Nano silver polyester biodegradable preservative film, preparation and application thereof

Abstract

The invention discloses a nano silver polyester biodegradable preservative film, which is prepared by steps of chain extension and modification of dihydric alcohol copolyester of diacid and fatty group by introducing aromatic group and fatty group, the nano silver polyester biodegradable preservative film has strong antibiosis, anticorrosion and fresh-keeping functions, greatly increases the storage and fresh-keeping period of the food, and has modified atmosphere function; in addition, the nano silver polyester biodegradable preservative film has the advantages of excellent performance, high molecular weight, high branching degree, high crystallization degree, less impurity, no toxicity, and biodegradable performance by burying in soil after discharging.

Description

technical field [0001] The invention relates to a polymer, in particular to a nano-silver polyester biodegradable fresh-keeping film and its preparation and application. Background technique [0002] At present, the general materials of domestic food preservation film are polyethylene (PE) preservation film, polypropylene (PP) preservation film, polyvinyl chloride (PVC) preservation film, or composite preservation film based on these materials. This type of plastic wrap usually needs to be mixed with some plasticizers, inorganic fillers, antibacterial agents, etc. to form a film. There are safety problems that some active materials cannot be mixed with plastics, and the added plasticizers are easy to dissolve. Organic antibacterial agents are prone to chemical changes during high-temperature mixing, thereby changing their antibacterial properties. Therefore in recent years green, safe, environment-friendly plastic wrap, and the research that adopts inorganic nano antibacter...

AI Technical Summary

Problems solved by technology

Currently developed aromatic polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT) and other such polyesters Strong water resistance, resistant to bacterial erosion, etc., cannot be biodegraded under natural conditions

Aliphatic polyesters such as poly 3-hydroxyalkanoate (PHA), polybutylene succinate (PBS), etc., such aliphatic polyesters are known for their good biocompatibility, biodegradability, etc. Its characteristics are attracting more and more attention, and it is applied in the fields of biomedical materials and injection molding products, but there are also some shortcomings in the process of practical application: such as relatively expensive price, too fast biodegradation rate, poor thermal stability, relatively poor mechanical properties, Easy hydrolysis, easy aging, high impurity content and other shortcomings, which limit the application of this type of polyester material in some fields

[0008] 1. The manufactured masterbatch cannot be restructured with polyethylene resin, but only physically mixed and filled. It is a form of encapsulation and cannot form a network bridging structure with a 'knot' effect, resulting in uneven degradation of the degradable film. , Incomplete, forming residual fragments or powder, causing secondary pollution to the land;

[0009] 2. It cannot solve the problem of the balance of hydrophobicity and hydrophilicity, the self-adhesiveness is poor, and the processed preservative film cannot be close to the surface of the food, and the functionality as a preservative film is poor;

[0010] 3. Due to the low crystallinity, low branching degree, and large and uneven particle size of the produced masterbatch, the blown plastic wrap is thicker, less transparent, more consumables, and higher cost, which is not convenient for large-scale production and processing

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