阅读说明：本技术 一种有机插层水滑石改性可发性聚苯乙烯珠粒的制备方法 (Preparation method of organic intercalated hydrotalcite modified expandable polystyrene beads ) 是由 刘本刚 刘明 于 2020-03-24 设计创作，主要内容包括：本发明提供一种有机插层水滑石改性可发性聚苯乙烯珠粒的制备方法。首先对水滑石进行有机插层改性；然后在苯乙烯、甲基丙烯酸脂类单体本体共聚时加入有机插层水滑石制备有机插层水滑石改性聚苯乙烯珠粒；后悬浮于水中将发泡剂浸渍到树脂内,制备有机插层水滑石改性可发性聚苯乙烯珠粒。通过离子交换法使插层单体进入到水滑石层间,一方面增大水滑石层间距有利于苯乙烯进入,另一方面在水滑石上引入活性基团参与到苯乙烯的聚合中,从而提高水滑石在树脂基体中的分散性能。利用水滑石的红外阻隔性能提高可发性聚苯乙烯的保温隔热性能。采用本方法制得的泡沫板材具有优异的保温隔热效果,广泛应用于建筑外墙、包装、冷库等领域。(The invention provides a preparation method of organic intercalated hydrotalcite modified expandable polystyrene beads. Firstly, carrying out organic intercalation modification on hydrotalcite; then adding organic intercalated hydrotalcite to prepare organic intercalated hydrotalcite modified polystyrene beads during the bulk copolymerization of styrene and methacrylate monomers; then suspending in water to impregnate the foaming agent into the resin to prepare the organic intercalated hydrotalcite modified expandable polystyrene beads. The intercalation monomer enters into the hydrotalcite layers by an ion exchange method, so that on one hand, the interlayer spacing of the hydrotalcite is increased to be beneficial to the entry of styrene, and on the other hand, active groups are introduced into the hydrotalcite to participate in the polymerization of the styrene, thereby improving the dispersion performance of the hydrotalcite in a resin matrix. The infrared blocking performance of the hydrotalcite is utilized to improve the heat preservation and heat insulation performance of the expandable polystyrene. The foam board prepared by the method has excellent heat preservation and insulation effects, and is widely applied to the fields of building external walls, packaging, refrigeration houses and the like.)

1. The preparation method of the organic intercalated hydrotalcite modified expandable polystyrene bead is characterized by comprising the following steps:

a) preparation of organic intercalated hydrotalcite

Adding hydrotalcite and absolute ethyl alcohol into a three-necked bottle, stirring for 0.5-2 hours at 40-70 ℃, adding sodium dodecyl sulfate and an intercalation monomer into deionized water, stirring until the sodium dodecyl sulfate and the intercalation monomer are uniformly dissolved, adding into the three-necked bottle, and adjusting the pH of the solution to be 3-5 by using dilute nitric acid. Stirring for 3-12 h at 40-75 ℃, cooling, standing for 12-24 h, filtering, washing with 50% ethanol solution for 1-2 times, washing with deionized water for 2-3 times, and drying at 20-30 ℃ to obtain organic intercalated hydrotalcite;

b) preparation of polystyrene beads

Adding the organic intercalated hydrotalcite prepared in the step a), styrene, methacrylate monomer, graphite and initiator into a reaction kettle, stirring and reacting for 3-12 hours at 110-148 ℃, and finally obtaining a conversion rate of 50-90%, removing unreacted monomer in vacuum, and preparing spherical particles in a molten state to obtain organic intercalated hydrotalcite modified polystyrene beads;

c) preparation of organic intercalated hydrotalcite modified expandable polystyrene bead

Adding the organic intercalated hydrotalcite modified polystyrene beads prepared in the step b), water and a dispersing agent into a reaction kettle, stirring for 0.5-1 h, adding a foaming agent, heating to 85-125 ℃ at the speed of 0.3-1 ℃/min, reacting for 4-16 h, ensuring that the pressure in the reaction kettle is not reduced, cooling to below 30 ℃, discharging, and carrying out centrifugal dehydration for post-treatment to prepare the organic intercalated hydrotalcite modified expandable polystyrene beads.

2. The method for preparing organic intercalated hydrotalcite modified expandable polystyrene beads according to claim 1, wherein the mass ratio of hydrotalcite, sodium dodecyl sulfate and intercalated monomer in step a) is 1: 3.5-11: 1.5 to 8.5.

3. The method for preparing organic intercalated hydrotalcite modified expandable polystyrene beads according to claim 1, wherein the intercalated monomer in step a) is one or more of sodium p-styrenesulfonate, sodium methallyl sulfonate and sodium vinyl sulfonate.

