Preparation And Properties Study Of Ethylene Adsorption Film With High Permeability

Ethylene is mature hormone for fruit and vegetables. It’s caused by the maturity offruit and vegetables, and it further promotes their ripening and senescence. Therefore, it’san important technology to remove ethylene in the field of fresh-keeping packaging. Atpresent, the research on that the porous minerals are used as ethylene adsorptionmaterial in the field of fruit and vegetables is under way. In order to achieve the removal ofethylene in the fruit and vegetables preservation bags, and expand the scope of theapplication of PE film, the zeolite which has adsorption performance for ethylene isprepared in the paper, and then melt blend with LDPE/LLDPE to make blend film with highpermeability and ethylene adsorption. The various properties of blend films have beentested and analyzed. With“zaojiubao”peach and banana bought from market as startingmaterials, the fresh-keeping performance of the different blend film is studied.Prepared five different Si/Al ratio zeolites, and studies have shown that when theSi/Al ratio is 26, the adsorption of ethylene of zeolite is the best. The zeolite with Si/Al ratioof 26 melt blend with matrix resin, 30 percent of LDPE and 70 percent of LLDPE, andprepared ten kinds of blending film with the percentage content for zeolite being 0%、0.5%、1%、2%、2.5%、3%、4%、5%、6% and 8%. Its performance results are as follows:①The mechanical properties of the thin films are related to the crystallinity. Highcrystallinity contributes to good ability to resist stretching. DSC and XRD studies show thatwhen the content of zeolite is less than or equal to 2.5%, the crystallinity of the blendingfilm has increased compared to the pure LDPE/LLDPE film; when its content is 0.5%, thecrystallinity of the film reached maximum value, increased by about 9.7%. As the zeolitecontent continues to increase, the crystallization of the films reduce, which results in thetensile strength and breaking elongation of the films first increased and then decreasedwith the zeolite content increasing.②Barrier properties and crystallinity of mosified film are closely related, high barrierwith good crystallinity. However, the zeolite has a poor compatibility with matrix resin,because it is high polar mineral. Low levels of zeolite lead to crystallinity of the films increased, but there are some flaws, which make the oxygen permeability and watervapor transmission rate increased with the increase of the zeolite.③The surface friction coefficient of the blend thin film first decrease and thenincrease with the zeolite content increasing.④Prepared to study the fresh-keeping effect of all kinds of modified films on“zaojiubo”peaches and bananas, and the results show that compared with the film withoutzeolite, modified films can do better in maintaining the nutrients in fruits and prolong shelflife. And preservative effect is obvious.