Preparation method of chitosan modified polylactic acid material by gamma-ray irradiation

A modification technology of polylactic acid material and chitosan, which is applied in the field of γ-ray irradiation preparation of chitosan modified polylactic acid material, can solve the problem of environmental protection and biodegradation characteristics of polylactic acid material, thermodynamic performance decline, degradation Uncontrollable performance and other problems, to achieve good thermodynamic performance, reduce dosage, easy to promote the effect

Active Publication Date: 2012-07-25
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The filling and blending method is one of the commonly used polylactic acid modification methods. It has the advantages of simple reaction system and easy operation. However, there are differences in compatibility, polarity and crystallinity between polylactic acid and most plasticized and filled materials. Decreased thermodynamic performance and uncontrollable degradation performance due to low inte...

Method used

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  • Preparation method of chitosan modified polylactic acid material by gamma-ray irradiation
  • Preparation method of chitosan modified polylactic acid material by gamma-ray irradiation

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] First put the polylactic acid in a vacuum drying oven at 60°C for 2 hours, weigh 100g of polylactic acid and add 1.5g of chitosan (molecular weight about 4000) and 1.5g of triallyl isocyanurate in sequence, and mix at room temperature; Heat to 190°C, stir for 1 hour, and mix well; pour the mixed melt into a preheated (90°C-120°C) mold, pressurize to 10MPa on a flat vulcanizer, and heat press at 150°C for 30min, keep The above-mentioned pressure is cooled and molded, and demoulded; the obtained material is put into an irradiation bag filled with nitrogen and sealed, and placed in a Co-60 γ-ray irradiation center at room temperature for irradiation treatment, and the γ-ray irradiation dose rate is about 2KGy. h -1 , when the absorbed dose reaches 50KGy, the irradiation bag is taken out to obtain chitosan-modified polylactic acid material.

[0020] The test results of the samples show that the gel fraction of the chitosan-modified polylactic acid material is 83%, the glas...

Embodiment 2

[0022] First put the polylactic acid in a vacuum drying oven at 60°C to dry for 2 hours, weigh 100g of polylactic acid and add 2.5g of chitosan (molecular weight about 4000) and 2.5g of triallyl isocyanurate in sequence, and mix at room temperature; Heat to 190°C, stir for 1 hour, and mix well; pour the mixed melt into a preheated (90°C-120°C) mold, pressurize to 10MPa on a flat vulcanizer, and heat press at 150°C for 30min, keep The above-mentioned pressure is cooled and molded, and demoulded; the obtained material is put into an irradiation bag filled with nitrogen and sealed, and placed in a Co-60 γ-ray irradiation center at room temperature for irradiation treatment, and the γ-ray irradiation dose rate is about 2KGy. h -1 , when the absorbed dose reaches 40KGy, the irradiation bag is taken out, and the chitosan-modified polylactic acid material is obtained.

[0023] The test results of the samples show that the polylactic acid material modified by chitosan after γ-ray irr...

Embodiment 3

[0025] First put the polylactic acid in a vacuum drying oven at 60° C. for 2 hours, weigh 100 g of polylactic acid and add chitosan (molecular weight 10 3 ~10 5 ,) 0.5g, trimethylolpropane triacrylate 0.5g, mix at room temperature; heat the above mixture to 240°C, stir for 2h, mix well; pour the mixed melt into preheated (90°C-120°C) In the mold, pressurize to 10MPa in stages on a flat vulcanizer, hot press at 180°C for 1h, keep the above pressure to cool and form, and demould; put the obtained material into an irradiation bag, seal it, and then vacuumize it (vacuum degree-0.09MPa ), put it into the Co-60 gamma ray irradiation center for irradiation treatment at room temperature, and the gamma ray irradiation dose rate is about 10KGy h -1 , when the absorbed dose reaches 150KGy, the irradiation bag is taken out to obtain chitosan-modified polylactic acid material.

[0026] The test results of samples show that the polylactic acid material modified by chitosan after γ-ray irr...

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Abstract

The invention discloses a preparation method of a chitosan modified polylactic acid material by gamma-ray irradiation. The preparation method comprises the steps of performing melt blending on polylactic acid, a natural polymer material of chitosan and a sensitizer, wherein the mass ratio of chitosan to polylactic acid is 0.5:100-20:100 and the mass ratio of the sensitizer to polylactic acid is 0.5:100-10:100; then performing hot pressing, cooling and demoulding forming; putting the obtained material into an irradiation bag and sealing after vacuumizing or introducing nitrogen; and performing irradiation treatment by Co-60 gamma-ray at room temperature to obtain the chitosan modified polylactic acid material. The chitosan modified polylactic acid material prepared by the preparation method is good in thermodynamic property, the gel fraction is 60-85%, the glass transition temperature is 64-70 DEG C and the tensile strength is 68-79MPa, and the properties are remarkably improved in comparison with those before modification, so that the chitosan modified polylactic acid material is wide in application prospect.

Description

technical field [0001] The invention relates to a gamma ray irradiation preparation method of chitosan modified polylactic acid material. Background technique [0002] Polylactic acid is prepared from plant resources such as corn and straw. It is rich in raw materials and has the advantages of non-toxicity, complete biodegradability, and environmental protection. It is an environmentally friendly new material that has gradually been praised by people. Broad application space and development prospects. However, polylactic acid is a semi-crystalline material, and its glass transition temperature (Tg) is about 60°C, which greatly limits its popularization and application. Polylactic acid is polycondensed from lactic acid molecules containing hydroxyl and carboxyl groups. There are a large number of unreacted hydroxyl and carboxyl groups at the end of the polymer. It has certain activity and will undergo a series of changes in the continuous and complex use environment. The st...

Claims

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Application Information

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IPC IPC(8): C08L67/04C08L5/08C08K5/3492C08K5/103C08J3/28C08J3/24
Inventor 常树全陈达戴耀东康斌张红旭李俊
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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