High-molecular epoxy polymerized silicate foam as well as preparation process and application thereof

Abstract

The invention relates to high-molecular epoxy polysilicate foam as well as a preparation process and application thereof, and the foam comprises the following components in parts by weight: 60-80 parts of epoxy resin; 70 to 100 parts of a curing agent; 2-5 parts of a foaming agent; 1-3 parts of a stabilizer; 1-3 parts of a sensitizing agent; 2-5 parts of a filler; 1-3 parts of a toughening agent; 10 to 15 parts of polymeric silicate; and 5-10 parts of thermoplastic expanded microspheres. According to the composite foam disclosed by the invention, dry ice is added in the preparation process, so that the porous composite foam with larger gaps can be prepared, and the weight of the foam in unit volume can be reduced.

Description

Technical Field

[0001] The invention relates to the field of polymer technology, and in particular to a polymer epoxy polymerized silicate foam and a preparation process and application thereof. Background Art

[0002] Polymer foam materials use general-purpose plastics as the base resin. With the advancement of technology, especially in the fields of national defense, military industry, aerospace, etc., the performance requirements for such materials have increased, such as high temperature resistance, radiation resistance, corrosion resistance and high mechanical strength, etc. Traditional polymer foams can no longer meet these requirements. Compared with metal materials, polymer materials have the advantages of light weight, simple production process, high design freedom, acid and alkali corrosion resistance and good impact resistance.

[0003] Lightweighting of polymer foam materials is one of the key research directions in the field of materials science. However, current technologies focus more on improving the flame retardancy and flexibility of materials, and there is relatively little research on lightweight properties. For example, Chinese patent CN105601856B studies a method for preparing an isocyanate-modified phenolic resin foam. The invention prepares a phenolic foam plastic with high fire resistance, high toughness and high stability to replace traditional polyurethane foam plastics and phenolic resin-modified polyurethane foam plastics, and solves the problem of flammable carbamates in the molecular structure of polyurethane foam plastics. In the present application, dry ice or carbon dioxide gas is used as an additional foaming gas, and at the same time, a silicate polymer is polymerized to form a high molecular weight epoxy polymerized silicate foam (PEMS, POLYMER EPOXY METASILICATE STRUCTURE FOAM) to further increase the structural strength and flame retardancy of the foam material, and to prepare a foam material with a larger gap. Summary of the invention

[0004] In order to solve the above technical problems, the object of the present invention is to provide a composite foam with smaller unit volume weight and higher strength.

[0005] The technical solution of the present invention is as follows:

[0006] A high molecular weight epoxy polymerized silicate foam comprises the following components in parts by weight:

[0007] Epoxy resin, 60-80 parts;

[0008] Curing agent, 70-100 parts;

[0009] Foaming agent, 2-5 parts;

[0010] Stabilizer, 1-3 parts;

[0011] Sensitizer, 1-3 parts;

[0012] Filler, 2-5 parts;

[0013] Toughener, 1-3 parts;

[0014] Polysilicate 10-15 parts

[0015] Thermoplastic expanded microspheres, 5-10 parts.

[0016] Furthermore, the epoxy resin is a phenolic resin, the curing agent is an isocyanate, and the polysilicate is polyaluminum iron silicate.

[0017] Furthermore, the foaming agent is one or more of N-nitroguanidine, silicone oil, and diethyl azodicarboxylate.

[0018] Furthermore, the stabilizer is one or both of hydroxyethyl cellulose and polyvinyl alcohol.

[0019] Furthermore, the sensitizer is one or both of divinylbenzene and polyvinyl methyl ether.

[0020] Furthermore, the filler is one or both of calcium carbonate and silicon oxide.

[0021] Furthermore, the toughening agent is polyethylene glycol.

[0022] A method for preparing a polymer composite foam, characterized in that the preparation method comprises the following steps:

[0023] S1. Add epoxy resin, stabilizer, sensitizer and filler into a stirring container D, and stir the mixture at a high speed of 800 to 1000 rpm for 5 to 20 minutes to obtain component A.

[0024] S2, adding the curing agent, foaming agent, toughening agent and polysilicate into the stirring container F, stirring and mixing with a high-speed stirrer at 800-1000 rpm for 5-20 minutes to obtain component B;

[0025] S3, placing dry ice in the circular groove (21) of the frame-shaped lower mold (2) with an opening, adding component A and component B as well as thermoplastic expanded microspheres into the lower mold (2), and covering with the upper mold (1);

[0026] S4, start the heater (3) connected to the lower circular groove (21) of the lower mold (2), so that the heater (3) heats at 65-80°C for 10-15 minutes and at 85-95°C for 30-60 minutes.