4. The method for preparing organic intercalated hydrotalcite modified expandable polystyrene beads according to claim 1, wherein the addition amount of the organic intercalated hydrotalcite, the methacrylate monomer, the initiator and the graphite in the step b) is as follows according to the mass percentage of styrene: organic intercalated hydrotalcite

0.5-10 wt%, 50-80 wt% of methacrylate monomer, 0.1-1 wt% of initiator, and graphite

0.3～6wt％。

5. The method for preparing organic intercalated hydrotalcite modified expandable polystyrene beads according to claim 4, wherein the methacrylate monomer is one of methyl methacrylate, ethyl methacrylate and butyl methacrylate, and the graphite particle size is 1-80 μm.

6. The method for preparing organic intercalated hydrotalcite modified expandable polystyrene beads according to claim 4, wherein the initiator is one of azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptonitrile, azobisbutyrylcarboxamide, azobisdicyclohexylcarbonitrile, dimethyl azobisisobutyrate, benzoyl peroxide tert-butyl ester and methyl ethyl ketone peroxide.

7. The process for preparing expandable polystyrene beads modified with organically intercalated hydrotalcite as claimed in claim 1, wherein the polymerization in step b) is thermally initiated without an initiator.

8. The method for preparing organic intercalated hydrotalcite modified expandable polystyrene beads according to claim 1, wherein the particle size of the organic intercalated hydrotalcite modified polystyrene beads in step b) is 0.1-6.0 mm, preferably 0.1-2.0 mm.

9. The method for preparing organic intercalated hydrotalcite modified expandable polystyrene beads according to claim 1, wherein the mass ratio of the organic intercalated hydrotalcite modified polystyrene beads, water, dispersant and foaming agent in step c) is 1: 0.5-2: 0.001-0.1: 0.01 to 0.2.

10. The process for preparing the expandable polystyrene beads modified with organically intercalated hydrotalcite as claimed in claim 9, wherein the blowing agent is an alkane having 4 to 5 carbon atoms, carbon dioxide or a mixture of both, preferably pentane.

Technical Field

The invention relates to a preparation method of organic intercalated hydrotalcite modified expandable polystyrene beads, and the prepared resin is used for producing polystyrene foam plates and has good heat insulation performance.

Background

The expandable polystyrene beads (EPS) are materials which are prepared by adding foaming agent into polystyrene resin and foaming the polystyrene resin to generate a plurality of sealed micropores, have the advantages of good thermal insulation performance, low relative density, shock resistance and the like, and are widely applied to industries such as buildings, packages, refrigeration houses and the like. With the deep promotion of national energy conservation and emission reduction, the EPS demand will gradually increase.

The heat conductivity coefficient of the EPS foam board is 0.038-0.052W/(m.K), and the EPS heat insulation performance is improved, so that people pay more and more attention to the EPS foam board. In order to reduce the thermal conductivity of EPS foam sheets, an infrared blocking agent, graphite, carbon black, metal oxide, metal powder or pigment, is generally added to the polystyrene resin matrix. The heat conductivity of EPS foam board is reduced by adding graphite into polystyrene in European patent EP0981574, and the heat conductivity of polystyrene foam is reduced by adding aluminum sheets in patent WO 00/043442. Most infrared blocking agents are inorganic materials, have poor compatibility with resin matrix, are easy to agglomerate in the production and processing process, and are not uniformly dispersed in the resin matrix, so that the use amount is increased, and the product performance is influenced. The infrared transmittance of the hydrotalcite is low, the loss of the radiant heat of the material can be effectively reduced in the resin matrix, and the heat insulation performance of the material is improved. The hydrotalcite has the characteristics of small particle, easy water absorption and agglomeration, so that the hydrotalcite has poor dispersibility in polystyrene resin, and the mechanical property of the material is reduced due to direct and large-amount filling, thereby having adverse effect on the appearance of the product.

The existing EPS bead production method comprisesThe float polymerization process, for example, patent CN99813364.7 and the melt blending extrusion process, for example, patent CN 03821004.5. The suspension polymerization method has high requirements on water quality, suspension media are difficult to recycle in the production process, a large amount of waste water is generated, and the environment protection is not facilitated. Melt-blending extrusion processes, such as that of patent CN03821004.5, are processes in which polystyrene is extruded with the addition of a blowing agent, and the resulting foamed particles are foamed by cutting a polymer melt containing the blowing agent at reduced pressure downstream of a nozzle. The foam particles prepared by the method have higher transportation cost and the bulk density of 15-25 kg/m³It is difficult to prepare lower density foams.

