Preparation method and application of melanin/polylactic acid film

A technology of melanin and polylactic acid, which is applied in the field of preparation of melanin/polylactic acid film, can solve the problems of waste of resources, discarding, pollution, etc., and achieve the effects of avoiding environmental pollution, excellent toughness, and prolonging the shelf life.

Pending Publication Date: 2021-01-29
ZHONGBEI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, apricot core shells are often discarded or burned as a kind of agricultural wa...

Method used

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  • Preparation method and application of melanin/polylactic acid film
  • Preparation method and application of melanin/polylactic acid film
  • Preparation method and application of melanin/polylactic acid film

Examples

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preparation example Construction

[0040] The invention provides a kind of preparation method of melanin / polylactic acid film, comprises the following steps:

[0041] (1) Extraction of melanin

[0042] S1, crushing: wash the apricot core and shell with tap water, dry at 70°C, after complete drying, use a pulverizer to crush the apricot core and shell into powder, pass through a 20-mesh sieve, and store in a dry environment spare;

[0043] S2, alkaline solution extraction: Weigh an appropriate amount of the apricot core-shell powder obtained in step S1, add 2mol / L NaOH solution according to the ratio of material to liquid 1:20, let stand for 3h, and centrifuge for 5min at the centrifuge speed of 8000r / min, Collect the supernatant, which is the crude extract of apricot core shell melanin;

[0044]S3, acid solution precipitation: add 6mol / L HCl solution to the crude extract of apricot core-shell melanin obtained in step S2 until the pH value is 2.20, centrifuge for 5min under the condition that the speed of the ...

Embodiment 1

[0060] Weigh 2g of polylactic acid into a beaker, then add 30mL of chloroform solution, then put the beaker on a magnetic stirrer, and fully stir for 1h at 25°C, 5000r / min, after the solution is evenly stirred, put the beaker Place it on a magnetic stirrer and stir it fully for 7 hours at 25°C and 5000r / min. After the stirring is completed, extract with ultrasonic assistance for 10 minutes, then centrifuge for 5 minutes at a speed of 8000r / min. Finally, pour the solution into 20cm ╳ 20cm PTFE board, dry at room temperature in a ventilated place for 12 hours, and tear off to get PLA film.

Embodiment 2

[0062] Weigh 2g of polylactic acid into a beaker, then add 30mL of chloroform solution, then place the beaker on a magnetic stirrer, and fully stir for 1 hour at 25°C, 5000r / min. After the solution is evenly stirred, weigh it accurately Add 0.5 mg of melanin particles obtained in step (2) into a beaker, then place the beaker on a magnetic stirrer, and fully stir for 7 hours at 25°C and 5000r / min. / min, centrifuge for 5min, and finally, pour the solution into a 20cm╳20cm polytetrafluoroethylene plate, dry it at room temperature in a ventilated place for 12h, and tear it off to get melanin / PLA 0.025% film.

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Abstract

The invention discloses a preparation method of a melanin/polylactic acid film, which sequentially comprises the following steps: 1. extraction of melanin: pulverizing and screening armeniaca sibiricacore-shell waste, drying for later use, extracting an armeniaca sibirica core-shell melanin crude extract by using an alkaline solution, and carrying out acid solution sedimentation, cellulase enzymolysis, glucoamylase enzymolysis, alkali dissolution and secondary acid precipitation, and obtaining a melanin crude extract; 2, melanin purification: washing the crude extract with an organic solvent,carrying out secondary alkali dissolution and acid precipitation, washing, and drying to obtain purified melanin; and 3, preparation of the film: mixing polylactic acid, a trichloromethane solution and melanin, and finally preparing the melanin/PLA film through stirring, ultrasonic-assisted extraction and centrifugal machine centrifugation. The melanin/PLA film can be used for fresh-keeping storage of fruits and vegetables, ensures the degradability of polylactic acid, endows melanin of the film with the characteristics of ultraviolet resistance, oxidation resistance and the like, and is an ideal green packaging material.

Description

technical field [0001] The invention relates to the technical field of polymer materials, in particular to a preparation method and application of a melanin / polylactic acid film. Background technique [0002] In order to reduce the use of petroleum-based plastics, protect the environment, and alleviate the increasingly severe shortage of petroleum resources, the development and utilization of bio-based degradable and environmentally friendly plastic materials has become a research focus in the field of packaging materials. [0003] Polylactic acid (PLA) is fermented into lactic acid from widely existing plant resources in nature, and then prepared by lactic acid polymerization. The whole preparation process is safe and harmless. If it is discarded, it can be degraded by the natural environment without causing environmental pollution. Recognized green polymer material. Polylactic acid material is one of the most widely used degradable plastics at present. As a packaging film...

Claims

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Application Information

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IPC IPC(8): C08J5/18C08L67/04C08K5/00
CPCC08J5/18C08J2367/04C08K5/00
Inventor 高莉黄晶晶赵英虎王海滨刘盼盼史楠王芳郭建峰刘琳琳郭丽晓
Owner ZHONGBEI UNIV
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