[0027] Furthermore, the upper mold (1) is connected to the heater (3) via an air pipe (4), and the air pipe (4) is also provided with an air branch pipe (41), and the air branch pipe (41) is connected to the side of the lower mold (2).

[0028] Furthermore, a connection port (22) communicating with the circular groove (21) is provided at the lower portion of the lower mold (2), and the connection port (22) is connected to the heater (3) via a vent pipe (23).

[0029] By means of the above scheme, the present invention has at least the following advantages:

[0030] The present invention adds thermoplastic expansion microspheres to specific components of the polymer composite foam. The volume of the thermoplastic expansion microspheres expands by 10-30 times after heating, and the expansion multiples vary according to the specific heating temperature. The volume of the thermoplastic expansion microspheres expands after the foaming process, thereby further reducing the density of the overall composite foam.

[0031] The present invention adds polysilicate to the specific components of the polymer composite foam, and the epoxy resin and the curing agent react to generate a high molecular linear structure polymer, which then reacts with the polysilicate through a crosslinking agent to form a body structure. Due to the crosslinking characteristics, the running wood has certain strength and impact resistance.

[0032] Another key point of the present invention is the use of dry ice in the preparation process. During the heating process, the dry ice can not only absorb the heat of the internal reaction to reduce the temperature, but also, during the entire heating process, the dry ice can circulate the sublimated carbon dioxide due to the high temperature input by the heater, and then can play an expansion role in the foaming process, thereby forming larger gaps and pores.

[0033] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the structure of the foaming device used in the present invention;

[0035] In the figure:

[0036] 1-upper mold; 2-lower mold; 21-circular groove; 22-connecting port; 23-ventilation pipe; 3-heater; 4-gas supply pipe; 41-gas supply branch pipe. DETAILED DESCRIPTION

[0037] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0038] See also Figure 1, is a foaming device used in the preparation process of the present invention, the device includes a lower mold 2, the lower mold 2 is a frame structure with an opening, and circular grooves 21 are arranged in an array on the bottom surface of the lower mold 2, specifically, the circular grooves 21 are arranged in three rows, and the number of each row is 11. A connecting port 22 connected to the circular grooves 21 is arranged at the bottom of the lower mold 2, and a vent pipe 23 is arranged at the lower part of the connecting port 22. The diameter of the vent pipe 23 is smaller than the size of the connecting port 22, which is to reduce the pressure of the gas after entering the connecting port 22 from the vent pipe 23.

[0039] The ventilation pipes 23 are all connected to the heater 3, which is a conventional heater capable of heating gas, and the heating temperature and time can be set.

[0040] The lower mold 2 is correspondingly provided with an upper mold 1, and the upper mold 1 is used to cover the lower mold 2 tightly. One end of the air pipe 4 is also connected to the upper mold 1, and the other end of the air pipe 4 is connected to the heater 3. The air pipe 4 is also provided with a air branch pipe 41, and the air branch pipe 41 is connected to the side of the lower mold 2.

[0041] In the foaming device, the gas is heated by the heater 3, so that the gas can circulate in the mold formed by the heater 3, the lower mold 2 and the upper mold 1, and the gas pipe 4, thereby achieving heating.

[0042] The polymer epoxy polymer silicate foam of the present invention comprises the following components in parts by weight:

[0043] The epoxy resin is phenolic resin, and the specific weight proportion can be 60-80 parts.

[0044] The curing agent is isocyanate, and the specific weight portion can be 70-100 parts;

[0045] The foaming agent is one or more of N-nitroguanidine, silicone oil, and diethyl azodicarboxylate, and the specific weight proportion can be 2-5 parts;

[0046] The stabilizer is one or both of hydroxyethyl cellulose and polyvinyl alcohol, and the specific weight proportion can be 1-3 parts;

[0047] The sensitizer is one or both of divinylbenzene and polyvinyl methyl ether, and the specific weight proportion can be 1-3 parts;

[0048] The filler is one or both of calcium carbonate and silicon oxide, and the specific weight proportion can be 2-5 parts;

[0049] The toughening agent polyethylene glycol is used, and the specific weight portion can be 1-3 parts;

[0050] The polysilicate is polyaluminium iron silicate, and the specific weight proportion may be 10-15 parts;

[0051] Thermoplastic expandable microspheres may be present in an amount of 5 to 10 parts by weight.

