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Preparation method of polymethacrylimide foam material

A polymethacrylimide and foam material technology, which is applied in the field of preparation of polymethacrylimide foam materials, can solve the problems of low production efficiency, uneven foam board, unsatisfactory effect and the like, and achieves low cost , broad application prospects, low toxicity effect

Active Publication Date: 2019-12-24
JIANGSU UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Therefore, the main disadvantages of the two-step method are: 1. In order to prevent violent polymerization, the copolymerization reaction can only be carried out below 60 °C, the reaction time is more than 48 h, and the production efficiency is low; The foam copolymer sheet is uneven, causing the foam sheet to be uneven
Evonik's current solution is to apply a layer of adhesive on the surface of the particles, but the effect is not satisfactory

Method used

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  • Preparation method of polymethacrylimide foam material
  • Preparation method of polymethacrylimide foam material
  • Preparation method of polymethacrylimide foam material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] (1) Mix 150 g acrylonitrile, 46 g methacrylic acid, 23 g N,N-dimethylacrylamide, 11.5 g butyl acrylate, 0.9 g ethylene glycol dimethacrylate, 1.27 g azobisiso Butyronitrile, 80 g n-pentane were stirred for 5 min to obtain a homogeneous oil phase;

[0040] (2) 1500 g deionized water, 70 g nano-silica, 450 g sodium chloride, 1 g polyvinylpyrrolidone, 0.6 g ethanol, 0.3 g sodium nitrite were homogeneously emulsified at 10000 rpm for 3 min, Adjust the pH value to 3 as the aqueous phase of the polymerization reaction;

[0041] (3) Slowly add the prepared oil phase into the water phase dropwise, and mechanically stir for 30 minutes to mix well to form an oil-in-water emulsion;

[0042] (4) The prepared emulsion was injected into the reactor, replaced by nitrogen for 3 times, the reactor was sealed, the initial pressure was controlled at 0.5 MPa, polymerized at 60 °C for 25 h, filtered, washed and dried to obtain thermally expandable microspheres.

[0043] (5) Add the prepar...

Embodiment 2

[0053] The difference between Example 2 and Example 1 is that, on the basis of Example 1, the oil phase is replaced with 150 g of acrylonitrile, 46 g of methacrylic acid, and 23 g of N,N-dimethylpropylene in step 2 Amide, 11.5 g methyl acrylate, 0.9 g ethylene glycol dimethacrylate, 1.27 g azobisisobutyronitrile, 80 g isohexane to prepare thermally expandable microspheres;

[0054] Step 5 is: Add the prepared thermally expandable microspheres into a pressing mold preheated to 50°C, use a plastic hydraulic press to foam, the mold pressure is 0.5~1 MPa, and adopt a stepwise heating method to foam: at 1°C / min The heating rate is raised to 140°C and kept for 20 minutes, and the temperature is raised to 205°C at a heating rate of 1.5°C / min. According to the different shapes of the components, the pressure is kept for 10-30 minutes. base acrylimide foam.

[0055] The average diameter of the microspheres prepared in this example is 52.6 μm.

[0056] Static thermomechanical analysis...

Embodiment 3

[0058] The difference between Example 3 and Example 1 is that, on the basis of Example 1, the oil phase is replaced with 150 g of acrylonitrile, 46 g of methacrylic acid, and 23 g of N,N-dimethylpropylene in step 2 Amide, 11.5 g ethyl acrylate, 0.9 g ethylene glycol dimethacrylate, 1.27 g azobisisobutyronitrile, 80 g isoheptane, made thermally expandable microspheres;

[0059] Step 5 is: Add the prepared thermally expandable microspheres into a pressing mold preheated to 50°C, use a plastic hydraulic press to foam, the mold pressure is 0.5~1 MPa, and adopt a stepwise heating method to foam: at 1°C / min The heating rate is raised to 140°C and kept for 20 minutes, and the temperature is raised to 210°C at a heating rate of 1°C / min. According to the different shapes of the components, the pressure is kept for 10-30 minutes. base acrylimide foam.

[0060] The average diameter of the microspheres prepared in this example is 52.4 μm.

[0061] Static thermomechanical analysis result...

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Abstract

The invention discloses a preparation method of a polymethacrylimide foam material. The preparation method comprises the following steps: firstly, preparing polymethacrylimide thermal expansion microspheres by adopting a Pickering emulsion suspension polymerization method, with unsaturated olefin monomers and a cross-linking agent being used as shell materials, and a low-boiling-point alkane foaming agent being used as a core material; screening the prepared thermal expansion microspheres to obtain thermal expansion microsphere powder for producing a polymethacrylimide foam material; and subjecting the prepared thermal expansion microspheres to hot-pressing foaming molding to obtain the polymethacrylimide foam plastic. The thermal expansion microspheres prepared by the method can be screened to directly obtain a foaming raw material, so that a grinding step is omitted, the polymethacrylimide foamed plastic can be obtained at one time by molding in a mold, and the market application prospect is wide.

Description

technical field [0001] The invention relates to the field of polymer foam materials, in particular to a preparation method of polymethacrylimide foam materials. Background technique [0002] Polymethacrylimide (PMI) foam is a thermosetting rigid foam material with 100% closed-cell structure, and its uniform cross-linked cell wall structure endows it with outstanding structural stability and excellent mechanical properties. The German Rohm company (now acquired by Evonik Industrial Group) first developed the first generation of polymethacrylimide with methacrylic acid (MAA), methacrylonitrile (MAN) as comonomers in 1966 PMI) foam plastics, the registered trademark is ROHCELL ® , the product was first successfully applied to the aircraft project and obtained the first aircraft material demonstration certificate. In recent years, with the continuous development of the aerospace industry, the application of PMI foam plastics has been continuously explored and researched at hom...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08J9/20C08J9/14C08F220/48C08F220/06C08F220/54C08F220/18C08F222/14C08F2/18C08F8/48C08L33/24
CPCC08J9/20C08J9/141C08F220/48C08F2/18C08F8/48C08J2333/24C08J2203/14
Inventor 张竞周一凡张宏礼张娇霞汤继俊
Owner JIANGSU UNIV OF SCI & TECH