stir until homogeneous to obtain the second mixture;

[0080] S4. Heat the second mixture to 135°C. While stirring, add bamboo charcoal powder and maintain for 8 minutes. The resulting adhesive is the polyvinyl chloride mortar modified with bamboo charcoal, denoted as B3.

[0081] Preparation of Comparative Example 4

[0082] The specific composition of each raw material of polyvinyl chloride mortar is shown in Table 1 below. Its preparation method is the same as that of Comparative Example 3. The polyvinyl chloride mortar modified with bamboo charcoal is prepared and is denoted as B4.

[0083] Preparation of Comparative Example 5-6

[0084] The specific composition of each raw material of polyvinyl chloride mortar is shown in Table 1 below. The preparation method of polyvinyl chloride mortar is the same as that of comparative example 3. The polyvinyl chloride mortar modified with bamboo charcoal is prepared and is denoted as B5-B6.

[0085] Preparation of Comparative Example 7

[0086] The specific composition of each raw material of polyvinyl chloride mortar is shown in Table 1 below. The preparation method of polyvinyl chloride mortar is basically the same as that of Comparative Example 3. The difference from Comparative Example 3 is that bamboo charcoal powder with a specific surface area of ​​100 m² / g is used in this preparation comparative example to prepare polyvinyl chloride mortar modified with bamboo charcoal, which is denoted as B7.

[0087] Table 1. Raw material composition of polyvinyl chloride putty prepared in Examples 1-4 and Comparative Examples 1-7

[0088]

[0089] Performance tests of examples and comparative examples

[0090] The properties of the polyvinyl chloride (PVC) putty prepared in Examples 1-4 and Comparative Examples 1-7 were tested according to the PVC putty industry standard JCT798-1997. The test results are shown in Table 1.

[0091] Table 1 Performance test results of polyvinyl chloride putty

[0092]

[0093]

[0094] As shown in Table 1, the performance test data of the bamboo charcoal-modified PVC mortar A1-A4 prepared by this invention demonstrate that, with appropriate proportions of each component, the bamboo charcoal-modified PVC mortar exhibits advantages such as high recovery rate (good elasticity), strong tensile adhesion, high water immersion elongation, and good low-temperature flexibility. Therefore, the bamboo charcoal-modified PVC mortar of this invention can be used as a waterproof joint material and has broad application prospects in water conservancy projects and building leak repair.

[0095] Comparing the data of A2, B1, and B2, it can be seen that when the filler is not bamboo charcoal powder or only partially bamboo charcoal powder, the tensile adhesion, water immersion elongation, and recovery rate of the prepared polyvinyl chloride mortar are much smaller than those of Example 2. This indicates that when the filler is bamboo charcoal powder, the bamboo charcoal powder has a large specific surface area and high porosity, which allows the polymer melt to fully flow into the pores of the bamboo charcoal powder, thereby enhancing the strength of interfacial interactions and improving the mechanical properties of the modified polyvinyl chloride mortar.

[0096] Comparing the data from A2 and B3, it can be seen that when the mass proportion of bamboo charcoal powder is too small, the prepared modified polyvinyl chloride mortar has a certain recovery rate and can meet the standard requirements, but the tensile adhesion and water immersion elongation are both low and do not meet the standard requirements.

[0097] Comparing the data from A2 and B4, it can be seen that when the mass ratio of bamboo charcoal powder is too high, the prepared modified polyvinyl chloride mortar will be relatively hard, compacted, and lack elasticity, with a low recovery rate. At high temperatures, the modified polyvinyl chloride mortar has small deformation and low sag. In addition, its tensile adhesion and water immersion elongation are also low. Furthermore, when the amount of bamboo charcoal powder is excessive, the polyvinyl chloride mortar is prone to pulverization, and all indicators fail to meet industry standards.

[0098] Therefore, to improve the performance of clay, the mass ratio of bamboo charcoal powder should be within a reasonable range. If the proportion is too small, the performance will not be improved, and if the proportion is too large, the clay will tend to be rigid, clump, or even pulverize.

[0099] Comparing the data of A2, B5, and B7, it can be seen that when the mass ratio of polyvinyl chloride resin to bamboo charcoal powder is within a reasonable range, the produced polyvinyl chloride mortar can improve in terms of high recovery rate, high tensile adhesion, and high water immersion elongation. The mass ratio of polyvinyl chloride resin to bamboo charcoal powder must be within a reasonable range; otherwise, it will affect the performance of the modified polyvinyl chloride mortar.

[0100] Comparing the data of A2 and B7, it can be seen that when the specific surface area of ​​bamboo charcoal powder is small, the properties of the modified polyvinyl chloride mortar prepared are not as good as those of the modified polyvinyl chloride mortar prepared in Example 2. Therefore, bamboo charcoal powder with a large specific surface area should be selected.

[0101] Application Example 1

[0102] The bamboo charcoal-modified polyvinyl chloride mortar prepared in Example 2 was poured hot onto the gaps in the house. The cooked mortar was then used to ensure good adhesion to the gap walls and to fill the gaps tightly, serving as a waterproof caulking material.

[0103] The above are merely embodiments of this application. The scope of protection of this application is not limited to these specific embodiments, but is determined by the claims of this application. For those skilled in the art, the scope of protection of this invention should be the substitutions and modifications that do not depart from the invention and are covered by the rights of this patent application.

Claims

1. A polyvinyl chloride mortar modified with bamboo charcoal, characterized in that, The bamboo charcoal-modified polyvinyl chloride mortar is prepared from the following raw materials in parts by weight: 100 parts coal tar; 10-15 parts of polyvinyl chloride resin; Plasticizer 10-15 parts; Stabilizer 0.5-1.0 parts; 15-36 parts bamboo charcoal powder; The bamboo charcoal powder has an average particle size of 100-3000 mesh and a specific surface area of ​​not less than 500 m². 2 / g; The plasticizer is at least one of dibutyl phthalate or dioctyl phthalate; the stabilizer is at least one of lead stearate, tribasic lead sulfate or calcium stearate.

2. The polyvinyl chloride mortar modified with bamboo charcoal according to claim 1, characterized in that, The bamboo charcoal powder accounts for 10.5-25% of the total mass of the raw materials used.

3. The polyvinyl chloride mortar modified with bamboo charcoal according to claim 1, characterized in that, The stabilizer is calcium stearate.

4. A method for preparing polyvinyl chloride mortar modified with bamboo charcoal as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Take 100 parts of coal tar, dehydrate it at 120-140℃, and then cool it down to 40-60℃ for later use. S2. According to the formula, add the stabilizer to the coal tar and stir evenly to obtain the first mixture; S3. According to the formula, mix the polyvinyl chloride resin and plasticizer into a paste, then add it to the first mixture and stir evenly to obtain the second mixture; S4. Heat the second mixture to 130-140℃. While stirring, add bamboo charcoal powder and maintain for 5-10 minutes. It will become a viscous substance, which is the polyvinyl chloride mortar modified with bamboo charcoal.

5. A type of polyvinyl chloride sealant modified with bamboo charcoal, used as a waterproof joint material, characterized in that... The polyvinyl chloride mortar modified with bamboo charcoal is prepared by the preparation method described in claim 4.

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