Biodegradable polylactic acid foamed particles and preparation method thereof

A technology of polylactic acid foaming and L-polylactic acid, which is applied in the field of biodegradable polylactic acid foamed particles and its preparation, can solve the problems of destroying the biodegradability of polylactic acid materials, unfavorable production costs, high saturation pressure, etc., and achieve reduction Production process, reduce production cost, increase the effect of expansion ratio

Active Publication Date: 2019-05-31
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The small particles of modified polylactic acid used in this method are obtained by extruding polylactic acid, amorphous α-olefin copolymer or petroleum resin and processing aids, and then introducing amorphous α-olefin copolymer or petroleum Resin The function of resin is to reduce the melting point of polylactic acid and promote the easy bonding of subsequent polylactic acid foamed particles, but their introduction will destroy the biodegradability of polylactic acid materials
In addition, the saturation pressure of this method is as high as 16 MPa, which requires high equipment and is not conducive to the reduction of production costs

Method used

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  • Biodegradable polylactic acid foamed particles and preparation method thereof
  • Biodegradable polylactic acid foamed particles and preparation method thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0030] In this embodiment, the preparation method of biodegradable polylactic acid expanded particles is as follows:

[0031] (1) Put the dextrorotatory polylactic acid into the extruder for melting and kneading, extrude it into a wire rod through a die, immediately introduce the wire rod into water for cooling, and then cut it into particles with a particle size of 0.8mm to prepare polylactic acid Foam masterbatch.

[0032] (2) Put the polylactic acid foaming masterbatch into the reactor, and feed CO as a foaming agent into the reactor. 2 Gas, control the temperature of the autoclave to 25°C and the pressure to 2.5MPa, maintain the aforementioned temperature and pressure for 60 minutes, then open the ventilation valve of the autoclave to reduce the pressure in the autoclave to normal pressure.

[0033] (3) Immediately place the polylactic acid foaming masterbatch with adsorbed gas obtained in step (2) in a heating tunnel heated to 70° C. to foam for 30 seconds to obtain poly...

Embodiment 2

[0036] In this embodiment, the preparation method of biodegradable polylactic acid expanded particles is as follows:

[0037] (1) Put 95 parts by mass of D-polylactic acid and 5 parts by mass of L-polylactic acid into an extruder for melting and kneading, extrude from a die into a wire rod, immediately introduce the wire rod into water for cooling, and then cut into particle size The polylactic acid foaming masterbatch was prepared with particles of 0.8mm.

[0038] (2) Put the polylactic acid foaming masterbatch into the reactor, and feed CO as a foaming agent into the reactor. 2 Gas, control the temperature of the autoclave to 25°C and the pressure to 2.5MPa, maintain the aforementioned temperature and pressure for 60 minutes, then open the ventilation valve of the autoclave to reduce the pressure in the autoclave to normal pressure.

[0039] (3) Immediately place the polylactic acid foaming masterbatch with adsorbed gas obtained in step (2) in a heating tunnel heated to 70°...

Embodiment 3

[0042] In this embodiment, the preparation method of biodegradable polylactic acid expanded particles is as follows:

[0043] (1) Put 97 parts by mass of D-polylactic acid, 3 parts by mass of L-polylactic acid, 3 parts by mass of dioctyl phthalate, and 1 part by mass of calcium carbonate into an extruder for melting and kneading, and extrude from a die To obtain a wire rod, immediately introduce the wire rod into water for cooling, and then cut the wire rod into particles with a particle diameter of 0.6 mm to prepare a polylactic acid foam masterbatch.

[0044] (2) Put the polylactic acid foaming masterbatch into the reactor, and feed CO as a foaming agent into the reactor. 2 Gas, control the temperature of the autoclave to 30°C and the pressure to 3MPa, maintain the aforementioned temperature and pressure for 30 minutes, then open the ventilation valve of the autoclave to reduce the pressure in the autoclave to normal pressure.

[0045] (3) Immediately place the polylactic a...

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Abstract

The invention provides biodegradable polylactic acid foamed particles taking PDLA as a matrix material or taking PDLA and PLLA as matrix materials. A preparation method of the polylactic acid foamed particles include: (1), subjecting the PDLA, the PLLA, a plasticizer and a foam nucleating agent to mixing, extruding, wiredrawing and pelletizing to obtain polylactic acid foamed masterbatch; (2), putting the polylactic acid foamed masterbatch into a reaction kettle, feeding fluid serving as a foamer into the reaction kettle, holding for a period of time at 0-40 DEG C and 0.2-6MPa, and lowering pressure in the reaction kettle to normal pressure; (3), adopting a temperature rising method to foam the polylactic acid foaming masterbatch after being treated in the step (2) to obtain the polylacticacid foamed particles. By the preparation method, biodegradability of the polylactic acid foamed particles and polylactic acid foamed products prepared from the same can be improved.

Description

technical field [0001] The invention belongs to the field of polymer foam materials, and relates to a biodegradable polylactic acid foam particle and a preparation method thereof. Background technique [0002] Polylactic acid (PLA) is a polymer obtained by polymerizing lactic acid as the main raw material. The source of lactic acid is sufficient and renewable. The production process of polylactic acid is pollution-free, and the product is biodegradable and can be recycled in nature. Therefore, polylactic acid is an ideal green polymer material. The commonly used polylactic acid is a semi-crystalline polymer with low crystallization rate, low crystallinity and poor toughness in actual production and processing, which limit the large-scale application of polylactic acid. Polylactic acid foam is prepared by carbon dioxide foaming process, so that polylactic acid not only maintains the advantages of good biocompatibility, but also saves material costs and makes materials lightw...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08L67/04C08J9/18
Inventor 廖霞严志辉李少杰王圭王伟
Owner SICHUAN UNIV
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