阅读说明：本技术 一种酚醛树脂发泡材料及其成型方法 (Phenolic resin foam material and forming method thereof ) 是由 廖华勇 张瑞铭 董然 王洪 王浩龙 陶国良 刘春林 于 2021-07-07 设计创作，主要内容包括：一种酚醛树脂发泡材料及其成型方法,属于发泡材料技术领域。所述酚醛树脂发泡材料的原料按质量份数配比如下：44.4～56.8份热固性酚醛树脂、37.9～45份POE、1～6份发泡剂、0.2～0.4份交联剂、1～10份填料、0.3～0.6份抗氧剂。本发明制备的酚醛树脂发泡材料泡孔均匀、密度小,该发泡材料具有良好的弹性和综合性能,可用于包装、汽车、热绝缘、建筑、缓冲衬垫、吸声降噪等领域。(A phenolic resin foaming material and a forming method thereof belong to the technical field of foaming materials. The phenolic resin foam material comprises the following raw materials in parts by weight: 44.4-56.8 parts of thermosetting phenolic resin, 37.9-45 parts of POE, 1-6 parts of foaming agent, 0.2-0.4 part of cross-linking agent, 1-10 parts of filler and 0.3-0.6 part of antioxidant. The phenolic resin foaming material prepared by the invention has uniform foam holes and small density, has good elasticity and comprehensive performance, and can be used in the fields of packaging, automobiles, thermal insulation, buildings, buffering liners, sound absorption and noise reduction and the like.)

1. The phenolic resin foam material is characterized by comprising the following raw materials in parts by mass: 44.4-56.8 parts of thermosetting phenolic resin, 37.9-45 parts of POE, 1-6 parts of foaming agent, 0.2-0.4 part of cross-linking agent, 1-10 parts of filler and 0.3-0.6 part of antioxidant.

2. The phenolic resin foam material of claim 1, wherein the cross-linking agent is dicumyl peroxide.

3. The phenolic resin foam material as claimed in claim 1, wherein the filler is at least one of mica powder, quartz powder and kaolin, and the particle size of the filler is 600-1250 mesh.

4. The phenolic resin foam material as claimed in claim 1, wherein the foaming agent is a microsphere foaming agent.

5. The phenolic resin foam material as claimed in claim 1, wherein the antioxidant is antioxidant 1010.

6. The phenolic resin foam material as claimed in claim 1, wherein the filler is surface-treated with 1 wt.% of coupling agent KH550, and the treatment method comprises the following steps: weighing the filling material, pouring alcohol into a beaker, wherein the ratio of the alcohol to the filling material is 1: 1, adding 1 percent of silane coupling agent KH550 into alcohol, immersing the KH550 alcohol solution in a beaker into the filling material, uniformly stirring, putting the mixture into an oven for 1 hour, volatilizing the alcohol, and leaving the treated filling material.

7. The forming method of the phenolic resin foaming material based on claim 1 is characterized by comprising the following steps:

step one, preparing the phenolic resin pre-foaming blending material: mixing thermosetting phenolic resin, POE, filler and antioxidant in an internal mixer for 5-10 min at 90 ℃ and at the rotating speed of 30-40 r/min, adding a cross-linking agent and a foaming agent, mixing for 1min, and uniformly dispersing the cross-linking agent and the foaming agent into the resin, or mixing thermosetting phenolic resin, POE, filler and antioxidant in an open mixer for 15min at 40 ℃ and at the rotating speed of 30-40 r/min, adding the cross-linking agent and the foaming agent, mixing for 3min, and uniformly dispersing the cross-linking agent and the foaming agent into the resin;

and step two, foaming the phenolic resin pre-foaming blending material through mould pressing.

8. The method for forming phenolic resin foam material of claim 7, wherein the phenolic resin pre-foamed blended material after open milling or banburying in the first step is taken out and flattened while hot, so as to facilitate the subsequent die pressing foaming.

9. The method as claimed in claim 7, wherein the foaming temperature in the second step is 180-.

Technical Field

The invention relates to the technical field of foaming materials, in particular to a phenolic resin foaming material and a forming method thereof.

