Preparation method of high-density ultra-thick wave-absorbing polymethacrylimide (PMI) foam composite material

A composite material and foam technology, applied in the field of preparation of functional composite foam, can solve the problems of low material utilization, long reaction time, sedimentation of wave absorbing agent, etc., and achieve the effect of improving wave absorbing performance, easy operation, and increasing reaction temperature

Active Publication Date: 2018-09-07
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] In order to overcome the problems of explosive polymerization, long reaction time, low material utilization rate, and sedimentation of wave-absorbing agent during the polymerization process in the process of preparing wave-absorbing PMI foam by bulk polymerization, the invention provides a wave-absorbing foam prepared by suspension polymerization. The method of PMI foam composite material, the preparation method is on the basis of free radical polymerization, through the suspension polymerization method, introducing suspending agent into the reaction system, adding wave absorbing agent to the prepolymer with certain viscoelasticity, in a specific mold Perform foam molding to directly obtain the required parts

Method used

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  • Preparation method of high-density ultra-thick wave-absorbing polymethacrylimide (PMI) foam composite material
  • Preparation method of high-density ultra-thick wave-absorbing polymethacrylimide (PMI) foam composite material
  • Preparation method of high-density ultra-thick wave-absorbing polymethacrylimide (PMI) foam composite material

Examples

Experimental program
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Effect test

Embodiment 1

[0037] Monomer: the molar ratio of acrylonitrile (AN) to methacrylic acid (MAA) is 1:1, and the total mass fraction is 100 parts.

[0038] Dispersion medium: the amount of deionized water is 100 parts, and the amount of suspending agent PVA1788 is 0.5 parts.

[0039] Initiator: azobisisobutyronitrile (AIBN), the dosage is 0.1 part.

[0040] Crosslinking agent: acrylamide (AM), the dosage is 0.5 parts.

[0041] Foaming agent: expanded microsphere foaming agent, the consumption is 1 part.

[0042] Wave absorbing agent: ferrite, the dosage is 10 parts.

[0043] Steps: first dissolve the suspending agent PVA in deionized water to prepare a suspending agent solution, put the solution into the reaction kettle, and turn on the stirring device at the same time. Add two kinds of reaction monomers in sequence, start heating, raise the temperature to 65°C, then add the initiator to the reaction kettle, adjust the rotation speed to 150r / min, and the viscosity of the suspension in the rea...

Embodiment 2

[0045] Monomer: The molar ratio of methacrylonitrile (MAN) to acrylic acid (AA) is 1:1, and the total mass fraction is 100 parts.

[0046] Dispersion medium: the amount of deionized water is 200 parts, and the amount of suspending agent PAAS is 2 parts.

[0047] Initiator: azobisisoheptanonitrile (ABVN), the dosage is 0.5 parts.

[0048] Cross-linking agent: acrylamide (AM), the dosage is 1 part.

[0049] Foaming agent: expansion microsphere foaming agent, consumption is 5 parts.

[0050] Wave absorbing agent: modified ferrite, the dosage is 15 parts.

[0051] Steps: first mix the suspending agent PAAS and deionized water, stir to obtain a colloid, and put the colloid into the reaction kettle, and the rest of the implementation process is similar to Example 1.

Embodiment 3

[0053] Monomer: the molar ratio of acrylonitrile (AN) to acrylic acid (AA) is 1.5:1, and the total mass fraction is 100 parts.

[0054] Dispersion medium: 150 parts of deionized water, suspending agent MgCO 3 The dosage is 3 servings.

[0055] Initiator: dibenzoyl peroxide (BPO), the dosage is 1 part.

[0056] Cross-linking agent: magnesium oxide (MgO), the dosage is 1.5 parts.

[0057] Foaming agent: azodicarbonamide (AC), the dosage is 8 parts.

[0058] Wave absorbing agent: ferrite, the dosage is 20 parts.

[0059] Steps: first add deionized water and suspending agent into the reaction kettle, adjust the stirring rate to 150r / min, add the monomer after stirring for 0.5h, and the rest of the implementation process is similar to that of Example 1. However, the follow-up foaming process is 180 ° C for 30 minutes, and the hot blowing process is 215 ° C for 2 hours.

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Abstract

The invention discloses a preparation method of a high-density ultra-thick wave-absorbing polymethacrylimide (PMI) foam composite material. (Methyl) acrylonitrile and (methyl) acrylic acid are taken as comonomers; free radical suspension polymerization is carried out in a form of small liquid drops in presence of a suspending agent, and a microwave absorbing agent is introduced into the reaction system, so that the wave-absorbing PMI foam composite material is prepared. The foam composite material prepared by using the method can be directly prepared into a molding part by being foamed in a specific mould; furthermore, the preparation method is high in production efficiency and simple and convenient to operate. The high-density ultra-thick wave-absorbing PMI foam composite material can beapplied to the military field.

Description

technical field [0001] The invention relates to a preparation method of functional composite foam, in particular to a preparation method of high-density ultra-thick wave-absorbing PMI foam composite material. Background technique [0002] The rapid development of modern radio technology and radar detection technology has greatly improved the ability of the aircraft detection system to search and track targets. Traditional combat weapon systems such as aircraft, missiles, ships and other large combat weapons are facing increasing threats. In order to improve the The research and application of stealth technology is of great significance for survivability, defense capability and attack capability in war. One of the important ways to realize electromagnetic shielding and stealth technology is to develop wave-absorbing materials with good structural stability, high absorption utilization rate and wide frequency band. [0003] According to the state of use, the absorbing materia...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08J9/32C08J9/10C08F220/48C08F220/06C08F220/42C08F220/46C08F220/56C08F2/20C08F2/18C08K9/00C08K3/22
CPCC08F2/18C08F2/20C08F220/06C08F220/42C08F220/46C08F220/48C08J9/103C08J9/32C08J2203/04C08J2203/22C08J2333/02C08J2333/18C08J2333/20C08K3/22C08K9/00C08F220/56C08F220/40
Inventor 姚正军钱逸周金堂徐体寿
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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