[0052] The thermoplastic expandable microspheres used in the present invention are composed of a thermoplastic polymer shell and sealed alkane gas, with a specific diameter range of 10 to 50 μm. When heated to below 180° C., the volume can be expanded by 10 to 30 times.

[0053] The specific preparation examples of the present invention are:

[0054] Example 1

[0055] Add 60 parts of phenolic resin, 1 part of hydroxyethyl cellulose, 1 part of divinyl benzene and 2 parts of calcium carbonate into a stirring container D, and stir the mixture at a high speed of 800 to 1000 rpm for 5 to 20 minutes to obtain component A;

[0056] Add 100 parts of isocyanate, 1 part of N-nitroguanidine, 1 part of polyethylene glycol, and 10 parts of polyaluminum ferrosilicate into a stirring container F, and stir the mixture at a high speed of 800 to 1000 rpm for 5 to 20 minutes to obtain component B;

[0057] Put dry ice in the circular groove 21 of the frame-shaped lower mold 2 with an opening, add component A and component B and thermoplastic expanded microspheres into the lower mold 2, and cover with the upper mold 1;

[0058] The heater 3 connected to the circular groove 21 at the lower part of the lower mold 2 is started, so that the heater 3 heats at 65-80° C. for 10-15 minutes and at 85-95° C. for 30-60 minutes.

[0059] Example 2

[0060] Add 65 parts of phenolic resin, 2 parts of polyvinyl alcohol, 1 part of polyvinyl methyl ether and 2 parts of silicon oxide into a stirring container D, and stir the mixture at a high speed of 800 to 1000 rpm for 5 to 20 minutes to obtain component A;

[0061] Add 90 parts of isocyanate, 3 parts of diethyl azodicarboxylate, 2 parts of polyethylene glycol, and 12 parts of polyaluminium ferrosilicate into a stirring container F, and stir with a high-speed stirrer at 800 to 1000 rpm for 5 to 20 minutes to obtain component B;

[0062] Put dry ice in the circular groove 21 of the frame-shaped lower mold 2 with an opening, add component A and component B and thermoplastic expanded microspheres into the lower mold 2, and cover with the upper mold 1;

[0063] The heater 3 connected to the circular groove 21 at the lower part of the lower mold 2 is started, so that the heater 3 heats at 65-80° C. for 10-15 minutes and at 85-95° C. for 30-60 minutes.

[0064] Example 3

[0065] 70 parts of phenolic resin, 1 part of polyvinyl alcohol and 1 part of hydroxyethyl cellulose, 1 part of divinyl benzene and 1 part of polyvinyl methyl ether, 2 parts of calcium carbonate and 3 parts of silicon oxide are added into a stirring container D, and mixed by high-speed stirring at 800-1000 rpm for 5-20 minutes to obtain component A;

[0066] Add 85 parts of isocyanate, 2 parts of N-nitroguanidine, 1 part of silicone oil, 2 parts of diethyl azodicarboxylate, 3 parts of polyethylene glycol, and 13 parts of polyaluminum ferrosilicate into a stirring container F, and stir the mixture at a high speed of 800 to 1000 rpm for 5 to 20 minutes to obtain component B;

[0067] Put dry ice in the circular groove 21 of the frame-shaped lower mold 2 with an opening, add component A and component B and thermoplastic expanded microspheres into the lower mold 2, and cover with the upper mold 1;

[0068] The heater 3 connected to the circular groove 21 at the lower part of the lower mold 2 is started, so that the heater 3 heats at 65-80° C. for 10-15 minutes and at 85-95° C. for 30-60 minutes.