Background

Phenolic resin is a thermosetting polymer material which has chemical resistance, wear resistance, heat resistance, electrical insulation, safety and the like and is easy to process and mold. Phenolic resins are generally classified into thermoplastic phenolic resins and thermosetting phenolic resins. Phenolic foam is widely used in petrochemical industry, building, transportation and other industries due to the advantages of heat insulation, sound absorption, flame retardancy, chemical corrosion resistance and the like, and people also utilize the fireproof, flame retardant, self-extinguishing and smokeless properties of phenolic resin to manufacture fireproof plates, fireproof walls, fireproof doors and the like.

Phenolic resins are generally classified into thermoplastic phenolic resins and thermosetting phenolic resins. The thermoplastic phenolic aldehyde is of a linear structure and has the characteristic of being soluble and meltable. The pure thermoplastic phenolic resin is not crosslinked and solidified by heating, and can be solidified only when a proper curing agent is added.

The curing temperature of the thermosetting phenolic resin is in a range of about 180 ℃ to about 200 ℃, with 180 ℃ being the most common.

Pure thermosetting phenolic resin (heated and cured) has poor foaming performance and very brittle foam, and the pure thermosetting phenolic resin needs to be modified to improve the foaming performance and the toughness. Generally by blending or filling.

The existing toughening materials comprise polyurethane prepolymer, chopped glass fiber, polyurethane, polyethylene glycol, polyether and epoxy modified polyether toughened phenolic resin, and the methods are complex. The technical scheme adopts a blending toughening method, and has simple process and good effect.

Disclosure of Invention

The technical problem to be solved is as follows: aiming at the technical problems, the invention provides a phenolic resin foam material and a forming method thereof, the prepared phenolic resin foam material has uniform foam holes and small density, has good elasticity and comprehensive performance, and can be used in the fields of packaging, automobiles, thermal insulation, buildings, buffer liners, sound absorption and noise reduction and the like.

The technical scheme is as follows: the phenolic resin foam material comprises the following raw materials in parts by mass: 44.4-56.8 parts of thermosetting phenolic resin, 37.9-45 parts of POE, 1-6 parts of foaming agent, 0.2-0.4 part of cross-linking agent, 1-10 parts of filler and 0.3-0.6 part of antioxidant.

Preferably, the crosslinking agent is dicumyl peroxide.

Preferably, the filler is at least one of mica powder, quartz powder and kaolin, and the particle size of the filler is 600-1250 meshes.

Preferably, the foaming agent is a microsphere foaming agent.

Preferably, the antioxidant is antioxidant 1010.

Preferably, the filler is a filler which is subjected to surface treatment by using 1 wt.% of coupling agent KH550, and the specific treatment method is as follows: weighing the filling material, pouring alcohol into a beaker, wherein the ratio of the alcohol to the filling material is 1: 1, adding 1 percent of silane coupling agent KH550 into alcohol, immersing the KH550 alcohol solution in a beaker into the filling material, uniformly stirring, putting the mixture into an oven for 1 hour, volatilizing the alcohol, and leaving the treated filling material.

The forming method based on the phenolic resin foaming material comprises the following steps:

step one, preparing the phenolic resin pre-foaming blending material: mixing thermosetting phenolic resin, POE, filler and antioxidant in an internal mixer for 5-10 min at 90 deg.C and 30-40 r/min. In this temperature range, POE can soften, encapsulating the phenolic resin, and the filler is uniformly dispersed in the resin matrix. Then adding a cross-linking agent and a foaming agent, banburying for 1min, uniformly dispersing the cross-linking agent and the foaming agent into the resin, wherein the foaming agent is not decomposed and is fully prepared for subsequent die pressing foaming, or mixing thermosetting phenolic resin, POE, a filler and an antioxidant in an open mill for 15min at the temperature of 40 ℃ and the rotating speed of 30-40 r/min according to the mass part ratio, then adding the cross-linking agent and the foaming agent, and then open milling for 3min, and uniformly dispersing the cross-linking agent and the foaming agent into the resin;

and step two, foaming the phenolic resin pre-foaming blending material through mould pressing.

Preferably, the phenolic resin pre-foamed blending material after open milling or banburying in the first step is taken out and then flattened while hot, so that the subsequent die pressing foaming is facilitated.