Disclosure of Invention

The invention provides a preparation method of organic intercalated hydrotalcite modified expandable polystyrene beads. Firstly, carrying out organic intercalation modification on hydrotalcite, then adding the organic intercalation hydrotalcite into styrene and methacrylate monomer bulk polymerization to prepare organic intercalation modified polystyrene beads, and then suspending the organic intercalation hydrotalcite and the methacrylate monomer bulk polymerization in water to prepare the organic intercalation modified polystyrene beads through soaking by a foaming agent, wherein the organic intercalation modified polystyrene beads are used for producing EPS foam materials.

The technical means adopted by the invention is the following preparation method of the organic intercalated hydrotalcite modified expandable polystyrene bead, which is characterized by comprising the following steps:

a) preparation of organic intercalated hydrotalcite

Adding hydrotalcite and absolute ethyl alcohol into a three-necked bottle, and stirring for 0.5-2 hours at 40-70 ℃. Adding sodium dodecyl sulfate and an intercalation monomer into deionized water, stirring until the sodium dodecyl sulfate and the intercalation monomer are dissolved uniformly, adding into a three-necked bottle, and adjusting the pH of the solution to be between 3 and 5 by using dilute nitric acid. Stirring for 3-12 h at 40-75 ℃, cooling, and standing for 12-24 h. And (3) filtering, washing for 1-2 times by using a 50% ethanol solution, washing for 2-3 times by using deionized water, and drying at 20-30 ℃ to obtain the organic intercalated hydrotalcite.

b) Preparation of polystyrene beads

Adding the organic intercalated hydrotalcite prepared in the step a), styrene, methacrylate monomer, graphite and initiator into a reaction kettle, stirring and reacting for 3-12 hours at 110-148 ℃, and finally obtaining a conversion rate of 50-90%, removing unreacted monomer in vacuum, and preparing spherical particles in a molten state to obtain the organic intercalated hydrotalcite modified polystyrene beads.

c) Preparation of organic intercalated hydrotalcite modified expandable polystyrene bead

Adding the organic intercalated hydrotalcite modified polystyrene beads prepared in the step b), water and a dispersing agent into a reaction kettle, stirring for 0.5-1 h, adding a foaming agent, heating to 85-125 ℃ at the speed of 0.3-1 ℃/min, and reacting for 4-16 h, wherein the pressure in the reaction kettle is not reduced in the process. Cooling to below 30 deg.C, discharging, and performing centrifugal dehydration for post-treatment. The organic intercalated hydrotalcite modified expandable polystyrene beads are prepared.

The mass ratio of the hydrotalcite, the sodium dodecyl sulfate and the intercalation monomer in the step a) is 1: 3.5-11: 1.5 to 8.5.

The interlayer monomer in the step a) is one or a combination of sodium p-styrene sulfonate, sodium methyl propylene sulfonate and sodium vinyl sulfonate.

The mass percentages of the addition amounts of the organic intercalated hydrotalcite, the methacrylate monomer, the initiator and the graphite relative to the styrene in the step b) are as follows: 0.5-10 wt% of organic intercalated hydrotalcite, 50-80 wt% of methacrylate monomer, 0.1-1 wt% of initiator and 0.3-6 wt% of graphite.

The methacrylate monomer is one of methyl methacrylate, ethyl methacrylate and butyl methacrylate. Wherein the particle size of the graphite is 1-80 μm.

The initiator is one of azodiisobutyronitrile, azodiisovaleronitrile, azodiisoheptanonitrile, azobutanenitrile formamide, azodicyclohexyl carbonitrile, dimethyl azodiisobutyrate, benzoyl peroxide tert-butyl ester and methyl ethyl ketone peroxide.

The polymerization in said step b) may be a thermally initiated polymerization without an initiator.

The particle size of the organic intercalated hydrotalcite modified polystyrene beads in the step b) is 0.1-6.0 mm. Preferably 0.1 to 2.0mm

The mass ratio of the organic intercalated hydrotalcite modified polystyrene beads, water, the dispersing agent and the foaming agent in the step c) is 1: 0.5-2: 0.001-0.1: 0.01 to 0.2.

The foaming agent is alkane containing 4-5 carbon atoms, carbon dioxide or a mixture of the alkane and the carbon dioxide. Pentane is preferred.