[0069] Example 4

[0070] 75 parts of phenolic resin, 2 parts of hydroxyethyl cellulose, 3 parts of divinyl benzene and 5 parts of calcium carbonate are added into a stirring container D, and mixed by a high-speed stirrer at 800 to 1000 rpm for 5 to 20 minutes to obtain component A;

[0071] Add 80 parts of isocyanate, 5 parts of diethyl azodicarboxylate, 3 parts of polyethylene glycol, and 14 parts of polyaluminium ferrosilicate into a stirring container F, and stir with a high-speed stirrer at 800 to 1000 rpm for 5 to 20 minutes to obtain component B;

[0072] Put dry ice in the circular groove 21 of the frame-shaped lower mold 2 with an opening, add component A and component B and thermoplastic expanded microspheres into the lower mold 2, and cover with the upper mold 1;

[0073] The heater 3 connected to the circular groove 21 at the lower part of the lower mold 2 is started, so that the heater 3 heats at 65-80° C. for 10-15 minutes and at 85-95° C. for 30-60 minutes.

[0074] Example 5

[0075] Add 80 parts of phenolic resin, 3 parts of polyvinyl alcohol, 3 parts of polyvinyl methyl ether and 5 parts of silicon oxide into a stirring container D, and stir the mixture at a high speed of 800 to 1000 rpm for 5 to 20 minutes to obtain component A;

[0076] Add 70 parts of isocyanate, foaming agent, 5 parts of polyethylene glycol, and 15 parts of polyaluminum ferrosilicate into a stirring container F, and stir with a high-speed stirrer at 800 to 1000 rpm for 5 to 20 minutes to obtain component B;

[0077] Put dry ice in the circular groove 21 of the frame-shaped lower mold 2 with an opening, add component A and component B and thermoplastic expanded microspheres into the lower mold 2, and cover with the upper mold 1;

[0078] The heater 3 connected to the circular groove 21 at the lower part of the lower mold 2 is started, so that the heater 3 heats at 65-80° C. for 10-15 minutes and at 85-95° C. for 30-60 minutes.

[0079] Comparative Example 1

[0080] Add 60 parts of phenolic resin, 1 part of hydroxyethyl cellulose, 1 part of divinyl benzene and 2 parts of calcium carbonate into a stirring container D, and stir the mixture at a high speed of 800 to 1000 rpm for 5 to 20 minutes to obtain component A;

[0081] Add 100 parts of isocyanate, 1 part of N-nitroguanidine and 1 part of polyethylene glycol into a stirring container F, and stir the mixture at a high speed of 800 to 1000 rpm for 5 to 20 minutes to obtain component B;

[0082] Put dry ice in the circular groove 21 of the frame-shaped lower mold 2 with an opening, add component A and component B into the lower mold 2, and cover it with the upper mold 1;

[0083] The heater 3 connected to the circular groove 21 at the lower part of the lower mold 2 is started, so that the heater 3 heats at 65-80° C. for 10-15 minutes and at 85-95° C. for 30-60 minutes.

[0084] The difference between the comparative example and Example 1 is that no thermoplastic expanded microspheres and polyaluminium ferrosilicate are added.

[0085] Comparative Example 2

[0086] Add 60 parts of phenolic resin, 1 part of hydroxyethyl cellulose, 1 part of divinyl benzene and 2 parts of calcium carbonate into a stirring container D, and stir the mixture at a high speed of 800 to 1000 rpm for 5 to 20 minutes to obtain component A;

[0087] Add 100 parts of isocyanate, 1 part of N-nitroguanidine, 1 part of polyethylene glycol, and 12 parts of polyaluminum ferrosilicate into a stirring container F, and stir the mixture with a high-speed stirrer at 800 to 1000 rpm for 5 to 20 minutes to obtain component B;

[0088] Add component A, component B and thermoplastic expanded microspheres into the lower mold 2, and cover with the upper mold 1;

[0089] The heater 3 connected to the circular groove 21 at the lower part of the lower mold 2 is started, so that the heater 3 heats at 65-80° C. for 10-15 minutes and at 85-95° C. for 30-60 minutes.

[0090] The difference between the comparative example and Example 1 is that no dry ice was used.

[0091] Preparation performance testing method of the present invention:

[0092] The apparent density of the foam is tested according to ISO 845, and the sample size is 100×100×50mm 3 .

[0093] The compressive strength of the foam was tested according to ASTM 1621B, and the sample size was 100×100×50mm 3 .

[0094] Tensile strength of foam ASTM C297 test, sample size is 100×100×50mm 3 .

[0095] Shear strength of foam ASTM C 273 test, sample size is 100×100×50mm 3 .

[0096] Thermal conductivity of foam ASTM D5470 test, sample size is 100×100×50mm 3 .

[0097] Water absorption of foam ISO2986 test, sample size is 100×100×50mm 3 .

