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Method for preparing polylactic acid foaming material subjected to radiation modification by utilizing supercritical fluid CO2

A supercritical fluid and polylactic acid foaming technology, applied in the field of polymer material processing, can solve the problems of difficult control of cell size, low strength of polylactic acid melt and difficult foaming, etc., to achieve uniform cells, low production cost, The effect of increasing the degree of cross-linking

Active Publication Date: 2013-02-06
ZHENGZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0014] The purpose of this invention is to provide a kind of utilizing supercritical fluid CO 2 Technology A new method for preparing radiation-modified polylactic acid microcellular foaming materials, which solves the problems of difficult foaming and difficult control of cell size due to the low melt strength of polylactic acid

Method used

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  • Method for preparing polylactic acid foaming material subjected to radiation modification by utilizing supercritical fluid CO2
  • Method for preparing polylactic acid foaming material subjected to radiation modification by utilizing supercritical fluid CO2
  • Method for preparing polylactic acid foaming material subjected to radiation modification by utilizing supercritical fluid CO2

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Embodiment 1

[0042] The viscosity-average relative molecular weight of 100 parts is 2.5×10 5 , L-polylactic acid particles with a melting point of 160°C and 3 parts of sensitizer TAIC relative to the weight of polylactic acid raw materials are melted, blended, extruded and calendered by a twin-screw extruder to make crystallinity below 30%, a certain width, A polylactic acid sheet with a thickness of 2 mm; 60 Co-γ-ray radiation, the absorbed radiation dose is 10kGy. The irradiated polylactic acid sheet was cut into 40mm×40mm test pieces and placed in a mold cavity with a mold temperature of 140°C, and sufficient volume expansion space required for swelling, penetration and nucleation was ensured. First fill with low pressure CO 2 Replace the air in the mold cavity, and then fill it with supercritical fluid CO with a pressure of 10MPa 2 , to carry out swelling and penetration, the swelling and penetration time is 15 minutes, after reaching the diffusion equilibrium, the pressure in the m...

Embodiment 2

[0045] The viscosity-average relative molecular weight of 100 parts is 3.0×10 5 , L-polylactic acid particles with a melting point of 160°C and 3 parts of sensitizer TMPTA relative to the weight of polylactic acid raw materials are melt-blended, extruded and calendered by a twin-screw extruder to make a crystallinity below 30% and a certain width , Polylactic acid sheet with a thickness of 2mm. take the sheet 60 Co-γ-ray radiation, the absorbed radiation dose is 15kGy. The irradiated polylactic acid sheet was cut into 40mm×40mm test pieces and placed in a mold cavity with a mold temperature of 145°C, and sufficient volume expansion space required for swelling, penetration and nucleation was ensured. First fill with low pressure CO 2 Replace the air in the mold cavity, and then fill it with supercritical fluid CO with a pressure of 10MPa 2 , carry out swelling and penetration, the swelling and penetration time is 25min, after reaching the diffusion equilibrium, the pressure...

Embodiment 3

[0048] The viscosity-average relative molecular weight of 100 parts is 2.5×10 5 , L-polylactic acid particles with a melting point of 160°C and a sensitizer PETA of 3 parts relative to the weight of the raw material of polylactic acid are melted, blended, extruded and calendered by a twin-screw extruder to make crystallinity below 30%. , Polylactic acid sheet with a thickness of 2mm. take the sheet 60 Co-γ-ray radiation, the absorbed radiation dose is 10kGy. The irradiated polylactic acid sheet was cut into 40mm×40mm test pieces and placed in a mold cavity with a mold temperature of 155°C, and sufficient volume expansion space required for swelling, penetration and nucleation was ensured. First fill with low pressure CO 2 Replace the air in the mold cavity, and then fill it with supercritical fluid CO with a pressure of 14MPa 2 , carry out swelling and penetration, the swelling and penetration time is 35min, after the diffusion equilibrium is reached, the pressure in the m...

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Abstract

The invention discloses a method for preparing polylactic acid foaming material subjected to radiation modification by utilizing supercritical fluid CO2 and belongs to the field of processing of high polymer materials. The method comprises the following steps of: 1) mixing polylactic acid with a sensitizer, and preparing a sheet through melt extrusion or injection molding; 2) performing 60Co-gamma ray radiation on the sheet; 3) putting the radiated sheet in a die cavity, filling the supercritical fluid CO2, and performing swelling penetration by controlling the swelling penetration time, the temperature and pressure; and 4) initiating nucleation foaming by controlling the pressure relief speed and cooling speed, and forming a polylactic acid microcellular foaming material which has uniform cells, the cell size of 5-500mu m and a controllable structure. By adoption of the 60Co-gamma ray radiation crosslinking, the difficulty that the polylactic acid melt is low in strength and difficult to foam is effectively solved, the method has the characteristics that the process is simple, green and environment-friendly, low in cost and high in production efficiency, and the prepared foaming material has excellent mechanical property and can be applied to the fields of biomedical use, food packaging and disposable tableware degradation.

Description

technical field [0001] The invention belongs to the field of polymer material processing, in particular to a method of using supercritical fluid CO 2 Preparation by foam technology 60 A method for polylactic acid microporous foam material modified by Co-γ-ray radiation. Background technique [0002] Because the polymer microcellular foamed material has a large number of micron-sized cells inside, it can significantly reduce the weight of polymer products without significantly reducing the mechanical properties of the material, and achieve the purpose of saving costs. With excellent shock absorption, heat insulation and sound absorption performance, it is widely used in shock absorption, sound absorption and sound absorption, food packaging, biomedical and disposable fully degradable tableware and other fields. [0003] Polylactic acid is an aliphatic polyester polymer material with excellent biocompatibility and complete biodegradability. It is a semi-crystalline polymer w...

Claims

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Application Information

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IPC IPC(8): C08J9/12C08J3/28C08L67/04
Inventor 牛明军陈金周郭凯谢鹏萍张丽王利霞毕婷婷袁永洁李新法
Owner ZHENGZHOU UNIV
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