Compared with the prior art, the invention has the following beneficial effects:

1. the organic intercalation modification is carried out on the hydrotalcite, so that the compatibility of the hydrotalcite and a resin matrix is improved, the dispersion performance of the hydrotalcite in the resin matrix is improved, and a good heat preservation effect is achieved by utilizing the infrared barrier performance of the hydrotalcite under the condition of low addition amount.

2. The suspension medium can be repeatedly used for a plurality of times, does not produce waste water, reduces the production cost and is beneficial to environmental protection.

3. And direct granulation is carried out after polymerization, so that the defects of resin molecular weight reduction and product mechanical property reduction caused by secondary processing are avoided.

Detailed Description

Example 1

(1) Adding hydrotalcite 20g and anhydrous ethanol 200ml into a three-neck bottle, and stirring at 40 ℃ for 0.5 h. 70g of sodium dodecyl sulfate and 30g of sodium p-styrene sulfonate are added into 500ml of deionized water, stirred until the sodium dodecyl sulfate and the sodium p-styrene sulfonate are dissolved uniformly, added into a three-necked bottle, and the pH value of the solution is adjusted to 3 by using dilute nitric acid. Stirring at 40 deg.C for 5 hr, cooling, and standing for 12 hr. And (3) filtering, washing for 2 times by using a 50% ethanol solution, washing for 2 times by using deionized water, and drying at 20 ℃ to obtain the organic intercalated hydrotalcite.

(2) Adding 15g of organic intercalated hydrotalcite prepared in the step 1), 1kg of styrene, 550g of methyl methacrylate, 30g of graphite and 5g of azobisisobutyronitrile into a reaction kettle, stirring and reacting for 3 hours at 110 ℃, and finally obtaining the conversion rate of 56%, removing unreacted monomers in vacuum, and preparing spherical particles in a molten state to obtain the organic intercalated hydrotalcite modified polystyrene beads.

(3) Adding 500g of organic intercalated hydrotalcite modified polystyrene beads with the particle size of 1.0-2.0 mm, 500g of water and 5g of dispersing agent, which are prepared in the step 2), into a reaction kettle, stirring for 0.5h, adding 50g of pentane, heating to 85 ℃ at the speed of 0.3-1 ℃/min, and reacting for 6h, wherein the pressure in the reaction kettle is not reduced in the period. Cooling to below 30 deg.C, discharging, and performing centrifugal dehydration for post-treatment. Preparing the expandable organic intercalated hydrotalcite modified expandable polystyrene beads.

Foaming with a batch-type foaming agent at 95 deg.C with steam set at 2.5kg/m³The steam pressure is 3.5kg/m by adopting a plate forming machine³. Through GB/T10294-2008 test, the EPS foam material prepared by the method has the heat conductivity coefficient of 0.038W/(m.K).

Example 2

(1) Adding 100g of hydrotalcite and 1L of absolute ethyl alcohol into a three-necked bottle, and stirring for 1h at 50 ℃. 500g of sodium dodecyl sulfate and 450g of methacrylic sulfonic acid are added into 2L of deionized water, stirred until the sodium dodecyl sulfate and the methacrylic sulfonic acid are dissolved uniformly, added into a three-necked bottle, and the pH value of the solution is adjusted to 4 by using dilute nitric acid. Stirring at 50 deg.C for 6 hr, cooling, and standing for 12 hr. And (3) filtering, washing for 2 times by using a 50% ethanol solution, washing for 2 times by using deionized water, and drying at 25 ℃ to obtain the organic intercalated hydrotalcite.

(2) Adding 120g of organic intercalated hydrotalcite prepared in the step 1), 5kg of styrene, 3kg of methyl methacrylate, 150g of graphite and 5g of benzoyl peroxide into a reaction kettle, stirring and reacting at 130 ℃ for 6 hours until the final conversion rate is 70%, removing unreacted monomers in vacuum, and preparing spherical particles in a molten state to obtain the organic intercalated hydrotalcite modified polystyrene beads.

(3) Adding 5kg of organic intercalated hydrotalcite modified polystyrene beads with the particle size of 1.0-3.0 mm, 7kg of water and 100g of dispersing agent, which are prepared in the step 2), into a reaction kettle, stirring for 0.5h, adding 400g of pentane, heating to 85 ℃ at the speed of 0.3-1 ℃/min, and reacting for 7h, wherein the pressure in the reaction kettle is not reduced in the process. Cooling to below 30 deg.C, discharging, and performing centrifugal dehydration for post-treatment. Preparing the expandable organic intercalated hydrotalcite modified expandable polystyrene beads.