[0098] After testing, the main properties of the foams obtained in Examples 1-5 and Comparative Examples 1-2 are shown in the following table.

[0099]

[0100] From the above test structure, it can be seen that compared with Comparative Examples 1 and 2, when the compressive strength, tensile strength, shear strength, thermal conductivity and water absorption properties of Examples 1-5 are similar, the apparent density of Examples 1-5 is significantly lower than that of Comparative Examples 1 and 2.

[0101] The advantages and working principles of the present invention are as follows:

[0102] The present invention adds thermoplastic expansion microspheres to specific components of the polymer composite foam. The volume of the thermoplastic expansion microspheres expands by 10-30 times after heating, and the expansion multiples vary according to the specific heating temperature. The volume of the thermoplastic expansion microspheres expands after the foaming process, thereby further reducing the density of the overall composite foam.

[0103] The present invention adds polysilicate to the specific components of the polymer composite foam, and the epoxy resin and the curing agent react to generate a high molecular linear structure polymer, which then reacts with the polysilicate through a crosslinking agent to form a body structure. Due to the crosslinking characteristics, the running wood has certain strength and impact resistance.

[0104] Another key point of the present invention is the use of dry ice in the preparation process. During the heating process, the dry ice can not only absorb the heat of the internal reaction to reduce the temperature, but also, during the entire heating process, the dry ice can circulate the sublimated carbon dioxide due to the high temperature input by the heater, and then can play an expansion role in the foaming process, thereby forming larger gaps and pores.

[0105] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A polymer epoxy polysilicate foam, characterized in that: The invention comprises the following components in parts by weight: Epoxy resin, 60-80 parts; Curing agent, 70-100 parts; Foaming agent, 2-5 parts; Stabilizer, 1-3 parts; Sensitizer, 1-3 parts; Filler, 2-5 parts; Toughener, 1-3 parts; Polysilicate 10-15 parts; Thermoplastic expanded microspheres, 5-10 parts.

2. The polymer epoxy polysilicate foam according to claim 1, characterized in that: The epoxy resin is a phenolic resin, the curing agent is an isocyanate, and the polysilicate is polyaluminum iron silicate.

3. The polymer epoxy polysilicate foam according to claim 1, characterized in that: The foaming agent is one or more of N-nitroguanidine, silicone oil and diethyl azodicarboxylate.

4. The polymer epoxy polysilicate foam according to claim 1, characterized in that: The stabilizer is one or both of hydroxyethyl cellulose and polyvinyl alcohol.

5. The polymer epoxy polysilicate foam according to claim 1, characterized in that: The sensitizer is one or both of divinylbenzene and polyvinyl methyl ether.

6. The high molecular weight epoxy polysilicate foam according to claim 1, characterized in that: The filler is one or both of calcium carbonate and silicon oxide.

7. The polymer epoxy polysilicate foam according to claim 1, characterized in that: The toughening agent is polyethylene glycol.

8. A method for preparing a polymer epoxy polysilicate foam according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: S1. Add epoxy resin, stabilizer, sensitizer and filler into a stirring container D, and stir the mixture at a high speed of 800 to 1000 rpm for 5 to 20 minutes to obtain component A. S2, adding the curing agent, foaming agent, toughening agent and polysilicate into the stirring container F, stirring and mixing with a high-speed stirrer at 800-1000 rpm for 5-20 minutes to obtain component B; S3, placing dry ice in the circular groove (21) of the frame-shaped lower mold (2) with an opening, adding component A and component B as well as thermoplastic expanded microspheres into the lower mold (2), and covering with the upper mold (1); S4, start the heater (3) connected to the lower circular groove (21) of the lower mold (2), so that the heater (3) heats at 65-80°C for 10-15 minutes and at 85-95°C for 30-60 minutes.

9. The high molecular weight epoxy polymerized silicate foam according to claim 8, characterized in that: The upper mold (1) is also connected to the heater (3) via an air supply pipe (4), and the air supply pipe (4) is also provided with an air supply branch pipe (41), and the air supply branch pipe (41) is connected to the side of the lower mold (2).

10. The high molecular weight epoxy polymerized silicate foam according to claim 8, characterized in that: The lower part of the lower mold (2) is provided with a connection port (22) communicating with the circular groove (21), and the connection port (22) is connected to the heater (3) via a vent pipe (23).

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