Preferably, the foaming temperature in the second step is 180-. In the temperature range, the phenolic resin is softened, melted and solidified, and is fused with POE (polyolefin elastomer), the microsphere foaming agent dispersed in the resin is heated, generated bubbles expand in a resin matrix, and meanwhile, DCP is decomposed, the resin matrix is partially crosslinked, so that the melt strength is improved, and the matching of foaming and crosslinking is facilitated.

In the invention, POE plays a role of a carrier and is a good material for improving the foaming performance of the phenolic resin. The filler plays a role of a bubble nucleating agent and improves the mechanical property of the foam. The banburying materials are taken out and flattened while hot, so that the subsequent die pressing foaming is facilitated.

Due to the adoption of the measures, the modified phenolic resin foam material with uniform cells and small density is prepared. The foam material has good elasticity and comprehensive performance, and can be used in the fields of packaging, automobiles, thermal insulation, buildings, buffer liners, sound absorption, noise reduction and the like.

Has the advantages that: in the invention, thermosetting phenolic resin and POE and other materials with good foaming performance are mainly blended, and a certain amount of filling materials such as mica, kaolin, quartz powder and the like are added, so that the melt strength of the material is improved, and the foaming performance is further improved. Because POE melt strength is high, foaming performance is good, and toughness is good, the POE melt is a suitable modifier. The filler also acts as a synergistic foam. Thus, the phenolic resin blended filling foaming material is prepared by mixing through an internal mixer and then carrying out mould pressing foaming.

In the present invention, POE plays three roles simultaneously: (a) POE plays a role of a foaming agent carrier, and the POE in the internal mixer is melted and then wrapped with components such as phenolic resin powder, a foaming agent, a crosslinking agent DCP, a filler and the like, so that the subsequent die pressing foaming is well prepared; (b) POE plays a role of a toughening agent, and because the pure phenolic resin foaming material is tested to be very brittle and has no practical value, the toughness needs to be improved; (c) the POE has good foaming performance, and the foaming performance of the phenolic resin is improved after the POE is blended with the phenolic resin.

The phenolic resin blending filling foaming material prepared by the invention has uniform foam holes, small density, good elasticity and comprehensive performance, and can play an important role in the fields of packaging, automobiles, thermal insulation, buildings and the like by utilizing the excellent mechanical strength, good insulativity, heat resistance and corrosion resistance of the foaming material.

Drawings

FIG. 1 is a structural diagram of a phenolic resin foam material prepared in example 1 of the present invention;

FIG. 2 is a structural diagram of a phenolic resin foam material prepared in example 2 of the present invention;

FIG. 3 is a structural diagram of a phenolic resin foam material prepared in example 3 of the present invention;

FIG. 4 is a structural diagram of a phenolic resin foam prepared in example 4 of the present invention;

FIG. 5 is a structural view of a phenolic resin foam prepared in example 5 of the present invention;

FIG. 6 is a structural view of a phenolic resin foam prepared in comparative example 1 of the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings and specific embodiments.

In the examples of the present specification, the filler was surface-treated with 1 wt.% of coupling agent KH550, specifically as follows: weighing the filling material, pouring alcohol into a beaker, wherein the ratio of the alcohol to the filling material is 1: 1, adding 1 percent of silane coupling agent KH550 into alcohol, immersing the KH550 alcohol solution in a beaker into the filling material, uniformly stirring, putting the mixture into an oven for 1 hour, volatilizing the alcohol, and leaving the treated filling material.

Example 1

The foaming formula comprises (by mass portions) thermosetting phenolic resin 44.4 portions, POE44.4 portions, kaolin (1250 mesh) 6.2 portions (surface treatment is carried out by 1 wt.% coupling agent KH 550), cross-linking agent dicumyl peroxide (DCP) 0.29 portions, foaming agent 4.4 portions and antioxidant 10100.29 portions.

The material is available in the following brands or types: thermosetting phenol resin (No. BR 2123), homan platinum-based casting materials ltd. Kaolin, 1250 mesh, available from Shandong Huatai chemical Co., Ltd. POE (number 8150) dow. Dicumyl peroxide (DCP), technical grade. Microsphere foaming agent model ML2000, Dongguan gold stone plasticizing raw materials Co. Antioxidant 1010, technical grade.