The EPS foam material prepared by the method has the thermal conductivity coefficient of 0.036W/(m.K) through GB/T10294-.

Example 3

(1) 200g of hydrotalcite and 1L of absolute ethyl alcohol are added into a three-necked bottle and stirred for 1h at 50 ℃. 2kg of sodium dodecyl sulfate and 300g of methacrylic sulfonic acid are added into 3L of deionized water, stirred until the sodium dodecyl sulfate and the methacrylic sulfonic acid are dissolved uniformly, added into a three-necked bottle, and the pH value of the solution is adjusted to 4 by using dilute nitric acid. Stirring at 50 deg.C for 10 hr, cooling, and standing for 24 hr. And (3) filtering, washing for 2 times by using a 50% ethanol solution, washing for 2 times by using deionized water, and drying at 30 ℃ to obtain the organic intercalated hydrotalcite.

(2) Adding 500g of organic intercalated hydrotalcite prepared in the step 1), 10kg of styrene, 5kg of ethyl methacrylate, 100g of graphite and 15g of benzoyl peroxide into a reaction kettle, stirring and reacting at 130 ℃ for 8 hours until the final conversion rate is 80%, removing unreacted monomers in vacuum, and preparing spherical particles in a molten state to obtain the organic intercalated hydrotalcite modified polystyrene beads.

(3) Adding 15kg of organic intercalated hydrotalcite modified polystyrene beads with the particle size of 0.1-2.0 mm, 20kg of water and 1kg of dispersing agent, which are prepared in the step 2), into a reaction kettle, stirring for 0.5h, adding 1.5kg of pentane, heating to 85 ℃ at the speed of 0.3-1 ℃/min, and reacting for 8h, wherein the pressure in the reaction kettle is not reduced in the period. Cooling to below 30 deg.C, discharging, and performing centrifugal dehydration for post-treatment. Preparing the expandable organic intercalated hydrotalcite modified expandable polystyrene beads.

The foaming mode is the same as that of example 1, and the EPS foam material prepared by the method has a thermal conductivity coefficient of 0.033W/(m.K) through GB/T10294-.

Example 4

(1) Same as example 3, step 1.

(2) Adding 560g of the organic intercalated hydrotalcite prepared in the step 1), 7kg of styrene, 5kg of methyl methacrylate and 100g of graphite into a reaction kettle, adopting thermal initiation polymerization, stirring and reacting for 10 hours at 147 ℃ until the final conversion rate is 90%, removing unreacted monomers in vacuum, and preparing into spherical particles in a molten state to obtain the organic intercalated hydrotalcite modified polystyrene beads.

(3) Adding 10kg of organic intercalated hydrotalcite modified polystyrene beads with the particle size of 0.1-2.0 mm, 7kg of water and 300g of dispersing agent, which are prepared in the step 2), into a reaction kettle, stirring for 1 hour, adding 1kg of pentane, heating to 90 ℃ at the speed of 0.3-1 ℃/min, and reacting for 8 hours, wherein the pressure in the reaction kettle is not reduced in the process. Cooling to below 30 deg.C, discharging, and performing centrifugal dehydration for post-treatment. Preparing the expandable organic intercalated hydrotalcite modified expandable polystyrene beads.

The EPS foam material prepared by the method has the thermal conductivity coefficient of 0.032W/(m.K) through GB/T10294-.

Example 5

(1) Same as example 3, step 1.

(2) Adding 500g of the organic intercalated hydrotalcite prepared in the step 1), 5kg of styrene, 2.5kg of methyl methacrylate and 100g of graphite into a reaction kettle, adopting thermal initiation polymerization, stirring and reacting for 10 hours at 147 ℃ until the final conversion rate is 95%, removing unreacted monomers in vacuum, and preparing spherical particles in a molten state to obtain the organic intercalated hydrotalcite modified polystyrene beads.

(3) Adding 6kg of organic intercalated hydrotalcite modified polystyrene beads with the particle size of 0.1-2.0 mm, 9kg of water and 100g of dispersing agent, which are prepared in the step 2), into a reaction kettle, stirring for 1 hour, adding 600g of pentane, heating to 95 ℃ at the speed of 0.3-1 ℃/min, and reacting for 8 hours, wherein the pressure in the reaction kettle is not reduced in the process. Cooling to below 30 deg.C, discharging, and performing centrifugal dehydration for post-treatment. Preparing the expandable organic intercalated hydrotalcite modified expandable polystyrene beads.

The EPS foam material prepared by the method has the thermal conductivity coefficient of 0.031W/(m.K) as tested by GB/T10294-.