3results about How to "Remain biodegradable" patented technology

This invention discloses a bio-based biodegradable synthetic leather material and its preparation method, belonging to the field of polymer synthetic leather material manufacturing and modification technology. The method includes: mixing and dehydrating castor oil polyol, lignin-based polyol, and bio-based polycarbonate diol; adding isocyanate and a bio-based chain extender containing dynamic disulfide bonds to react and obtain a bio-based polyurethane resin; dissolving the resin in a solvent; adding amphiphilic modified nanocellulose whiskers, polydopamine-modified silica, bio-based epoxidized soybean oil, a pore-forming agent, and a stabilizer to obtain a synthetic leather coating solution; coating the coating solution onto a base fabric to form a wet film; gradient solidification; washing with water; and drying to obtain the bio-based biodegradable synthetic leather material. This invention improves the crosslinking stability and interlayer bonding force of the material under hygrothermal aging by using dynamic disulfide bond self-repair, nanoparticle interface enhancement, and gradient solidification to regulate the pore structure, reducing the release of volatile organic compounds, and balancing water resistance, moisture permeability, and biodegradability.

[Problem] This invention provides a mixture of PLA and CNC that retains the biodegradability inherent in PLA while improving its general-purpose properties without increasing environmental impact. [Solution] The PLA and CNC mixture of this invention is as follows: CNC with a crystallinity of 90% or higher and no chemical modification, consisting only of biodegradable substances, is added to PLA. The CNC dispersed in PLA becomes crystal nuclei, forming numerous crystals, thus forming ligands that span multiple crystals, creating a PLA crystal network structure. This structure improves the physical properties of PLA. The improvement is not achieved by cross-linking or polymerizing PLA into environmentally burdensome substances or other chemical substances, nor by adding environmentally burdensome chemicals. Instead, it is achieved by modifying the crystallinity and crystal structure of PLA by adding biodegradable, non-toxic, and environmentally unburdensome CNC. Therefore, this mixture of PLA and CNC improves the physical properties while maintaining the biodegradability inherent in PLA.

The application discloses a preparation method and application of a collagen packaging film, and belongs to the technical field of bio-based food packaging materials. According to the method, animal-derived collagen is dissolved in an acetic acid solution with a pH of 3.5-4.5 to form a solution with a concentration of 3-5%, and then 15-25% of genipin and 8-12% of cellulose nanowhiskers by dry weight of the collagen are added in sequence to perform a cross-linking reaction at 35-40 DEG C, so as to construct a three-dimensional network structure. Subsequently, the solution is soaked in 70-80% ethanol containing 0.5-1.5% propyl gallate, and the surface hydrophobicity is improved through the specific combination of phenolic hydroxyl groups and the hydrophobic region of collagen. Finally, vacuum drying and 60-70% humidity environment balancing treatment are performed, so that the degradable film material with high mechanical strength and moderate waterproofness is obtained. The preparation method is especially suitable for the preservation packaging of chilled meat products, and can effectively prolong the shelf life of food while maintaining the biodegradability of the material.