The forming process of the phenolic resin foaming material comprises the following steps:

(1) preparing a phenolic resin pre-foaming blending material: the thermosetting phenolic resin, the POE, the kaolin and the antioxidant 1010 are subjected to banburying mixing in an internal mixer for 8min according to the weight ratio, the temperature is 90 ℃, and the rotating speed is 35 r/min. In this temperature range, POE softens and encapsulates the phenolic resin powder, and the kaolin filler is uniformly dispersed in the resin matrix. Then adding a crosslinking agent dicumyl peroxide (DCP) and a microsphere foaming agent, banburying for 1min, and uniformly dispersing the DCP and the microsphere foaming agent into resin. The banburying materials are taken out and flattened while hot, so that the subsequent die pressing foaming is facilitated.

(2) Preparing a foaming material: the phenolic resin pre-foaming blending material is foamed through mould pressing. The foaming temperature is 180 ℃, the pressure can be controlled at 10MPa, and the foaming time is 15 min. And taking out the foaming material. The foam density was found to be 0.31g/cm³Tensile strength of 1.5MPa and elongation at break of 85%. The foam structure is shown in figure 1. The diameter of the cells is about 0.08-0.1 mm.

Example 2

The foaming formula comprises (by mass portions) thermosetting phenolic resin 45.2 portions, POE 45.2 portions, mica powder (800 meshes) 4.5 portions (surface treated by 1 wt.% coupling agent KH 550), cross-linking agent dicumyl peroxide (DCP) 0.29 portions, foaming agent 4.5 portions, and antioxidant 10100.29 portions.

The material is available in the following brands or types: thermosetting phenol resin (No. BR 2123), homan platinum-based casting materials ltd. POE (number 8150) dow. Mica powder, 800 mesh, baofeng mica processing ltd, lingshou county, hebei shi jiazhuang, city. Dicumyl peroxide (DCP), technical grade. Microsphere foaming agent model ML2000, Dongguan gold stone plasticizing raw materials Co. Antioxidant 1010, technical grade.

The forming process of the phenolic resin foaming material comprises the following steps:

(1) preparing a phenolic resin pre-foaming blending material: and banburying and mixing the thermosetting phenolic resin, the POE, the mica powder and the antioxidant 1010 in an internal mixer according to the weight ratio for 8min at the temperature of 90 ℃ and the rotating speed of 35 r/min. In this temperature range, POE can soften, encapsulating the phenolic resin powder, and the mica powder filler is uniformly dispersed in the resin matrix. Then adding a crosslinking agent dicumyl peroxide (DCP) and a microsphere foaming agent, banburying for 1min, and uniformly dispersing the DCP and the microsphere foaming agent into resin. The banburying materials are taken out and flattened while hot, so that the subsequent die pressing foaming is facilitated.

(2) Preparing a foaming material: the phenolic resin pre-foaming blending material is foamed through mould pressing. The foaming temperature is 180 ℃, the pressure can be controlled at 10MPa, and the foaming time is 15 min. And taking out the foaming material. The foam density was found to be 0.44g/cm³The tensile strength was 2.1MPa, and the elongation at break was 54%. The foam structure is shown in figure 2. The diameter of the cells is about 0.2-0.3 mm.

Example 3

The foaming formula comprises (by mass parts) thermosetting phenolic resin 45.2 parts, POE 45.2 parts, quartz powder (600 meshes) 4.5 parts (surface treated by 1 wt.% of coupling agent KH 550), cross-linking agent dicumyl peroxide (DCP) 0.29 parts, foaming agent 4.5 parts, and antioxidant 10100.29 parts.

The material is available in the following brands or types: phenolic resin (No. BR 2123), homan platinum-based casting materials ltd. POE (number 8150) dow. Quartz powder, 600 mesh, Tang Xin Lei mineral powder processing plant, Hebei province. Dicumyl peroxide (DCP), technical grade. Microsphere foaming agent model ML2000, Dongguan gold stone plasticizing raw materials Co. Antioxidant 1010, technical grade.

The forming process of the phenolic resin foaming material comprises the following steps:

(1) preparing a phenolic resin pre-foaming blending material: and banburying and mixing the thermosetting phenolic resin, the POE, the quartz powder and the antioxidant 1010 in an internal mixer according to the weight ratio for 7min at the temperature of 90 ℃ and the rotating speed of 35 r/min. In this temperature range, POE can soften, encapsulating the phenolic resin powder, and the quartz powder filler is uniformly dispersed in the resin matrix. Then adding a crosslinking agent dicumyl peroxide (DCP) and a microsphere foaming agent, banburying for 1min, and uniformly dispersing the DCP and the microsphere foaming agent into resin. The banburying materials are taken out and flattened while hot, so that the subsequent die pressing foaming is facilitated.

(2) Preparing a foaming material: the phenolic resin pre-foaming blending material is foamed through mould pressing. The foaming temperature is 180 ℃, the pressure can be controlled at 10MPa, and the foaming time is 15 min. And taking out the foaming material. The foam density was found to be 0.38g/cm³Tensile strength of 2.0MPa and elongation at break of 58%. The foam structure is shown in figure 3. The diameter of the cells is about 0.2-0.3 mm.

The applicant adopts toughening materials EVA and LDPE to replace POE, but the toughening materials POE are selected because the internal mixing products of the EVA, the LDPE and the phenolic resin powder are extremely difficult to take out during internal mixing and difficult to post-treat, and compared with the POE, the sheet obtained by final tabletting has insufficient toughness and slightly higher hardness. The EVA can not be melted at 100 ℃ and 110 ℃ of LDPE in an internal mixer, but at the temperature, the foaming agent and the crosslinking agent DCP can be decomposed, which is not beneficial to the foaming of the material.

Example 4

The foaming formula comprises (by mass parts) thermosetting phenolic resin 45 parts, POE45 parts, mica (800 meshes) 4.5 parts (surface treated by 1 wt.% of coupling agent KH 550), cross-linking agent dicumyl peroxide (DCP) 0.3 parts, foaming agent 5 parts and antioxidant 10100.3 parts.

The material is available in the following brands or types: phenolic resin (No. BR 2123), homan platinum-based casting materials ltd. Mica, 800 mesh, baofeng mica processing ltd, lingshou county, hebei Shijiazhuang, city. POE (number 8150) dow. Dicumyl peroxide (DCP), technical grade. Microsphere foaming agent, model ML2000, commercially available. Antioxidant 1010, technical grade.

The forming process of the phenolic resin foaming material comprises the following steps:

(1) preparing a phenolic resin pre-foaming blending material: mixing thermosetting phenolic resin, POE, mica and an antioxidant 1010 in an open mill for 15min according to the weight ratio, wherein the temperature is 40 ℃ and the rotating speed is 35 r/min. In this temperature range, the POE softens, encapsulating the phenolic resin powder, and the mica filler is uniformly dispersed in the resin matrix. Then adding a crosslinking agent dicumyl peroxide (DCP) and a microsphere foaming agent, then open milling for 3min, and uniformly dispersing the DCP and the microsphere foaming agent into the resin. The milled materials are taken out and flattened while being hot, so that the subsequent die pressing foaming is facilitated.

(2) Preparing a foaming material: the phenolic resin pre-foaming blending material is foamed through mould pressing. The foaming temperature is 180 ℃, the pressure can be controlled at 10MPa, and the foaming time is 15 min. And taking out the foaming material. The foam density was found to be 0.34g/cm³The tensile strength was 1.84MPa, and the elongation at break was 45%. The foam structure is shown in figure 4. The diameter of the cells is about 0.08-0.1 mm.

The material obtained by the milling process of this example was less dense and had slightly lower properties than the banburying process of example 1.

Example 5 (comparison with example 1)

The foaming formula comprises (by mass parts) thermosetting phenolic resin 44.4 parts, POE44.4 parts, kaolin (1250 mesh) 6.2 parts (without surface treatment), cross-linking agent dicumyl peroxide (DCP) 0.29 parts, foaming agent 4.4 parts and antioxidant 10100.29 parts.

The material is available in the following brands or types: phenolic resin (No. BR 2123), homan platinum-based casting materials ltd. POE (number 8150) dow. Kaolin, 1250 mesh, available from Shandong Huatai chemical Co., Ltd. Dicumyl peroxide (DCP), technical grade. Microsphere foaming agent, model ML2000, commercially available. Antioxidant 1010, technical grade.

The forming process of the phenolic resin foaming material comprises the following steps:

(1) preparing a phenolic resin pre-foaming blending material: mixing thermosetting phenolic resin, POE, kaolin and an antioxidant 1010 in an open mill according to a weight ratio for 15min at the temperature of 40 ℃ and the rotating speed of 35 r/min. In this temperature range, POE can soften and encapsulate the phenolic resin powder. Then adding a crosslinking agent dicumyl peroxide (DCP) and a microsphere foaming agent, then open milling for 3min, and uniformly dispersing the DCP and the microsphere foaming agent into the resin. The milled materials are taken out and flattened while being hot, so that the subsequent die pressing foaming is facilitated.

(2) Preparing a foaming material: the phenolic resin pre-foaming blending material is foamed through mould pressing. The foaming temperature is 180 ℃, the pressure can be controlled at 10MPa, and the foaming time is 15 min. And taking out the foaming material. The foam density was found to be 0.45g/cm³The tensile strength was 0.9MPa and the elongation at break was 15%.

Example 6

The difference from example 1 is that the foaming formula comprises (by mass): 56.8 parts of thermosetting phenolic resin, 37.9 parts of POE (polyolefin elastomer), 1 part of microsphere foaming agent, 0.2 part of dicumyl peroxide (DCP) serving as a crosslinking agent, 1 part of filler (kaolin, which is subjected to surface treatment by using 1 wt.% of coupling agent KH 550) and 10100.3 parts of antioxidant.

The material is available in the following brands or types: thermosetting phenol resin (No. BR 2123), homan platinum-based casting materials ltd. Kaolin, 1250 mesh, available from Shandong Huatai chemical Co., Ltd. POE (number 8150) dow. Dicumyl peroxide (DCP), technical grade. Microsphere foaming agent model ML2000, Dongguan gold stone plasticizing raw materials Co. Antioxidant 1010, technical grade.

The forming process of the phenolic resin foaming material comprises the following steps:

(1) preparing a phenolic resin pre-foaming blending material: the thermosetting phenolic resin, the POE, the kaolin and the antioxidant 1010 are subjected to banburying mixing in an internal mixer for 8min according to the weight ratio, the temperature is 90 ℃, and the rotating speed is 35 r/min. In this temperature range, POE softens and encapsulates the phenolic resin powder, and the kaolin filler is uniformly dispersed in the resin matrix. Then adding a crosslinking agent dicumyl peroxide (DCP) and a microsphere foaming agent, banburying for 1min, and uniformly dispersing the DCP and the microsphere foaming agent into resin. The banburying materials are taken out and flattened while hot, so that the subsequent die pressing foaming is facilitated.

(2) Preparing a foaming material: the phenolic resin pre-foaming blending material is foamed through mould pressing. The foaming temperature is 180 ℃, the pressure can be controlled at 10MPa, and the foaming time is 15 min. And taking out the foaming material. The foam density was found to be 0.66g/cm³The tensile strength was 2.6MPa and the elongation at break was 45%.

Example 7

The foaming formula is the same as that of example 1, except that the foaming formula comprises (by mass parts) thermosetting phenolic resin 44.4 parts, POE 35 parts, foaming agent 10 parts, crosslinking agent dicumyl peroxide (DCP) 0.4 part, filler 10 parts (kaolin, surface treated by 1 wt.% coupling agent KH 550) and antioxidant 10100.6 parts.

The material is available in the following brands or types: thermosetting phenol resin (No. BR 2123), homan platinum-based casting materials ltd. The filler is kaolin, 1250 meshes and sold by Shandong Huatai chemical Co. POE (number 8150) dow. Dicumyl peroxide (DCP), technical grade. The foaming agent is a microsphere foaming agent, model ML2000, gold stone plasticizing raw material Co., Ltd. Antioxidant 1010, technical grade.

The forming process of the phenolic resin foaming material comprises the following steps:

(1) preparing a phenolic resin pre-foaming blending material: the thermosetting phenolic resin, the POE, the kaolin and the antioxidant 1010 are subjected to banburying mixing in an internal mixer for 8min according to the weight ratio, the temperature is 90 ℃, and the rotating speed is 35 r/min. In this temperature range, POE softens and encapsulates the phenolic resin powder, and the kaolin filler is uniformly dispersed in the resin matrix. Then adding a crosslinking agent dicumyl peroxide (DCP) and a microsphere foaming agent, banburying for 1min, and uniformly dispersing the DCP and the microsphere foaming agent into resin. The banburying materials are taken out and flattened while hot, so that the subsequent die pressing foaming is facilitated.

(2) Preparing a foaming material: the phenolic resin pre-foaming blending material is foamed through mould pressing. The foaming temperature is 180 ℃, the pressure can be controlled at 10MPa, and the foaming time is 15 min. And taking out the foaming material. The foam density was found to be 0.3g/cm³Tensile strength of 1.3MPa and elongation at break of 72%.

Comparative example 1

This comparative example is the comparative example (open mill process) of example 3, as follows:

the foaming formula comprises (by mass parts) thermosetting phenolic resin 45.2 parts, POE 45.2 parts, quartz powder (600 meshes) 4.5 parts (surface treated by 1 wt.% of coupling agent KH 550), cross-linking agent dicumyl peroxide (DCP) 0.29 parts, foaming agent 4.5 parts, and antioxidant 10100.29 parts.

The material is available in the following brands or types: phenolic resin (No. BR 2123), homan platinum-based casting materials ltd. POE (number 8150) dow. Quartz powder, 600 mesh, Tang Xin Lei mineral powder processing plant, Hebei province. Dicumyl peroxide (DCP), technical grade. Microsphere foaming agent model ML2000, Dongguan gold stone plasticizing raw materials Co. Antioxidant 1010, technical grade.

The forming process of the phenolic resin foaming material comprises the following steps:

(1) preparing a phenolic resin pre-foaming blending material: mixing thermosetting phenolic resin, POE, quartz powder and antioxidant 1010 in an open mill for 15min at 40 ℃ and at 35 r/min. In this temperature range, POE can soften, encapsulating the phenolic resin powder, and the quartz powder filler is uniformly dispersed in the resin matrix. Then adding a crosslinking agent dicumyl peroxide (DCP) and a microsphere foaming agent, then open milling for 3min, and uniformly dispersing the DCP and the microsphere foaming agent into the resin. The milled materials are taken out and flattened while being hot, so that the subsequent die pressing foaming is facilitated.

(2) Preparing a foaming material: the phenolic resin pre-foaming blending material is foamed through mould pressing. The foaming temperature is 180 ℃, the pressure can be controlled at 10MPa, and the foaming time is 15 min. And taking out the foaming material. Measured as a foam density of0.43g/cm³The tensile strength was 1.74MPa, and the elongation at break was 38%. The foam structure is shown in figure 6. The diameter of the cells is about 0.2-0.3 mm. This example is slightly denser and has slightly lower performance than example 3.

Comparative example 2

The foaming formula comprises (by weight parts) thermosetting phenolic resin 69.6 parts, EVA25 parts, cross-linking agent dicumyl peroxide (DCP) 0.3 part, foaming agent 5 parts, and antioxidant 10100.3 parts.

The material is available in the following brands or types: phenolic resin (No. BR 2123), homan platinum-based casting materials ltd. EVA (grade 7470M), Taiwan die group. Dicumyl peroxide (DCP), technical grade. Microsphere foaming agent model ML2000, Dongguan gold stone plasticizing raw materials Co. Antioxidant 1010, technical grade.

The forming process of the phenolic resin foaming material comprises the following steps:

(1) preparing a phenolic resin pre-foaming blending material: mixing thermosetting phenolic resin, EVA and antioxidant 1010 in an open mill for 15min at 40 deg.c and 35 r/min. In this temperature range, EVA is able to soften, encapsulating the phenolic resin powder. Then adding a crosslinking agent dicumyl peroxide (DCP) and a microsphere foaming agent, then open milling for 3min, and uniformly dispersing the DCP and the microsphere foaming agent into the resin. The milled materials are taken out and flattened while being hot, so that the subsequent die pressing foaming is facilitated.

(2) Preparing a foaming material: the phenolic resin pre-foaming blending material is foamed through mould pressing. The foaming temperature is 180 ℃, the pressure can be controlled at 10MPa, and the foaming time is 15 min. And taking out the foaming material. The foam density was found to be 0.61g/cm³The material was too brittle to measure performance.

The EVA was converted to LDPE ((designation 2102TN26, Qilu petrochemical) and the material density was determined to be 0.8g/cm³The material was too brittle to measure performance.